Deciduous Maxillary Second Molar

The overall morphology of the deciduous maxillary second molar is similar to the permanent maxillary first molar. Although the small size, whiteness, short root trunk, and wide divergent roots differentiate the deciduous maxillary second molar from the permanent maxillary first molar. 

Development and Eruption

Following is the summary of the development and eruption of the deciduous maxillary second molar.

• First evidence of calcification: 19 weeks in utero
• Completion of enamel: 11 months
• Tooth eruption: 29 months
• Root Completion: 3 years
• Exfoliation: 10-11 years

The deciduous maxillary second molar is replaced by the maxillary second premolar.

Buccal Aspect

• The maxillary deciduous second molar has two well-developed buccal cusps. The cusps are equal in length and development.
• The names of two buccal cusps are the mesiobuccal cusp and the distobuccal cusp.
• A shallow buccal developmental groove is present between the two buccal cusps.
• The crown of the deciduous maxillary second premolar is much larger as compared to the deciduous maxillary first molar.
• The root trunk of this root is also short and the point of division of the root is close to the cementoenamel junction.
• There are three roots. Mesial, distal, and palatal root.
• The roots appear slender, longer, and heavier as compared to the deciduous maxillary first molar.

Lingual Aspect

• Three cusps are visible from the lingual aspect. The cusps are the mesiolingual cusp, distolingual cusp, and supplementary cusp.
• The supplementary cusp is known as the fifth cusp or tubercle of carabelli.

Mesial Aspect

• The crown of the deciduous maxillary second molar has a typical molar outline because of more buccolingual dimensions. The length and development of the root also contribute to the molar-like appearance of this tooth.
• Three cusps are visible from this aspect those are the mesiobuccal cusp, mesiolingual cusp, and supplementary or fifth cusp.
• The mesial marginal ridge connects the mesiobuccal cusp with the mesiolingual cusp.
• Little curvature of the cervical line is evident towards the crown surface.

Distal Aspect

• The overall distal calibration of the crown is less as compared to the mesial aspect. Due to this convergence of the crown part of the buccal and palatal aspect of the crown is visible from the distal aspect.
• Distobuccal and distolingual cusps are small and are of equal size
• The curvature of the cervical line is nearly straight.
• All three roots mesial, distal, and palatal roots are visible from the distal aspect. The visibility of all three roots is because the overall dimensions of the distal root are less.

Occlusal Aspect

• From the occlusal aspect, all four major cusps (Mesiobuccal cusp, Mesiolingual cusp, Distobuccal cusp, and Distolingual cusp) and one supplementary cusp are visible.
• The central fossa is the major fossa on the occlusal aspect of the tooth. The center of the fossa contains the central pit.
• Adjacent to the mesial marginal ridge and distal marginal ridges there are two minor fossae called mesial and distal triangular fossae.
• A well-defined developmental groove called the central developmental groove crosses the occlusal surface of the tooth.
• From the central developmental groove, the buccal groove originates that serves as a demarcation between mesiobuccal and distobuccal cusps. Similarly, the lingual developmental groove originates from the central developmental groove and serves as a demarcation between mesiolingual and distolingual cusps.
• Supplementary grooves often originate from the main developmental groove.
• A prominent oblique ridge is present that connects the mesiolingual cusp with the distobuccal cusp.

Video Lecture explaining the morphology of the Deciduous Maxillary Second Molar

Demonstration of the Morphology of Deciduous Maxillary Second Molar on Tooth models