Maxillary First Premolar Anatomy and Characteristics

Maxillary First Premolar

Tooth with two major cusps, larger first premolar.

Eruption Age of the maxillary 1st premolar

Occurs between 10 and 11 years.

Root Completion Age of the maxillary 1st premolar

Completes between 12 and 13 years.

Crown Size of the maxillary 1st premolar compared to the max canine

Shorter

Proximal Concavities of the maxillary 1st premolar cause

Difficult scaling due to mesial concavities.

The Maxillary 1st premolar is its widest at the

contact area

The Maxillary 1st premolar is its narrowest at the

cervix area

The mesial and distal outlines are nearly what from the contact areas to the CEJ of the maxillary 1st premolar

Straight

Contact areas of the maxillary 1st premolar

Distal and mesial both at junction of occlusal and middle third but distal is slightly cervical

Are imbrication lines present in the maxillary 1st premolar

yes

Buccal Cusp Tip of the maxillary 1st premolar

High and Sharp, slight distal to the long axis of tooth

Mesial Cusp Ridge of the maxillary 1st premolar

Longer and flatter than distal cusp ridge.

Buccal Ridge of the maxillary 1st premolar

Prominent ridge located in the crown's middle.

Lingual view of the maxillary 1st premolar

narrower than the buccal view

Lingual Cusp of the maxillary 1st premolar

Shorter than the buccal cusp.

Lingual cusp tip of the maxillary 1st premolar

Bent or Positions towards the Mesial

Roots of the maxillary 1st premolar

Most have 2 Roots that are bifurcated in the apical third
2 pulp canals

Lingual root of the maxillary 1st premolar

More blunted and shorter than the buccal root apex

Crown Depression of the maxillary 1st premolar

Only premolar with mesial crown depression that continues onto the deep mesial root developmental depression

Mesial Marginal Groove of the maxillary 1st premolar

Groove crossing mesial marginal ridge cervically.

CEJ Curvature of the maxillary 1st premolar

Greater on mesial surface than distal.

Occlusal Shape of the maxillary 1st premolar

Hexagonal shape with six distinct sides.

Buccal-lingual measurement compares to the Mesial-Distal measurement of the maxillary 1st premolar

Buccal-lingual measurement is greater

Two well developed cusps of the maxillary 1st premolar

Lingual and Buccal cusps

Buccal and lingual cusp of the maxillary 1st premolar

Buccal: sharper and higher
Lingual: rounder, duller, and shorter

Cusps of the maxillary 1st premolar

Each cusp has four descending ridges.

Central Groove of the maxillary 1st premolar

Long developmental groove dividing tooth buccolingually.

Which tooth has fewer supplemental grooves?

maxillary 1st premolar

Transverse Ridge

Formed by two triangular ridges.

Mesial Triangular Fossae of the maxillary 1st premolar

Depressions at ends of triangular grooves where the mesial is deeper

Supplemental Grooves of the maxillary 1st premolar

Additional grooves not classified as developmental but maxillary 1st premolar have fewer than the seconds

Distal Surface of the maxillary 1st premolar

Similar to mesial but lacks crown depression.

Developmental Grooves of the maxillary 1st premolar

Mesiobuccal and distobuccal grooves present.

Maxillary Sinus Relation of the maxillary 1st premolar

Roots may penetrate maxillary sinus area.