CLINICAL EVALUATION OF THE DENTOALVEOLAR SYSTEM IN EXCESSIVE TOOTH ABRASION AND TEMPOROMANDIBULAR DISORDERS
Authors: Magera N.S. 
Published: July 2019

The purpose of the study was to determine the features of the state of the dentoalveolar system in patients with excessive abrasion of teeth with and without temporomandibular disorders (TMDs) in a comparative aspect.
The study group included 68 patients, 31 (45.6%) of which were males and 37 (54.4%) females, aged from 21 to 70.
Patients are divided into two groups: the control group and the study group. The control group included 31 patients who were diagnosed with excessive tooth abrasion alone in combination with possible other occlusal disorders. The study group included 37 patients with excessive abrasion of teeth, possible other occlusal disorders and various forms of temporomandibular disorders: muscular, articular, and combined.
A preliminary clinical dental examination was based on instant diagnosis according to Hamburg protocol.
Additional examination methods included clinical diagnostic techniques (to determine features of the mandibular movements, loading tests of the TMJ, palpation of masticatory muscles, muscles of the neck and shoulders, etc.), as well as imaging techniques of the TMJ (panoramic radiography, zonography, 3D radiography of the TMJ, MRI, ultrasound of the TMJ and muscles), as well as the condylography.
The comparative analysis of prosthetic pathology, which was revealed in the oral cavity of patients depending on the groups, showed the following data.
Excessive tooth abrasion without other occlusal pathologies was diagnosed only in 3 of 31 patients accounting for 9.7% in the group of patients with excessive tooth abrasion without signs of TMDs (control group).
Among patients in this group, a fairly high percentage is attributed to the pathological eruption of the third molars – 32.1% and "multiple dental defects" – 21.5%, which together account for 53.6%.
Excessive tooth abrasion alone without other occlusal disorders was diagnosed in 6 of 37 patients accounting for 16.2% in the group with both excessive tooth abrasion and temporomandibular disorders (study group).
Prosthetic pathology was determined to occur three times more often among patients with both excessive tooth abrasion and TMDs compared to the patients with excessive tooth abrasion alone (38.7% in the group with TMDs vs. 14.3% in the control group, p<0.01). However, the pathological eruption of the third molars, on the contrary, was detected 2 times more often in the group with excessive tooth abrasion alone compared with the group of patients with TMDs (32.1% in the control group vs. 16.1% in the study group, p<0.05).
A homogeneous distribution of the generalized type of tooth abrasion and its local type was found to be specific to the controls (51.6% with the generalized type and 49.4% with the local type of abrasion).
However, for the local type of abrasion in this group of patients, it was determined that a significant predominance was specific to the frontal area in comparison with the distal regions of the tooth abrasion (the rates reached 41.9% for the frontal area vs. only 6.5% for the distal regions; p<0.01).
A significant predominance of the local type of excessive abrasion (83.7% of the local type vs. 16.3% of the generalized type, p<0.001) was determined in patients with both excessive tooth abrasion and TMDs. Moreover, the distribution was almost homogeneous in relation to the frontal or distal regions (43.2% for frontal and 40.5% for distal areas).
Probably, the loss of distal occlusal support in the area of the lateral teeth is a factor that can provoke the development of TMD. Such features should be taken into account when providing prosthetic care to such patients.
The revealed features in the diagnosis of patients with excessive tooth abrasion, other occlusal disorders in the settings of temporomandibular disorders should be taken into account in their treatment and, especially, in the provision of prosthetics to such patients.