Abstract
It is known that there are small pits on the cuspal portion of human teeth named the crestal pits. SEM observation of the crestal pits on human permanent molars have been reported already by the authors. However, the SEM observation of the crestal pits on unerupted human permanent molars has not yet been reported.
This paper presents the SEM observation of the crestal pits of 20 unerupted human permanent first molars, bilaterally on the same individual, which were obtained from 10 mandibulars of dry Indian skulls. The results were compared with those of previously published crestal pit studies on erupted permanent molars.
1) The crestal pits were observed in 8 mandibulars out of 10 mandibulars (80.0%). Ninety eight crestal pits were found in 14 teeth out of 20 observed teeth (51 and 47 crestal pits were found in 7 teeth of the right and left sides of first permanent molars respectively). No statistically significant difference was seen between the bilateral molars of the number of crestal pit.
2) The maximum 19 and the minimum one and the average 7 crestal pits were found per tooth on unerupted permanent first molars. This average value is larger than that of erupted permanent molars (4.9). No statistically significant difference was seen between that of unerupted permanent first molars and erupted permanent molars.
3) Similar to that of erupted permanent molars, the most common opening shape of crestal pits found on unerupted permanent first molars was the round shape (53.1%).
4) The highest concentration of crestal pits found on unerupted permanent first molars was located on the mesio-buccal cuspal portion.
5) Concerning the opening diameters of the crestal pits on unerupted permanent first molars, on the right side the maximum was 180μm and the minimum 9μm with an average of 47.7μm; on left side the maximum was 150μm and the minimum 9μm with an average of 37.6μm. No statistically significant difference was seen between the diameters of crestal pits on the right and left sides of unerupted permanent first molars. The average diameter of the crestal pits of unerupted permanent first molars on both sides was 42.9μm, the maximum 180μm and the minimum 9μm. This average was much smaller than that of erupted permanent molars (173μm). No significant statistical difference was seen in the average value of the diameter of the crestal pits between the unerupted permanent first molars and erupted permanent molars.
