Fractal Analysis of Mandibular Condyles in Patients with Temporomandibular Disorder

Fractal analysis (FA) is a mathematical method used to evaluate irregular and complex shapes. The numerical result obtained from FA is called fractal dimension (FD). FA can detect subtle bone changes in diseases that affect bone microstructures such as temporomandibular disorder (TMD), even when these changes are not visible on radiographs. It provides objective results that can improve clinical diagnosis without creating extra burden for patients. This study aimed to evaluate the relationship between FD values and both the severity of TMD and degenerative changes in temporomandibular joints (TMJ). Specifically, we aimed to assess the diagnostic capacity of FA for TMD. This study included 161 participants. The presence and severity of TMD in the participants were evaluated using the Fonseca Anamnestic Index (FAI). Degenerative bone changes in the participants' mandibular condyles were categorized as flattening, osteophytes, and erosion on panoramic radiographic Images. FA was performed using ImageJ 1.49 software on panoramic radiographs. Data were analyzed using independent samples t-test and one-way ANOVA. Post hoc multiple comparisons were evaluated with the least significant difference test (LSD). Statistical significance was considered at p < 0.05. The severe TMD group had the lowest mean FD value (1.36 ± 0.11), whereas the group with no TMD (1.48 ± 0.11) had the highest mean FD value. In each case, the mean FD value was found to be statistically significantly lower in participants with flattening, osteophyte, or erosion than in those without (p < 0.001 for each comparison). Our main findings suggest that FD values were significantly associated with both the severity of TMD and with each type of degenerative bone changes we investigated. FA may provide valuable, quantitative information to improve the diagnosis of TMD. As such, FA may support clinicians in making early and accurate diagnoses and treatment decisions.