The anatomy and Impression
What is the fovea palatine?
-this is the two openings of the minor salivary glands located at the midline posterior to the junction of the hard palate. Its clinical significance is that it determines how far posterior the upper complete denture can extend. The denture should be 2mm from the fovea.
what is the labial frenum?
-this its the attachment site of the lower lip. The clinical significance is that this is a relief area.
what are the characteristics for a primary stress bearing region?
1. Keratinized tissue 2. Support from compact bone 3. perpendicular to the forces of mastication
what are the five objectives of the final impression ?
1. Preservation of soft and hard oral tissues 2. Support (ensures maximum coverage ) 3. Stability (adaptation to the mucosa) 4. Retention 5. Esthetics (border moldings define proper lip support )
What is the prosthetic significance of the intra-oral landmarks?
1. Supporting Structures 2. Limiting Structures they are essential for Retention, Stability, and Support of the denture.
What is the vibrating Ah line ?
This is the junction between the movable and immovable part of the soft palate -It runs between the two hamular notches on the soft palate -It is determined functionally in the patient by asking them to say ah. -it is the posterior border of the posterior palatal seal
What is the Naso-Labial Sulcus?
This is the line that extends from the Ola of the nose down to the corner of the mouth. -The prosthetic significance is that during a full denture, you want to reduces the depth of the crease.
what is the lingual pouch (retromyeloid space ) ?
This is the lingual vestibule posterior to the myelohyoid muscle -Important for movement of the tongue. Must be relieved Boundaries of Retromylohyoid area:- Anterior: Mylohyoid muscle-Posterolaterally: Superior constrictormuscle-Posteromedially: Palatoglossus muscle-Medially: Tongue-Lateral: Mandible
what are secondary stress bearing areas?
these are the areas that can withstand stress but does not have all the characteristics of a primary stress bearing are. Maxilla: Palatine Rugae , and inclined part of the hard palate. Mandibular: Residual Ridge
What is the Canthus-Tragus line ?
this is an extra oral landmark. Imaginary line running from the Canthus of the eye to the Tragus of the ear. The clinical significance is to locate the condyle, as its 11-13mm from the tragus on this line
what is the buccal frenum?
this is folds of mucosal tissue that do not contain significant muscle fibers located at the buccal and connected to the cheek. its clinical significance is that it required a v-shaped relief on the denture. this is thicker than the labial frenum -IT is Larger than the labial frenum because of the buccinator
What is the maxilla residual ridge?
this is the alveolar process and the corresponding soft tissue that remains after an extraction. the highest part of the ridge is called the crest.
What is the retromolar pad?
this is the area located distally to the lower 3rd molar. -its clinical significance is that it is a primary stress bearing area for the mandible. It is made of compact bone, and is a relatively unchanged structure that can be used to determine the occlusal plane location. It contains:1- glandular tissue 2-Fibres ofPterygomandibular raphe 3- Fibersof the Buccinator 4- Fibres ofSuperior constrictor 5- Fibers of theTemporal tendon.
what is the buccal shelf of the bone?
this is the area that is bordered externally by the oblique line and internally by the slope of the residual ridge. The prosthetic significance is that it is a primary stress bearing area for the mandible.
what is retention of a Denture ? How does saliva play a role?
-this is the resistance to the dislodging forces along the path of the placement. -saliva is a major retentive agent for a denture. People with zerostomia have difficulty with attachment
Why is it important in knowing the landmarks when creating a denture?
It important to be aware of where the extra oral and intra oral landmarks are to prevent over extension, and to know where the limiting structures , and the supporting structures are in the mouth. Extra oral landmarks also help with aesthetics.
What is the incisive papilla? what is its prosthetic significance?
Pear-shaped pad of tissue that covers the incisive foramen -the prostethic significance is that it is a landmark for setting the teeth, that should be relieved in the denture to avoid burning sensation from compression of the nerves located in this area.
what is the posterior palatal seal area?
distal to the junction of the hard and soft palate at the vibrating line -It is a limiting area that provides the seal. Therefore the denture must cover this ares to provide the suction cup seal, and maximum retention
what is the prosthetic significance of the posterior palatal seal?
- If there is over extension, this can lead to pain and lack of retention -Under extinction can lead to lack of retention. Therefore, this is a area that must be carefully make and covered by the denture to ensure proper retentive seal
what is the Mandibular Residual ridge?
- This is the alveolar process not he mandible that is covered by soft tissue, that remains after an extraction.
