This paper reports the four cases of the condylar head fractures of the mandible. The diagnostic images with panoramic radiograph and CT are presented. From 4 cases of condylar head fractures, the incidence, causes, and mechanisms are also discussed together with previous report.

We report on a family in which three individuals, a male and two females were affected with nonsyndromal diffuse cystic dysplasia of the kidneys. The parents had no renal abnormality. The occurrence of diffuse cystic dysplasia in three sibs born to normal parents suggests autosomal recessive inheritance. © 1996 Wiley‐Liss, Inc.

Desmoplastic fibroma rarely occurs in the jaw bone. However, we describe our recent experience with this type of desmoplastic fibroma developing in the left angle of the mandible of an 11-year-old girl. The patient had already recognized a lump in the left angle of the mandible about 1 and a half years previously and visited a pediatric clinic, but no definitive diagnosis was made at that time. Because the lump tended to enlarge thereafter, she visited a dental clinic and was then referred to our clinic for a detailed examination. As for the oral findings at admission, a bone-like hard lump was felt in the left angle of the mandible, associated with mild tenderness. Radiographic examination showed a unilocular transparent image with a slightly obscure borderline in the left angle of the mandible. Surgical resection was performed under general anesthesia. The histopathological findings suggested that the lump was composed of fibroblastic cells and collagen fibers. As of 11 months after operation, no local relapse has been noted.

Summary:The condylar process is the most common site of mandibular fracture; however, the biomechanics of this site are not well understood. Vascular endothelial growth factor (VEGF) is a marker for vasculogenesis and the formation of bone. Alkaline phosphatase (ALP) is also a biochemical marker of bone formation. To better understand the biomechanics of the condylar process, we examined the structure of the heads and necks of human mandibles from 35 male cadavers aged 25 to 90 years (mean, 61.5 years) using cone-beam computed tomography (CBCT). In addition, we used immunohistochemistry to assess the expression of the vascular markers VEGF and CD31 as well as the bone formation marker ALP. Significant differences were observed in the thickness of the posterolateral region of the cortical bone in the head of the mandible (p < 0.05) as well as in the medial (p < 0.001) and posterior (p < 0.01) regions of the neck of the mandible. VEGF accumulated more in deformed heads than in heads with oval-shaped structures. ALP was found in numerous small cavities of cortical bone in oval-shaped heads. These differences may be related to dislocation caused by muscle tension or the occlusion of temporomandibular joint movement.