Predicting vertical growth of the mandibular ramus via hand–wrist radiographs

Abstract

The purpose of this study was to investigate whether growth increments of the mandibular ramus in the vertical direction can be predicted using cephalometric variables in combination with a hand-wrist radiograph. Our data comprised cephalograms taken at the beginning (T1) and end (T2) of orthodontic treatment, and hand-wrist radiographs taken at T1 of 49 adolescent patients with a Class I malocclusion. Cephalograms were scanned and analyzed with the aid of a computer. Relative growth increments (in %) of body height and different cephalometric variables during the observation period were recorded. Growth changes were compared statistically to each other and to the growth prediction assessed with the hand-wrist radiograph according to Greulich and Pyle (GPP). Stepwise linear regression (SPSS®) was used to statistically analyze the impact of gender, age, body height, growth prediction as assessed with a hand-wrist radiograph, and cephalometric variables at T1 on changes in the increase in the height of the mandibular ramus. Growth prediction assessed via hand-wrist radiographs at the beginning of treatment did not enable a reliable prediction of the remaining vertical growth of the mandibular ramus. Only the patient's gender and height of the mandibular ramus at the beginning of treatment had a statistical impact on growth changes in the ramus height that occurred during the observation period. Our results suggest that the vertical growth potential of the mandibular ramus cannot be predicted by analyzing hand-wrist radiographs or by evaluating cephalometric variables other than the initial mandibular ramus height.