[Association between cephalometric parameters and anteroposterior position of the upper first permanent molar]

ABSTRACT

In Angle classification, the maxillary first molar furnishes more nearly than any other tooth or point in the anatomy an exact scientific basis from which to reason on malocclusion. Angle believed that malocclusions are of the mandibular origin. The purpose of this study was to evaluate the association between some cephalometric parameters and sagittal position of the maxillary first permanent molar. This was a descriptive analytical study in which 250 lateral cephalometric samples that were randomly selected before orthodontic treatment were examined. The samples were divided into two groups marked as mixed dentition and permanent dentition. Statistical analyses including the linear correlation coefficients and student t-test were used to compare the upper molar position in two groups. There was no significant correlation between the age, maxillary length, and ANB in two groups. The position of maxillary first molar in the permanent dentition demonstrated a significant positive relationship with ANS-PNS, Jaraback index, and Ba-PTM whereas a significant negative correlation was found with FMA and Basal angle. Moreover, the maxillary first molar position in the mixed dentition showed a significant positive relationship with Ba-A and Ba-PTM. Based on results found in the present study, the sagittal position of maxillary molar between mixed and permanent dentition was different. Maxillary first molar position in the permanent dentition showed a significant relationship with facial growth pattern, facial depth, and maxillary length. However, more longitudinal studies to confirm the findings of this study are needed