Mandibular First Molar Buccal Aspect

Buccal Aspect of Mandibular First Molar

• The five cusps are visible from the buccal aspect, with the mesiolingual cusp being the longest and the distal cusp being the smallest.
• 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.

Buccal Grooves

• There are two buccal grooves: the mesiobuccal and distobuccal grooves.
• The mesiobuccal groove is longer and separates the mesiobuccal cusp from the distobuccal cusp, often ending in a deep pit at its cervical end.
• The distobuccal groove is shorter and separates the distobuccal cusp from the distal cusp, also ending in a pit.

Contact Points

• The mesial contact is located more occlusally than the distal, close to the junction of the middle and occlusal thirds of the crown.
• The distal contact is located more cervically, in the middle third of the crown.

Crown Characteristics

• 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.
• The occlusal outline slopes shorter cervically from mesial to distal, giving a tipped appearance.

Roots

• The mandibular first molar has two roots: a slightly longer mesial root and a distal root.
• Both roots are 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 and twisted, with its apex in line with the mesiobuccal groove of the crown.
• The distal root is usually straighter and ends in a more pointed apex.