OMsite 2006

82. Fracture of alveolar process during the extraction of a tooth is usually due to: A. use of excessive amounts of uncontrolled force. B. presence of adjacent crowded teeth. C. periapical infection. D. expansion of surrounding alveolar bone.

Answer: A RA TIONALE: If the alveolus is fractured, dissect the alveolus off the root, replace the periosteum and alveolus which will act as a vascularized graft. If soft tissue is inadvertently dissected from the alveolus, the segment of bone will likely undergo necrosis. If the maxillary tuberosity is fractured, and the tooth cannot be dissected from the alveolus, replace and splint for 6 - 8 weeks. Later surgically extract the tooth. If the tuberosity is completely avulsed without soft tissue pedicle, then smooth the remaining bony edges and close, checking for oral antral communication.

87. Whichofthefollowinghasafavorableaestheticimpactonanimplant-supportedrestoration? A. Thick biotype B. Thin biotype C. Restorative table >6 mm apical to the contact point of the adjacent tooth. D. Positive IL-1 genotype

Answer: A Rationale: A thick biotype provides greater stability for the peri-implant soft tissues with more predictable healing response following surgery and around restorations. Thin biotypes predispose not only to unpredictable healing but also may allow titanium "show through". When implant restorative tables are placed more than 5 mm below the contact point of an adjacent tooth, loss of the papilla is common, having an adverse effect on the final aesthetic result. Finally, genetic testing utilizing a swab has identified that positive intraleuken-1 (IL-1) genotype patients have an increased risk of developing periodontitis with enhanced risk of peri-implant complications.

122. A 40-year-old male comes to your office as a new patient upon referral from his family physician for recurrent pericoronitis of a lower third molar. He is currently asymptomatic, and desires a deep sedation for third molar removal. His physical examination reveals an early systolic click and a 2/6 murmur in the aortic area. In the referral letter, his physician notes the following test results: ECG is normal; echocardiogram shows a bicuspid aortic valve without significant flow obstruction. His ventricle size and function are normal. What intervention would be warranted prior to proceeding with an office anesthetic and surgery for this patient? A. Antibiotic endocarditis prophylaxis B. Aortic valve replacement C. Balloon valvuloplasty D. No intervention

Answer: A Rationale: All patients with bicuspid aortic valves --- even those with no significant stenosis or regurgitation --- should be given antibiotic prophylaxis for bacterial endocarditis for surgeries involving the aerodigestive tract. As much as 2% of the population has congenitally bicuspid aortic valves. A bicuspid aortic valve may present as an incidental finding on physical examination or echocardiography done for other reasons. On physical examination, the cardinal sign of a bicuspid aortic valve is an early systolic ejection click. If no significant hemodynamic abnormality is present, either no murmur or a soft ejection murmur may be heard; a very mild murmur of aortic regurgitation (AR) is not uncommon, even with hemodynamically insignificant bicuspid aortic valves. Aortic stenosis (AS) or AR from any other cause will produce similar findings. Both the presence of a bicuspid aortic valve and its hemodynamic significance can be determined by echocardiography. Serial studies are useful in following the progression of the lesion.. Patients with AR from a bicuspid valve who are asymptomatic and have normal systolic function are followed with echocardiograms and physical examinations at regular intervals. If they begin to show decreasing systolic function, symptoms of heart failure, or progressive dilation of the left ventricle, surgical replacement of the aortic valve is indicated.

102. Which statement is correct regarding pericoronitis of a mandibular 3rd molar? A. Initial treatment can be limited to lavage of material alba and debris B. Pericoronitis occurs only in immunosuppressed patients C. Antibiotics are mandatory D. Extraction should be delayed until completion of a course of antibiotic therapy

Answer: A Rationale: Antibiotics are a key aspect in localizing an infection and limiting its spread to adjacent tissue organs, areas, and spaces. Pericoronal infections that are localized to the immediate enveloping tissues and give no evidence of spread to adjacent tissue planes require local debridement and definitive treatment consisting of removal of the erupting tooth and/or pericoronal tissues. Antibiotics are not mandatory, and tooth extraction need not to be delayed to complete a course of antibiotics.

159. Botulinum toxin type A (Botox) works by: A. inhibition of acetylcholine release. B. postsynaptic binding of acetylcholine. C. blockade of calcium channels. D. blockage of epinephrine release.

Answer: A Rationale: Botulinum toxin type A blocks neuromuscular conduction by binding to receptor sites on motor nerve terminals, inhibiting the release of acetylcholine. This effect is temporary, usually lasting 3 to 6 months.

141. Which of the following lab tests should be ordered when considering carbamazepine therapy for trigeminal neuralgia? A. Complete blood count B. Serum electrolytes C. prothrombin time D. Serum calcium and phosphate

Answer: A Rationale: Carbamazepine is the treatment of choice for trigeminal neuralgia. This anticonvulsant provides relief to greater than 75% of trigeminal neuralgia patients. However, potential life- threatening side effects include agranulocytosis, aplastic anemia, or thrombocytopenia. Changes in levels of serum electrolyte levels, clotting factors/profactorslevels, or calcium/phosphate are not generally thought to be within the side effect or complication profile of carbamazepine.

136. A 70 kg, 35-year-old female is undergoing removal of a submandibular gland for sialolithiais under intubation general anesthesia. She was induced with 100mg propofol, and was given vecuronium as the paralytic agent. Isoflurane was used for maintenance of general anaesthesia. The case took approximately 60 minutes. At the end of the procedure she continued to have significant neuromuscular blockade. She was awake, able to open her eyes able and follow commands with difficulty. Her neurologic exam was nonfocal. She exhibits the following: respiratory rate 16/ min, tidal volume 100cc. end tidal CO2 55mmHg. What is the first diagnostic test that would be appropriate? A. Edrophonium (Tensilon) Test B. Head CT C. Electromyography D. Pyridostigmine Test

Answer: A Rationale: Myasthenia gravis is an acquired autoimmune disorder affecting transmission at neuromuscular junction. It is an autosomal dominant condition. 80-90% of patients will have auto antibodies to the acetylcholine receptors of the post synaptic membrane. Patients exhibit prolonged neuromuscular blockade to non-depolarizing muscle relaxants; but usually show some resistance to the muscle paralysis of succinylcholine. When MG is suspected the first test that may be performed is the Tensilon test using edrophonium 2mg IV wait 30 seconds for effect, assess for improvement in muscle strength that lasts for 5minutes. Repeated doses of 8mg may be given. If this test is positive supportive care is required until the neuromuscular blockade improves. In a myesthenic crisis plasmapheresis may be indicated for temporary relief, but not as first line measure. Head CT would not be the first line diagnostic test in an awake patient who has a nonfocal neurologic examination. Electromyography and muscle biopsy can be used as definite test for MG. Pyridostigmine is used for treatment of MG, and not usually for diagnosis due to its slower onset and longer duration of action.

123. Which of the following may be observed in pulmonary sarcoidosis? A. Distortion or obstruction of the airway B. Obstructive lung disease C. Pneumothorax in early stages D. Sparing of parenchyma

Answer: A Rationale: Sarcoidosis is a multisystem granulomatous disease. Respiratory manifestations include laryngeal granulomas or nodules as well as intrathoracic nodes that may compress or distort the airway. Involvement of the recurrent laryngeal nerve can cause unilateral vocal cord paralysis. Obstruction of the lower airways can result in atelectasis, but local obstruction is not the same as obstructive lung diseases. Sarcoidosis is a restrictive lung disease, with the majority of pulmonary damage occurring in the parenchyma. Patients may be prescribed steroids and perioperative care must ensure appropriate steroid coverage. Pulmonary fibrosis seen in advanced stages of the disease and may result in a pneumothorax. Patients generally take rapid shallow breaths to compensate for the physiologic changes. Hypoxemia is common at rest in severe disease.

86. The most important factor associated with the success of osteotome-mediated sinus floor elevation technique is: A. the height of the residual alveolar bone. B. implant design. C. type of graft material used. D. method of sinus in-fracture.

Answer: A Rationale: The ability to obtain primary implant stability is associated with the height of the residual alveolar ridge, and is the primary factor related to success when implants are placed in conjunction with osteotome mediated sinus floor elevation. Implant design graft material and method of sinus in-fracture have minimal influence on survival; however, factors such as osteoporosis, type of final prosthesis, and operator experience may also impact the success of this technique.

97. The minimal bone height required for placement of a transmandibular implant is how many millimeters? A. 3 B. 6 C. 9 D. 12

Answer: A Rationale: The cortical screws for the TMI system are available in lengths of 5,8,11, & 14 mm. Protocol is for the cortical screws to extend beyond the bone for a length of 2mm, but not pierce the periosteum. This allows for tenting of the periosteum and thought to lead to subsequent bone growth. A 3mm mandible is the minimum mandibular height to allow 2mm of "tenting" with the 5mm cortical screw.

129. Which of the following decreases pulmonary diffusion capacity? A. Acute respiratory distress syndrome B. Diaphragmatic paralysis C. Chylothorax D. Pleural effusion

Answer: A Rationale: The diffusion capacity of the lungs for any gas is dependent upon the diffusion coefficient (for the gas in question), the surface area and thickness of the alveolar-capillary membrane, and the partial pressure gradient across the barrier. Changes in any of these variables will affect the diffusing capacity. The alveolar -capillary membrane is made up of various layers. These layers traveling from the alveolus toward the capillary are: surfactant layer, alveolar epithelium, interstitial space, pulmonary capillary endothelium, plasma, and red blood cell. On average, this barrier is about 0.5 μm in thickness. Alveolar edema or exudates such as in acute respiratory distress syndrome increases the thickness of the blood-gas barrier in the lung, which increases the time necessary for equilibration of CO2 and O2 across the blood- gas barrier. Diaphragmatic paralysis will inhibit air exchange but not the ability to equilibrate gaseous exchange across the alveolar/capillary surface. A pleural effusion and chylothorax are is present in the pleural space and therefore will not directly affect the diffusion of gases in the alveoli of the lung.

