Assessment of Positional Variation of Maxillary Permanent First Molar with respect to the Infrazygomatic Crest (Key Ridge) in Skeletal Class I, II and III Cases

Abstract

ABSTRACT Introduction To assess the positional variations of maxillary first permanent molar in horizontal and vertical plane with respect to infrazygomatic crest (key ridge) in skeletal class I, II and III cases. Materials and methods A total of 103 lateral cephalograms comprising of 40 skeletal class I (control group), 35 class II and 28 class III cases were selected and analyzed. Six parameters were chosen to compare the vertical and the horizontal variations of first permanent molars. Results The angulation of maxillary first molar with respect to key ridge in class II and III was 2.42° and 6.97° as compared to class I which was 5.35°. The mesiobuccal cusp tip of maxillary first molar from key ridge in class II and III was 2.11 and 5.46 mm respectively as compared to class I (1.62 mm). The mesiobuccal root tip of maxillary first molar from key ridge in class II and III was 2.14 and 2.82 mm as compared to class I (1.27 mm). Conclusion The maxillary first molar was not directly under the infrazygomatic crest and was ahead of the key ridge in all the groups. The maxillary first permanent molar was placed more mesially in class II and III cases as compared to the class I cases but, in class III, it was more upright as compared to class I and II. How to cite this article Kamble R, Hazarey A, Hazarey P, Singh J. Assessment of Positional Variation of Maxillary Permanent First Molar with respect to the Infrazygomatic Crest (Key Ridge) in Skeletal Class I, II and III Cases. World J Dent 2013;4(4):228-234.