Introduction. Class III malocclusions are characterized by a more prominent lower jaw compared to the upper jaw and a Class III skeletal and dentoalveolar relationship according to Angle. In the scientific literature, there is a small amount of data on the morphological characteristics of malocclusion in different populations, so there is a justified need to examine the morphological characteristics of Class III malocclusion in the population of Vojvodina. The aim of this study was to determine the morphological characteristics of Class III malocclusions, to compare them with the average values found in the scientific literature, and to determine the correlation between the examined parameters of the upper and lower jaw. Material and Methods. This retrospective study included subjects with Class III dentoalveolar malocclusion treated at the Dentistry Clinic of Vojvodina in Novi Sad. The method of random selection was used to select 50 study models. The data were statistically processed with a significance level of p < 0.05. Results. The obtained results indicate that the sum of crown width of the mandibular incisors, the length of the mandibular dental arch, and the mandibular apical base in subjects with Class III malocclusion are higher than the average values in the general population. The values of the posterior width of the maxillary dental arch in the examined group are lower compared to the average values in the general population. Conclusion. Subjects with Class III malocclusion present with a greater mandibular dental arch in regard to the maxillary dental arch.

Introduction/Objective. The evaluation of sagittal jaw relationship is crucial in orthodontic diagnostics, orthodontic treatment planning, and monitoring of its results. A large number of parameters have been established for their assessment. The aim of this study was to determine the significance of the correlation between the indicators of sagittal jaw relationship, ANB, AOBO, AFBF, NAPg, and OJ, one with another, and with indicators of the sagittal position of the jaws, SNA and SNB, in children with skeletal class III malocclusion. Methods. A total of 100 children with mixed dentition, of both genders, based on the profile cephalometric analysis, were divided into two equal groups: group 1 (test group) ? children with skeletal class III (n = 50), group 2 (control group) ? children with skeletal class I (n = 50). Results. In children with skeletal class III malocclusion, significant correlations were found among the indicators of sagittal jaw relationships ANB, AOBO, AFBF, NAPg, OJ, mutually, except between AOBO and AFBF. Significant correlations of these parameters were also found with the SNB angle, but not with the SNA angle. Conclusion. Confirmed significant correlation between tested indicators in the sagittal jaw relation indicates that, if we find skeletal jaw relationship class III, or just a simple reversed incisors overbite in children in routine application of any of the above mentioned parameters in everyday work, it should be indubitably checked and monitored using a larger number of parameters, especially those that define the sagittal position of the mandible.

Introduction. Low-strength forces of the soft tissues are closely related to the stomatognathic system morphology. The muscles of the lips have a significant influence on the position of the front teeth. The goals of our research were to: 1. Examine the electromyographic activity of the circular muscle of the lips in Class I and Class II division 2 patients with incisor retrusion in the position of physiological rest and centric occlusion at maximum voluntary muscle contraction; 2. Examine the existence of a correlation between the electromyographic activity of the lip muscles and the position of the incisors in the examined groups. Material and Methods. The action potentials of the circular muscle of the lips were registered at different positions of the lower jaw. Intramuscular coaxial electrodes were placed according to the Greenfield scheme. Measurements were performed bilaterally, summed up with ten muscle levels, in 100 patients aged 8 - 12 years; 30 patients were in the control group with neutroclusion, i.e. Class I and 70 patients in the study group with Class II division 2, according to Angle. Results. The results are given in microvolts as average cumulative voltage of action potential amplitudes, which were used to determine changes in the orbicular muscle activity. After statistical analysis of the obtained data, it was concluded that the bioelectrical activity of the examined muscles at all measured positions was lower in patients with distoclusion, except for the lower lip in patients with Class II division 2, where this activity was significantly higher. Conclusion. The results of the study show that the determined changes in the action potentials of the circular muscles of the lips in subjects with distoclusion indicate a cause-and-effect relationship between muscle function and occlusion. A significantly increased activity of the lower lip in deep bite can be considered responsible for the steep position of the upper incisors.

Introduction. Mandibular advancement devices are used in the treatment of mild to moderate obstructive sleep apnea. We have created different types of devices over the years and come up with a design of an acrylic two-part adjustable device as the best one so far. New design of the mandibular advancement device. A 36-year-old male patient has been referred for polysomnography to the Sleep Medicine Center of the Institute of Pulmonary Diseases of Vojvodina due to primary problems in the form of drowsiness during the day, reduced concentration and witnessed cessation of breathing during sleep. By evaluating respiratory parameters, the patient was diagnosed with mild obstructive sleep apnea with an Apnea-Hypopnea Index of 10.3. Hygienicdietary regimen of life and the use of mandibular advancement device were prescribed to the patient. Control polysomnography was performed six months after the use of the mandibular advancement device. Evaluation of respiratory parameters has registered the apnea-hypopnea index of 6.2 with predominant hypopneas. The average oxygen blood saturation was 94.4%. Snoring was mild and rare. Patient did not have any long-term side effects of the device and he got used to it easily. Conclusion. Mandibular advancement device is an effective way to treat obstructive sleep apnea in clearly indicated cases. Dentists who indicate and make it must be well educated, informed and they must cooperate with the sleep medicine centers to monitor the effectiveness of the therapy.