Prosthetic Dentistry II: Anatomical Points PDF

DEN203 Prosthetic Dentistry II Lecturer: Dr. Rana Turunç Oğuzman & Dr. Demet Ayvalıoğlu E-posta: [email protected] Complete Dentures Altınbaş Üniversitesi Rana Turunç Oğuzman [email protected] DEN203 Protetik Diş Tedavisi 2 Complete Denture • Is a removable dental prost...

DEN203 Prosthetic Dentistry II Lecturer: Dr. Rana Turunç Oğuzman & Dr. Demet Ayvalıoğlu E-posta: [email protected] Complete Dentures Altınbaş Üniversitesi Rana Turunç Oğuzman [email protected] DEN203 Protetik Diş Tedavisi 2 Complete Denture • Is a removable dental prosthesis that replaces the entire dentition and associated structures of the maxilla or mandible Indications of Complete Dentures • Edentulous patient • Gross decay or abscesses •Extensive bone loss and periodontal disease • Lack of financial resources for alternative treatments • Patient refused partial dentures Anatomical Landmarks Altınbaş Üniversitesi Rana Turunç Oğuzman [email protected] DEN203 Protetik Diş Tedavisi 2 Extraoral Landmarks • Nasolabial Sulcus • Mentolabial Sulcus • Philtrum • Vermillion border • Angle of the mouth • Modiolus Nasolabial Sulcus • Crease that extends laterally and downward from the ala of the nose to corner of the mouth • Not easy to remove but may be reduced by denture Mentolabial sulcus • Runs horizontally between the lower lip and the chin • Indicates maxillo mandibular relationship Philtrum • This area under the nose is called the ‘’philtrum’’ Vermillion Border • Transitional epithilium between the mucous membrane of the lips and the skin • In edentulous face there is diminution in amount of vermillion border seen on the upper lip and relative fullness of the lower lip. Angle of mouth (commisure) • Denture should support the mouth angle to avoid angular chelitis which is fissuring and inflammation of mouth angle as a result of continuous wetting by saliva. Modiolus • The meeting point of the buccinator muscle and other facial muscles near the mouth angle. • With teeth loss the modiolus is displaced and this causes the appearance of sunken cheecks. • The buccal surface of the lower denture at premolar region must be thin to avoid the modiolus lifting the denture. Ala of the nose The tragus of the ear Ala tragus line • An imaginary line that extends from the ala of the nose to the tragus of the ear. Intraoral Landmarks • The oral cavity is divided into vestibule and oral cavity proper • The vestibule is divided into labial and buccal vestibule • After extraction of the teeth alveolar bone is resorbed and remaining part is called residual ridge. Maxillary Anatomical Landmarks Alveolar Ridge • The portion of alveolar process and its covering soft tissue that remains after extraction of teeth. • The highest portion is called ‘crest of the ridge’ • Considered the primary stress bearing area in the upper jaw. Maxillary Tuberosity • Rounded prominence behind and slightly above the distal end of maxillary residuel ridge • Its size is affected by extending of maxillary sinus • Should be included in the impression as it permits coverage of more area and good bearing surface. • Extremely large tuberosities need surgical correction. Hamular notch/ Pterygo Maxillary Notch • Depression distal to maxillary tuberosity • Used as landmark for correct extension of the upper denture • Deepest point in the retromolar area; overlying the gap between the pterygoid hamulus and maxillary tuberosity Palatine Vault • Formed anteriorly by the hard palate and posteriorly by the soft palate. • May be high and Vshaped, or flat and shallow, the more common is high and U- shaped and its more desirable. Median Palatine Raphe • The suture that joins the two palatine proccesses at the midline. • Covered with thin, dense mucoperiostium with little or no mucosa. • Improper relief of it may cause instability of the upper denture, so it should be relieved properly. Incisive papilla • Pad of fibrous connective tissue overlying the nasopalatine canal. • Used as landmark for correct placement of artificial central incisors. • Relieve the upper denture to avoid pressure on the incisive nerve, otherwise it may cause burning sensation. Torus Palatinus • Is raised, bony ridge running down the center of hard palate from the anterior palatine to the posterior border. • If it’s too big, it should be surgically removed. • If it’s small, the denture should be relieved. Rugae • Irregular shaped ridges of the connective tissue covered by mucous membrane in the anterior third of the hard palate. • Play part in speech. • Shouldn’t be disturbed by impression for maximum comfort. Fovea Palatinae • Openings of ducts of minor salivary gland. • Found at the midline just posterior to the junction of the hard palate and soft palate. • Landmark for posterior border extension of the upper denture. Mandibular Anatomical Landmarks Alveolar ridge • Like maxilla Retromolar Pad • Pear shaped area found on each side of the distal end of the residual mandibular ridge. • It is important to avoid displacement of the retromolar pad while making the impression. • Used as guide to locate the occlusal plane of the mandibular denture. Occlusal plane must not be higher than half of its vertical height. • Must be covered by denture to avoid