Lecture 2: Anatomy & Final Impression Flashcards
(39 cards)
List the extra oral landmarks
- Inter pupillary line 2. Ala-Tragus line (Camper’s Line) 3. Canthus-Tragus line 4. Vermillion Border 5. Philtrum 6. Naso-labial sulcus 7. Naso-labial angle 8. Mento-labial sulcus 9. Modiolus
What is the inter pupillary line?
a. Extra-oral landmark b. Imaginary line running between the two pupils of the eye when the patient is looking straight forward c. Prosthetic significance: anterior occlusal plane of the denture’s teeth should be parallel to inter-pupillary line
What is the Ala-Tragus line (Camper’s line)?
a. Extra-oral landmark b. Imaginary line running from the inferior border of the Ala of the nose to the superior border of the Tragus of the ear. c. Prosthetic significance: posterior occlusal plane of the denture’s teeth should be parallel to the Ala-Tragus line
What is the Canthus-Tragus line?
a. Extra-oral landmark b. Imaginary line running from the outer canthus of the eye to the superior border of the tragus of the ear. c. Prosthetic significance: the position of the Condyl’s hinge axis is 11-13 mm from the Tragus of the ear on this line.
What is the vermillion border?
a. Extra-oral landmark b. Transitional epithelium between the mucous membrane of the lip and the skin c. Prosthetic significance: - After extraction it becomes thinner in the upper lip - Complete denture construction will provide labial support with restoration of esthetics
What is the philtrum?
a. Extra-oral landmark b. Diamond-shaped area between the center of the upper lip and the base of the nose. c. Prosthetic significance: after extraction of teeth it becomes flattened and can be restored by a complete denture
What is the nasio-labial sulcus?
a. Extra-oral landmark b. Depression that extends from the ala of the nose in a downward and lateral direction to the corner of the mouth. c. Prosthetic significance: after extraction of teeth it becomes accentuated and can be restored by complete denture
What is the nasio-labial angle?
a. Extra-oral landmark b. Angle between the Columella of the Nose and the Philtrum of lip. Normally is 90 degrees when viewed from the profile. c. Prosthetic significance: After extraction of teeth it becomes more obtuse and can be restored by a complete denture.
What is the mento-labial sulcus?
a. Extra-oral landmark b. Horizontal depression that runs between the lower lip and chin. c. Prosthetic significance: Classification: 1 - Angle class [I]: Normal ridge relationship. 2 - Angle class [II]: Retruded mandibular position 3 - Angle class [III]: Protruded maxillo-mandibular relationship
What is modiolus?
a. Extra-oral landmark b. Intersection point of the facial expression muscles. Is situated laterally and slightly superiorly to the corner of the mouth. c. Prosthetic significance: - Sunken cheeks appearance and dropped angle observed by loss of maxillary teeth and can be restored by the maxillary complete denture. - Very forceful area which can influence the labial flange thickness of the maxillary
What are the two groups of intra-oral structures?
a. Supporting structures b. Limiting structures
Define retention.
Resistance to the dislodging forces along the path of placement.
Define stability.
Resistance to displacement by functional horizontal or rotational stresses.
Define support.
Resistance to the tissue-word forces and provided by the foundation area on which the denture rest.
Define primary stress bearing area.
a. Intra-oral structure b. Area under the denture which can withstand stresses and resist tissue words movement. These area should have the following characters: 1) Covered by keratinized mucosa 2) Supported by a compact bone (no change) 3) Horizontal to the masticatory force with no lateral force formation (increase support stability)
What are the primary stress bearing area for the maxilla and mandible?
Maxilla: Horizontal part of the hard palate, well formed residual ridge Mandible: Buccal shelf of bone and retro-molar pad area
Define secondary stress bearing area.
a. Intra-oral structure b. Area that can withstand stresses, but don’t have all 3 characters of the primary stress bearing area.
What are the secondary stress bearing area for the maxilla and mandible?
Maxilla: palatine rugae area (inclined part of the hard palate) Mandible: residual ridge
Define relief area.
a. Intra-oral structure b. Any area that causes pain or instability upon pressure on it, these area should be relieved.
What are the relief areas for the maxilla and mandible?
Maxilla: median palatine raphe (rocking & pain), incisive papilla (pain) Mandible: knife edge residual ridge, mental foramen, genial tubercles and mylohyoid ridge
What is the maxillary residual ridge?
a. Intra-oral structure (maxilla) b. Portion of the alveolar process and its soft tissue coverage that remains after extraction, the highest continuous surface of the ridge is called Crest of the ridge c. Prosthetic significance: primary stress bearing area
What are the shapes that the maxillary ridge and palate form?
a. Intra-oral structure. b. “U” shape c. “V” shape d. Flat e. Rounded
What is the maxillary tuberosity?
a. Intra-oral structure (maxilla) b. Prominent bulge located just behind the distal end of the maxillary ridge c. Prosthetic significance: 1) well formed tuberosities provide wide coverage with enhancement of support, stability, and retention (primary stress bearing area) 2) large maxillary tuberosity i. relieved over the undercut ii. modify the path of insertion (unilateral enlargement) iii. surgical excision of extremely large tuberosity which interfere with the denture base space
What is the incisive papilla?
a. Intra-oral landmark (maxilla) b. Pear-shaped elevation present in the midline behind the 2 central incisors c. Prosthetic significance: 1) landmark for setting of teeth (8-10 mm lingual to the maxillary central incisors) 2) after extraction of teeth it migrates to the crest of the ridge 3) Should be relieved to avoid the burning sensation of the palate (nasopalatine nerve)