ANALYSIS OF STRUCTURAL AND IATROGENIC FACTORS DETERMINING THE SEVERITY OF FUNCTIONAL DISORDERS IN TEMPOROMANDIBULAR DISORDERS

Abstract

Aim – to determine the structural and iatrogenic factors that most significantly influence the severity of functional disorganization of the dentognathic system in patients with temporomandibular disorders (TMD) and to establish their prognostic value for planning prosthetic rehabilitation. Methods. A cross-sectional study was conducted involving 125 patients with verified TMD (DC/TMD Axis I), divided into three groups: Group I (n=50) – dentition defects, Group II (n=40) – generalized pathological tooth wear, Group III (n=35) – iatrogenic TMD. Clinical examination according to DC/TMD, classification of dentition defects according to Kennedy with Applegate’s rules, the author’s functional disorganization index (FPDI), and multiple linear regression analysis were used to determine predictors of functional disorganization. Statistical processing was performed using IBM SPSS Statistics 29.0 with descriptive statistics, Pearson’s χ² test, one-way analysis of variance (ANOVA) with Tukey post-hoc test, and multiple linear regression analysis (stepwise method). Differences were considered statistically significant at p<0.05. Scientific novelty. For the first time, based on multiple regression analysis, the contribution of structural factors (loss of distal occlusal support, number of functional occlusal pairs, symmetry of dentition defects) and iatrogenic factors (occlusal interferences, violation of interalveolar height, irrational prosthetic constructions) to the formation of functional disorganization of the dentognathic system in patients with TMD was quantitatively assessed. It was established that the topographic classification of dentition defects according to Kennedy does not fully reflect their functional consequences, which substantiates the expediency of a functionally oriented approach to the assessment of occlusal status. A prognostic model explaining 71.4% of the variability of the FPDI index was developed. Conclusions. The leading structural factors of functional disorganization of the dentognathic system are loss of distal occlusal support (β=0.38; p<0.001) and reduction in the number of functional occlusal pairs (β=- 0.29; p<0.01). Among the iatrogenic factors, occlusal interferences after restorations and prosthetic constructions are of the greatest importance (β=0.24; p<0.01). The most unfavorable factors are violations of interalveolar height and irrational prosthetic constructions, which are accompanied by the highest FPDI values (7.8±2.3 and 7.4±2.1 points, respectively). The obtained data confirm the expediency of a functionally oriented approach to the diagnosis and planning of prosthetic rehabilitation in patients with TMD.