Mandibular Molars Anatomy

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Questions and Answers

What is the primary difference in the morphology of the lingual and buccal cusps?

The lingual cusps are longer and more pointed (correct)

The buccal cusps are shorter and more rounded

The lingual cusps are shorter and more rounded

The buccal cusps are longer and more pointed

What is the characteristic of the cervical line on the proximal aspect of mandibular molars?

It is concave faciolingually

It is convex buccolingually

It is relatively flat mesiodistally (correct)

It is straight from buccal to lingual

Which of the following is a characteristic of the distal cusp of the first molar?

It is the smallest of the five cusps (correct)

It is the highest and widest cusp

It is located on the MB line angle

It is sharper than the mesiobuccal cusp

What is the primary difference between the mesial and distal proximal contacts of mandibular molars?

The mesial contact is located at the junction of the occlusal and middle thirds Signup and view all the answers

What is the distinctive feature of the crest of curvature on the buccal surface of mandibular molars?

It is located in the cervical third Signup and view all the answers

What is the characteristic of the groove anatomy on the occlusal surface of mandibular first molars?

The central groove is zigzag Signup and view all the answers

What is the characteristic shape of the crown of mandibular molars?

Wider mesiodistally than high cervico-occlusally Signup and view all the answers

What is the typical shape of the second molar crown on the proximal aspect?

Tilted lingually on the root base Signup and view all the answers

What is the function of the buccal pit on the first molar?

It is a site of caries Signup and view all the answers

What is the primary characteristic of the distal proximal aspect of mandibular molars?

The crown is narrower on the distal than the mesial Signup and view all the answers

Which of the following is a characteristic of the second molar?

The MB cusp is usually wider mesiodistally than the DB cusp Signup and view all the answers

What is the characteristic of the distobuccal groove on the first molar?

It is shorter than the MB groove Signup and view all the answers

What is the characteristic of the occlusal aspect of mandibular molars?

The molars are wider mesiodistally than faciolingually Signup and view all the answers

What is the characteristic of the ML cusp on mandibular third molars?

It is the longest and largest of the cusps Signup and view all the answers

What is the variation in the crown structure of mandibular molars?

The distal cusp is absent 1/5 of the time Signup and view all the answers

What is the characteristic of the tapering of the crown from contact areas to the cervical line?

There is proportionally more tapering on first molars than second molars Signup and view all the answers

What is the characteristic of the roots of mandibular third molars?

They can be either fused or separate Signup and view all the answers

What is the characteristic of the groove anatomy on the occlusal surface of mandibular second molars?

The central groove is straight Signup and view all the answers

What is the characteristic of the lingual cusp tips on the second molar?

They are usually visible from the buccal aspect Signup and view all the answers

What is the characteristic of the mesiolingual cusp on the first molar?

It is the highest and widest cusp Signup and view all the answers

What is the characteristic of the root bifurcation of a mandibular first molar?

It is near the cervical line Signup and view all the answers

What is the difference between the roots of mandibular first and second molars?

First molars have more curved roots, second molars have more parallel roots Signup and view all the answers

What is the characteristic of the distal root of a mandibular first molar?

It is straighter than the mesial root and may possess a pointed apex Signup and view all the answers

What is the relationship between the apex of the mesial root and the mesiobuccal groove?

The apex of the mesial root may be in line with the mesiobuccal groove Signup and view all the answers

What can be seen in the apical portion of the roots of mandibular molars?

A distal curve in the apical portion of the roots Signup and view all the answers

How do the roots of mandibular first and second molars differ in terms of length?

Both roots are nearly twice as long as the crown Signup and view all the answers

What is the characteristic of the root trunk of a mandibular first molar?

It is relatively short Signup and view all the answers

What is the characteristic of the mesial root of a mandibular first molar?

It is bent in the middle Signup and view all the answers

What is the characteristic of the proximal contacts of mandibular molars?

They are not mentioned in the text Signup and view all the answers

What is the characteristic of the buccal surface features of mandibular molars?

They are not mentioned in the text Signup and view all the answers

Study Notes

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.

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Description

Test your knowledge of the permanent mandibular molars' anatomy, including crown shape, cusps, and dimensions. Learn about the unique features of the first molar and more. Identify the different aspects of the buccal surface of mandibular molars.