A new dimension to cephalometry: DW plane

Abstract

Context: An accurate jaw relationship is critically important in orthodontic diagnosis and treatment planning. Various angular and linear measurements that have been proposed can be erroneous because they depend on various factors. Aim: The purpose of this study is to establish a new cephalometric measurement to assess the skeletal jaw discrepancy using Walker's point. Settings and Design: Lateral cephalogram of 100 Indian subjects with age range (8–11, 12–18, 19-27) were obtained. Inclusion criteria were – clinically Class I occlusion; normal overjet and overbite; orthoganthic profile; competent lips and cephalometrically normal ANB; Wits appraisal; Rakosi Jarabak's angle of inclination and mandibular plane angle. Materials and Methods: Four skeletal landmarks: Point A, Point B, Walker's point (W) and Wing point (w) were used to indicate the severity and type of skeletal dysplasia. Double W (DW) was constructed joining the Walker's and Wing point. Statistical Analysis Used: Analysis of variance test and Student's t -test was applied which showed significant results. Results: The difference between Walker's perpendicular to A Point and Walker's perpendicular to B Point gave the sagittal jaw discrepancy and was found to be 8.2 ± 0.9 mm. This measurement remained relatively constant throughout life. Conclusions: DW plane is an effective way to accurately establish the skeletal jaw relationship. It analyses the variance between linear measurements to determine the sagittal jaw relationship, linear measurements for vertical maxillary height and angular measurements to determine rotational jaw changes.