First upper Molar
The largest of the three molars (crown width 10.5 mm, root length 12.5 mm, tooth length 20.5 mm). It belongs to the class I pillar according to Voldrich.
The buccal surface of the dental crown is trapezoidal, narrower in the area of the tooth neck. It is slightly arched, divided by a fissure, which divides the whole surface into two equally sized parts - mesial and distal.
The palatal surface is slightly arched, also trapezoidal. The fissure, which divides the two palatine bumps of the masticatory surface, passes onto the palatine plateau, which it divides into a smaller distal and a larger mesial one.
The approximal plates are square in shape. They end in the enamel mound of the occlusal plateau. The mesial surface is higher, flat, slightly concave at the neck of the tooth. The approximal distal surface is lower and shorter.
The occlusal surface is diamond-shaped with four bumps separated by three fissures. The mesiobuccal tubercle is the largest, together with the mesiopalatine tubercle, followed by the distobuccal and the smallest distopalatine tubercle. In about 17% of cases, a fifth interpalatine bump called tuberculum anomale Carabelli may form.
Roots' The first upper molar has three roots, two are located buccally, one palatally. The palatine root is the largest, straight, conical in shape. It is circular in transverse section. The buccal roots are oval in cross-section. The roots of the upper molar often extend into the base of the maxillary sinus.
The buccal cavity is spacious, tapering in the region of the neck and continuing into the roots as root canals. The palatine canal is straight and widest. The buccal canals are narrower. A bifurcation may occur in the interbuccal canal.