Data from the quality of life, presence of anxiety, temporomandibular joint disturbances, tooth wear, and the occlusal vertical dimension are studied independently and individually [13-17]. The collective assessment of these data together constitutes the original dimension of this study.
In the present study, patients constitute a randomly selected group within the society because there is no planning, orientation, grouping, separation, or prejudice in the determination of the patients. For this reason, this clinical study gives information about the general population.
The age for the inclusion criteria is only the adult age group, 18–64 years old. As a result of this criterion, the average age was 31.34. The average age of the study is consistent with the 20–40 age range, which is most common in the literature for TMD [18].
There was a statistically significant difference between tooth wear and average age (p < 0.05), confirming similar studies in the literature [19, 20]. According to the statistical data, the average age of the group with high tooth wear was older than the other tooth wear groups. Also, the moderate tooth wear group's average age was found to be older than the group with no tooth wear group average age. No statistically significant difference was observed between the average ages of the other tooth wear groups (p > 0.05). This data proves the fact that tooth wear increases with age.
Of the individuals involved in this study, 91 (79.8%) were women, and 23 (20.2%) were men with TMD. These findings support the literature stating that TMD has been observed more frequently in women than in men [21-23]. Furthermore, when the statistical data was evaluated regarding vertical dimension ratios according to sex, the vertical dimension in women was statistically lower than in men (p < 0.05). These results support the anthropometric study [24].
48.25% (55 persons) of the study is the married individuals. Although this ratio is higher than a previous study [25], the results were found to be relatively similar. There is no significant relation between vertical dimension and marital status; however, there is a statistically significant difference between marital status distributions of tooth wear groups. The married individuals were found to be the highest in the moderate tooth wear and be the highest tooth wear groups. These results suggest that individuals' marital status and the severity of tooth wear are correlated. There is a need for more extensive literature and clinical trials to assess this situation.
The literature reports that cigarette smoking can affect the formation of pain in allergic and inflammatory ways, thereby increasing the susceptibility to TMD [26]. According to the statistical data, there was no significant relationship between smoking and vertical dimension, but statistically, a significant difference was observed between smoking and tooth wear (p < 0.05). Furthermore, smoking was high in moderate and high tooth wear groups. This situation is in line with similar studies in the literature, suggesting that smokers have more tooth wear [26, 27].
In a study conducted in 2016, it was reported that the presence of pain in obesity and TMD are associated [28]. This study showed statistically significant differences between the body mass index averages and the vertical dimensions (p < 0.05). The body mass index averages of the high vertical-dimension group were statistically higher than the low vertical-dimension group (p < 0.05), and no statistical difference was observed between the other vertical-dimension groups (p > 0.05). The statistical data also showed a statistically significant difference between the body mass index averages and tooth wear (p < 0.05). Body mass index averages of high tooth wear groups were statistically higher than other tooth wear groups, and there was no significant difference between the no tooth wear and low tooth wear groups. This study showed the importance of body mass index evaluation. As the weight and related problems increase in all communities, the importance of body mass index assessment is also increasing.
The quality of life is the fundamental concept of modern health [29]. Many studies evaluate the quality of life correlations with TMD [30, 31]. The literature proved that the severity of TMD was inversely related to the quality of life [32, 33]. Also, tooth wear adversely affects the quality of life [34]. However, there seems to be no literature evaluating the quality of life with a vertical dimension. This study showed no statistically significant correlation between the quality of life, occlusal vertical dimension, and tooth wear. This result indicates within the limitations of this study as a vertical dimension or tooth wear does not affect the quality of life.
STAI was used to assess anxiety levels. In a study by Kafas and Leeson, pain with anxiety and depression was observed in the presence of chronic pain [35]. Depression evaluations have been made with axis II of the DC/TMD form. The depression and vertical dimensions showed a statistically significant relation(p < 0.05). Moderate and severe depression is high in the group with a low vertical dimension. However, there was no statistically significant difference between depression and tooth wear. The results of this study are consistent with the results of the literature (36,38) as the data shows a significant relationship between vertical dimension and depression.
DC/TMD form updated in 2014 as DC/TMD (Diagnostic Criteria for TMD) [36]. The updated form was used for this study, prepared in Turkish by Serkan Polat in 2016 [37] The results were evaluated under two main headings, Axis I and II. Axis I is used to describing physical assessments, and axis II is used to describe psychosocial assessments.
The results obtained from this study support the literature [38], and the pain was determined to be one of the most frequently observed symptoms. The data shows a statistically significant difference between the left lateral motion pain and the vertical-dimension groups (p < 0.05). In addition, statistically significant differences were observed between masseter muscle pain presence and tooth wear (p < 0.5). This data suggests that changes in vertical dimension and tooth wear are predisposed to pain. Also, this study had no statistically significant relationship between headache and vertical dimension or tooth wear.
Deviation of the mouth opening pattern is the path taken by the lower jaws during mouth opening and evaluated as deflection and deviation. In this study, 62.28% of the cases had a deviation of the mouth opening. Vertical dimension and tooth wear groups were divided into right and/or left deflection presence distributions and right and/or left deviation distribution distributions with no statistically significant difference.
Statistically, vertical dimension and tooth wear groups did not significantly correlate with vertical or horizontal mandibular opening movements. The maximum mandibular opening average was found to be similar to the literature. In this study, 29 (25.44%) of the cases had limited mouth opening, myofascial pain without limitation of mouth opening was present in 31 patients (27.19%), and myofascial pain with limited mouth opening in 27 patients (23.68%).
Joint sounds are one of the common symptoms of TMD, and this study proves this fact again. Joint sounds were observed in 57.89% of the cases. Crepitus sound was observed in 40.35% of the patients, and click sound was observed in 29.82%. No statistically significant differences were observed between the vertical dimension (click and/or crepitus) or tooth wear and the distribution of joint sounds.
There was no statistically significant difference between axis II CPG distributions of vertical-dimension groups. However, statistically, a significant difference was observed between tooth wear groups and CPG distributions (p < 0.05). In addition, grade 0 presence was statistically significantly higher in the no tooth wear group than in all the other tooth wear groups. These results show that if there is no tooth wear, there seems to be no chronic pain, so the clinician must make a CPG assessment if the patient has tooth wear.
In this study, the vertical size dimensions were determined according to the method of the same triples, and the photographs were evaluated using the Wright method. The reason for choosing these methods is that they are easy to use in every clinic, economical, and the vertical dimension can be determined without exposing the patient to radiation. 54 (47.37%) of the subjects included in the study had an average, 21 (18.42%) high, and 39 (34.21%) low vertical dimensions.
In this study, contrary to expectation, no statistically significant difference was observed between tooth wear distributions and vertical dimensions. This observation can be explained by the presence of the dentoalveolar compensation mechanism [39]. Therefore, a decrease in vertical dimension may be expected as tooth wear becomes frequent. However, often the compensation mechanism works, and the worn teeth extrude to prevent the vertical dimension from changing [40].