Mandibular Molars Anatomy

Lingual Aspect of Mandibular Molars

• The lingual aspect of mandibular molars tapers to the lingual, with the lingual taper more evident in first molars.
• The lingual cusps are longer and more pointed than the buccal cusps.
• The mesiolingual cusp is usually longer and wider (slightly) than the distolingual cusp.

Lingual Aspect of Mandibular Molars: Grooves

• The lingual groove separates the mesiolingual cusp from the distolingual cusp.
• The groove terminates in the occlusal third with no pit.

Lingual Aspect of Mandibular Molars: Cervical Line

• The CEJ is relatively flat mesiodistally.
• Can dip cervically between the roots over the bifurcation (similar to buccal).
• A depression can be seen between the cervical line and the bifurcation.

Mesial Roots of Mandibular Molars

• The roots are narrower on the lingual aspect than the buccal.

Proximal Aspect of Mandibular Molars

• The crowns appear relatively short occlusocervically compared to faciolingually.
• The crowns are tilted lingually on the root base.
• The buccal outline is convex in the cervical third.

Crest of Curvature

• The height of contour on the buccal surface is within the cervical third.
• On molars, this buccal bulge is called the buccal cervical ridge.
• It is more prominent on second molars than first molars.

Proximal Aspect of Mandibular Molars: Cusp Height

• The lingual cusps are more conical and pointed than the buccal.
• They are the largest of the four to five cusps.

Distal Proximal Aspect of Mandibular Molars

• Due to the distal tilt of the crown and the sloping of the occlusal surface, most of the occlusal surface and all cusps can be seen from the distal.
• The crown is more narrow on the distal than the mesial.
• Can see some of the buccal and lingual surface from the distal due to this taper.

Proximal Aspect of Mandibular Molars: Cervical Line

• The mesial CEJ of both first and second molars slopes occlusally from buccal to lingual.
• The distal cervical line is nearly straight.

Occlusal Aspect of Mandibular Molars

• Due to lingual inclination, a considerable portion of the buccal aspect can be seen from this view.
• The molars are wider mesiodistally than faciolingually.

Occlusal Aspect of Mandibular Molars: Shape

• The second molar is roughly rectangular.
• The first molar with the distal cusp is more like a pentagon.
• The two mesial cusps are larger than the two distal cusps.

Occlusal Aspect of Mandibular Molars: Taper

• The crown is narrower buccolingually on the distal than the mesial.
• The crown is narrower mesiodistally on the lingual than the facial.

Occlusal Aspect of Mandibular Molars: Ridges

• On both first and second molars, the MB and ML cusp's triangular ridges form a transverse ridge.
• The same is true for the DB and DL cusps.
• Since lingual cusps are taller, they possess longer triangular ridges than the buccal.

Occlusal Aspect of Mandibular Molars: Fossae

• Mandibular molars possess three fossae, a large central fossa, a smaller mesial, and the smallest distal fossa.
• Each or all may possess a pit.

Occlusal Aspect of Mandibular Molars: Grooves

• The central groove is more zigzag on the first molar.
• There are two buccal grooves instead of one found on lower second molars.
• The groove is simpler on the second molar and resembles a cross.
• Central groove is straighter than that of the first molar.
• Buccal and lingual grooves are usually continuous on the second molar.

Mandibular Third Molars

• The crown may resemble a first or second molar.
• Generally have bulbous crowns.
• Lingual cusps are the longest and largest, with ML being the biggest.
• Irregular groove pattern with multiple supplemental grooves.
• The roots are shortest of mandibular teeth.
• The two roots tend to be short and are often fused.
• If the roots are separate, the root trunk will be long.
• Can possess one or more extra roots.