聴力増進手術を行つた，耳小骨畸形を伴えるDysostosis mandibulofacialisの1例

　序言

　1944年Franceschetti及びZwahlenは頭部畸形の内，次の症候群を有するものをDysostosismandibulofacialisと称し，先ず2例を報告した（第1図）。

　1）眼裂が下外方に傾斜し（Antimongoloid），外1/3の下眼瞼が著明に弯曲してS型を呈し，上下眼瞼の外方にColobom形成がある。

　Owada and H. Nishihata report a case of dysostosis mandibulofacialis accompanied by malformation of the middle ear ossicles. The patient, a woman aged 21, showed no abnormality in the external canal of the ears but further examination of the tympanic membrane showed the handle of the maleus to be extremely elongated and to be placed in perpendicular position. The patient suffered hearing loss that failed to stand the test of being proved the result of otosclerosis and for which tympano-stapediopexie was performed. It was at the time of this operation that malfarmation of the middle ear ossicles was revealed, Following the operation the patient is watched closely for changes in hearing acuity. Microscopic examination of the bony tissues removed at the time of operation revealed that developmental process in the bones around the attic had prematurely stopped.