177. The "doll's hair look" is usually seen with the use of which of the following hair transplant grafts: A. punch graft. B. minigraft. C. micrograft. D. single hair transfer.

Answer: A Rationale: The doll's hair look is seen with the cylindrical plugs. The new techniques of minigrafts and micrografts eliminate this look.

162. The recommended dosage and number of injections for treating glabellar frown lines is: A. 20 units given with 5 injections. B. 40 units given with 10 injections. C. 40 units given with 5 injections. D. 20 units given with 10 injections.

Answer: A Rationale: The dosage for proper treatment of glabellar frown lines is 20 units given with 5 injections (4 units per injection): two injections in each corrugator muscle, and 0ne midline injection in the procerus muscle.

182. At the corner of the mouth, the marginal mandibular branch of the facial nerve runs: A. deep to the platysma until about 2 cm lateral to the corner of the mouth. B. superficial to the platysma until about 2 cm lateral to the corner of the mouth. C. deep to the platysma until about 4 cm lateral to the corner of the mouth. D. superficial to the platysma until about 4 cm lateral to the corner of the mouth.

Answer: A Rationale: The marginal mandibular branch of the facial nerve lies deep to the platysma in this area until about 2 cm lateral to the commissural of the mouth, at which stage, it penetrates the undersurface of the facial mimetic muscles, and is found more superficially.

179. The modiolus: A. influences the configuration of the nasolabial fold. B. is a confluence of three muscles of facial expression. C. is a confluence of nerves influencing expression. D. influences the configuration of the brow area.

Answer: A Rationale: The modiolus is an area of confluence of five muscles of facial expression, located lateral to the corner of the mouth. The five muscles are the levator anguli oris, zygomaticus major, risorius, platysma, and depressor anguli oris. This group of muscles is bound to the buccinator by connective tissue, and along with the cheekbone, represent the configuration of the nasolabial fold. The modiolus is not comprised of nerves and has no influence on the brow area.

47. A 22-year-old male presents with a tumor compressing his optic chiasm. What visual field defect would you expect to see on physical examination? (Shaded areas indicate visual field deficit.)

Answer: A Rationale: The optic chiasm, contains axons from the nasal half of each retina, which look at the temporal half of the visual field and cross to the side contralateral to their eye of origin. The axons from the temporal retina remain uncrossed. Thus, if crossing fibers are destroyed in the optic chiasm, for example, by pressure from an expanding tumor (such as from the hypothalamus), the result is bitemporal hemianopsia., with the visual field deficit illustrated in A. Answer B is homonymous hemianopia and is associated with severe contralateral optic tract defects or hemispheric lesion. Answer C is binasal hemifield defect. These defects are associated with lesions lateral to chiasm such as aneurysms; and other causes may include glaucoma or optic disk drusens. Answer D. is altitudinal hemianopia and is associated with occipital cortex ischemia and defects of the posterior occipital circulation.

91. In 75% of patients, in order for the dental papilla to fill the embrasure space of a single tooth dental implant supported restoration, the maximum distance between the crestal bone and the contact point is: A. 6mm. B. 5mm. C. 4mm. D. 3mm.

Answer: A Rationale: The presence or absence of a peri-implant papilla mainly depends on the distance between the alveolar crest and the contact point. In single-tooth gaps, the bone height at adjacent teeth determines the status of the papilla. A clinical study by Dennis Tarnow , et al, demonstrated that a distance of 6mm or more from the alveolar crest to the contact point reduces the probability of intact papillae.

168. The use of dermal or alloplastic material into the lips primarily achieves: A. increased lip volume and vermillion exposure. B. enhanced white roll definition. C. reduced perioral rhytides. D. improved definition of cupid's bow.

Answer: A Rationale: The use of autogenous or alloplastic materials into the lips primarily achieves an increase in lip volume and vermillion exposure. Improvement of white roll definition, perioral rhytides, or cupid's bow is inconsistent with implants.

178. Which on the following has no effect on the survival of adipocytes when harvesting fat: A. harvesting site. B. harvesting technique. C. preparation technique. D. handling techniques.

Answer: A Rationale: The yield of adipocytes does not vary with the harvesting site. It is well established that the harvesting technique, preparation of fat for transfer, and handling techniques such as prolonged exposure to air can affect the yield of viable adipocytes.

85. Which of the following can cause premature loss of temporary implants used for the purpose of providing orthodontic anchorage? A. Non-keratinized surrounding mucosa B. Type of intended tooth movement C. Mini-plate implant configuration D. Mini-screw implant configuration

Answer: A Rationale: While success rates for mini-implants are high, studies like that of Chang and Tseng demonstrate that implants placed through non-keratinized mucosa have a higher rate of failure. Another factor that may have an adverse affect on success is placement in the posterior mandible. Implant type (mini-screw of mini-plate) does not effect failure rates of rigid orthodontic anchorage.

83. If the lingual alveolar plate is fractured and mobile during removal of an erupted mandibular third molar, the fractured segment should be: A. stabilized to avoid damage to the lingual nerve. B. left in place with minimal manipulation. C. removed with careful subperiosteal dissection. D. removed and the lingual nerve explored for evidence of injury.

Answer: B Rational: Minimal manipulation of the segment will provide the greatest chance of maintaining the periosteal attachment, and thus the blood supply to the segment. If soft tissue is inadvertently dissected from the alveolus, the segment of bone will likely undergo necrosis. Removal of the segment is generally not advised, dissection in this region would increase the risk of injury to the lingual nerve.

134. In a healthy individual, the major factor in regulation of alveolar ventilation is arterial: A. PaO2 B. PaCO2 C. pH D. HCO3

Answer: B Rationale: A number of factors play a role in controlling alveolar ventilation. The central areas of inspiratory and expiratory control lie in the medulla, and primarily respond to increases in hydrogen ion concentration in the cerebrospinal fluid. Although hydrogen ion concentration is the most important stimulus to the chemosensitive centers in the medulla, these ions cross from blood through the blood-brain barrier to cerebrospinal fluid with difficulty. In contrast, CO2 readily crosses the blood-brain barrier to react with water to form carbonic acid in the CSF, which dissociates to provide the required hydrogen ion necessary for stimulation. Peripheral chemoreceptors transmit signals via cranial nerves ten (to the aortic bodies) and nine (to the carotid bodies) to the inspiratory area of the medulla and pons. These signals help control breathing frequency and lung inflation. The peripheral receptors respond to drops in arterial oxygen pressure. Generally speaking, carbon dioxide pressure plays a much greater influence on ventilation than oxygen pressure. To exemplify the role that the PaCO2 plays in controlling alveolar ventilation, a 50% increase in arterial PaCO2 produces a tenfold increase in alveolar ventilation, while a 40mmHg decrease in arterial PaO yields only a 1.5 fold increase in alveolar ventilation. The high blood flow through the richly vascularized peripheral chemoreceptors allows the needs of the receptors to be almost entirely met by dissolved oxygen, and excess oxygen bound as oxyhemoglobin is not used by the receptors. As a result, the PaO2 determines the level of peripheral receptor stimulation rather than the arterial oxygen saturation (SaO2).

137. Which of the following is characteristic of absence seizures (petit mal)? A. Sudden cessation of ongoing conscious activity and loss of postural control without convulsive activity B. Pathognomonic electroencephalogram showing 3 Hz spike and wave discharges C. Difficulty of control with anti-epleptogenic medication D. Initial presentation generally in middle age ENDTEXT

Answer: B Rationale: Absence seizures have cessation of conscious activity without any convulsions or loss of postural control. These tend to be very brief, lasting seconds to sometimes a few minutes, and are usually diagnosed in young children. The EEG is pathognomonic and often shows that the child is having many more seizures than was evident. Antiepileptic drugs usually are effective for treatment.

84. Thebiologicalwidthsurroundingnaturalteethandfreestandingosseointegratedrootform implants demonstrate a relatively constant thickness of: A. 1mm. B. 3 mm. C. 5 mm. D. 7 mm

Answer: B Rationale: An appreciation of biologic width is important in best determining implant positioning to allow for an aesthetic result. Numerous studies document the dimensions of biological width for both natural teeth and implants. Biologic width is comprised of the zone of supracrestal connective tissue that measures approximately 1 mm and epithelial structures, including the junctional and sulcular epithelium that measure about 2 mm in height.

124. Which laboratory study is the most informative in the diagnosis of asthma? A. Plane chest radiography B. Spirometry C. Arterial blood gas determination D. Stethoscopy

Answer: B Rationale: Asthma diagnosis rests upon the measurement of peak expiratory flow rates (spirometry) before and after administration of an inhaled beta adrenergic agonist; the reversibility of lowered expiratory flows being diagnostic for this disorder. Alterations in plane chest radiographs, arterial blood gases, and in auscultation of the chest by stethoscope may occur with asthma, but changes in these are not specific for the diagnosis of asthma.

165. Of the following, the best indication for collagen replacement therapy in lip augmentation is: A. the scarred cleft lip. B. the aged lip with lack of definitive white roll. C. perioral rhytides. D. very small lips.

Answer: B Rationale: Collagen replacement therapy for lip augmentation is used to achieve fullness in the white roll area of the lip. Collagen has limited or no use in the scarred cleft lip or small lips. Perioral rhytides are best managed by other means (laser resurfacing, chemical peel, Restylane).

89. Whichofthefollowingisanabsolutecontraindicationfordentalimplantplacement? A. Oral lichen planus B. Uncontrolled periodontal disease C. Insulin dependent diabetes mellitus D. Cigarette smoking

Answer: B Rationale: Contraindications for the use of an implant restoration are in developing patients (particularly in the maxilla, where vertical growth continues after permanent teeth are fully erupted), uncontrolled periodontal disease, aesthetic areas with thin, highly scalloped gingiva, adjacent periapical pathology, and non motivated patients. Relative contraindications where adjacent root flaring precludes placement (correction needed with orthodontics), smokers (increased failure rate especially in type IV bone), connective tissue diseases, and diabetes and autoimmune diseases.

132. An early diagnostic test used to test infants suspected of having cystic fibrosis is: A. urine sodium. B. sweat chloride. C. fecal aluminum. D. sputum alcohol level.