its moving backwards. External Oblique Ridge • Ridge of dense bone extending above the mental foramen superiorly and distally. • The lower denture must cover but not extend beyond it, to avoid displacement by powerful musculature in this area. Buccal Shelf Area • Bound externally by the external oblique ridge and internally by the slop of the residual ridge. • In this area bone is dense and can withstand the masticatory forces • Should be covered by lower denture to provide support. • Is primary stress bearing area. Mental foramen • Located in the buccal surface of mandible in premolar region • Mental nerve and vessels pass through it. • Relieve denture in this area to avoid pain and numbness of the lower lip. Torus mandibularis • Bony projection on the inner surface of the mandible in especially premolar region • May be unilateral or bilateral • The lower denture should be relieved in this area • If it’s large, it must be surgically removed Internal oblique ridge • Ridge that extends near the inferior border of the mandible in incisal region and progress higher posteriorly. • Give attachment to mylohyoid muscle • Shoul be included in the denture bearing area • If it’s sharp or prominent, it should be reduced surgically. Genial Tubercles • Two small prominences on the inner surface of the mandible on each side of the symphisis. • In extreme bone resorption it may be located at crest of ridge. In such case, the denture should be relieved on this area. Denture Foundation area • Foundation area on which the dental prosthesis rest. • The surface of oral vestibule to support the denture • The amount of force applied is inversely proportional to the amount of surface area that the denture covers Stress Bearing Areas • Primary Stress Bearing Areas -Able to resist the vertical forces of occlusion -Formed of cortical bone In maxillary arch; The crest of the ridge The flat areas of palate In mandibular arch; The buccal shelf area The crest of the ridge if well formed Relief areas • Portion of the denture that is reduced to eliminate excessive pressure on spesific part on the supporting tissue • In the maxillary arch and palate Insicive papilla Median raphe Torus palatinus Sharp bony prominances Mandibular arch Relief Areas • Genial tubercle • Sharp mylohyoid ridge • Crest of a knife edge ridge • Mental Foramen • Sharp bony prominances Border Structures that limits the periphery of the denture • Maxillary Denture 1. The labial frenulum 2. Labial vestibule 3. Buccal Frenulum 4. Buccal Vestibule 5. Hamular notch 6. Vibrating line of soft palate Border Structures that limits the periphery of the denture • Mandibular Facial border anatomy 1. Labial Frenulum 2. Labial vestibule 3. Buccal frenulum 4. Buccal vestibule 5. Masseter muscle influencing area 6. Retromolar pad Border Structures that limits the periphery of the denture • Mandibular Lingual Border anatomy 1. Palatoglossal arch 2. Lingual pouch 3. Sublingual salivary gland area 4. Lingual Frenulum Maxillary Labial Frenulum • It may be single or multiple, appearing as a fold of mucous membrane extending from the mucous lining of the lips toward the crest of the residual ridge on the labial surface Labial vestibule • It extends on both sides from the labial frenulum to the buccal frenulum Buccal frenulum • It is a fold or folds of mucous membrane that extends from the mucous membrane to the crest of the residual ridge Buccal vestibule • It is the space distal to the buccal frenulum. It is bounded externally by the cheek and internally by the residual ridge Hamular notch • It is a notch located between the maxillary tuberosity anteriorly and the pterygoid hamulous posteriorly • The upper denture must extend between hamular notch of each side. Vibrating line of the soft palate • The extension of the posterior palatal border of the upper denture depends on the functional activity of the soft palate. Mandibular Labial Frenulum • It is a fold of mucous membrane that connects the mucosa of the lower lip to the mucosa of the alveolar process at the midline. Mandibular Labial Vestibule • That part of the denture that extends in this area is called the mandibular labial flange. Mandibular Buccal Frenulum • This is a fold of mucous membrane in the premolar area attaching the lip to the alveolar ridge. Buccal vestibule • It extends posteriorly from the buccal frenulum to the anterior border of the ramus of the mandible. Masseter muscle influencing area • The distobuccal corner of the mandibular denture is in relation to the masseter muscle, so this corner of denture should not extend to that area, otherwise retention will be negatively affected. Palatoglossal arch • It is formed by the palatoglossus muscle. • Over-extension of the distolingual border of the lower denture will cause sore throat as a result of pressure on this muscle. Lingual pouch • It is bounded posteriorly by palatoglossus muscle anteriorly by the mylohyoid muscle and medially by the lateral aspect of the tongue and laterally by the medial aspect of the mandible. Sublingual salivary gland area • It should not be covered by the denture base Lingual frenulum • It is a fold of mucous membrane that extends from the floor of the mouth to the lower surface of the tongue in the midline.