Identifying and Managing Extraction Complications

The prevalence of post-extraction problems is strongly related to the exodontia technique [1-5]. The replacement of traditional dental repulsion (under general anaesthesia) and of the standard lateral buccotomy techniques with standing oral extraction and the development of less invasive exodontia techniques for teeth with incomplete clinical crowns, including Steinmann pin repulsion and minimally invasive transbuccal extractions has greatly reduced the overall prevalence of post-extraction problems [2,4,5]. Nevertheless, post-extraction problems can still occur, even following careful extractions by skilled veterinarians [3,4].

Due to the great length (up to 9 cm long) of equine cheek teeth reserve crowns, significant and prolonged mechanical force is required to fully disrupt their periodontal membranes and to deform the alveolar bone to allow their exodontia. Deformation of the dense layer of bone that lines the alveolus (i.e., bundle bone or cribriform plate – radiologically termed the lamina dura (denta)) into the underlying spongy bone may fracture the alveolar bone and/or disrupt the local alveolar bone blood supply. The most common reason for equine cheek teeth exodontia is apical infection of the tooth apex (with infection of the adjacent periodontal membranes and alveolar bone), mainly with anaerobic bacteria. Extraction-related damage to the alveolus can allow more extensive alveolar bone infection by these pathogens to develop. Consequently, post-extraction complications are higher following extraction of teeth with apical infections compared with those with fractures [4].

Individual exodontia techniques can cause specific problems. Repulsion always damages the apical aspect of the alveolus and can predispose to oromaxillary, oronasal or orocutaneous fistulae unless a fine punch (e.g., a Steinmann pin) is used. A repulsion punch can also damage adjacent teeth unless carefully monitored by intraoperative radiography. The minimally invasive transbuccal technique can potentially cause damage to the buccal nerves, facial vasculature and parotid duct as well as to adjacent intraoral structures and the apical aspect of the alveolus.

The most common post-extraction complication is sequestration of segments of alveolar bone with or without alveolar infection and these problems occur more commonly in mandibular compared with maxillary cheek teeth [1-4], possibly related to differences in their blood supply.

Following cheek teeth extraction, the alveolar packing, e.g., polysiloxane or surgical swabs, should be removed about 1 week later, and the alveolus digitally examined to ensure it is lined by smooth developing granulation tissue. Any areas of rough exposed bone can be palpated and if loose, removed digitally or with picks under dental mirror or endoscopic guidance. The alveolus should be gently lavaged and repacked and re-examined 1–2 weeks later (most care is needed following extraction of mandibular teeth with apical infection) for evidence of further sequestration. If the supporting bones are very swollen and the alveolus has obvious infection (usually malodorous), systemic and local antibiotics should be administered. Further examinations including imaging to detect new sequestrate (or uncommonly dental fragments) should be performed until the alveolus has fully granulated.

The presence of exposed, often tan-coloured bone that remains firmly attached to the supporting bone and remains vital more deeply is termed dry ‘socket’. Such alveoli need repeated monitoring and packing and may take many weeks to heal.

The failure of dental sinusitis cases to resolve following exodontia may be related to alveolar damage (as well as to other causes) and such cases should have the affected alveolus examined and managed as above if it contains sequestra or is infected.

The presence of a food-containing nasal discharge is indicative of an oronasal or oromaxillary communication and likewise, the presence of food at a repulsion site indicates the presence of an orocutaneous communication, and if untreated, all of the above may become fistulas. These tracts need to be cleared of food and debrided of epithelium if present. A barrier, e.g. a PMMA plug, can be used to prevent further food ingress into the alveolus until it heals.

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