Answer: B Rationale: Cystic fibrosis is an autosomal recessive inherited disease of the exocrine glands, primarily affecting the GI and respiratory systems, and usually characterized by COPD, exocrine pancreatic insufficiency, and abnormally high sweat electrolytes (particularly chloride > 60 mEq/L). In addition to thickened sputum and pancreatic enzyme dysfunction, males often have azospermia secondary to obstruction of the vas deferens by thickened secretions.

119. Woff-Parkinson-White (WPW) Syndrome: A. is treated with verapamil IV. B. requires extra-nodal conduction. C. is characterized by severe bradycardia. D. is unresponsive to radiofrequency ablation.

Answer: B Rationale: During normal embryonic cardiogenesis, strands of electroconductive tissue form connections between the atria and ventricles outside of the normal conduction pathway. These strands normally become non-functional shortly after birth. In WPW, persisant connections via extranodal pathways bypass part of all of the normal conduction system and function in a re-entry capacity. In WPW the accessory pathway is called the Kent Bundle and connects the atria directly to the ventricles and is a cause of atrial fibrillation. This can result in a ventricular rate of 250-300 beats/min. Treatment of WPW, especially if atrial fibrillation is present, with IV verapamil may decrease the accessory pathway refractory period, increasing the ventricular rate and potentiating ventricular fibrillation. Radiofrequency ablation has become one of the procedures of choice in ablating the accessory conductive pathways in WPW syndrome.

156. Which of the following are predictive factors for the development of hepatorenal syndrome in patients with liver disease and ascites? A. Low serum sodium B. Proteinuria C. Low plasma rennin D. Presence of hepatomegaly

Answer: B Rationale: Hepatorenal syndrome is a relatively frequent complication in cirrhotic patients with ascites that is associated with an extremely short survival. It is a complication of advanced cirrhosis characterized by renal failure due to severe renal vasoconstriction, increases in systemic blood pressure, and increased activity of endogenous vasoactive systems. Absence of hepatomegaly, high plasma renin activity, and low serum sodium concentration are predictors of hepatorenal syndrome occurrence in these patients. The fundamental problem in hepatorenal syndrome is renal ischemia secondary to hypotension and profound renal cortical vasoconstriction, leading to renal tubular dysfunction and proteinuria. Portal hypertension and its associated splanchnic arterial vasodilatation initiate a cascade of events leading to activation of systemic and local vasoconstrictors and depletion of local renal vasodilators. Therapy with vasopressin V(1) receptor and alpha-adrenergic agonists, and plasma expanders, reverses type I and type II hepatorenal syndrome and improves survival. The first detailed description of HRS reported 9 patients with cirrhosis or acute hepatitis who developed renal failure without associated proteinuria and with very low urinary sodium excretion. On autopsy, these kidneys showed normal histology. It was later shown that kidneys from patients with HRS regain their function when transplanted into patients without cirrhosis and that HRS can be reversible following liver transplantation if done prior to irreversible renal damage.

152. From which cranial nerve does the parasympathetic fibers to the globe arise? A. II B. III C. IV D. VI

Answer: B Rationale: In the parasympathetic autonomic nervous system, pre- and post-ganglionic fibers synapse close to the target organ, not close to the spinal cord, as occurs in the sympathetic nervous system. Parasympathetics to the eye synapse behind the globe in the ciliary ganglion and arise from CN III. Parasympathetics to the parotid synapse in the otic ganglion and arise from CN IX. Parasympathetics to the palatal minor salivary glands and nose synapse in the pterygopalatine ganglion and arise from CN VII. The neurotransmitter at this site is acetylcholine. The optic nerve (II) has no sympathetic component.

128. Montelukast has its primary mechanism in reducing inflammation associated with asthma through: A. inhibition of prostaglandins. B. antagonism of leukotrienes. C. direct beta-2 stimulation. D. blocking production of arachidonic acid.

Answer: B Rationale: Leukotrienes are potent biochemical mediators that are released from mast cells, eosinophils, and basophils. Leukotrienes work to contract airway smooth muscle, increase vascular permeability and mucus secretions, and attract and activate inflammatory cells in the airways of patients with asthma. They are produced by the oxidation of arachidonic acid through the enzyme lipoxygenase. The action of leukotrienes can be blocked through either of two specific mechanisms: 1) inhibition of leukotriene production and, 2) antagonism of leukotriene binding to cellular receptors. The FDA has approved three products thus far. Zafirlukast and montelukast are both selective and competitive leukotriene receptor antagonists of leukotriene D and E. These are components of slow-reacting substance of anaphylaxis. Zileuton, a specific inhibitor of 5-lipooxygenase, inhibits leukotriene formation, especially LTB1, LTC1, LTD1, LTE1. As a leukotriene antagonist, SingulairR (montelukast) has no effect on lipoxygenase or arachidonic acid function. Arachidonic acid is produced by membrane phospholipids through the enzyme phospholipase A2 which is blocked by corticosteroids. Cyclooxygenase inhibitors (i.e. NSAIDs, COX inhibitors) block the production of prostaglandins. Beta-2 stimulation results in bronchodilation and is the main mechanism of medications such as albuterol and not the leukotriene inhibitors.

184. Where is McGregor's patch located? A. an area near the posterior border of the sternocleidomastoid inferior to the ear lobule, where important nerves are found. B. an area near the zygomatic prominence where a plexus of vessels is found. C. an area near the antegonial notch and inferior mandible where the facial artery is found. D. the preauricular area where the facial nerve crosses the zygomatic arch.

Answer: B Rationale: MacGregor's patch is also known as the "bloody gulch." It is named after the strong zygomaticodermal fibrous attachments that often present as skin dimpling or retraction. It is also pertinent because a plexus of vessels supplied by the facial artery and transverse facial artery becomes superficial in this area. Also, the buccal nerve lies just deep to this danger zone, and the zygomatic branch of the facial nerve becomes more superficial in this area.

170. A medium depth chemical peel agent will penetrate the skin to the level of the: A. papillary dermis. B. upper reticular dermis. C. mid reticular dermis. D. lower reticular dermis.

Answer: B Rationale: Medium depth peel will penetrate to the level of the upper reticular dermis. Superficial peel will penetrate to the level of the papillary dermis. A deep depth peel will penetrate to the level of the mid reticular dermis.

110. The diagnosis of mitral valve prolapse is associated with which of the following? A. Early systolic murmur B. Von Willebrand's syndrome C. Murmur accentuated by respiration D. Patent ductus arteriosus (PDA)

Answer: B Rationale: Mitral valve prolapse is a common condition affecting 2%-5% of the population. It likely is inherited as an autosomal dominant trait, and is more common in women. The murmur associated with mitral valve prolapse occurs late in systole and is not affected by respiration. MVP is associated with ventricular premature beats, paroxysmal atrial tachycardia, atrial fibrillation, Von Willebrand's syndrome, polycystic kidney disease, atrial secundum defects and Marfan's syndrome.

140. Which one of the following regarding muscular dystrophy is true? A. This group of disorders is characterized by progressive abnormalities at the acetylcholine receptor site in the neuromuscular junction B. Patients with Duchenne's muscular dystrophy may be safely managed with a nitrous/opioid anesthetic technique C. Succinylcholine causes prolonged muscle paralysis in this disorder D. Muscular dystrophy is a progressive, irreversible disease that usually leads to death in the early 50s due to cardiac failure

Answer: B Rationale: Muscular dystrophy (MD) has historically been diagnosed and categorized based on the age of onset, affected muscle groups, and genetic inheritance. Nearly one-third of new cases are spontaneous mutations, but two-thirds are inherited. Duchenne's is by far the most common form of MD and is due to abnormal and deficient dystrophin; other forms of MD may involve other myocyte proteins. Administration of a depolarizing muscle relaxant to a patient with MD would be likely to cause a massive potassium release that could precipitate cardiac arrest due to hyperkalemia. MD patients, especially those with Duschenne's type, are susceptible to malignant hyperthermia and therefore the use of triggering agents such as depolarizing muscle relaxants (succinylcholine) and halogenated potent volatile anesthetics should be avoided. A nitrous oxide/opioid ("nitrous/narcotic") anesthetic technique would be appropriate for such a patient. Prolonged muscle paralysis with succinylcholine is typical of a cholinesterase deficiency, not muscular dystrophy. These patients also have delayed gastric emptying time, with the associated risk of aspiration if the airway is not adequately protected. Demise from MD usually occurs in the 20's from respiratory failure.

142. A 35-year-old female patient with myasthenia gravis is scheduled for a bilateral saggital ramus osteotomy. When the patient is induced for general anesthesia, what reaction would you expect? A. Reacts the same with all types of muscle relaxants B. Increased sensitivity to nondepolarizing relaxants C. Decreased sensitivity to nondepolarizing relaxants D. Increased sensitivity to depolarizing relaxants

Answer: B Rationale: Myasthenia gravis is an autoimmune disorder that occurs 1/20,000 persons and is characterized by injury of the acetylcholine receptors at the postsynaptic neuromuscular junction. These patients exhibit marked sensitivity to nondepolarizing muscle relaxants and slight resistance to succinylcholine

125. A 28-year-old patient suffers a prolonged laryngospasm in your office. Upon breaking the spasm through the use of positive pressure oxygen and succinylcholine, the patient is still somewhat somnolent and difficult to arouse. His respiratory rate is 16/min and there are crackles heard throughout his lung fields, especially near the bases. At this point the patient will likely require: A. bronchial alkalinization. B. positive end expiratory ventilation. C. pleurocentesis. D. antibiotics.

