dental anatomy lab Permanent maxillary right first molar Summary

1. Summary
Permanent Maxillary Right First Molar

2. •CROWN
•Roughly trapezoidal.
•Contact area ;
Mesial- at junction of middle and occlusal third Or halfway between cervical line
and cusp tip.
Distal- at middle of middle third.
•Sulcus depth = 1 mm.
•Intercuspal distance = 5 mm (2.5mm mesial, 2.5mm distal).
•Outline;
Mesial - straight.
Distal - convex (Spheroid).
•Buccal cusps;
mesiobuccal obtuse angle (round).
Distobuccal right angle (sharp) and Longer.
•Part of mesiolingual cusp and distolingual cusp appear.
Buccal Surface

3. •ROOT
•Three roots ;
1- mesiobuccal
2- distobuccal
3- lingual (Longer).
•Root Trunk 5 mm from cervical line to
trifurcation.
•Interapical distance = 4 mm
( 1 mm mesial / 3 mm distal ).
Same length
Buccal Surface

4. •CROWN
• Buccal outline; short arc then shallow concavity then convex.
Crest of curvature within cervical third.
• Lingual outline; curved outward smoothly curved arc.
Crest of curvature near the middle third.
• Sulcus depth = 1.5 mm from lingual cusp.
• Intercuspal distance = 6 mm.
• Buccal cusp shorter than lingual cusp ~ 0.5 mm.
• Cusps in sight;
1- mesiobuccal.
2- mesiolingual.
3- Fifth cusp (cusp of Carabelli).
• Mesial marginal ridge irregular 1/5 crown length = 1.5
Mesial Surface

5. •ROOT
•Mesiobuccal root hide distobuccal root.
•Lingual root appears at line with mesiolingual
cusp.
•Root trunk two thirds from cervical line
= 5 mm from cervical line.
•Interapical distance = 6 mm
( 3 mm Buccal , 3 mm Lingual).
•Buccal roots shorter than lingual root ~ 1mm.
Mesial Surface

6. Occlusal Surface
•Rhomboidal outline
•Crown wider buccolinguallly than mesiodistally ~ 2 mm.
•Cusps (5) ;
1- mesiolingual (Larger).
2- mesiobuccal.
3- Distolingual.
4- Distobuccal.
5- Fifth cusp (smaller).
•1,2,4 Primary cusps.
•3 Common cusp in upper molars.
•5 Secondary cusp
1
2
4
3
5
Obtuse
Obtuse
Acute
Acute
Lingual
Buccal
Distal Mesial

7. •Fossae;
1- Two majors
A- Central- roughly triangular(concave area).
B- Distal- roughly linear.
2- Two Minors
A- Mesial triangular.
B- Distal triangular.
•From occlusal;
Mesial wider than distal.
Lingual wider than buccal.
Occlusal Surface
1A
1B
2A
2B
Lingual
Buccal
Distal Mesial

8. •Grooves;
1- Buccal developmental.
2- Central developmental.
3- Transverse groove of oblique ridge.
4- Distal oblique.
5- Lingual developmental.
6- Fifth cusp (Cusp of Carabelli).
Occlusal Surface
1
2
4
3
5 6
Lingual
Buccal
Distal Mesial

9. END