Dental Anatomy Spotlight: Primary Maxillary First Molar

Dental Anatomy Spotlight: Primary Maxillary First Molar

Describe in detail about Primary Maxillary First Molar.
Answer:

Primary Maxillary First Molar Buccal Aspects:

• The maxillary first molar is the widest at the mesial and distal contact area.
• The crown converges at the cervix.
• The occlusal line is slightly scalloped. The buccal surface is smooth.
• Slight developmental grooves are noted.
• The roots are slender, long, and widely spread.
• The distal root is shorter than mesial
• The bifurcation of the roots begins almost immediately at the site of the cervical line.

Primary Maxillary First Molar Lingual aspects:

• The crown converges in a lingual direction.
• The mesiolingual cusp is the most prominent cusp, the longest and sharpest cusp.
• The distolingual cusp is poorly defined, small, and rounded.
• Distobuccal cusp is seen as longer and better developed.
• All three roots are seen with the lingual root being larger.

Primary Maxillary First Molar Mesial aspect:

• The dimension at the cervical third is greater than that at the occlusal third.
• Pronounced convexity is seen at the cervical third.
• The cervical line mesially shows some curvature in the occlusal direction.
• The mesiobuccal root is hidden behind the mesiobuccal root.

Primary Maxillary First Molar Occlusal aspect:

• The calibration of the distance between the mesiobuccal line angle and the distobuccal line angle is greater than the calibration between the mesiolingual line angle and the distolingual line angle.
• The crown converges lingually, distally.
• It is more nearly rectangular in shape with the shortest sides being the marginal ridges.
• A mesial triangular fossa is inside the mesial marginal ridge, with a mesial pit in this fossa and a sulcus with its central groove connecting the two fossae.
• Buccal development groove divides the mesiobuccal cusp and distobuccal cusp occlusally.
• Supplemental grooves radiate from the pit in the mesial triangular fossa one buccally, one lingually and one towards the marginal ridge.
• A well-developed triangular ridge called oblique ridge connects mesiolingual cusp with the distobuccal cusp.
• The central development groove extends from mesial pit to distal developmental groove.
• The distal marginal ridges is thin and poorly developed.