Alveolar bone infection and osteomyelitis of the supporting bones
The most common indication for equine cheek teeth exodontia is infection of the tooth apex that is usually caused by mixed anaerobic bacterial infections (with concurrent infection of some or all pulp horns, the adjacent periodontal membranes and alveolar bone). Extraction-related damage to the alveolar bone may allow more extensive bone infection by these pathogens to develop. Consequently, post-extraction complications are higher following extractions of apically infected as compared to fractured teeth without clinical apical infection (Kennedy et al.2020) and especially in horses with pars pituitary intermedia dysfunction. Concurrent alveolar sequestration is common with alveolar and supporting bone infections and it may not be possible to determine which came first (Fig 6 ).
If the supporting mandibular or maxillary bones are swollen and painful on palpation, the alveolus is obviously infected and will usually contain malodorous exudate. Systemic and possibly local antibiotic therapy should be administered to such cases along with removal of sequestrae and alveolar lavage. Repeat examinations, even weeks later may show development of new sequestrae that also must be removed. Because many of the bacteria involved in dental infections are partial or full anaerobes and possibly 50% cannot be conventionally cultured, broad-spectrum antimicrobial treatment that is effective for anaerobic infections should be administered to such cases. Further examinations including imaging to assess the degree of bone infection and detect new sequestrae should be performed until the alveolus has complete granulation tissue cover indicating alveolar healing (Fig 7 ).