05. Maxillary Molars (CD) - Dentition

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Text of 05. Maxillary Molars (CD) - Dentition

  • 1.Surface Anatomy of Maxillary Permanent Molars

2. BUCCALPALATALOCCLUSALMESIALDISTAL 3. BUCCAL SURFACE* The geometric outline: Trapezoidal with the small uneven side present cervically * Outline form : D Mesial outline: Nearly straight till the contact area at the junction of the occlusal and middle 1/3 Distal outline: Convex till the contact area at the middle 1/3M 4. Occlusal outline: presenting mesio-buccal & disto-buccal cusps.DCervical outline: Irregular and slightly convex toward the rootM 5. Surface anatomy: * Convex buccal surface with the crest of curvature at the cervical 1/3 representing Cervical ridge. D *Buccal groove may terminate by buccal pit. Mesio-buccal cusp is broader, shorter and less sharp than the disto-buccal cuspM 6. PThe Roots: * Root trunk: 4 millimetersDBMB*3 roots are seen from the buccal surface which are widely diverge . * The axis of the roots are inclined D distally * Deep developmental groove extend on root trunkM 7. LINGUAL SURFACE * It is the reverse of the buccal surface with No lingual convergence Mesial outline: Nearly straight and form with the mesial slope of the ML cusp M Distal outline: Convex and form semicircle with the distal slope of the DL cuspD 8. Occlusal outline: ML cusp is the largest and longest cusp. DL cusp is spheroidal M Cervical outline: Irregular and slightly convex toward the rootD 9. Surface anatomy: *Convex lingual surface with the crest of curvature at the middle 1/3. *Tubercle of Carabelli is found on the lingual surface of ML cusp. *Lingual developmental groove ends with palatal pit .MD 10. MESIAL SURFACE The geometric outline: Trapezoidal with small uneven side occlusally. Buccal outline: * Convex with the B maximum convexity at the cervical 1/3 denoting cervical ridge. Concave at the middle 1/3 denoting the* termination of the buccal developmental .groove Convex at the occlusal 1/3 representing* .circumscribed MB cuspL 11. Lingual outline: * Convex with the crest of curvature at the middle 1/3. B * The lingual outline dips inward to illustrate the tubercle.L 12. Occlusal outline: * Represented by ML , MB cusps * Irregular MMR which curve cervically. Cervical outline: Irregular and convex occlusally Anatomical landmarks Mesial contact area at the junction between middle and occlusal 1/3, buccal to the center 13. DISTAL ASPECTMESIAL ASPECT*Distal Convergence* Wider mesial surface*Convex distal surface* Flat mesial surface* Mesial marginal ridge *Distal MR curved less curved cervically Continue 14. MESIAL ASPECTDISTAL ASPECT MBPPDB*Straight cervical line*Cervical line convex occlusally*Root trunk= 5mm*Root trunk = 3mm*3 roots are seen*2 roots are seen 15. OCCLUSAL SURFACEThe geometric outline:BDMRhomboidal. L > B & M > D surfaces. Note : * Disto-buccal convergence.* ML, BD angles are obtuse. *MB, DL angles are acute .The ML & DB cusps are found at the obtuse angles.L 16. B Anatomical landmarks: Elevations: *4 cusps with 4 triangular ridges and D tubercle.The ML is the largest cusp followed by MB,then DL and lastly DB which is the smallest cusp. Oblique ridge between ML&DB* .triangular ridges MMR and DMR*ML 17. BAnatomical landmarks: Depression: DM(major fossae ( central and distal 2* Minor fossae ( mesial and distal 2* (.triangular fossae *Developmental grooves (Buccal, Central, transverse groove of oblique ridge, Distal oblique groove and Lingual groove(.L 18. Pulp cavity Pulp Chamber: The pulp chamber is broader Bucco-lingually than mesio.distally There is pulp horn beneatheach cusp - The floor is apical to the cervical line. 19. Pulp cavity :Root Canals -3 main root canals. -MB root may have 2 root canals Note: Cervical cross section: Rhomboidal Mid root section: MB root canal ( Oval- Kidney( DB root canal (Round-Oval( P root canal ( Round- Oval( 20. Enumerate the names of the following ?elevations and depression DMR-1 Oblique ridge-2 Distal linear fossa-3 Central fossa- 4 Buccal groove- 5 Mesial triangular fossa- 6 Lingual groove- 7 21. PALATALBUCCALOCCLUSALMESIALDISTAL 22. BUCCAL SURFACE67MDDMin 7 the crown is smaller, narrower & shorter .The MB cusp is larger and longer than DB cusp ,theroots are close & parallel .The root trunk is longer than in 6 23. LINGUAL SURFACE67DMD*The crown converge lingually.The DL cusp is smaller in 7 .It may be missed ( 3 - cusp type) No cusp of carabelli in 7 * 24. MESIAL SURFACE7D6M* No cusp of carabelli in 7 MB and P roots in 7 are confines within the* BL outlines of the crownD 25. DISTAL ASPECTDistal Convergence * ** Convex distal surface ***Distal MR curved cervically BL 26. OCCLUSAL ASPECT BBDM L cusp type 4 outline typical to 6 Disto- lingual convergence No tubercle of carabelliM L cusp type 3 shape typical to 8 No disto-lingual cusp, No lingual or distal oblique grooves 27. Pulp cavity Pulp Chamber: The pulp chamber is broader Bucco-lingually than mesio.distally There is pulp horn beneatheach cusp - The floor is apical to the cervical line. 28. Pulp cavity :Root Canals -3 main root canals. -MB root may have 2 root canals Note: Cervical cross section: Rhomboidal Mid root section: MB root canal ( Oval- Kidney) DB root canal (Round-Oval) P root canal ( Round- Oval) 29. PALATALBUCCALOCCLUSALMESIALDISTAL 30. BUCCAL SURFACEMB cusp is wider and longer than DB cusp The roots are often fused making one large short root 31. LINGUAL ASPECTUsually one large lingual cusp without lingual groove 32. MESIAL SURFACECharacterized by fusion of the roots and the bifurcation in the apical 1/3 33. DISTAL SURFACEConvex surface with no* contact area*The distal surface short and narrow. So most of the occlusal surface is seen. 34. OCCLUSAL ASPECTcusp type 3 shape is typical to 7 No disto-lingual cusp, No lingual or distal oblique groovescusp type 4 outline typical to 6 There are disto- lingual cusp, Lingual groove .and oblique ridge 35. OCCLUSAL SURFACE:Notes The occlusal surface of 8 has- 1 numerous supplemental grooves The pulp cavity showed great- 2 variation in the size and shape The pulp chamber of 8 is larger than- 3 other molars because it is younger than other molars by 9-11 years