Читать книгу Management of Complications in Oral and Maxillofacial Surgery - Группа авторов - Страница 62

 Etiology: excessive and inappropriate force, patient risk factors

 Management: soft non‐chew diet, closed treatment, open reduction, and internal fixation

Mandibular fracture following third molar surgery is a rare occurrence, and most often associated with deeply impacted third molars in patients over 40 years of age [17]. The reported incidence of mandibular fracture, both intraoperatively and in the postoperative period, ranges from 0.0049% to 0.00003%, with a mean time to fracture ranging from 6.6 to 14 days following surgery according to studies by Iizuka et al. and Krimmel et al., respectively [18, 19]. Fractures occurring up to 28 days following surgery have been reported, and no spontaneous mandible fractures have been reported beyond six weeks after surgery [18, 19]. This time period for the fracture to occur correlates with increased masticatory forces due to decreased trismus, pain, and edema. Libersa et al., in their review of 37 fractures from 750 000 extractions, found that 8 of 10 late fractures occurred in men, with 6 occurring during mastication [17]. Risk factors for fracture include age >40, male sex, advanced atrophy, associated pathology such as cysts or tumors, osteoporosis, full dentition, and bruxism [17–19]. The angle region of the mandible is of particular risk for fracture due to its relatively decreased cross‐sectional area and nearly 90° bend from body to ramus. The presence of a deeply impacted, fully developed third molar can occupy a significant portion of this cross‐sectional area (especially the external oblique ridge) leaving little bone support following surgical extraction of a mandibular third molar [18]. Intraoperative mandibular fracture is almost exclusively due to the application of excessive, or inappropriately directed, forces applied during the third molar surgery. Often, it occurs during the use of dental elevators, combined with the application of heavy pressure beyond, which is typically required to extract the tooth [4]. In patients over 40 years of age presenting with partial bone impactions (loss of the external oblique ridge) and other risk factors, even light forces may induce a mandible fracture [17].

Fig. 2.1. Bilateral nondisplaced mandibular angle fracture following mandibular third molar extractions.

If a fracture occurs during, or after, third molar surgery, it should be managed promptly. Frequently, these immediate fractures are minimally displaced and favorable in nature. Open reduction and internal fixation can be easily accomplished in this region using the Champy monocortical plate and screw fixation technique with tension band plating (Figure 2.1). Alternatively, closed reduction with intermaxillary fixation may be appropriate in certain cases. Regardless of the technique, the complication should be communicated to the patient and/or guardian, and treatment initiated as soon as possible.