Patients and methods

This research was approved by the Ethical Committee for Human Research, School of Dentistry of Ribeirao Preto, University of Sao Paulo, Brazil (Project n° 2006.1.841.58.4), and written informed consent was obtained from all subjects in the study.

There were 700 files of patients with facial trauma who had been treated between August 2002 and December 2005. In 126 patient files, 201 mandibular fractures associated, or not, with other facial bone fractures were found.

Data were collected regarding gender, age, race, date of trauma, date of surgery, addictions, dentition, oral hygiene condition, etiology, signs and symptoms, fracture area, treatment performed, date of hospital discharge, and drug therapy. Complications such as suture dehiscence, malocclusion, infection, nonunion, and presence of scars were recorded.

All patients were treated by the same oral and maxillofacial surgeon. When each patient arrived at the hospital for the first medical appointment, all dentate and some partially dentate subjects who presented with mandibular fractures in the body mandible, parasymphysis, and symphysis, were treated initially with a dental splint for reapproximation and immobilization of fractures. A circumdental stainless-steel wire was used on at least two stable teeth on each side of the fracture to achieve immobilization. The RIF technique was used in all surgical treatments, and intermaxillary fixation (IMF) was not necessary beyond the intraoperative period. Fixation of mandibular fractures was performed using 1.5-mm, 2.0-mm, 2.4-mm or 2.7-mm fixation systems (MDT Industria e Comercio de Implantes Ortopedicos, Rio Claro, São Paulo, Brazil). A single fixation system was used for each patient, except in a few specific cases. None of the cases was treated exclusively using IMF as a method of fracture treatment.

Antero-posterior, lateral-oblique, submental-vertex, and Towne radiographs of the mandible were carried out to determine fracture diagnosis. Immediate preoperative and postoperative radiographs of all patients were taken for fracture assessment.

Initial radiographs were necessary for preoperative evaluation and establishment of a treatment plan. The postoperative radiographs were used to check fracture reduction and the position of plates and screws. Radiographs were also used for long-term follow-up. All patients were asked to return for post-surgery clinical evaluations. Follow-up visits were scheduled weekly up to one month post-surgery and monthly thereafter.

Results

Mandibular fractures occurred in 100 male patients (79%) and 26 female patients (21%), resulting in a male:female ratio of 4:1. Of these 126 patients, there were 88 Caucasian patients (70%), 30 mixed race patients (24%), and 8 Afro-Brazilian patients (6%). Their ages ranged from 2 to 81 years; patients 21–30 years were affected most frequently ( Fig. 1 ).

Distribution of patients’ age.

Of the 126 patients, 50 (40%) received their first treatment on the same day as the injury, whereas the remaining 76 (60%) received their first treatment an average of 3.8 days after the trauma. The mean time between trauma and surgery was 5.4 days, although most patients underwent treatment within 2–4 days after injury ( Fig. 2 ). The mean time between surgery and hospital discharge was 1.1 days.

Period between trauma and surgery.

At least one social risk factor at the time of the maxillofacial trauma was found in 48% of the patients. Smoking was observed in 17 patients (14%), alcohol abuse was observed in 18 patients (14%), and both risks were observed in 20 patients (16%). Two patients (2%) reported use of nonintravenous drugs, smoking, and alcoholic drinks, while two patients (2%) reported use of nonintravenous drugs and smoking, and one patient (1%) reported use of only nonintravenous drugs.

Pain was reported by 114 subjects (91%), 98 (78%) reported changed dental occlusion and 35 (28%) reported mental nerve paresthesia. Two subjects reported no symptoms, and in another two files, this information was missing.

The distribution of signs of mandibular fractures in this sample is shown in Table 1 . The most common sign was facial swelling (74%), followed by limitation of mouth opening (55%) and malocclusion (48%). There was only one case of otorrhea (1%).

The etiology most frequently observed in this study was traffic accidents, which affected 59 patients (47%) ( Fig. 3 ). Fifteen patients (12%) suffered car accidents, 25 (20%) motorcycle accidents, 18 (14%) bicycle accidents, and one (1%) was hit by a car. Of 15 car accident victims, 12 (80%) were wearing seat belts. All motorcyclists were wearing a helmet during the accident; 22 (88%) of these helmets were open helmets and that the remaining 3 (12%) were closed. Two patients had been kicked by a horse, and another two had their mandibles fractured during tooth extraction and were classified as ‘other’ etiology.