What is torus palatinus?
- this is a bony prominence that is usually present on both sides of the midline of the palate. the prosthetic significance is that it should be relieved, and surgically removed.
what is the mento-labial sulcus ?
- this is the horizontal depression that runs between the lower lip and the chin.
what are the limiting structures of the maxilla?
-Hamular notch -Vestibules -Frenums -Fovea Palatinus -Ralphe
what is the criteria for an ideal impression?
-It should cover the maximum possible area without interferingwith normal muscle movements. -It should record the fine details ofthe tissues. -It should be of even thickness with well rounded flanges.
what is the prosthetic significance of the vermillion border?
-The vermillion border becomes thinner in the upper lip after an extraction for complete dentures, causing wrinkles on the corners of the lips. -In doing a complete denture, the goal is to restore Vermillion border thickness to remove the wrinkles
What is the philtrum, and what is its prosthetic significance?
-This is the diamond shaped on the center of the upper lip, between the nose. The Prosthetic significance is that after an extraction, its is flattened. Therefore, during a complete denture, the goal is to restore the shape.
what is stability of a denture?
-This is the resistance to displacement from functional horizontal and rotational forces.
what are the different palatine forms of the maxilla residual ridge?
-U shaped -V shaped -Flat - Round
What should you recommend the patient to do before taking the final impression ?
-You should recommend the patient to leave out their final impression for 24 hours before final impression
what are the primary stress bearing area of a denture?
-these are the areas under the denture that can withstand the abrasive forces of the denture such as Maxilla -Hard palate Mandible -Buccal shelf, and retro-molar pad. Floor of the mouth
what is the palatine Rougae?
-this is an irregular elevation that arrises from he midline of the anterior part of the palate. the prosthetic significance is that it is a secondary stress bearing area, that is essential for preventing forward movement of the denture.
what is the naso-labial angle?
-this is the angle between the Columella of the nose and the Philtrum of the lip. Normally it is 90 degrees, but it increased during edontulism (becomes more obtuse) -the prosthetic significance is the restore it
What is the maxillary tuberosity? What is the prosthetic significance?
A rounded prominence of bone that extend posterior the third molar region, after an extraction. -the prosthetic significance is that a well formed tuberosity can serve as a primary stress bearing area, that adds to resistance, retention, and support. -However , a large maxillary tuberosity should be relieved under the denture. -If its too big, it can surgically be removed if it affects spacing for the teeth.
What is the ala-tragus line?
An imaginary line of the tragus of the ear to the ala of the nose Extra-Oral landmark
What are the anterior and posterior borders of the posterior palatal seal ?
Anterior boarder is the hard pallet The posterior border is the Ah line
What type of bone is found in the horizontal part of the palate?
Compact bone . It is covered by dense keratinized tissue, and served as a primary stress bearing area.
what is the support of a denture?
Support of a denture is provided by the tissue by which the denture rest.
What muscle of the soft palate causes the vibrating Ah line?
Tensor Veli Palatini
what is the prostetic significance of the Ala-Tragus line?
The prostetic significance is to position the posterior occlusal plane of the denture parallel to the Ala-tragus line.
What is the prosthetic significance of the inter-pupillary line?
The prosthetic significance to to ensure that the anterior occlusal plane is parallel to the the eyes (inter-pupillary line)
What is the vermillion border?
The vermillion border is the transitional epithlium between the mucous membrane of the lip and the skin.
what is the inter pupillary line?
imaginary line running from the two pupil when patient is looking straight forward. Extra-oral landmark
What is the median palatine Raphe?
midline ridge of tissue on the hard palate. This is mucoperiosteum -the prosthetic significance is that it should be relived in the denture. Lack of relief can lead to : 1. Rocking of denture 2.Tissue Ulceration 3. Midline- denture fracture.
What is the hamular notch?
notch between hamular process and maxillary tuberosity
What are the relief areas ?
these are areas that can cause pain if compressed. There should be relief established in the denture. Maxilla: Median palatine Raphe, incisive papilla Mandible: Knife edge residual ridge, mental foramen, genial tubercles and mylohyoid ridge.
What is the modiolus?
this is the attachment point of the 8 muscles of facial expression. located laterally and superior to the corner of the mouth. the prosthetic significance is that during maxilla edontulism, there is a drop angle observed from the maxillary teeth, which can be restored with a maxillary denture. Its also a forceful area due to all the muscles, which can influence the flange thickness when taking the impression.