Answer: B Rationale: Patients who have had a laryngospasm may be susceptible to secondary pulmonary edema. This can be the result of negative alveolar pressure of an expanding diaphragm against a closed glottis, or due to barotrauma from positive pressure ventilation. Pulmonary trauma arising from laryngospasm may become clinically evident hours after the spasm. In this case, signs arising immediately after the treated laryngospasm may indicate imminent pulmonary failure which may require endotracheal intubation and airway support using positive end expiratory pressure, and possibly diuretics. While this patient may have had an aspiration, the management of this complication would not be alkalinization of the airways. It is unlikely that the acute onset of dyspnea in this case was due to pleural effusion or pneumonia

173. A 62-year-old female comes to your office and requests treatment of facial wrinkles. She has white skin. She states that she usually burns in the sun and tans minimally. Based on the above information, she can be classified as a Fitzpatrick type: A. type I. B. type II. C. type III. D. type IV

Answer: B Rationale: The Class II skin type patient has a white skin color that usually burns and tans minimally. The Class I skin type always burns and never tans. The Class III skin type tans moderately and burns moderately. The Class IV skin type burns minimally and tans easily.

149. Which of the following correctly couples the muscle with the nerve that innervates it? A. tensor tympani - VIII B. posterior digastric -VII C. geniohyoid - IX D. superior oblique muscle -VI

Answer: B Rationale: The anterior digastric is innervated by the mylohyoid branch of the mandibular nerve (V), while the posterior belly of the digastric is innervated by the facial nerve (VII). They are actually 2 embryologically distinct muscles originating from branchial arches I and II, respectively. The tensor tympani receives its motor innervation from a branch of the mandibular nerve (V). The intrinsic (genioglossus and geniohyoid) and extrinsic tongue musculature receives motor input from the hypoglossal nerve (XII). The glossopharyngeal nerve (IX) provides special sensory innervation (taste) to the posterior tongue, innervates the carotid sinus, and carries autonomic input to the parotid gland and oropharynx. The abducent (VI) nerve innervates the lateral rectus muscle, while the trochlear nerve (IV) innervates the superior oblique muscle.

108. What stage of root development is optimal for the transplantation of a developing mandibular third molar to a first molar extraction site? A. Less than 1/2 B. Between 1/2 and 2/3 C. Between 2/3 and complete D. Complete

Answer: B Rationale: The donor third molar roots should be no less than half and preferably about two thirds developed.

106. Which of the following statements regarding adjunctive medications administered to an 18-year- old healthy male during removal of 3rd molars, is true? A. Prophylactic antibiotics are recommended to prevent post-operative infection. B. Local measures are as effective as systemic antibiotics in the reduction of postoperative dry sockets. C. Perioperative steroids administered to reduce post-operative swelling have no appreciable affect on dry socket incidence D. Maximum control of swelling requires no additional steroid doses other than the initial perioperative dose

Answer: B Rationale: The usage of prophylactic antibiotics involves the issue of risk versus benefits. Without further extenuating conditions, the increase of antibiotic-related complications, e.g. allergy, resistant bacteria, gastrointestinal side effects, and secondary infections, is not outweighed by the benefits in an otherwise uncomplicated 3rd molar surgery. Perioperative steroids do have a major clinical impact on swelling in the early postoperative period but, for maximum control, additional steroids must be given for 1 or 2 days following surgery. The administration of perioperative steroids may increase the incidence of alveolar osteitis after third molar surgery, the data are lacking as to the precise degree of increase.

151. A 43-year-old alcoholic male has acute onset confusion and amnesia and is brought to the ER for further evaluation. His toxicology screen is negative. His head CT shows some focal demyelination and gliosis of the thalamus, cerebellum and periaqueductal grey matter, without evidence of intracranial mass or bleeding. Further careful physical examination reveals bilateral lateral rectus palsy. What is his most likely diagnosis? A. Korsakoff syndrome B. Wernicke's encephalopathy C. Parkinson's disease D. Diffuse axonal injury

Answer: B Rationale: Wernicke's encephalopathy is a finding often associated with chronic alcoholism and is thought to be due to thiamine (Vitamin B1) deficiency. It is associated with an acute confusional state, amnesia, ataxia and opthalmoplegia. The pathogenesis is due to demyleination, neuronal loss and gliosis of the thalamus, periaqueductal gray matter, cerebellum and cranial nerve III, VI and VII. Kosakoffs syndrome is also found in chronic alcoholism is the inability to form new memories and usually seen later than Wernickes encephalopathy. It too is associated with thiamine deficiency; however A is not the answer since the episode was of acute onset. Parkinson's disease is the most common neurologic disorder in patients over 65 years old and is a progressive movement disorder. Parkinson's disease is caused by the progressive loss of dopamine-producing neurons in the substantia nigra. Diffuse axonal injury is usually seen in patients in a prolonged coma, where neurologic recovery is slow.

94. Whenperformingimmediateplacementofanimplantintoextractionsiteofamaxillarycentral incisor, which of the following statements is true? A. The tooth socket must be completely obliterated by the dental implant. B. Immediate placement is not recommended if buccal plate integrity is lost. C. The thick flat gingival biotype has a higher risk of buccal plate resorption. D. The implant should be placed adjacent to the buccal wall of the extraction site.

Answer: B Reference: Hämmerle CHF, et al, Consensus Statements and Recommended Clinical Procedures Regarding the Placement of Implants in Extraction Sockets, Int. J of Oral & Maxillofacial Implants, Vol 19 Supp, pp 26-28

176. The chromophore for the Q-switched Nd-YAG laser is: A. hemoglobin. B. water. C. melanin. D. protein.

Answer: C Rationale: A chromophore is a compound or chemical capable of selective light absorption. Lasers with different wavelengths of energy will be selectively absorbed by different chromophores, therefore allowing the laser to target specific structures. The chromophore of the CO2 laser is water. For the argon laser it is hemoglobin. For the Q-switched Nd-YAG laser it is melanin. Proteins are heterogenous and do not have a specific wavelength absorption range.

174. Which of the following is a contraindication to CO2 laser resurfacing: A. history of retinoid use 5 years ago. B. Fitzpatrick type II skin classification. C. history of hypertrophic scar formation. D. history of herpetic lesion.

Answer: C Rationale: A history of herpetic lesions is not a contraindication to CO2 laser skin resurfacing. Recent retinoid use can predispose a patient to hypertrophic scar formation. Fitzpatrick Class V would predispose a patient to pigmentary changes.

103. Which of the following statements, regarding alveolar osteitis, is true? A. Generally develops 7-10 days after surgery B. Represents a localized bone infection C. Is theorized to be caused by lysis of a fully formed blood clot prior to its replacement by granulation tissue D. Requires vigorous bone scraping under local anesthesia to stimulate new blood clot formation

Answer: C Rationale: Alveolar osteitis is essentially an inflammation of the bony socket from a recently extracted tooth. Treatment consists of debridement of the socket and placement of a suitable obtundent until the area becomes asymptomatic. Usually no local anesthesia is required.

115. An obese 60-year-old male presents for extraction of tooth #32. His past medical history is significant for angina, syncopal episodes and congestive heart failure. A crescendo-decrescendo systolic murmur is noted upon auscultation of the precordium. The most likely diagnosis is: A. aortic regurgitation. B. mitral stenosis. C. aortic stenosis. D. mitral regurgitation.

Answer: C Rationale: Aortic stenosis is the most common congenital cardiac abnormality. Patients typically present with angina, syncope and congestive heart failure. The classic murmur of aortic stenosis is a harsh systolic ejection murmur. The only effective treatment is valve replacement. Aortic regurgitation is associated with a high pitched diastolic decrescendo murmur. Mitral stenosis auscultation yields a diastolic rumble, loud S1, and an opening snap. Mitral regurgitation creates a holosystolic murmur with radiation to the axilla.

99. In regard to measured periodontal attachment at the distal of the second mandibular molar following extraction and complete healing of the third mandibular molar, the following is true: A. the best results are obtained when guided tissue regeneration techniques are used at the third molar extraction site. B. the best results are obtained when demineralized bone powder is placed within the third molar extraction site. C. third molar extraction sites that undergo no special treatment demonstrate periodontal attachment levels similar to those treated with guided tissue regeneration techniques or demineralized bone powder. D. use of demineralized bone powder within the third molar extraction site more commonly results in formation of a chronic giant cell reaction and periodontal attachment loss.

Answer: C Rationale: At the time of third molar extraction, different techniques can be implemented in an attempt to improve the periodontal attachment levels distal to the second molar. A study divided patients undergoing third molar extraction into three different perioperative treatment groups (Guided tissue regeneration (GTR), Demineralized bone powder (DMP), and no special treatment). There were 12 patients in each group. There were no statistical differences between any of the treatment groups in probing depth or attachment level around the second molar. Neither GTR nor DMP techniques showed any advantage over simple healing following third molar extraction

138. Which of the following concerning Bell's Palsy is true? A. The transitory facial muscle paresis is usually due to a CNS vasospastic phenomenon B. This disorder has a peak incidence in men in the sixth decade of life C. Treatment for Bell's palsy include an antiviral combined with a glucocorticoid D. Diagnosis of Bell's palsy is made based on increased creatine phosphokinase (CPK) greater than 145mU/ml. secondary to low level rhabdomyolysis

