Lower Facial Morphometrics in Children upon the Eruption of First Permanent Molars

摘要

Transition from primary to early mixed dentition brings about various changes in the occlusion and facial appearance. After complete eruption of primary teeth, the occlusion seems to be relatively stable till eruption of first permanent molars. Transition from primary to early mixed dentition is characterised by increase in the vertical dimensions, increase in the arch perimeter, and increase in the intercanine width. However, skeletal changes characterising the first transitional phase are not completely explored. With more emphasis on early diagnosis and treatment planning, it is essential to have a thorough knowledge of the complete developmental changes that can be considered during diagnosis and deciding the treatment needs.Aim: To determine the developmental changes in the lower facial dimensions upon the eruption of first permanent molar.Materials and Methods: A longitudinal prospective study was planned to study developmental changes in the lower facial dimensions. Lateral cephalometric radiographs of 46 children with primary dentition (Mean age 5.5 years) were taken. The sample comprised of 27 males and 19 females. All the subjects had complete primary dentition with normal occlusion and well balanced facial proportions. The lateral cephalometric radiographs were repeated on the same subjects after a period of two years. Cephalometric analysis was done using Nemoceph software (version 10.4.2). The data was compiled and the following statistical analysis tests were performed: descriptive statistics, Paired t-test, Benjamin and Hochberg multiple testing correction and unpaired t-test.Results: Among primary and early mixed dentition, males exhibited larger dimensions than females. However, all the variables were not statistically significant. There was significant increase in the dimensions upon the eruption of first permanent molars. However, mandibular inclination, jaw relationship and gonial angle decreased during this transition phase.Conclusion: Eruption of first permanent molars contributes significantly towards the changes in the lower craniofacial dimensions. Initial signs of mandibular rotations and displacement correspond with the eruption of first permanent molars.