Orthodontics and Pediatric Dentistry
What is the usual order of extraction of teeth if serial extraction is chosen as the treatment to alleviate severe crowding? A.Primary second molars, primary first molars, permanent first premolars, primary canines B.Primary canines, primary first molars, permanent first premolars C.Primary first molars, primary second molars, primary canines D.Primary canines, permanent canines, primary first molars, permanent first premolars
A?? 10. B. Primary canines are extracted to encourage alignment of the crowded incisors. However, the incisors align and upright, borrowing space otherwise needed for eruption of the permanent canine. Primary first molars are extracted to encourage eruption of the first premolar so that it may be extracted to make room for the permanent canine to erupt.
Congenitally missing teeth are the result of failure in which stage of development? A.Initiation B.Morphodifferentiation C.Apposition D.Calcification
A?? 13. A. Initiation and proliferation are the only possibilities for congenitally absent teeth, the bud and cap stages, respectively. In the histodifferentiation stage, the teeth are present; failure in this stage results in structural abnormalities of the enamel and dentin. Failure in the morphodifferentiation stage results in size and shape abnormalities.
During an emergency dental visit in which a tooth is to be extracted because of extensive pulpal involvement, a moderately developmentally challenged 5-year-old child becomes physically combative. The parents are unable to calm the child. What should the dentist do? A.Discuss the situation with the parents. B.Force the nitrous oxide nosepiece over the child's mouth and nose. C.Use the hand over mouth exercise (HOME). D.Use a firm voice control.
A?? 14. A. For any child patient, it is imperative to discuss any kind of physical restraint with the parent to obtain an informed consent. An informed consent includes recommended treatment, reasonable alternatives to that treatment, and the risk of no treatment. If the dentist wants to use a firm voice control, it is recommended that a discussion take place beforehand as well.
The enamel rods in the gingival third of primary teeth slope occlusally instead of cervically as in permanent teeth. The interproximal contacts of primary teeth are broader and flatter than the interproximal contacts of permanent teeth. A.The first statement is true, and the second statement is true. B.The first statement is true, and the second statement is false. C.The first statement is false, and the second statement is true. D.The first statement is false, and the second statement is false.
A?? 16. A. Both of these statements are true. As a result of these differences, there are modifications in preparation design for class II amalgams. Beveling the gingival seat of class II amalgams is not recommended. There is a greater convergence from cervical to occlusal of the buccal and lingual walls of class II amalgam preparations because of the broad and flat contact areas.
Formocresol has been shown to have a very good success rate when used as a medicament for pulpotomy procedures. Why is there continued interest to find another medicament that performs as well as or better than formocresol? A.Application of formocresol is a clinically time-consuming procedure. B.Formocresol is toxic, and there is the possibility of blood-borne spread to vital organs. C.It has been demonstrated that formocresol may cause spontaneous abortion. D.It has been demonstrated that formocresol may cause failure to develop adequate lung capacity in children.
A?? 17. B. There have been concerns regarding the blood-borne spread of formocresol at least since 1983, when a study was published describing the tissue changes induced by the absorption of formocresol from pulpotomy sites in dogs. Ferric sulfate and mineral trioxide aggregate have been demonstrated to be reasonable alternatives to formocresol.
The following teeth are erupted in an 8-year-old patient. What is the space maintenance of choice? 3 ABC 7 8 9 10 H I 14 30 T S R 26 25 24 23 M L K 19 A.Band-loop space maintainer B.Lower lingual holding arch C.Nance holding arch D.Distal shoe space maintainer
A?? 18. A. A band-loop space maintainer would work well in this case because the maxillary first bicuspid normally erupts before the loss of either the second primary molar or the primary cuspid.
In a 4-year-old patient, the maxillary right primary central incisor was traumatically avulsed 60 minutes ago. What is the treatment of choice? A.Replant, splint, and primary endodontics B.Replant, splint, and formocresol pulpotomy C.Replant, no splint, and primary endodontics D.None of the above
A?? 22. D. Replanting primary teeth has a poor prognosis but could be considered if performed within 30 minutes. A primary tooth that is replanted is likely to require splinting. The patient should be placed on antibiotics, be restricted to a soft diet, and undergo a primary endodontic procedure accomplished.
