First lower Molar
From WikiLectures
First Lower Molar is the largest tooth on the mandible (crown width 11 mm, root length 14 mm, tooth length 21.5 mm). It is a pillar class I tooth according to Voldrich. The first lower molar is mesiodistally elongated, the shape is given by the bumps of the masticatory plate.
The buccal surface of the dental crown: has the shape of a mesiodistally elongated trapezoid. It is very convex, the central bump protruding buccally. The fissure between the mesiobuccal and median tubercle is deep to the buccal plate, where it often ends in a blind hole (foramen caecum). It separates the mesial and distal parts of the buccal plate. The buccal area is larger and higher than the lingual area and is tapered towards the neck of the tooth.
- Lingual surface
- convex and shorter than the buccal surface.
- Mesial approximal
- the surface is flat. It tends to be higher than the distal surface.
- Distal approximal surface
- is convex.
- Occlusal surface
- has a five-pronged arrangement. The interdistally running fissure divides the masticatory surface into two unequal parts - the lingual part has two bumps, the buccal part three. The lingual bumps are equal in size, unlike the buccal bumps, where the largest bump is interbuccal.
- Roots
- there are two and they are placed in the dental arch one mesially and the other distally. They tend to be massive, the mesial being broader, the mesiodistal being sheathed. They slope distally.
- Gingival cavity
- has a cylindrical shape. It is extensive. It projects into three root canals.
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References used[edit | edit source]
- JANSOVÁ, K and M EBER. Preclinical dentistry : part I - morphological. 2nd edition. Olomouc : Palacký University, 1996. 72 p. ISBN 80-7067-596-9.
- ČIHÁK, Radomír and Miloš GRIM. Anatomy. 2nd edition. Prague : Grada Publishing, 2002. 470 p. vol. 2. ISBN 80-247-0143-X.