Garner, LaForrest D.Cowan, Richard EdwardPotter, Rosario H.Mitchell, David F.Tomich, Charles E.Hutton, Charles E.Weinberg, R. Bernd2023-07-062023-07-061975https://hdl.handle.net/1805/34147http://dx.doi.org/10.7912/C2/3204Indiana University-Purdue University Indianapolis (IUPUI)This study was carried out to evaluate the factors which may vary the soft tissue response in non-growing subjects. Pretreatment and post-treatment lateral cephalometric radiographs of twenty-nine postadolescent orthodontic patients were measured with a sonic digitizer using facial plane as the reference. Stepwise multiple regression analysis was performed to select those factors from the original set of 6 according to the statistical significance of their contribution in the prediction of the soft tissue response. It was found that 30.84% of the horizontal upper lip response is due statistically to the maxillary incisor change and the pretreatment upper lip thickness at the vermillion border. This study also revealed that 67.76% of the horizontal lower lip response is due statistically to the mandibular incisor change, the pretreatment upper lip thickness at A-Point, and the mandibular postural change. Additionally, 16.50% of the vertical upper lip response is due statistically to the mandibular incisor change. Further, 33.39% of the vertical lower lip response is due statistically to the mandibular postural change and the pretreatment upper lip thickness at A-Point. Finally, the majority of the total variation in lip response is still not accounted for and therefore further research is needed.en-USCephalometryFaceThesis