Читать книгу Management of Complications in Oral and Maxillofacial Surgery - Группа авторов - Страница 66

 Etiology: excessive force, patient anatomy

 Management: removal of devitalized bone, maintain bone with attached periosteal blood supply, separate teeth from bone, fixation of fractured bone

During the process of third molar extraction, and more specifically maxillary third molar extraction, the surrounding bone is at risk for inadvertent fracture. The most likely places for bone to fracture during removal of maxillary third molars are the buccal cortical plate and maxillary tuberosity. The incidence of maxillary tuberosity fracture in association with third molar extraction is approximately 0.6% and is most often caused by excessive force with forceps or elevators. The combination of type IV bone, no distal support, and often significant space involvement by the maxillary sinus all contribute to the potential for a tuberosity fracture [3, 22] (Figure 2.4).

Maxillary tuberosity fracture, or buccal cortical plate fracture, can compromise future prosthetic rehabilitation as the maxillary tuberosity is an important anatomical retention point for complete dentures. Buccal plate fracture can lead to soft tissue tearing and irregular remaining alveolar bone. To avoid these complications, the surgeon should ensure appropriate force application and remove bone in a controlled fashion when excessive force is necessary for extraction. In addition, placement of a periosteal elevator distal to the third molar to elevate the tooth and separate it from the periodontal ligament and tuberosity can assist the surgeon in avoidance of tuberosity fracture.

When a fracture of the buccal cortical plate occurs, the surgeon should assess the stability, size, and soft tissue attachment (periosteum) of the fractured segment. In general, if the periosteum is intact on the fractured bone segment, consideration should be given toward maintaining the bone segment, but if the periosteum is detached, the bone segment is a “nonvascularized” segment of bone, and the surgeon must weigh the risks and benefits of maintaining a devitalized bone fragment based upon its size, the magnitude of the defect, and the amount of soft tissue available to support the bone segment if maintained. If the surgeon has been supporting the alveolus with finger pressure during extraction, early cortical plate fracture can be assessed. At this point, the cortical plate should be dissected free from the tooth with an elevator or other sharp instrument while the tooth is stabilized with forceps. Once the bone and soft tissue are dissected free, the tooth is extracted and the tissues approximated and secured with sutures. If a soft tissue flap is reflected from bone, the blood supply to the segment has been compromised, and if not removed, that segment will become necrotic. Maxillary tuberosity fractures should be treated in a similar manner. Once recognized, the fractured segment should be dissected free from the tooth. Using a handpiece, the bone segment can be separated from the tooth and the roots sectioned to allow for atraumatic extraction. If adequate soft tissue attachment (periosteum) remains, the tuberosity is stabilized through good soft tissue closure with sutures. In the event that the tuberosity cannot be dissected free from the tooth, the primary reason for extraction should be reevaluated. If asymptomatic, the tooth and attached tuberosity segment can be fixated for six to eight weeks via arch bar or orthodontic fixation followed by surgical extraction with controlled bone removal and tooth sectioning on a later date. If symptomatic, the tooth must be extracted, and in doing so, the tuberosity will be removed. The remaining bone should be smoothened and the soft tissues should be approximated with sutures. The overall goal of treatment in tuberosity fractures is to maintain the bone in place unless its removal is deemed absolutely necessary [3, 22].

Fig. 2.4. Fractured tuberosity with extraction of second molar.