Lecture 14 Dental Anatomy PDF
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Al-Turath University College
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Summary
This document provides detailed information on the anatomy of mandibular molars, including the second and third molars. It describes various aspects such as their features, the number of roots, shape of cusps, and grooves. It also includes a comparison between upper and lower molars.
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Lecture 13 Lecture(14) MANDIBULAR SECOND MOLAR Principal identifying features 1- Rounded square occlusal outline. 2- Four cusps, 2 buccal, and 2 lingual. 3- Not as than 6, and close to...
Lecture 13 Lecture(14) MANDIBULAR SECOND MOLAR Principal identifying features 1- Rounded square occlusal outline. 2- Four cusps, 2 buccal, and 2 lingual. 3- Not as than 6, and close together. wide Mesio distally as 6. 4- Buccal aspect has one groove. 5- Many suppl. gr. on the occlusal. surface 6- Two roots which are less broad Buccal aspect 1- The crown is shorter and narrower Mesio-distally than 6. 2- There is one dev. groove dividing the Mesio-buccal and disto-buccal cusps which are equal in size. 3- Two roots (mesial and distal) are less broad and closer together. Lecture 13 Lingual aspect:- Only the lingual cusp is in view because the tips of the lingual cusps are higher than the buccal cusps. Mesial aspect:- 1- The cervical ridge buccally is less pronounced, and the occlusal surface is constricted bucco-lingually. 2- The cervical line shows no curvature. 3- The 2 roots may be seen from this aspect. Lecture 13 Distal aspect 1- Absence of distal cusp and disto-buccal groove. 2- Most of the occlusal surface can be seen from this aspect. Occlusal aspect 1- It is roughly rectangular. 2- The central groove is in the center, with the lingual and buccal dev. grooves meeting with the central groove at right angle. 3- Four cusps, 2 buccal (Mesio-buccal, and disto-buccal) and 2 lingual (Mesio-lingual and disto-lingual). 4- Many supplemental grooves radiating from the developmental grooves. Lecture 13 Mandibular third molar: Principal identifying features 1- The crown is similar to 7 but smaller, and more rounded. 2- Two roots, short, underdeveloped, and often fused. 3- Four cusps (but may be more). 4- Lingually inclined buccal surface. 5- A great number of supplemental grooves. DIFFERENCES BETWEEN UPPER AND LOWER MOLARS subject maxillary mandibular 1 Shape of occlusal aspect Rhomboidal Rectangular 2 Crown width Wider Bucco- Wider mesio- lingually distally than mesio- than bucco- distally lingually 3 Number of roots 3 2 4 Presence of oblique ridge yes no 5 Functional cusps 4 5 6 Shape of cusps (mesial Buccal cusp is Buccal cusp is aspect) sharp rounded Lingual cusp Lingual cusp is rounded is sharp 7 Buccal cusp is rounded no yes Lingual cusp is sharp 8 Developmental groove 6 4 9 Fossa 4 3