Answer: C Rationale: Because the facial nerve has so many functions and is so complex, damage to the nerve or a disruption in its function can lead to many problems. Symptoms of Bell's palsy, which vary from person to person and range in severity from mild weakness to total paralysis, may include twitching, weakness, or paralysis on one or both sides of the face, drooping of the eyelid and corner of the mouth, drooling, dryness of the eye or mouth, impairment of taste, and excessive tearing in one eye. These symptoms usually begin suddenly and reach their peak within 48 hours. Other symptoms may include pain or discomfort around the jaw and behind the ear, ringing in one or both ears, headache, loss of taste, hypersensitivity to sound on the affected side, impaired speech, dizziness, and difficulty eating or drinking. Palsy occurs when the nerve that controls the facial muscles is swollen, inflamed, or compressed, resulting in facial weakness or paralysis. Exactly what causes this damage, however, is unknown. Most scientists believe that a viral infection such as viral meningitis or the common cold sore virus - herpes simplex - causes the disorder. Bell's palsy afflicts approximately 40,000 Americans each year. It affects men and women equally and can occur at any age, but it is less common before age 15 or after age 60. It disproportionately attacks pregnant women and people who have diabetes or upper respiratory ailments such as the flu or a cold. There is no cure or standard course of treatment for Bell's palsy. The most important factor in treatment is to eliminate the source of the nerve damage. Bell's palsy affects each individual differently. Some cases are mild and do not require treatment as the symptoms usually subside on their own within 2 weeks. For others, treatment may include medications and other therapeutic options. Recent studies have shown that steroids are an effective treatment for Bell's palsy and that an antiviral drug such as acyclovir- used to fight viral infections-combined with an anti-inflammatory drug such as the steroid prednisone-used to reduce inflammation and swelling-may be effective in improving facial function by limiting or reducing damage to the nerve. Analgesics such as aspirin, acetaminophen, or ibuprofen may relieve pain. Another important factor in treatment is eye protection. Bell's palsy can interrupt the eyelid's natural blinking ability, leaving the eye exposed to irritation and drying. Therefore, keeping the eye moist and protecting the eye from debris and injury, especially at night, is important. Lubricating eye drops, such as artificial tears or eye ointments or gels, and eye patches are also effective. Facial massage and exercises may help prevent permanent contractures (shrinkage or shortening of muscles) of the paralyzed muscles before recovery takes place. Moist heat applied to the affected side of the face may help reduce pain. Other therapies that may be useful for some individuals include relaxation techniques, acupuncture, electrical stimulation, biofeedback training, and vitamin therapy (including vitamin B12, B6, and zinc), which may help nerve growth. A diagnosis of Bell's palsy is made based on clinical presentation-including a distorted facial appearance and the inability to move muscles on the affected side of the face-and by ruling out other possible causes of facial paralysis. There is no specific laboratory test to confirm diagnosis of the disorder. Generally, a physician will examine the individual for upper and lower facial weakness. In most cases this weakness is limited to one side of the face or occasionally to the forehead, eyelid, or mouth. A test called electromyography (EMG) can confirm the presence of nerve damage and determine the severity and the extent of nerve involvement. An x-ray of the skull can help rule out infection or tumor. A magnetic resonance imaging (MRI) or computed tomography (CT) scan can eliminate other causes of pressure on the facial nerve.

98. Whencomparingtheapicallyrepositionedflaptechniqueandtheclosederuptiontechniquefor exposure of an unerupted labially positioned maxillary canine lying high in the alveolus, the closed eruption technique results in:

Answer: C Rationale: Both techniques allow for maintenance of the attached gingiva. In the closed eruption technique, a crestal incision is made, and a full-thickness flap is reflected. Bone is carefully removed around the crown and a bracket attached. The flap is closed and the tooth is allowed to erupt down through the crestal incision site as traction is placed on the ligature. The referenced study, comparing the two techniques, shows that although the periodontal attachment level was the same in the two techniques, the labially impacted maxillary anterior teeth uncovered w/ apical flap techniques had more unaesthetic scarring, increased clinical crown length, and greater risk of intrusive relapse. The results of treatment with the closed technique were aesthetically superior and there was less relapse.

160. Resistance to Botulinum toxin type A (Botox) is increased by which of the following: A. low doses of Botox. B. decreased frequency of treatments. C. decreased time interval between treatments. D. speed of injection.

Answer: C Rationale: Botox resistance is caused by high doses (>150 units), increased frequency of treatments, and decrease time interval between treatments, which become significant if given less than two months apart. This leads to antibody formation to the toxin.

135. A 24-year-old male motorcyclist is involved in a head on collision with a stationary vehicle. His GCS on arrival is 8. As you are completing the secondary survey his blood pressure acutely rises to 220/140. A ventriculostomy is placed and indicates his intracranial pressure is 40mmhg. What is his cerebral perfusion pressure? A. 20mmHg B. 70mmHg C. 130mmHg D. 170mmHg

Answer: C Rationale: Cerebral perfusion pressure is calculated by the following formulae: Mean arterial pressure: diastolic blood BP + 1/3 (systolic BP - diastolic BP) 140 + 1/3 (220-140) 167 Cerebral perfusion pressure (CPP): Mean arterial pressure-Intracranial pressure (ICP) 167 - 40 127 (about 130) Cerebral blood flow is constant when CPP is maintained between 50-150mmHg. To maintain cerebral blood flow, the MAP should be between 60-160mmHg and the ICP between 5- 15mmHg. As the ICP begins to rise, cerebral autoregulation occurs increasing cerebral vascular resistance causing cerebral hypertension in an attempt to maintain cerebral blood flow.

148. Which of the following headaches is described by unilateral, orbital or temporal distribution; intense, steady pain; onset usually within 2 or 3 hours of falling asleep; lacrimation, nasal congestion and then rhinorrhea? A. Common migraine B. Classic migraine C. Cluster headache D. Tension headache

Answer: C Rationale: Cluster headaches have a much higher incidence in men than women. The pain is often retro- orbital and is described as intense and boring in character. In addition to the above symptoms, there may be miosis, ptosis, flush and cheek edema which may last for two hours. It recurs nightly for weeks to months followed by months to years of relief from symptoms. Cluster headaches can sometimes be precipitated by vasodilating agents such as alcohol, nitroglycerin, or tyramine containing foods. Cluster headaches may be prophylaxed with ergot preparations at bedtime, amitriptyline or lithium carbonate. Classic migraine headache involves painless prodromes such as visual changes (scotoma) followed by (usually unilateral) throbbing headache lasting for 6 to 8 hours and often accompanied by fatigue and photophobia. Common migraines may not be as painful or intense as classic, and do not have a prodrome. Controversy revolves around "tension headaches," as some think they are musculoskeletal in origin although some may have a partial vascular component.

88. Which of the following is the best method to determine the completion of facial growth? A. Use of hand/wrist films. B. Completion of changes in skeletal height C. Use of serial lateral cephalograms D. Attainment of maturity by the Tanner classification

Answer: C Rationale: Completion of skeletal height does not correspond to completion of facial growth. A hand- wrist radiograph is inappropriate for assessing facial growth, because it is not specific enough for each patient. The best method of evaluating the completion of facial growth is by superimposing sequential cephalometric radiographs. Most boys do not complete their facial growth until the late teenage years. A 14- or 15-year-old boy may not have gone through his adolescent growth spurt. It is advisable to wait until an adolescent male has completed growth in height. At that point, a cephalometric radiograph should be taken. Another radiograph should be taken at least 6 months to a year later. If these radiographs are superimposed, and there are no changes in vertical facial height (nasion to menton), this indicates that most of the facial growth has been completed. Achievement of Tanner stage V indicates maturity in development of secondary sexual characteristics, but not skeletal maturity.

113. A 20-year-old female presents for routine third molar surgery. She appears emaciated, has indicated that she has an "eating disorder" and you confirm that she has anorexia nervosa. Which one of the following pre-operative tests is most indicated prior to surgery? A. AST, GGT, ALT, and alkaline phosphotase B. 24 hour urine for metanephrines C. serum electrolytes D. Coagulation tests (PT, PTT, fibrin degradation products)

Answer: C Rationale: Dysfunction is found in most organ systems in the severely malnourished patient, but the most dangerous are fluid/electrolyte disorders. Amongst the answers given, a determination of electrolyte status would be the most appropriate in this situation. Other pertinent pre-op tests would include an electrocardiogram and complete blood count. Metabolic alkalosis, hypocalemia, and hypokalemia may manifest with prolongation of the QT interval. Sudden death in these individuals is often precipitated by ventricular arrhythmias. AST, GGT, ALT and alkaline phosphatase are blood screening tests for hepatic function. Although anorexia may affect the hepatobiliary system, cardiac function associated with anorexia would have the greatest potential impact in safely managing this patient. A 24 hour urine measuring the levels of metanephrines would be an appropriate study in the differential diagnostic work up for an adrenal neoplasm (such as a pheochromocytoma). This study will not yield any data that would assist in the diagnosis or management of anorexia nervosa. Although Prothrombin time (PT) and Partial Thromboplastin Time may be prolonged secondary to liver disease, these are not usually associated with anorexia. Fibrin degradation products are associated with disseminated intravascular coagulopathy (DIC), not with anorexia.

172. Erythema that persists more than 3 month after chemical peels can be treated with: A. antibiotic ointment. B. hydroquinone cream. C. topical steroid cream. D. CO2 laser.

Answer: C Rationale: Erythema up to three month is treated by observation. Erythema that persists after this period is treated with topical steroid creams. Hydroquinone is used to treat pigmentary changes. CO2 laser is of no benefit. Prolonged uses of antibiotic ointments have been implicated with persistent erythema.

117. Idiopathic Hypertrophic Subaortic Stenosis (IHSS): A. obstructs right ventricular outflow. B. diminishes diastolic valvular function. C. affects left ventricular outflow. D. hypertrophies the tricuspid valve.

Answer: C Rationale: IHSS is usually an inherited autosomal dominant characteristic, and can be associated with long term hypertension. Depending on the area of hypertrophy, the systolic left ventricular outflow can be significantly obstructed during systole. Fatal dysrhythmias and sudden death may result even in healthy teenagers with undiagnosed hypertrophy.

93. In order to maintain the crestal bone between adjacent dental implants, the implants should be placed at least how far apart? A. 2.0 mm B. 2.5 mm C. 3.0 mm D. 3.5 mm

Answer: C Rationale: In sites with adjacent implants, bone resorption of 1 to 2 mm at the proximal aspects of the implant leads to a flattening of the inter-implant bone and consequently a short inter-implant papilla. A distance of at least 3 mm has been recommended between 2 adjacent implants to minimize this bone resorption.

