10+ Year Member
7+ Year Member
Oct 8, 2007
Chicago, IL
Dental Student
can you guys help me with a few questions about the premolars:

1) which premolars have a transverse ridge? I have read that both maxillary and the first mandibular have transverse ridges. I have also read that only the mandibular 1st has a transverse ridge.

Anyone know for sure?

2) the 1st premolar has a mesial depression. ok. The intraradicular groove? Is that just the portion of the depression that extends on the cementum/root area.

3) Does the mesiolingual groove of the mandibular 1st premolar extend onto a proximal surface? A old released exam asks which groove on a premolar extends onto the proximal surface. The answer was the mesiolingual groove of the mand 1st. I have never heard this. We learned that the groove is lingual only.

4) What is the occlusal outline SHAPE of a 3 cusped mandibular 2nd premolar? I have conflicting sources. One source says square or rectangle, while another source says pentagonal. I can see either one being the answer. Is there a general consensus answer?


Ultra Senior Member
10+ Year Member
7+ Year Member
Oct 25, 2006
Mosby's Review pg 293 says Transverse ridge in all PM except mand 2.

It also says the occlusal view of the Mand PM 2 is square/round.

It doesn't answer the other questions.
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