D1 · 24 min
Posterior anatomy
D1
Cusps, fossae, grooves, the oblique ridge, and the fifth cusp of the mandibular first molar.
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Cusps are named by corner
MB, DB, ML, DL. Mandibular first molars add a distal (fifth) cusp on the buccal. Maxillary first molars may add a Cusp of Carabelli on the ML. Stamp cusps (functional) are palatal on the maxilla and buccal on the mandible in a Class I occlusion.
The oblique ridge
A union of the triangular ridges of the ML and DB cusps of a maxillary molar. It is not a fissure. Do not carve a groove through it because a smooth brush felt like it.
Fossae and grooves
Central fossa, mesial and distal triangular fossae, central groove, buccal and lingual grooves. The mandibular second molar reads as a plus sign. The mandibular first premolar has an afunctional lingual cusp and a mesiolingual groove.