CLINICAL AND LABORATORY JUSTIFICATION OF THE EFFICIENCY OF USING IMPROVED METHODS OF DETERMINING AND FIXING OCCLUSAL RELATIONSHIPS IN PATIENTS WITH PARTIAL EDENTULOUS

Abstract

Abstract. Considering the anatomical and functional indicators of the maxillofacial area in the case of complex treatment with fixed and removable denture structures (FPD and RPD) is an important direction in prosthetic dentistry. We have proposed improved methods of determining central occlusion/relation position of jaws, muscle deprogramming at the stages of manufacturing of dental prosthesis and during the period of adaptation to them. Important methods for confirming the effectiveness of the proposed improvements are digital analysis of occlusion and electromyography of masticatory muscles. The aim of the study – to establish the effectiveness of the proposed methods of determining and fixing the occlusal relationships based on the study of clinical indicators in patients who simultaneously use FPD and RPD for prosthetic therapy. Materials and Methods. Our study included 120 patients aged 55–70 years with partial edentulous who came to the Department of Stomatology of Postgraduate Education of Ivano-Frankivsk National Medical University for prosthetic treatment. Prosthetic treatment was carried out with FPD, RPD using the proposed methods of forming occlusal relationships (group 1) and generally accepted methods (group 2). Each group was divided into subgroups: a – without occlusal disorders, and b – with occlusal disorders and vertical occlusion dimension (VOD) loss. The examination included determining the functional state of occlusion using the computerized digital occlusion analysis complex “T-Scan Novus” and determining of bioelectric activity of the masticatory “Neuro-EMG-Micro”. Results and Discussion. Analysis of the functional occlusion showed the absence of patients with an “excessive” degree of asymmetry among patients of 1a and 1b subgroups during all observation periods according to the T-Scan Novus indicators and their appearance in 2a subgroup (3.3% of people) and 2b (16.7% of people). The average value of the occlusion time did not differ from the indicators of the control group in subgroups 1a and 1b during observation, but it was significantly higher in 2a subgroup after a year, in 2b subgroup – during all observation periods (p<0.05). The average values of the bioelectric activity amplitudes (at rest, during maximal contraction and voluntary chewing ) of the right and left m. masseter did not significantly differ from the values of the control group after a year of observation in patients of 1a subgroup, in contrast to the values of 2a subgroup patients (p<0.05). There was a significant increase of average amplitude values of the bioelectric activity by 18% for the right and 30.7% for the left m. masseter in patients of subgroup 1b during maximal contraction and by 15.4% for the right and 16.3% for the left m. masseter during voluntary chewing in patients of 1b subgroup a year after prosthetic treatment, compared with the data of 2b subgroup (p<0.05). Conclusions. The implementation of proposed improved methods in the prosthetic treatment of patients with a combination of PRD and FPD allows to evenly distribute the occlusal load, prevent overload of periodontal tissues of the abutment teeth, balance the function of the masticatory muscles of the left and right sides, which in the complex improves the quality of dental care.