筋突起切離術により治療した下顎骨筋突起過形成による開口障害の一例

This report describes a case of hyperplasia of the mandibular coronoid process treated by coronoidotomy. A 26-year-old man visited our clinic complaining of restricted mouth opening. Panoramic radiography revealed marked hyperplasia of the right mandibular coronoid process. Three-dimensional CT showed that the coronoid process touched the temporal surface of the zygomatic bone at the maximal mouth opening position. His maximum mouth opening range was 27mm. The coronoid process was amputated about 8mm in width, and mouth opening training was done for a year after the surgery. Although the coronoid process and mandibular ramus reunited, the maximum mouth opening range was maintained at 40mm 13 months after the surgery

Hyaline Ring Granuloma of the Mandibular Periosteum

AbstractHyaline ring granuloma (HRG) is a comparatively rare inflammatory condition occurring mainly in the oral region, and is characterized by hyaline rings (HRs) formed in the granulation tissue. This study describes a case of HRG occurring in the mandibular periosteum of an 18-year-old male. Histopathologic, histochemical and electron microscopic studies were performed on surgically excised materials. Histopathologically, ovoid bodies(OBs) surrounded by thin hyaline walls and HRs showing pale-stained eosinophilic thick hyaline walls were both detected. Histochemical study revealed that the OBs contained many granules chiefly composed of starch. Ultrastructurally, the HRs presented a stratiform structure due to the accumulation of cross-banded collagen fibrils with a basement membrane-like lining containing cellulose microfilaments. These results suggest that HRs are formed as follows: the exogenous vegetable materials are encapsulated by collagen, then the component is gradually degraded; the residual cellulose fraction adheres to the inner surface of the collagenous capsules, and the continuous deposition of collagen at the outer surface of the capsules increases its thickness. Finally, thick hyaline walls of HRs are formed. The possible pathogenesis of this curious lesion is discussed for stomatologists