Kenichi Tomitsuka

Aetiology of maxillofacial fracture

The aetiological factors associated with maxillofacial fractures, and the trends in these factors over a 13 year period are reported. The First Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Tokyo Medical and Dental University, managed 695 patients with maxillofacial fractures between 1977 and 1989. The male to female ratio was 3.2:1 and the majority of patients were aged between 10 and 30 years old. Road traffic accidents and accidental falls were the main causes of fractures throughout the 13 year study period. Mandibular fractures occurred in 477 patients (68.6%). A high percentage of patients were treated by closed reduction and maxillo-mandibular fixation, or occlusal splinting.

Maxillofacial fractures in children

A clinico-statistical and long-term follow-up study was performed on 81 pediatric fractures seen during the 14 years between 1977 and 1990. Of all maxillofacial fractures, the incidence of pediatric fractures was 14.7%. The ratio of boys to girls was 2.1:1, and the highest incidence involved boys over 13 years of age. Fractures of the upper alveolar bone and mandible were common. Conservative therapy, such as maxillomandibular fixation using orthodontic brackets was usually performed and was found to be successful. The long-term follow-up study revealed that 5 out of 21 patients with alveolar fractures complained of malocclusion and it is suggested that a longer duration of intramaxillary fixation and long-term follow-up might be needed for alveolar fractures in children.

Basic properties of superelastic Ni-Ti alloy ligature wires for a new intermaxillary fixation method

A new continuous wiring method of intermaxillary fixation with super-elastic Ni-Ti alloy ligature wires was developed to avoid the risk in postoperative emergency. Differential scanning calorimetry, three-point bending tests and fastening tests were carried out to investigate basic properties of the wires. Transformation temperatures of the Ni-Ti alloy wires were in the range suitable for exhibiting super-elasticity at body temperature. The Ni-Ti alloy wires possessed enough bending flexibility to be used in the continuous wiring method and showed great recoverable displacement in the fastening test. With use of these properties, easy removal in an emergency and uniform fixation can be attained.