The mandible is a site that is easily subject to direct external forces, and biting and chewing abnormalities are often recognized due to mandibular fractures. Here, we report the clinical characteristics of cases with mandibular joint protrusion fracture managed in our department, with a review of the literature.
This study included 29 cases （25 unilateral cases and 4 bilateral cases; 33 sides） diagnosed as fracture of the mandibular condyle after undergoing oral surgery at Tokyo Dental College Suidobashi Hospital from January 2018 to March 2021.
The survey items were sex, age, cause of injury, place of injury, medical examination route, number of days until our consultation, fracture site （SORG classification）, mode of fracture （classification described by MacLennan）, treatment, opening amount before and after treatment, and period of interchinular fixation.
The study included 16 men and 13 women with an average age of 49.8 years. The most common cause of injury was falling （23 people）, and most injuries were sustained on the road. In terms of consultation, most referrals （20 people） were from the dental clinic associated with our hospital. There were 16 sides in the condyle neck of the mandibular fracture and 16 sides in the subcondylar area of the mandibular fracture. Displaced fracture was the most common type of fracture, while subcondylar area was the most common form of fracture. The treatment strategies included conservative treatment in seven cases （seven sides）, non-invasive reduction and fixation in 14 cases （16 sides）, and surgical treatment in five cases （seven sides）. All seven cases of invasive reduction and fixation were basilar displaced fractures. Two sides were approached from the oral cavity and five from outside the oral cavity. Among the cases that underwent oral surgery, facial nerve paralysis was observed in two cases. Osteosynthesis was performed using one titanium mini-plate on five sides and two titanium mini-plates on two sides. The opening increased in all cases regardless of the treatment strategy. The average duration of opening restriction was 17.3 days for non-invasive reduction and fixation and 11.8 days for surgery.
This study confirmed that the opening in all cases increased regardless of the treatment strategy. In addition, because there are cases where opening restrictions were difficult due to cases of elapsed time and intellectual disabilities, the study results also reaffirm the importance of selecting an appropriate treatment taking into account the patients’ background.
