A Case of Surgical Correction of Micrognathia by the Horizontal Sliding Osteotomy in the Mandibular Body

This is to report a surgical correction of the small lower jaw in a child. The ll-yr-old girl had sufferred from micrognathic facial disfigurement forming bird-shape chin. The rcentgenologic exam disclosed hypoplastic ascending ramus & condyle of the Rt. mandible. The early arrest of the mandibular growth might be induced by infection or trauma of the temporomandibular joint within 5years after birth. The orthognathic surgery in a child bas been usually delayed until the completion of bone growth, and the handicapped child should have been patient of impaired jaw function and unfaborable appearance. In this case, the horizontal sliding osteotomy in the mandibular body was attempted to lengthen the body and to move the chin forwardly. Reporting this case with review of literature, the following points may be noted; 1. The horizontal osteotomy in ther mandibular body could be approached intra-orally without extensive hemorrhage or neurologic complications. 2. circum-mandibular wiring was of value to immobilize the bony segments, without any interference of masticcatory or phonetic function during the bone healing. 3. The occlusion and opening of the jaw were not disturbed by this procedure and the appositional further growth could be expected. 4. The sliding reposition of the inferior body lengthened the mandible as long as 10mm and extened the facial height as high as 4mm in vertical direction. Therefore, the augmentaion surgery of the mandibular body may not be abandoned until the complete growth of the jaw.