Distribution of trauma etiologies.

The distribution of the 201 mandibular fracture sites is shown in Table 2 . The most common fracture site was the condyle (28%), followed by the body (25%) and the symphysis and parasymphysis (22%). There was a slight side predilection in the condyle and angle sites.

Several maxillofacial fractures were associated with mandibular fractures. The distribution of other maxillofacial fractures associated with mandibular fracture is shown in Table 3 .

Classification of the fractures revealed that 119 (59%) were open and 82 (41%) were closed fractures. 159 (79%) were simple fractures, while 38 (19%) were multiple, and 4 (2%) were incomplete fractures. The incomplete fractures occurred in the angle and body mandible areas.

For surgical treatment, general anesthesia was used in 103 patients (82%). 21 patients (17%) in the sample were treated as outpatients. Among the outpatients, 17 (14%) underwent a non-surgical treatment consisting solely of a soft diet therapy, physiotherapy, and clinical follow-up until complete recovery, without the use of RIF or IMF. Three patients (2%) underwent a surgical treatment under local anesthesia with a mixture of nitrous oxide and oxygen, and one patient (1%) received only a treatment under local anesthesia because their health insurance did not approve treatment under general anesthesia. These four cases comprised simple fractures in the angle, body, symphysis, and parasymphysis mandible. These patients were treated with surgery and RIF system devices in order to keep the fracture stable.

94 fractures (60%) were treated using the intraoral approach, 52 (33%) using the extraoral and 12 (8%) using the transoral approach.

Fractures in the symphysis and parasymphysis were always stabilized using two plates through an intraoral approach. The same pattern of treatment was used for body fractures; but the extraoral approach was used in a few cases (e.g. complex fractures).

For fractures in the mandibular angle, the treatment of choice was to apply one plate through the intraoral approach. In unfavorable fractures two plates were applied through the transoral approach in order to stabilize the bone fragments.

Fractures in the ramus mandible were treated using two plates using an extraoral approach. Coronoid fracture treatment consisted of the removal of the fragment containing the coronoid process.

For condylar fractures, both surgical and non-surgical treatments were applied. The surgical treatments were applied in adult patients who had occlusion changes and subcondylar fractures, as classified by L indhal . In cases where surgery was indicated, the extraoral approach was used. Non-surgical therapy was the treatment of choice in children and in adults with condylar head fractures with stable occlusion. The non-surgical treatment consisted of clinical follow-up, 2 weeks of a soft diet, and physiotherapy until recovery of the normal mandibular function was achieved. Of the 57 condylar fractures, 13 non-surgical treatments were applied.

284 plates were used in the treatment of the mandibular fractures. The fixation system most commonly used was the 2.0-mm system, accounting for 252 plates (89%), followed by 21 plates (7%) from the 2.7-mm system, 6 plates (2%) from the 2.4-mm system, and 5 plates (2%) from the 1.5-mm system. The 1.5-mm system was never used alone and was always combined with other systems in order to improve bone fragment stability.

With the exception of fractures in the angle, in most cases two plates were used as a bone fixation technique. The plate positioned on the tension band of the fracture was fastened monocortically, while the plate positioned on the compression band was fastened bicortically.

In this study, antibiotic therapy was applied during the preoperative period only in cases with multiple mandibular fractures, extensive lacerations, and association with non-facial fractures. Prophylactic antibiotic therapy was applied in all cases, starting at the beginning of surgery during the intraoperative period. Antibiotics were not routinely administered in the postoperative period. Antibiotics were prescribed in the postoperative period in the same cases that received antibiotics during the preoperative period and when the surgical treatment was performed more than one week after the day of injury. 66 patients (52%) did not receive antibiotic therapy during the postoperative period, while the remaining 60 (48%) did.

Sensorial mental nerve dysfunction was the most common transient complication, affecting 28 patients (23%), of whom 11 (9%) had this complication on the right side, 11 had it on the left side (9%), and 6 patients (5%) were affected on both sides.

Infection was observed in 10 patients (8%); 8 male and 2 female. By cross-checking the data collected on infection and etiology, it was observed that 4 cases (40%) of violence and 6 cases (60%) of traffic accidents developed infection.

A salivary fistula occurred in one patient (1%). Postoperative evaluation was lacking for 10 patients (8%) because they did not return for follow-up evaluation.