Dental Anatomy: Permanent mandibular 1st molar

Permanent mandibular 1st molar
?Generally, it opposes the (upper) first molar and second premolar in normal class I occlusion.
?The first molar is usually the first permanent tooth to erupt.
Permanent mandibular 1st molar
?The function is similar to that of all molars in regard to grinding being the principal action during mastication (chewing).
?The permanent mandibular molars are non-succedaneous teeth, the deciduous molars are followed by the permanent premolars.
Principle identifying features of the permanent mandibular 1st molar
?It is the largest tooth in the mandibular arch. Its occlusal surface is rectangular in shape.
?Usually, it has five well-developed cusps, two buccally, two lingually, and one distal.
?It has two well-developed roots, one mesial and one distal.
?dimension of the crown mesiodistally is greater by about 1 mm than the dimension buccolingually.
Buccal aspect
The buccal surface has two grooves. The buccal (mesiobuccal) groove, which acts as a line of demarcation between mesiobuccal and distobuccal cusps or lobes. The distobuccal groove separates the distobuccal cusp or lobe from the distal cusp or lobe.
?The mesial contact area is at the junction of the occlusal and middle thirds. While, the distal contact area is a little bit lower than the mesial contact area.