158. You are evaluating a patient who has a left submandibular infection of three days duration. His medical history is significant for hypertension and Type II diabetes mellitus controlled with oral hypoglycemic agents. Which of the following is true regarding this patient's diabetes? A. Treatment with oral medications should continue without change B. Concomitant infection will cause a decrease in serum glucose, oral medications should be discontinued C. Concomitant infection will cause an increase in serum glucose, insulin administration should be considered D. Serum potassium will rise in this patient and should be treated immediately

Answer: C Rationale: Infections cause gluconeogenesis and glycogenolysis. Even in Type II diabetics, exogenous insulin administration is often necessary in order to control glucose levels. Ketoacidosis leading to academia and hyperkalemia is not commonly seen even in severe hyperglycemia with Type II diabetics. However, in Type I individuals severely elevated glucose levels are indicative of insulinopenia. In severe insulin deficiency, glucose is not delivered through the cell membrane and intracellular metabolilsm uses proteins and fats, causing release of ketoacids. As ketoacidosis causes potassium shifts from inside the cells to the extracellular fluid, serum potassium values initially rise to critical levels, but total body potassium depletion occurs by renal potassium excretion.

185. The nerve that is most commonly injured in face lift procedures is the: A. marginal mandibular branch of facial nerve. B. spinal accessory nerve. C. greater auricular nerve. D. temporal branch of the facial nerve.

Answer: C Rationale: Injury to the facial nerve causing paralysis is rare, and reported only to occur in 0.53 to 2.6 % of patients. 85 % of motor nerve injuries resolve spontaneously, and results of surgical repair are unpredictable and not very encouraging. Injury to the greater auricular nerve is most common, and occurs in up to 7 % of patients. Temporary neuropraxia usually resolves in 2-4 months, and causes numbness/paresthesia around the inferior portion of the ear and surrounding skin. Transection of the nerve is best treated with immediate microanastomosis.

116. Tricuspid valve insufficiency initially produces: A. atrial fibrillation. B. left Ventricular dilitation. C. volume overload of right atrium/ventricle. D. ventricular Tachycardia.

Answer: C Rationale: Insufficiency of the tricuspid valve initially produces a volume overload to the right atrium and ventricle, which dilate as a compensatory mechanism. This gives rise to elevated central venous pressures which cause right sided "congestive failure." If the tricuspid regurgitation is massive, under-filling of the left heart can result.(this last sentence need a little work)

153. In treatment of diabetic ketoacidosis, maximal insulin effect is desired. This can be achieved through: A. plasma insulin levels of 300-350 μu/ml. B. fluid restriction. C. IV insulin at a rate of 2-10 units/hour. D. sodium polystyrene resin.

Answer: C Rationale: Maximal insulin effect is reached with plasma levels of 20-200 u/ml. This can be accomplished (ideally in an intensive care setting) by administering IV insulin with an initial bolus of 10-15 units, followed by a continuous infusion at a rate of 2-10 units/hour. The ketoacidotic patient generally presents with decreased intravascular volume, requiring volume expansion and not fluid restriction. Although serum potassium is commonly elevated by ketoacidotic shift from intracellular fluids, total body potassium is often decreased and insulin can rapidly drop serum potassium to dangerously low levels. Often, potassium is judiciously given IV with insulin to keep serum potassium at a safe level.

121. Which of the following is most likely to be associated with untreated mitral stenosis? A. Increased pulse pressure B. Right atrial hypertrophy C. Pulmonary hypertension D. Left ventricular hypertrophy

Answer: C Rationale: Mitral stenosis is associated with diminished pulse pressure as there may be impaired left ventricular filling. A triad of symptoms associated with MS includes left atrial hypertrophy, pulmonary hypertension and right ventricular hypertrophy due to stenosis of the mitral valve. This condition requires the cardiac structures upstream from the mitral valve to overcome increased resistance across a stenotic mitral valve resulting in hypertrophic changes in those areas. Note: pulmonary hypertension is the result of smooth muscle hypertrophy involving the pulmonary arteriolar bed.

145. An 89-year-old male presents with the following: akinesia, a resting 'pill rolling' tremor, rigidity and a shuffling gait. What is the pathophysiology of this condition? A. Focal areas of demylination followed by reactive gliosis B. Lewy bodies present in the temproparietal lobe, cerebellum and basal ganglia C. Dopamine depletion in the substansia nigra of the basal ganglia D. Antibody-mediated neuromuscular receptor depletion

Answer: C Rationale: Parkinson's disease is the leading cause of neurologic disease in people older than 65-years- old and affects approximately 1 million Americans. Typically it is characterized as an idiopathic movement disorder with akinesia, 'resting pill' rolling tremor and a shuffling gait. The primary pathogenesis is dopamine depletion in the substansia nigra of the basal ganglia. Lewy bodies (cytoplasmic inclusions) can be seen in Parkinson's disease however are localized to the cerebellum, basal ganglia, sympathetic ganglion and spinal cord and not usually the temporparietal lobe. Focal areas of demylination followed by reactive gliosis is seen in multiple sclerosis. Myesthenia gravis is an autoimmune disease causing muscular weakness from antibody mediated destruction of the acetylcholine receptor in the neuromuscular junction. Weakness is temporarily ameliorated by the administration of edrophonium, and is diagnostic for the disease.

Which of the following medical conditions is a relative contraindication for the use of phenol peel: A. pulmonary disease. B. gastric Disease. C. hepatic disease. D. endocrine disease.

Answer: C Rationale: Phenol is metabolized in the liver and excreted in the kidney, also has been associated with cardiac dysrhythmias. These diseases are relative contraindications to its use.

183. When planning a facelift procedure, the incidence of skin flap necrosis is found to be ______ times higher in smokers when compared to non-smokers. A. 5 B. 8 C. 12 D. 15

Answer: C Rationale: Some surgeons consider smoking as an absolute contraindication; however, most recommend that smoking be stopped at least 1-2 weeks before surgery and for 2 weeks postoperatively. The overall complication rate for patients who continue to smoke is more than twice those who stop smoking.

96. When considering immediate loading of a dental implant, the minimum insertional torque with which the implant must be placed is: A. 10 - 15 N/cm2. B. 20 - 25 N/cm2. C. 30 - 35 N/cm2. D. 40 - 45 N/cm2.

Answer: C Rationale: Studies that use insertion torque values are in general agreement that the values should be at least 30 to 35 Ncm."

111. Intravenous conscious sedation is being administered to a 62-year-old male with a history of exertional angina. Local anesthetic without a vasoconstrictor has been infiltrated and extraction of tooth #12 has been accomplished. Abruptly, the patient's blood pressure rises 60% above baseline. Conservative measures fail to reduce the blood pressure and pharmacologic intervention is now required. Which antihypertensive agent is contraindicated in this setting? A. Esmolol B. Clonidine C. Hydralazine D. Labetalol

Answer: C Rationale: Sustained elevated blood pressure can lead to left ventricular failure, pulmonary edema, myocardial ischemia, and cardiac dysrhythmias. Antihypertensive agents must be chosen carefully when a patient with a history of ischemic heart disease is being treated. Labetalol is a selective Alpha, and nonselective Beta-blocker. Reflex tachycardia is not seen after administration and cardiac output is not changed. Pulmonary artery and wedge pressures decrease. Esmolol is a rapid acting cardioselective beta blocker which does not increase cardiac output or cardiac oxygen consumption. Oral clonidine is a centrally acting alpha agonist with a wide margin of safety. Hydralazine is a parenteral antihypertensive that acts as a direct vasodilator., and may result in unopposed beta stimulation with significant reflex increases in cardiac output. Hydralazine is contraindicated when a patient has a history of ischemic heart disease.

144. Which of the following statements regarding temporal arteritis is true? A. Predilection for adolescent females B. Rarely causes severe headaches C. Masticatory muscle pain during chewing D. Unresponsive to corticosteroid therapy

Answer: C Rationale: Temporal arteritis is a chronic inflammatory disease involving large arteries of the carotid system, particularly in those with a prominent elastica, occurring primarily in the elderly. This disorder commonly causes pain on mastication in the masseter, temporals, and tongue muscles. Estimated prevalence is about 1/1000 in patients > 50 yo with a slight predilection in females. Symptoms typically include a severe headache, scalp tenderness, and visual disturbances. It can cause blindness secondary to ischemic optic neuropathy in less than 20% of patients; but this occurrence is very rare after high-dose steroid treatment.

175. A patient that undergoes laser skin resurfacing and is on Valacyclovir 1000mg once daily, develops a herpetic outbreak in the postoperative period. Which of the following is the recommended treatment? A. Change to Acylovir 400mg three time/day B. Continue the current regimen for another two weeks C. Change to Valacyclovir 1000mg three times/day D. Treat the outbreak with Zithromax for 10 days

Answer: C Rationale: The dose should be increased to a herpes zoster dose. Herpetic outbreaks are very rare when the patient is taking antiherpetic medication but they do occur. Answer A is wrong since this is a prophylactic dose for acyclovir.

105. Which of the following statements is correct regarding the mandibular third molar? A. The tooth germ is usually visible on a radiograph by the age of 6. B. By age 11, the tooth is located within the anterior border of the ramus with the occlusal surface facing superiorly. C. The orientation of the crown within the alveolus may be affected by underdevelopment or overdevelopment of its mesial or distal roots. D. The tooth's position from ramus to alveolus is determined strictly by growth of the mandibular body.

Answer: C Rationale: The mandibular 3rd molar, visible radiographically as a tooth germ usually by age 9 within the anterior border of the ramus, progresses with mandibular growth to the body due to resorption of the anterior border of the ramus. The tooth's anterior facing occlusal surface changes orientation to vertical, usually by age 20, during its root development. The failure to progress to final vertical orientation may be attributed to one or more factors including: Over or under development of the mesial and/or distal roots Insufficient arch length to accommodate the normal position of the tooth within the arch

101. What stage of root development is optimal for the surgical uprighting of an impacted mandibular second molar? A. Less than 1/3 root B. 1/3 C. 2/3 D. Complete

Answer: C Rationale: The procedure is best performed after 2/3 of root development is completed. At this stage the risk of root fracture is minimal. Performing this procedure when less than 2/3 of root development has been completed could result in the second molar floating in its new position. Although the procedure has been performed when root development is complete, the incidence of subsequent pulpal necrosis or calcification is increased.

163. The muscle groups to be injected for treating glabellar frown lines with Botox include: A. frontalis, corrugator, and procerus muscles. B. frontalis and procerus muscles. C. corrugator and procerus muscles. D. frontalis and corrugator muscles.

