Cephalometric characteristics of bimaxil lary protrusion in adolescents

Abstract EN

Aims : the purpose of this study was to identify the cephalometric features of bi maxillary protrusion in adolescents.

Materials and Methods: Nanty four students were selected aged (12-15) years from secondary schools in Mosul City.

Forty four with class I protrusion which were chosen to have an interincisal angle less than 110o, and 50 with class I normal occlusion.

A standardized lateral cephalometric radiograph was taken for each student, sixteen variables, (9 angular and 7 linear) were used in this study.

Results: Significant differences were seen in the majority of the linear and angular measurements used in this study, the total anterior facial height, lower anterior facial height, upper anterior dental height , lower anterior dental height, the angle defines the antroposteriorly position of maxilla in relation to anterior cranial base, the angle indicates the antroposteriorly position of the mandible in relation to the anterior cranial base, mandibular plane angle, palatomandibular plane angle, genial angle, the angulation of upper central incisor to anterior cranial base and the angulation of lower central incisor to mandibular plane were significantly higher in bi maxillary protrusion than normal occlusion in both sexes and total sample No significant differences were seen in other measurements : upper anterior facial height, posterior facial height, ramus height and the angle of palatal plane inclination in relation to anterior cranial base.

Interincisal angle was significantly smaller in bi maxillary protrusion than normal occlusion.

Conclusions : most of the anterior facial measurements were significantly higher in bi maxillary protrusion than normal occlusion if compared to posterior facial height and ramus height due to the downward and backward rotation of the mandible in bi maxillary protrusion.