Anatomical Landmarks of the Denture-Bearing Area PDF

Mandible Marketing Department Mon. Feb. 21. 2018 Anatomy of the mandible Anatomy of the mandible Supporting Structures of the Mandible  Supporting structures 1. Fibrous C.T. covering alveolar ridge 2. External oblique ridge 3. Buccal shelf of bone 4. Mental foramen 5....

Mandible Marketing Department Mon. Feb. 21. 2018 Anatomy of the mandible Anatomy of the mandible Supporting Structures of the Mandible  Supporting structures 1. Fibrous C.T. covering alveolar ridge 2. External oblique ridge 3. Buccal shelf of bone 4. Mental foramen 5. Retromolar pad 6. Internal oblique ridge 7. Torus Mandibularis 8. Genial tubercles 9. Tongue  1. Fibrous Connective Tissue Covering Alveolar Ridge Covers the crest of lower ridge Thin, not firmly attached specially in lower ridge Relief Affects denture stability  2. The External Oblique Ridge Extending upwards and backwards on the external surface of the body of the mandible from mental foramen along the anterior border of the Ramus  3. Buccal Shelf Of Bone Bounded medially by residual ridge and laterally by external oblique ridge Primary stress- bearing area, why?? It is an area bounded on the medial side by the crest of the residual ridge, on the lateral side by the external oblique ridge, in the mesial area by the buccal frenulum, and on the distal side by the masseter muscle. It is just anterior to the premasseteric notch area.  4. Mental Foramen Located on external surface of body of mandible between roots of premolars Resorption → moves upwards→ crest of ridge Mental Transmits mental nerve and foramen vessels that supply what?? Therefore??  5. Mylohyoid Ridge “Internal Oblique Ridge” Extending downward and forward from 3rd molar area on the inner surface of body of mandible Attachment of ?? Surgically removed if sharp and prominent 6. Torus Mandibularis  7. Genial Tubercles Located on inner surface of mandible in Symphis region Normally, they can not be palpated In extreme bone resorption, might be located on crest of ridge → Relief 8. Retromolar Pad  Retromolar Pad Pear-shaped area of mucous membrane at the posterior end of the lower ridge, anterior to the Pterygo-mandibular Raphae Contains : i. Mucous glands ii. Temporalis tendon iii. Fibers of Buccinators and Superior Constrictor muscles  The retro molar pads should be covered by the denture, and the plane of occlusion is generally located at the level of the middle to upper-third of this pad.  Extending from the hamulus above to the area of the retromolar pad below is the pterygomandibular raphé fold.The pterygomandibular raphé, which underlies the fold, is the junction between the buccinator (cheek muscle) and the superior constrictor muscle of the pharynx. It is often visible in the maxillary impression and, when present, is an excellent landmark for determining the distal extent of the maxillary denture. It is usually insignificant when making the mandibular impression  9-Tongue The tongue is located in the floor of the mouth. It is important to become familiar with the normal features of the tongue because many systemic disease processes, such as iron deficiency anemia and pernicious anemia, for example, can cause changes in the tongue.  The tongue is important in denture construction because of its significant mobility and because of its involvement with deglutition and speech. Its activities must be accounted for when making impressions and when arranging the teeth on the mandibular denture. Limiting Structures Of The Lower Denture 1-Frena 2-Vestibules Buccal Frenum It is a fold of mucous membrane in the premolar area. Movement of the lip and the cheek move the frenum. A notch is made in the lower denture to accommodate the frenum.  Mandibular limiting structures Buccal Vestibule The denture in this area is related to the buccinator muscle.  3-Masseter Muscle-influencing Area Related to the distobuccal corner of the lower denture Buccal flange must converge medially to avoid displacement of the denture upon contraction of this muscle  Distobuccal area (masseter influencing area ) 4-Distolingual area  Lingual Pouch Lingual pouch Posteriorly : The palatoglosssus muscle. Anteriorly : The Mylohyoid muscle. Medially : The tongue. Laterally : The medial aspect of the mandible and most anterior border of medial pterygoid muscle. 5-Sublingual gland area. Sublingual salivary gland area. Sublingual salivary gland area Sublingual salivary gland area With excessive resorption of the mandible the gland may bulge superiorly above the body of the mandible. At the medial end of each fold is a little swelling referred to as the sublingual caruncle, where the submandibular salivary gland duct opens into the oral cavity 6-Lingual frenum Thank You