Variants of proportionality of gonional-occlusal and condylar-occlusal height of the mandibular branch in physiological occlusion of permanent teeth

The variability in the size of the branches of the lower jaw determines the relevance of assessing the proportionality of its main parts. In intravital conditions, X-ray methods of examination occupy a special place in diagnosis. Purpose. To determine the main vertical parameters of the mandibular branch and its components in physiological occlusion of permanent teeth. Material and methods. An analysis of 74 sets of radiographs, including orthopantomograms and teleradiographs of people with signs of physiological occlusion, was carried out. The mandibular branch was conditionally divided by a line running through the distal occlusal point into two sections, the upper occlusal articular and the lower occlusal gonional. Results and discussion. In the course of the analysis of radiographs of people with physiological types of occlusion, it was found that the height of the mandibular branch averaged (61.28 ± 1.24) mm. The ratio of the upper part to the lower part was 1.97 ± 0.07. The relative ratio in the range from 1.8 to 2.1 allowed us to distinguish 3 groups. The first group included radiographs in which the relative indicator corresponded to the mean values (1.8–2.1). The second group included radiographs with a reduced ratio of parts of the mandibular branch (less than 1.7). In the third group, the ratio of parts of the mandibular branch exceeded 2.2. Conclusion. On average, the height of the upper occlusal articular part of the branch was twice the size of the lower occlusal gonional part, which can be used both in the clinic of orthodontics and maxillofacial surgery when planning operations to model the branch of the lower jaw.