Answer: C Rationale: The treatment of glabellar frown lines with Botox requires injection of the procerus and corrugator muscle groups.

180. Your preoperative esthetic evaluation of a patient reveals brow ptosis, and an upper eyelid crease which is more than 12 mm above the upper eyelid margin with lid ptosis. This patient is best treated by: A. transcutaneous upper eyelid blepharoplasty and brow lift. B. brow lift only, but only via a coronal approach. C. levator aponeurosis or Muller's muscle surgery and brow lift. D. transconjunctival upper eyelid blepharoplasty and brow lift.

Answer: C Rationale: Transcutaneous blepharoplasty does not correct eyelid retraction, and occasionally will worsen the condition due to skin removal. Brow lift procedures will correct brow ptosis, but not lid ptosis. Surgery of the muscles of the upper eyelid is often performed to correct lid ptosis. Lid ptosis must be evaluated and corrected prior to a blepharoplasty procedure. A transconjunctival blepharoplasty will not correct eyelid retraction.

120. Which of the following concerning acute chest pain is true? A. ST depression and chest pain with positive cardiac troponins are an indication for thrombolytic therapy B. Q-wave MI's contraindicate percutaneous coronary angioplasty C. Unstable angina is an indication for antiplatelet medication D. Heparin may not be used with fibrinolytic therapy

Answer: C Rationale: Unstable angina is a pre-infarctive condition, in which the developing thrombus is platelet rich and where antiplatelet drugs are indicated. ST depression with lack of Q waves and positive cardiac troponin indicate an early or intermittent infarction (termed a non-Q-wave myocardial infarction.) The thrombus at this stage is a mixture of a fibrin clot and platelets; and treatment at this time with a thrombolytic may liberate clot-bound thrombin, enlarging or embolizing the clot and may paradoxically worsen coronary occlusion. Q wave MIs indicate total thrombotic occlusion and are an indication for prompt coronary angioplasty. Heparin is commonly used with both fibrin specific thrombolytics and with angioplasty procedures.

104. Indication for removal of impacted 3rd molars include: A. prevention of mandibular anterior tooth crowding. B. to allow for postoperative regeneration of bone distal to a 2nd molar with chronic periodontitis. C. prior to anticipated sagittal split osteotomy. D. deeply impacted maxillary third molars, prior to anticipated LeFort I osteotomy.

Answer: C Rationale: While somewhat controversial, crowding of mandibular incisor teeth appears to be associated with deficient arch length rather than the mere presence of impacted teeth. After 3rd molar removal the bone height distal to the 2nd molar usually remains at the pre-operative level. Removal of 3rd molars at mandibular advancement osteotomy reduces the thickness and quality of lingual bone at the proximal aspect of the distal segment where fixation screws are usually applied. During a LeFort osteotomy, removal of deeply impacted maxillary 3rd molars from the maxillary sinus side may be done safely without compromising the soft tissue vascular pedicle of the maxilla.

139. A patient who sustained a sharp blow to the chin was referred for evaluation of left TMJ pain. The patient complained of attenuated hearing on the left side. Otoscopic examination revealed blood in the middle ear. A positive Rinne test would suggest: A. damage to cranial Nerve VIII. B. damage to Cranial Nerve VII. C. air conduction greater than bone conduction. D. bone conduction greater than air conduction.

Answer: D Rationale: A Rinne test involves evaluating a subject's ability to hear a vibrating tuning fork when it is held next to the ear and when it is placed on the mastoid process. Normally, air conduction is greater than bone conduction. A positive Rinne test exhibits diminished hearing acuity through air and somewhat heightened hearing acuity through bone, and is symptomatic of conduction deafness. Testing for damage to cranial nerve VIII vestibular function (such as cold water irrigation of the external auditory canal) often reveals nystagmus and for cochlear function reveals hearing loss. Therefore, a patient with VIII nerve disruption would have neither bone nor air conductive hearing. Injury to the facial nerve would be manifest by loss of facial animation and loss of taste on the involved side.

157. You are called to the Emergency Department to evaluate a patient presenting with a right mandibular angle fracture. You note a history of severe alcoholism and anorexia in this cachetic individual. She exhibits peripheral edema, and is ataxic and confused. Which is the most likely diagnosis? A. Korsakoff's psychosis B. nutritional polyneuropathy C. Wernickes encephalopathy D. Wet beriberi

Answer: D Rationale: All of the listed disorders can be caused by the thiamine deficiency common in malnutrition, such as found in anorexic or alcoholic individuals. Chronically malnourished individuals can manifest with numerous metabolic and electrolyte disorders, and careful nutritional diagnosis and support is vital in this patient population. Wet beriberi is a thiamine-depletion cardiovascular disorder with three major derangements: 1) peripheral vasodilatation with high-output cardiac failure 2) sodium retention and peripheral edema 3) biventricular heart failure. Wernicke's encephalopathy (cerebral beriberi) is an acutely evolving disease. Its most common manifestations include vomiting, nystagmus, ophthalmoplegia, and ataxia. Korsakoffs psycosis is primarily a disturbance of the ability to form new memories. Nutritional polyneuropathy, or dry beriberi, is a polyneuropathy involving the distal peripheral nerves. It primarily affects sensory innervation.

112. A thin appearing 52-year-old male with a long history of alcohol abuse is having multiple dental extractions under local anesthesia when he suddenly becomes disoriented and confused. An ECG reveals RR 22. A. B. C. D. a polymorphic ventricular tachycardia. His vital signs are as follows: BP 85/55, HR 165, Which is the most appropriate drug to administer? Epinephrine Amiodarone Lidocaine Magnesium

Answer: D Rationale: Chronic alcoholism and malnutrition is frequently associated with hypomagnesemia which can provoke a polymorphic ventricular tachycardia, torsades de pointe, with a prolonged QT interval. The immediate treatment is to administer magnesium. Epinephrine may increase myocardial irritability and worsen the tachycarida. Amiodarone prolongs the QT interval which can cause a worsening of the torsades. Lidocaine may be given but is not as efficacious as magnesium for this type of arrhythmia. If available, overdrive pacing is an acceptable alternative to magnesium.

126. Which is a characteristic feature of pulmonary emphysema? A. Increased hematocrit B. Cor pulmonale C. Decreased functional residual capacity D. PaCO2 is normal to slightly decreased

Answer: D Rationale: Chronic obstructive lung disease encompasses chronic obstructive bronchitis and emphysema. With both disorders, FEV/ FVC is decreased; but residual volume, functional residual capacity and tidal volume are generally increased. Chronic obstructive bronchitis is referred to as "blue bloater". The disease is characterized by obstruction of small airways secondary to mucus and inflammation. Patients with chronic bronchitis have significant decreases in PaO2 (< 65 mmHg is typical.) Compensatory consequences include erythrocytosis. PaCO2 is also chronically elevated. This results in pulmonary hypertension and cor pulmonale. Physiologic changes found with emphysema include destruction of lung parenchyma, enlargement of airway spaces, loss of lung elasticity and closure of small airways. Rapid, shallow respirations generally result in a PaCO2 which is normal to slightly decreased and a PaO2 > 65 mmHg. This disease is categorized as "pink puffer" and is generally not associated with cor pulmonale.

166. When treating deep rhytides in the perioral region in a 68 year old female with sun damaged skin, the treatment of choice would be: A. Botox. B. Myobloc. C. Bovine collagen. D. Restylane.

Answer: D Rationale: Deep perioral rhytides can be caused by many factors: habits (such as smoking), sun damage, loss of elastic collagen in the dermal layers, and overhanging, ptotic skin. Botox and Myobloc would have minimal effect in this scenario and are not recommended for patients over age 65. Bovine collagen can exhibit a severe inflammatory response. It is also short lived, lasting as little as two months. Restylane is longer acting with fewer side effects and would be the treatment of choice.

154. A patient presents with the following oral/perioral conditions: metallic bad taste, halitosis, excessive salivation, stomatitis, and parotid swelling. These symptoms are most consistent with: A. alcoholic cirrhosis. B. gastric ulcer. C. hepatocellular carcinoma. D. chronic renal failure.

Answer: D Rationale: Elevation of blood urea nitrogen in renal failure results in salivary ammonia excretion. Uremic stomatitis can occur in severe renal failure. This presents with symptoms of foul taste, halitosis, excessive salivation, as well as signs and symptoms of soft tissue stomatitis. Parotid as well as submandibular swelling may be seen in chronic renal failure with or without accompanying signs of stomatitis. Additionally, parotid swelling may be part of a malnutrition syndrome such as in alcoholism.

181. Where is Erb's point located? A. 3 cm inferior to the lobule of the ear and along the anterior border of the sternocleidomastoid. B. 3 cm inferior to the lobule of the ear and along the posterior border of the sternocleidomastoid. C. 6 cm inferior to the lobule of the ear and along the anterior border of the sternocleidomastoid. D. 6 cm inferior to the lobule of the ear and along the posterior border of the sternocleidomastoid

Answer: D Rationale: Erb's point is approximately 6 cm inferior to the lobule of the ear and along the posterior border of the sternocleidomastoid muscle, where the platysma crosses it obliquely. Remaining superficial to the fascia over the sternocleidomastoid muscle in this region ensures that injury to the greater auricular and accessory nerves is avoided.

169. Patients undergoing chemical peel that are taking hormone replacement therapy are at increased risk of which of the following: A. hypertrophic scar formation. B. delayed healing. C. persistent erythema. D. pigmentary changes.

Answer: D Rationale: Hormone replacement therapy may contribute to melanocyte activity and pigmentary changes. It is recommended that therapy be stopped one month prior to surgery to decrease incidence.

92. The osteotome technique for implant placement: A. is primarily used in the mandible. B. is used in Type I bone. C. compromises vascularity. D. compresses bone laterally.

Answer: D Rationale: In soft maxillary bone, preparation of the implant osteotomy site can be completed using a series of osteotomes rather than burs. Because the maxillary bone is soft, an osteotome can be used to split or widen a narrow ridge to receive an implant. In addition, the osteotome condenses and laterally compresses the soft bone at the osteotomy site, placing a denser, compressed bone immediately adjacent to the implant..

