[Cone beam computed tomography in the diagnosis of temporomandibular joint osteoarthrosis].

Objective: To evaluate the clinical use of cone beam dental CT in the diagnosis of temporomandibular joint osteoarthrosis.

Methods: Forty-eight cases diagnosed as temporomandibular joint osteoarthrosis (OA) and disk displacement with or without reduction accompanied by OA changes were included, and a total of 96 joints received both trans-pharyngeal radiography and cone beam CT (CBCT) examination. The detectable rate for OA radiographic changes was compared between the two examinations.

Results: The radiographic appearances of osteoarthrotic condyle included six types: loss of the lamina dura density of condyle surface (type I), destructive and erosive bone changes (type II), flattening of the articular surface (type III), sclerosis (type IV), osteophytes (type V), and false cyst change (type VI). The detectable ratio of CBCT for all types of osteoarthrosis was 65.63%, 37.50%, 27.08%, 31.25%, 28.13%, 1.04%, respectively, and the detectable ratio of trans-pharyngeal radiographs was 52.08%, 19.79%, 32.29%, 23.96%, 12.50%, 2.08% respectively. Intraobserver and interobserver reproducibility for type I and type II was in good agreement with both the trans-pharyngeal radiographs and CBCT, Kappa > 0.60.

Conclusions: CBCT had higher detectable rates for pathological changes of osteoarthrosis, and could show the exact location, size, and the types of pathological changes. CBCT may be used as a measure in evaluating disease severity and progression, and in clinical trials of disease treatment.