OALAB - MX 1ST VS MX 2ND

MX 1ST

Largest permanent tooth.

MX 1ST

Only tooth that is broader lingually than buccally.

MX 1ST

First permanent maxillary tooth to erupt.

MX 1ST

Has most prominent oblique ridge of all maxillary molars.

MX 1ST

Only tooth with a pronounced distal concavity at the CEJ, which can make scaling difficult.

MX 1ST

Has a long buccal groove with a central pit.

MX 1ST

Has a distolingual groove with a pit (on all MAXILLARY molars).

MX 1ST

Occlusal shape is rhomboidal; proximal shape is trapezoidal.

MX 1ST

Cusp heights: ML > MB > DB (primary cusp triangle) > DL (secondary cusp triangle) ›

Carabelli.

MX 1ST

Primary cusp triangle: formed by ML, MB, and DB cusps (same for all MAXILLARY molars).

MX 1ST

Secondary cusp triangle: formed by DL cusp.

MX 1ST

Only tooth with two triangular ridges on one cusp (ML cusp): form the transverse and oblique ridges.

MX 1ST

The transverse groove of the oblique ridge connects the central and distal fossae (same for all MAXILLARY molars).

MX 1ST

• 3 roots:

  • Palatal - Longest

  • Mesiobuccal

  • Distobuccal - Shortest

MX 1ST

Distance from furcation entrance to CEJ:

1. Mesial (3.6 mm)

2. Buccal (4.2 mm)

3. Distal (4.8 mm).

MX 1ST

Apices are closest to MAXILLARY sinus.

MX 1ST

MB root has more common (94%) and deeper (0.3 mm) concavities than other roots.

MX 1ST

Occludes with MD 1ST & 2ND M.

MX 2ND

Similar to maxillary first angular but smaller and more angular.

MX 2ND

Second most common tooth to have cervical enamel projections (next to mandibular second molar).

Cervical enamel projections:

1. MD 2nd

2. ?

Significance: No PDL/recession

MX 2ND

Closest tooth to the opening of Stenson’s (parotid) duct.

MX 2ND

Has a short buccal groove without a pit.

MX 2ND

• Occlusal table is usually rhomboidal, but can be heart-shaped if the DL cusp is absent;

• Proximal shape is trapezoidal.

MX 2ND

4 cusps: MB, ML (largest), DB, DL (smallest).

MX 2ND

Has smaller oblique ridge with a transverse groove.

MX 2ND

• Roots are typically longer, closer together, and more distally inclined than the maxillary first molar.

• Occasionally fused.

MX 2ND

Longer root trunk than maxillary first molar.

MX 2ND

Occludes with mandibular second and third molars.