Match the exhibited behavior of a child dental patient with the classification of potentially cooperative patient. Exhibited Behavior Classification ____ A.Gripping the arms of the chair very tightly 1.Timid ____ B.Patient says "I don't want to" and does not open the mouth 2.Defiant ____ C.Temper tantrum 3.Tense-cooperative ____ D.Shielding behavior 4.Uncontrolled
4,1,3,2?? 32. A—3, B—2, C—4, D—1. It is important to observe the behavior of the child to better treat the patient.
A young permanent incisor with an open apex has a pinpoint exposure as a result of a traumatic injury that occurred 24 hours previously. Which of the following is the best treatment? A.Place calcium hydroxide on the pinpoint exposure B.Open the pulp chamber to find healthy pulp tissue and perform a pulpotomy C.Initiate a calcium hydroxide pulpectomy D.Initiate conventional root canal treatment with gutta-percha
A?? 23. B. Because the exposure site is likely significantly contaminated from the injury that occurred 24 hours previously, direct pulp capping with calcium hydroxide is contraindicated. A calcium hydroxide pulpectomy should not be the automatic procedure performed because continued root elongation and closure of the pulp canal will likely not occur. A calcium hydroxide pulpotomy is preferable for a traumatized tooth with an open apex with either a large exposure or a small exposure of several hours or days postinjury. Clinically, the tooth should be anesthetized, and, under sterile conditions, the clinician should open the pulp chamber to search for healthy pulp tissue. It is likely that vital tissue will be present within 24 hours of the injury.
In general, the width of the incisors in the primary dentition is smaller than the width of their successors in the permanent dentition. This is called the "leeway space" and provides room for eruption of the permanent incisors. A.Both statements are true. B.Both statements are false. C.The first statement is true, and the second statement is false. D.The first statement is false, and the second statement is true.
A?? 29. C. The width of the permanent incisors is greater than the deciduous or primary incisors, so it is normal and desirable for there to be spacing between primary incisors so that the permanent successors have adequate space to erupt. However, this extra space is not the leeway space. The term leeway space refers to the extra width of the primary canine, primary first molar, and primary second molar (combined) compared with their permanent successors (permanent canine and first and second premolars). This extra leeway space becomes available when these posterior teeth exfoliate, and the permanent teeth, which are typically smaller, erupt.
According to Scammon's growth curves, which of the following tissues has a growth increase that can be used to help predict timing of the adolescent growth spurt? A.Neural tissues B.Lymphoid tissues C.Reproductive tissues
A?? 3. C. Reproductive tissues grow at the same time as the adolescent growth spurt, and the appearance of secondary sexual characteristics can be used to help predict the timing of growth.
Which of the following is the definition of conscious sedation? A.A minimally depressed level of consciousness that retains the patient's ability to maintain an airway independently and continuously and respond appropriately to physical stimulation or verbal command B.A significantly depressed level of consciousness in which the patient's ability to maintain an airway independently and continuously and respond appropriately to physical stimulation or verbal command is retained C.A minimally depressed level of consciousness in which the patient's ability to maintain an airway independently and continuously is retained D.A significantly depressed level of consciousness in which the patient's ability to maintain an airway independently and continuously is retained
C?? 15. A. Conscious sedation is defined as a minimally depressed level of consciousness as opposed to deep sedation or general anesthesia. There are four stages of anesthesia (analgesia → delirium → surgical anesthesia → respiratory paralysis), and the patient is conscious only in the first stage (analgesia). The patient should be able to maintain an airway and respond to stimulation and command.
Which of the following statements best describes the prognosis of a 12-year-old boy with moderate mandibular anterior crowding whose permanent dentition is fully erupted? A.Crowding is likely to improve as the arches expand during the adolescent growth spurt. B.Crowding is likely to improve as the mandible continues to grow anteriorly during the adolescent growth spurt. C.Crowding is likely to improve as resorption of the anterior portion of the ramus occurs over time. D.Crowding is not likely to improve over time.
A?? 31. D. When the permanent dentition is fully erupted, there is little or no likelihood that crowding will resolve on its own without intervention. Widening of the dental arches during occlusal development continues to occur naturally to a small degree during growth until the permanent canines are erupted. There is some increase in space available for the dentition as the permanent premolars erupt to replace the primary molars owing to the leeway space. However, there is no increase in the length of the mandible that occurs within the dental arches during growth. The mandible grows by addition of bone at the condyle and deposition of bone at the posterior ramus. Resorption of bone at the anterior border of the ramus provides room for the posterior teeth (first molar, second molar and, perhaps later, third molar) to erupt but does not provide room for anterior dental crowding to resolve.
