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Objective The aim of this study was to compare root surface area (RSA) measurements of single-root teeth in a sheep mandible based on cone beam computed tomography (CBCT) with measurements made with an optical scanner. Study Design Eight anterior teeth of a sheep cadaver mandible were scanned in situ by using CBCT with 3 different exposure parameters, followed by treatment with smoothing software. The teeth were then extracted and scanned individually with an optical scanner. Three-dimensional digital models of the teeth were reconstructed on the basis of CBCT and optical scanner data. RSA data were calculated, and an equivalence test was used to statistically compare the measurements with significance of difference established at α = 0.05. Results The means of the differences between RSA measurements from CBCT and optical scanning ranged from 0.33% to 3.01%. There were no statistically significant differences between the 2 methods. The smoothing parameters for good fitness of the linear regression were determined to be 0.8 for the smooth factor, 8 for iterations, and 0 for compensate shrinkage. Conclusions The proposed CBCT technique to measure RSA is feasible. RSA data obtained from CBCT in situ are as accurate as optical scanner measurements ex vivo.

Objective The aim of this study was to evaluate osseous changes accompanying anterior repositioning splint (ARS) therapy in patients with temporomandibular joint disk displacement. Study Design Cone-beam computerized tomography (CBCT) data of 36 patients with intermittent or permanent closed-lock were used; 23 patients with permanent closed-lock had their displaced disks physically reduced by mandibular manipulation before ARS therapy. CBCT was performed before and ∼6 months after ARS therapy. The presence and location of “double contour” images suggesting condylar bone remodeling were statistically analyzed. Results The “double contour” images after ARS therapy were observed in ∼80% of patients, more frequently in joints with signs of displaced disks. The “double contour” appeared more often on the posterior bevel as well as the medial and middle part of condyles (P Conclusions ARS therapy can facilitate regenerative remodeling of condyles. CBCT is a useful tool for monitoring osseous changes in condyles.

Little is known about avascular necrosis of the mandibular condyle, which is necrosis of the epiphyseal or subarticular bone secondary to a diminished or disrupted blood supply in the absence of infection. We present a case of a large subarticular cystlike lesion that was found using cone-beam computed tomography (CBCT). There was an absence of osteoarthrosis, and the condylar articular surface was relatively intact. The patient's history, physical examination, and magnetic resonance images supported the diagnosis of avascular necrosis of the mandibular condyle. After 4 months of conservative therapy, new bone was observed in the cystlike marrow lesion, and a smooth articular surface was reestablished. Subarticular cystlike lesions without the collapse of the articular surface of mandibular condyles may be an early indicator of avascular necrosis.