The inclination of the occlusal plane in relation to the sagittal and vertical parameters in cephalometrics

Introduction: A correlation between the inclination of the occlusal plane and vertical dental and skeletal relation has been known since the studies of Schudy (1963). Various therapeutic strategies attempt such a context for sagittally related malocclusions as well. Question: Are there statistically significant relationships between the inclination of the occlusal plane and the sagittal and vertical parameters in cephalograms? Materials and Methods: For the investigation a sample of 442 lateral cephalograms (mean age 28.3 years, SD 7.8 years; 175 male, 267 female) of orthodontically untreated adults was available. All cephalograms were analysed according to Segner and Hasund, expanded by Tweed analysis, ODI, APDI, overbite and overjet (a total of 14 dependent variables). The inclination of the occlusal plane was determined in relation to the mandibular plane (OP-MP) and to the Frankfort horizontal (FH-OP). Using correlation analysis (Pearson) for linear dependencies of the variables and t-test (given normal distribution) was searched and tested for significance. Results: Of the 14 variables studied, only ArGoGn (r = 0.643, p = 0.000), ML-NSL (r = 0.633, p = 0.000), the index (r = -0.541, p = 0.000) and ODI (r = -0.544, p = 0.000) showed a strong correlation with OP-MP. For FH-OP, only ML-NSL (r = 0.596, p = 0.000) showed a strong correlation. There are also weaker correlations (0.3 Keywords: occlusal plane, cephalometrics, regression