An adult patient with a class II molar relationship and a cephalometric ANB angle of 2 degrees has which type of malocclusion? A.Class II dental malocclusion B.Class II skeletal malocclusion C.Class I dental malocclusion D.Class II skeletal malocclusion
A?? 5. A. The molars are class II, but the skeletal relationship described by a normal ANB measurement is normal, so the malocclusion is dental in origin.
Order the sequence of events that occur when heavy orthodontic forces are placed on teeth. ____ A.The PDL experiences compression on the side toward which the tooth is moving ____ B.The alveolar bone experiences undermining resorption ____ C.The PDL undergoes hyalinization ____ D.Frontal resorption occurs at the surface of the alveolus
ACBD?? 26. A—1, B—3, C—2, D—4. When heavy forces are applied during orthodontic treatment, the tooth is moved in the direction in which the force is pushing, compressing the PDL on the side toward which the tooth is moving. The area of the compressed PDL becomes necrotic or hyalinized. Cell migration occurs from surrounding bone marrow spaces, and undermining resorption occurs. As the force dissipates over time and repair occurs, frontal resorption can begin to occur.
9.When class III elastics are used, the maxillary first molars ______. A.Move distally and intrude B.Move mesially and extrude C.Move mesially and intrude D.Move mesially only; there is no movement in the vertical direction
D?? 9. B. Class III elastics are worn from the maxillary first molars to the mandibular canines. The force system created by class III elastics produces mesial movement and extrusion of the maxillary first molars.
Which of the following are likely contraindications for performing a pulpotomy on a primary molar? (Choose three.) A.A patient requiring infective endocarditis antibiotic premedication B.A 3-year-old patient C.Swelling associated with the tooth D.Furcation radiolucency E.Marginal ridge breakdown owing to extensive decay F.A patient with amelogenesis imperfecta G.A 5-year-old patient with a pinpoint carious pulp exposure
A， B，F?? 35. A, C, D. Choice A: Pulp therapy is generally contraindicated in children who have serious illnesses. Extremely serious complications secondary to acute infection can arise should the pulp therapy fail. Choice B: A patient's chronologic age has little to do with decisions regarding pulp therapy. The clinician instead should be cognizant of the dental age of the patient, stage of development and position of the permanent successor, and other factors in the decision-making process. Choices C and D: Teeth with caries involvement that are mobile, have swelling, furcation radiolucency, pain to percussion, and spontaneous pain likely either have advanced inflammation or are necrotic. The pulpotomy procedure is reserved for vital teeth only. Choice E: Marginal ridge breakdown is a common issue with severely decayed teeth. This condition alone does not rule out a pulpotomy procedure unless the caries is very extensive and renders the tooth nonrestorable either by extending cervically excessively or by interproximal space loss secondary to the carious process. Choice F: Amelogenesis imperfecta is not a contraindication to a pulpotomy procedure. Choice G: Carious exposures with normal pulp tissue are typically treated with a pulpotomy procedure.
12.Reduction of overbite can be accomplished most readily by which of the following tooth movements? A.Intruding maxillary incisors B.Uprighting maxillary and mandibular incisors C.Using a high-pull headgear to the maxillary molars D.Using a lip bumper
B?? 12. A. Intruding incisors would decrease overbite while uprighting teeth, and using a high-pull headgear could make overbite correction more difficult. A lip bumper would likely have little effect on overbite.
Bones of the cranial base include which of the following? A.Maxilla, mandible, and cranial vault B.Ethmoid, sphenoid, and occipital C.Palatal, nasal, and zygoma D.Frontal and parietal
B?? 2. B. The cranial base includes, from anterior to posterior, the ethmoid, sphenoid, and occipital bones.
A permanent incisor with an open apex is extruded 4 mm following an injury 15 minutes ago. What is the treatment of choice? A.No immediate treatment; monitor closely for vitality B.Reposition, splint, and monitor closely for vitality C.Reposition, splint, and initiate calcium hydroxide pulpotomy D.Reposition, splint, and initiate calcium hydroxide pulpectomy
B?? 24. B. An extruded permanent incisor with an open apex should be repositioned, splinted, and monitored closely for loss of vitality. Because of the open apex, the tooth may remain vital and continue to develop; immediate pulp treatment is contraindicated
Which of the following is the most likely cause of pulpal necrosis after trauma to a tooth? A.Ankylosis B.Calcific metamorphosis C.Pulpal hyperemia D.Dilaceration
B?? 25. C. The other three answer choices may occur as the result of trauma but do not cause loss of vitality. Pulpal hyperemia causes increased intrapulpal pressure and swelling, which may result in an interruption of the pulp's blood supply. Without an adequate blood supply, the pulp becomes necrotic. This process can take time, and symptoms (either radiographic or clinical) may not manifest for weeks or months. Typically, follow-up examination and radiographs are indicated at 1-, 2-, and 6-month intervals after a traumatic incident.
