The permanent maxillary second molar helps the maxillary first molar in the grinding and commination of food. It is smaller in size as compared to the first molar. No accessory cusp is associated with the maxillary second molar.
Development and Eruption of the Permanent Maxillary Second Molar
Following is a summary of the development and eruption of permanent second molar.
- Initiation of calcification of the molar: 2.5 years
- Crown Completion of the molar: 7 – 8 years
- Eruption of the molar: 12 – 13 years
- Root Completion of the molar: 14 – 16 years
Buccal Aspect of Permanent Maxillary Second Molar
- The crown of the maxillary second molar is shorter cervicoocclusally and narrower mesiodistally as compared to the maxillary first molar.
- Two cusps are completely visible from the buccal aspect mesiobuccal cusp and the distobuccal cusp.
- The distobuccal cusp is small as compared to the mesiobuccal cusp. Due to the small size of the distobuccal cusp part of the distal marginal ridge and distolingual cusp is visible from the buccal aspect.
- There are three roots. The name of the roots is the mesiobuccal root, distobuccal root, and palatal root.
- The three roots of this tooth are less divergent as compared to the maxillary first molar.
- All three roots have a slight distal inclination in the apical third portion.
Lingual Aspect of Permanent Maxillary Second Molar
- There are two lingual cusps. The mesiolingual cusp is larger in dimension as compared to the distolingual cusp.
- In between the two lingual cusps of the maxillary second molar, a lingual developmental groove is present.
- No accessory cusp or cusp of Carabelli is associated with the mesiolingual cusp of the maxillary second molar.
Mesial Aspect of Permanent Maxillary Second Molar
- The mesiobuccal and the mesiolingual cusp are visible from the mesial aspect of Permanent Maxillary Second Molar.
- The mesial marginal ridge is well developed and connects the mesiobuccal cusp with the mesiolingual cusp.
Distal Aspect of Permanent Maxillary Second Molar
- The distobuccal and the distolingual cusps are visible from the distal aspect.
- The height of the distal cusps and the distal marginal ridge is at a lower level. Therefore, part of the occlusal surface is visible from the distal aspect.
- The crown of the maxillary second molar tapers towards the distal aspect. Therefore, part of the buccal aspect of the tooth is also visible from the distal aspect.
- The dimensions of the distobuccal root are less. Therefore, part of the mesiobuccal root is also visible from the distal aspect.
- The cervical line is straight and has no curvature towards the occlusal aspect.
Occlusal Aspect of Permanent Maxillary Second Molar
- The buccolingual dimensions of the crown are more as compared to the mesiodistal dimensions.
- All four cusps of the maxillary second molar are visible from the occlusal aspect.
- The mesiolingual and the mesiobuccal cusps are well developed as compared to the distobuccal and the distolingual cusps.
- Among the four cusps, the distolingual cusp is the smallest cusp.
- An oblique ridge is also present in the maxillary second molar. The ridge extends from the distobuccal cusp to the mesiolingual cusp.
- The fossae that are present on the occlusal surface of this tooth are the mesial triangular fossa, central fossa, and distal triangular fossa.
- The grooves that are present on the occlusal aspect are the central developmental groove, buccal developmental groove, and lingual developmental groove.
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