130. Which of the following can be used to classify an airway in the Fujita system? A. Epworth Sleep Scale B. Polysomnography C. Bed partner interview D. Nasopharyngoscopy

Answer: D Rationale: Nasopharyngoscopy , especially supine and using Mueller's Maneuver (holding the nose and mouth closed against forced inspiration) is the most useful to diagnose the level of airway obstruction in the sleep apnea patient. A Fujita Type II airway obstruction occurs at both the retropalatal (oropharyngeal) and retrolingual (hypopharyngeal) areas; while a Type I is retropalatal and Type III is retrolingual. Polysomnography establishes the diagnosis of obstructive sleep apnea but not the location of obstruction. The Epworth Sleep Scale is a subjective evaluation of daytime hypersomnolence and is useful in the referral of patients for further sleep disorder work up. The interview of a bed partner, especially as to sonorous breathing, loud snoring, or observed obstructive apneas is highly sensitive for the presence of obstructive sleep apnea and should prompt the practitioner to further sleep disorder work up including polysomnography.

118. Which of the following statements concerning intravascular replacement is true? A. 0.9% saline is isosmolar to lactated Ringer's solution B. Renal resorption of potassium makes intravenous supplementation unnecessary C. Excessive lactated Ringer's solution administration can cause hypermagnesemia D. One liter of 5% dextrose in water yields 200 kilocalories

Answer: D Rationale: One liter of 5% dextrose in water yields 50 g of dextrose; with available calories:4 kcal/gm, or 200 kcal. O.9% (normal) saline has an osmolality of 308; while lactated Ringer's solution is 273. Obligate renal potassium losses are about 40 mEq/day, and requires replacement (either from oral intake or by a parenteral supplement.) Ringer's lactate has no magnesium hence no possibility of hypermagnesemia.

155. After an orthognathic surgical procedure with prolonged induced hypotension and transfusion of two units of autodonated and one unit of banked red blood cells, you suspect olioguric acute renal failure. Which of the following is more predictive for your diagnosis? A. Urine specific gravity elevated B. Urine sodium decreased C. Urine osomality elevated D. Serum creatinine increased

Answer: D Rationale: Patients in renal failure typically exhibit specific gravity which is isothenic (1.010) or less. Also, urine osmolality is low (<300) and sodium is high (>20mmol/L). Serum creatinine will be markedly elevated quickly in the initial (oliguric) phase of acute renal failure. This case of failure is probably due to ischemic hypoperfusion from prolonged hypotension. However, deposition of myoglobin from surgical insult or hemoglobin from transfusion may also be contributing to renal tubular dysfunction.

114. During cardiac exercise stress testing, ECG monitoring during or after exercise would look for signs of ischemia based on: A. excessively tall QRS complexes. B. prolonged P-R intervals. C. biphasic P-waves. D. ST depression.

Answer: D Rationale: Patients with stress-induced symptoms of ischemia usually provide the best assessment of risk for adverse events from CAD. Ischemic tendencies would be evidenced by the presence of ST depression or inverted T waves. The addition of cardiac imaging increases the sensitivity of the stress test, especially when resting ECG abnormalities exist or conditions are present that may cause abnormal stress-induced ECG changes not secondary to ischemia. Excessively tall QRS complexes may indicate ventricular hypertrophy. Prolonged P-R intervals indicate conduction delay at a location between the atria and the ventricles (such as at the A-V node.) Biphasic P waves are indicative of atrial hypertrophy.

164. The minimum pore size for porous facial implants for resistance to bacterial infection is: A. <1 micron. B. 10 to 25 microns. C. 26 to 50 microns. D. >50 microns.

Answer: D Rationale: Porous implants have the potential for ingrowth of bacteria that are introduced at the time of surgery or post-operatively from tissue breakdown. This occurs when the pore size is >1micron. Macrophages require a pore size of >50 microns to enter and engulf bacteria that have infected the implant. Therefore, the ideal porous implant would have pores smaller than 1 micron to avoid bacterial inoculation or >50 microns to allow macrophages to engulf the bacteria.

95. Soft tissue peri-implantitis occurs most frequently with which of the following implant restorations? A. Single tooth replacement B. Implant and tooth supported fixed prosthesis C. Implanted supported fixed prosthesis D. Implant supported overdenture

Answer: D Rationale: Soft tissue peri-implantitis occurs most commonly in association with implant supported overdentures, with a reported frequency of 11% to 32%. Rates of soft tissue peri-implantitis associated with implant supported fixed prostheses range from 7% to 20%.

100. A 20-year-old presents with a radiolucency associated with an impacted tooth. What is the most common pathologically significant lesion detected on histopathologic examination of the pericoronal tissue? A. Odontogenic keratocyst B. Ameloblastoma C. Odontoma D. Dentigerous cyst

Answer: D Rationale: The cited study reported the histopathologic diagnoses of a large series of pericoronal lesions in adults submitted to an oral and maxillofacial pathology biopsy service. Of the 2646 lesions submitted, 33% showed demonstrable pathology. The most common pathology was dentigerous cyst (28.4%), followed by OKC (3%), odontoma (0.7%), and ameloblastoma (0.5%).

127. Whichofthefollowingstatementsconcerningpulmonarythromboembolismistrue? A. ELISA test for d-dimer yields the quickest diagnostic results B. Helical CT is highly specific indicator for subsegmental emboli C. Fluid replacement is indicated for decreased left ventricular output D. Serial deep venous ultrasonography is indicated if other tests yield equivocal results

Answer: D Rationale: The diagnosis of pulmonary thromboembolism can be difficult, and the results of clinical, laboratory, and radiologic exams can be equivocal. Testing is generally based upon risk stratification (according to clinical presentation, medical history, surgical procedures, and other risk factors both for developing PE and for risks of this disorder.) The most common suspected site of origin for pulmonary thrombi are from deep leg veins; so in the case of suspected but unconfirmed PE, repeat serial leg vein ultrasound is indicated. ELISA tests vary in sensitivity the d-dimer breakdown products from thrombi; with the results generally not immediately available. Venous contrast helical CT is being advocated as a screening tool for PE, but this modality has not proven to be highly sensitive or specific for (small) subsegmental PE's, which are notoriously difficult to diagnose. Decreased in left ventricular output are an ominous sign in PE, caused by decreased left atrial filling. Fluid bolus therapy in these patients, who already are in right heart failure, is contraindicated.

150. During an elective genioplasty under deep sedation in your office, you note that the right mental nerve is severed. What type of injury is this according to the Seddon classification system, and how should it be repaired? A. Neurotmesis; repair with perineurial neurorrhaphy B. Neurapraxia; repair with epineurial neurorrhaphy C. Axonotmesis; repair with perineurial neurorrhaphy D. Neurotmesis; repair with epineurial neurorrhaphy

Answer: D Rationale: The outer layer of the trigeminal nerve is the epineurium; this encloses the perineurium, which is the connective tissue surrounding groups of nerve fascicles. The endoneurium is the connective tissue layer surrounding individual fascicles within the perineurium. Seddon classified nerve injuries into neurapraxia (brief conduction loss due to manipulation with rapid recovery and no axonal degeneration), axonotmesis (more severe injury with axonal damage and demyelination) and neurotmesis (complete nerve transaction). Repair of this injury should be with 2 or 3 fine non-resorbing sutures placed in the epineurial layer. Neurorrhaphy is the term for directly suturing 2 nerve ends together.

131. Which of the drugs listed below is appropriate for use in the epileptic patient with asthma? A. Piroxicam B. Methohexital C. Morphine D. Ketamine

Answer: D Rationale: The sources of asthmatic airway processes are rapid release of chemical mediators, abnormalities of airway neuroregulation, or an intrinsic defect of airway smooth muscle. Ten percent of patients with asthma can experience bronchial constriction and rhinorrhea in response to aspirin or NSAIDs such as prioxicam. The mechanism is via blockade of prostaglandin synthesis, causing leukotriene build up. Methohexital may be epileptogenic (unlike other barbiturates); and histamine release by methohexital or morphine may also precipitate an asthma attack. Ketamine acts as a bronchidilator and does not possess epileptogenic properties.

133. Which antibiotic has the greatest potential for adverse interaction with theophylline? A. Penicillin B. Clindamycin C. Cephalexin D. Ciprofloxacin

Answer: D Rationale: Theophylline, a thioxanthine, acts centrally as an indirect adrenergic, causing dilation of bronchial smooth muscle and is used in the management of refractory asthma. Toxicity is manifested as hyperadrenergia including tachycardia, hypertension, and hyperreflexia. Erythromycin reversibly inhibits hepatic degradation of theophylline and can lead to toxic serum levels of the bronchodilator. The same is true with concomitant use of theophylline with cimetidine, ciprofloxacin, and allopurinol. Clindamycin, cephalexin, and penicillin do not diminish theophylline metabolism.

143. The signs of causalgia (reflex sympathetic dystrophy) include: A. hypoesthesia. B. pain of short duration. C. exacerbation of symptoms with a regional sympathetic block. D. skin flushing or pallor.

Answer: D Rationale: This complex regional pain syndrome typically occurs after a relatively minor injury resulting in a persistent, burning sensation with hyperesthesia and hyperpathia. This is thought to occur from a heightened sympathetic outflow. Peripheral vasodilation (skin flushing and warmth) or vasoconstriction (skin pallor and coolness) may occur. Diagnosis and treatment depend on pain relief following sympathetic blockade.

161. The best approach to avoiding upper lid ptosis when treating forehead lines with Botox is: A. injecting at the hairline and letting the toxin diffuse inferiorly. B. injecting only midline at the procerus muscle. C. injecting only the frontalis muscle. D. injecting at least 1 cm above the supraorbital rim.

Answer: D Rationale: Treatment of glabellar lines is easy to accomplish with minimal side effects. The most common side effect is lid ptosis, which is caused by diffusion of Botox to the superior lid muscles (levator palpebrae superioris). Lid ptosis is best done by staying 1cm above the supraorbital rim when injecting the corrugator muscles.