Children in the primary dentition most often present with a (an) ______. A.Increased overbite B.Decreased overbite C.Ideal overbite D.Significant open bite
B?? 4. B. Young children often present with minimal overbite or anterior edge-to-edge relationship. Habits such as thumb sucking increase the likelihood that less overbite will be present.
Which of the following reactions is least likely to be observed during orthodontic treatment? A.Root resorption B.Devitalization of teeth that are moved C.Mobility of teeth that are moved D.Development of occlusal interferences
B?? 6. B. Root resorption is common during orthodontic treatment, although lesions often resolve on the root surface. Mobility of teeth is also common as the PDL reorganizes and widens during tooth movement. It is uncommon for teeth to become devitalized as a result of orthodontic movement, unless they have also been substantially compromised by injury or infection.
Which of the following are characteristics of primary tooth anatomy? (Choose three.) A.Occlusal table is wider B.Enamel is thinner C.Greater constriction at the cementoenamel junction D.Interproximal contacts are broader and flatter E.Enamel rods in gingival third slope cervically F.Pulp chamber is relatively smaller
B， C， ，D？？ 34. B, C, D. The enamel is thinner and the pulp chambers are relatively larger; therefore, restorative preparations must be shallower than typical permanent teeth. The greater constriction at the cement-enamel junction allows for a retentive area for stainless steel crowns; however, this feature also may cause a problem in attaining a gingival seat when a class II preparation is prepared too cervically. Interproximal contacts are broader and flatter in primary teeth and therefore, preparations for primary teeth are altered by preparing relatively wider gingival seats with increased convergence to the occlusal, thereby removing more lateral interproximal decay while maintaining a conservative occlusal outline form.
1.Which of the following statements regarding crowding of the dentition is true? A.Crowding of the primary dentition usually resolves as the permanent teeth erupt. B.Spacing in the primary dentition usually indicates spacing will be present in the adult dentition. C.Approximately 15% of adolescents have crowding severe enough to consider extraction of permanent teeth as part of treatment. D.Lower incisor crowding is more common in African-American individuals than white individuals.
C 1. C. According to available data, approximately 15% of adolescents have severe crowding that would require major expansions or numerous extractions to resolve. The other statements are false. Crowding in the primary dentition is very rare and would indicate crowding will occur in the permanent dentition; spacing in the primary dentition is normal; and African-Americans generally have less crowding than whites.
The mother of a 5-year-old patient is concerned about the child's thumb-sucking habit. On examination 6 months ago, the patient had a 5-mm overjet and a 3-mm anterior open bite. Today, the patient has a 10% overbite and a 3.5-mm overjet. The mother says that the child only sucks his thumb every night when falling to sleep. Which of the following is the best advice? A.Refer to a speech pathologist B.Recommend tongue thrust therapy C.Recommend a thumb-sucking appliance D.Counsel the parent regarding thumb sucking, and recall the patient in 3 months
C?? 19. D. The patient's overbite and overjet improved from the previous examination, and so it is likely that the patient's thumb-sucking habit had decreased significantly. The mother stated that the patient sucks his thumb only while falling asleep. When thumb sucking occurs for a limited time per day, not only is tooth movement normally associated with thumb sucking unlikely, but also it is possible for teeth to return to a more normalized position. The risk of malocclusion as related to habitual activity is a function of amount of time per day the habit is practiced, the duration of the habit in terms of weeks and months, and the intensity of the habit. Because the occlusion seems to be improving and because the habit has significantly decreased, the best treatment is to counsel the parent regarding thumb sucking and recall the patient in 3 months.
20.Which of the following statements regarding orthodontic closure of a midline diastema in a patient with a heavy maxillary frenum is true? A.Orthodontic closure is accomplished before frenum surgery. B.Orthodontic closure is accomplished after frenum surgery. C.After orthodontic closure, frenum surgery is typically not indicated. D.After frenum surgery, orthodontic closure is typically not indicated.
