Buccal Aspect of Mandibular First Molar

Buccal Aspect of Mandibular First Molar

• All five cusps are visible from the buccal aspect, with the mesiolingual cusp being the longest and the distal cusp being the shortest.
• The mesiobuccal cusp is the largest and widest on the buccal side, while the distobuccal cusp may be sharper.
• The mesiolingual cusp is visible behind the mesiobuccal cusp, and the distolingual cusp tip is visible behind the distobuccal cusp.
• There are two buccal grooves: the mesiobuccal groove, which separates the mesiobuccal cusp from the distobuccal cusp, and the shorter distobuccal groove, which separates the distobuccal cusp from the distal cusp.
• The mesial contact is located more occlusally, close to the junction of the middle and occlusal thirds of the crown, while the distal contact is located more cervically, in the middle third.
• The cervical lines of both mandibular first and second molars are often nearly straight across the buccal surface.
• The crown tapers proportionally from the contact areas to the cervical line.

Roots of Mandibular First Molar

• The mandibular first molar has two roots: a slightly longer mesial root and a distal root, both nearly twice as long as the crown.
• The root bifurcation is near the cervical line, resulting in a relatively short root trunk.
• The mesial root is curved, bows out beyond the mesial root outline of the crown, and then curves back distally, placing its apex in line with the mesiobuccal groove of the crown.
• The distal root is usually more straight and ends in a more pointed apex that lies distal to the distal outline of the crown.