Occurrence And Pattern Of Mandibular Fractures Seen At Two Referral Health Facilities In Nairobi, Kenya

Abstract

BACKGROUND: Mandibular fractures are among the most common maxillofacial injuries in Kenya and all over the world. Aetiological factors vary with geographical, socio-economic and demographic variables. They are largely due to road traffic crashes and interpersonal violence. The vulnerable groups include motorcyclists, bicyclists, and pedestrians. This is mainly due to lack of compliance to road safety measures and poor enforcement of traffic laws. Alcohol abuse is one of the key risk factors in road traffic crashes. Few studies have focused on mandibular fractures and associated aetiological factors in Kenya most of which are studied as a subset of maxillofacial injuries in general. No previous local study has subjected mandibular fractures and the aetiological factors to statistical analysis. STUDY OBJECTIVE: To investigate the socio-demographics, aetiology, pattern of occurrence and management of mandibular fractures at two referral health facilities in Nairobi, Kenya. MATERIAL AND METHODS: This was a descriptive retrospective cross-sectional study done at Kenyatta National Teaching and Referral Hospital Department of Dentistry and University of Nairobi Dental Hospital. It comprised records of patients with radiographically confirmed fractures over a 5-year period from June 2014 to May 2019. Data was collected using a researcher administered data collection form. This data was retrieved from the patient’s files and review of the available radiographic investigations. Data collected included age, sex, place of residence, time of injury, alcohol use, aetiology, site and number of fractures, imaging modality, management modality and complications. RESULTS: A total 534 patients’ records were examined with 469 (87.8%) being males and 65 (12.2%) were females giving a male to female ratio of 7.2:1. The overall mean age was 30±11.6 years with an age range of 1 to 74 years. Mandibular fractures were more common in patients in 3rd and 4th decades. Fractures were least common in extreme age groups. Interpersonal violence (IPV) was the leading cause with 42.5%, followed closely by RTC (40.1%) and falls (14.4%). IPV was more common in males (92%) than females (8%). Of the RTCs, 120 (56.1%) patients sustained mandibular fractures from motor cycle accidents whereas 83 (39%) were from motor vehicle crashes. Notably, motor vehicle drivers, motorcycle riders and hand cart pushers combined comprised the largest proportion (n = 92, 43.2%,) of patients involved in RTCs The leading sites of fractures were body (28.2%), parasymphyseal (24.3%) and angle of the mandible (19.9%). There was a statistically significant site predilection of fractures caused by IPV with angle and body commonly affected (p < 0.001). Isolated mandibular fractures occurred in 269 (50.4%) cases whereas 265 (49.6%) fractures presented with other associated injuries. The commonest concomitant injuries were maxillary fractures (14.2%), zygomatic (8.8%) and traumatic brain injuries (8.1%). RTCs were commonly associated with concomitant injuries (𝓧2 = 43.084, p < 0.001). Majority of mandibular fractures (n = 340, 63.7%) were treated by closed reduction (MMF) followed by ORIF (n = 122, 22.8%). Malocclusion was the leading complication (30.8%) followed by mal-union (22%). There was a statistically significant association between sex and alcohol use with more males being affected (𝓧2 = 22.139, p < 0.001). Most of IPV-related mandibular fractures occurred at night (𝓧2 = 38.528, p < 0.001). CONCLUSIONS: Interpersonal violence and road traffic crashes were the leading causes of mandibular fractures in patients seen at the two referral centres in Nairobi, Kenya. Falls were the commonest cause in children. Most fractures occurred in patients in their third and fourth decades. Mandibular fractures occurred seven times more in males than in females. Closed reduction by maxillomandibular fixation (MMF) was the main mode of management of mandibular fractures in two thirds of the patients followed by open reduction and internal fixation (ORIF) in a quarter of the patients. RECOMMENDATIONS: Interventional preventive strategies of mandibular fractures should focus on reduction of interpersonal violence and improvement of road safety especially in regard to motorcycle-related crashes. Young males should be a priority in the public health awareness and prevention campaigns. Open reduction and internal fixation should be made readily available and affordable as an option of treatment for indicated cases. This is due to early return to function, personal convenience, and early return to work and professional engagement. There is need to conduct studies that objectively evaluate BAC in RTC patients reporting prior consumption of alcohol. 1