C?? 20. A. Orthodontic closure of a midline diastema is accomplished before the periodontal surgery. If a frenectomy is performed before orthodontic treatment, it is possible that scar tissue could form in the area, which may impede orthodontic tooth movement.
The nature of the bond between the enamel and the resin used to attach an orthodontic bracket is ______. A.Chemical B.Mechanical C.Dependent on whether the resin used is light-cured or chemically cured D.Dependent on whether the surface preparation used is conventional etch or self-etch primer
C?? 28. B. Acid etching of the enamel performed during the orthodontic bonding procedure causes microporosities in enamel, which are filled with bonding primer and resin to achieve a mechanical interlocking between the tooth and composite resin material. The composite itself can be chemically cured or light-cured. However, the bond between the tooth and resin is mechanical, not chemical.
A wire with a low load/deflection rate is capable of generating constant forces that do not depend much on the amount of activation. Bending loops into an archwire reduces its load/deflection rate by increasing wire length. A.Both statements are true. B.Both statements are false. C.The first statement is true, and the second statement is false. D.The first statement is false, and the second statement is true.
C?? 30. A. Low/load deflection means that a low amount of force is required to create a particular amount of deflection of a wire. That means that the wire is very flexible compared with a high load/deflection wire (a stiffer wire), which would require a greater amount of force to deflect it the same amount. If the amount of force change per unit of deflection is small, the amount of force delivered does not change much as the wire is activated more and more. Increasing the length of a wire (by adding loops or helices to its design) makes it more springy (less stiff), reducing its load/deflection.
Doubling the force applied at the bracket of a tooth would have what effect on the moment affecting tooth movement? A.The moment would decrease by 50% B.The moment would not change C.The moment would double D.The moment would increase fourfold
C?? 7. C. Because M = Fd, doubling the force would double the moment, or tendency to rotate, tip, or torque.
Order the four plateaus of stage I anesthesia (analgesia). ____ A.Drift ____ B.Paresthesia ____ C.Dream ____ D.Vasomotor
D,B,A,C?? 33. A—3, B—1, C—4, D—2. It is important to know these stages in order to effectively manage the expectations of the patient and to prevent deeper stages that may lead to nausea, vomiting, and other adverse outcomes.
A 7-year-old patient has a 4-mm maxillary midline diastema. Which of the following should be done? A.Brackets should be placed to close it. B.A radiograph should be taken to rule out the presence of a supernumerary tooth. C.Nothing should be done. It will close on its own. D.Nothing should be done. Treatment should be deferred until the rest of the permanent dentition erupts.
D?? 11. B. When a large diastema greater than 2 mm is present, it likely will not close on its own. Diagnostic tests, such as a radiograph, should be performed to rule out the presence of a supernumerary tooth, usually a mesiodens.
In a 4-year-old patient, tooth E was traumatically intruded, and approximately 50% of the crown is visible clinically. What is the treatment of choice? A.Reposition and splint B.Reposition, splint, and primary endodontics C.Reposition, splint, and formocresol pulpotomy D.None of the above
D?? 21. D. Unless it can be determined that the primary tooth is impinging on the permanent successor, intruded primary teeth are left alone in the hopes that they will spontaneously reerupt. Intruded permanent teeth have a poorer prognosis. If there is an open apex, an intruded permanent tooth should be closely monitored for spontaneous eruption. An intruded permanent tooth with a closed apex should be repositioned orthodontically, and a calcium hydroxide pulpectomy should be performed 2 weeks after the injury.
Which of the following orthodontic wire types would be the best choice for a patient with a known nickel allergy? A.Stainless steel B.Nickel titanium C.Beta titanium D.Multistranded cobalt chromium
D?? 27. C. Beta titanium is a titanium and molybdenum alloy that does not contain nickel. Stainless steel used in orthodontic wires is generally 8% nickel and 18% chromium. Cobalt chromium has a small amount of nickel in its composition. Nickel titanium is the wrong answer because it has "nickel" in its name.
Class II elastics are used by stretching an elastic between which of the two following points? A.From the posterior to the anterior within the maxillary arch B.From the posterior to the anterior within the mandibular arch C.From the posterior of the maxillary arch to the anterior of the mandibular arch D.From the posterior of the mandibular arch to the anterior of the maxillary arch
D?? 8.D. Class II elastics work in the direction that would be used to correct a class II malocclusion, to pull the mandibular teeth forward and the maxillary teeth distally.
