Injuries to the alveolar bone

Alveolar fractures involving a block of alveolar bone, or sometimes the labial and lingual socket walls, usually occur in the anterior or premolar region. The commonest posterior fracture is an iatrogenic fracture of the maxillary tuberosity, which may complicate the extraction of upper molar teeth. As with other facial fractures the treatment of displaced alveolar fractures involves reduction and fixation. Closed reduction of the alveolar segment is usually achieved by finger manipulation and a suitable splint is then applied. Care needs to be taken to avoid displacing loose teeth during the reduction, and any splint used must extend to enough sound teeth to achieve satisfactory immobilization. Open reduction is rarely performed in alveolar fractures unless access is possible as part of the treatment of an underlying jaw fracture.

A rigid wire and composite splint is effective in the anterior region but is more difficult to apply in the posterior maxillary arch. Arch bars and interdental wiring have the drawback of being more traumatic to the gingival tissues and there is a real risk of avulsing loose teeth as the wires are tightened. The individual teeth in the alveolar fragment need to be examined carefully and treated appropriately if damaged. A minor problem with isolated displaced alveolar fractures is that it is sometimes difficult to avoid leaving the teeth slightly 'high' after reduction. This results in premature contact and continuing trauma to the teeth. The occlusion needs to be checked carefully and the bite adjusted if necessary. Occasionally a short period of intermaxillary fixation is a sensible precaution, particularly if the fragment is very mobile.

Comminuted fractures of the alveolus in the incisor area, with or without comminution of associated teeth, usually necessitate the removal of the portions of teeth and alveolus and careful soft-tissue repair of the resulting alveolar defect. The operator should preserve any portions of alveolus which appear to have a chance of survival. Lacerated wounds in the lip should be carefully explored, and any fragments of teeth removed. The edges of the wound are then trimmed if necessary and closure carried out.

Extraction of damaged teeth from a block of fractured alveolus should be avoided if at all possible. Unless a careful surgical technique is used there is a significant risk of tearing the mucosal attachment and avulsing the whole segment. Ideally any extractions of teeth or roots should be delayed for 6-8 weeks when bone healing will be advanced and the mucoperiosteal tissues healthy.

This principle extends to fractures of the tuberosity. This complication occurs because of ankylosis or root bulbosity affecting the maxillary molar teeth. The thin supporting alveolar bone and antral floor fractures on attempted forceps extraction. The operator becomes aware that a whole dento-alveolar block extending to the tuberosity is mobile on moving the tooth. On occasion the palatal mucoperiosteum tears longitudinally as a result of the forcible buccal movement with the extraction forceps. If the tuberosity is completely detached from the periosteum it should be carefully dissected out and the resulting soft-tissue defect sutured to prevent any residual opening into the maxillary sinus.

If the tuberosity, with or without associated teeth, appears to be well attached to the periosteum, it can be left alone with or without splinting. Splinting of a tooth left attached to the fragment and immobilizing it to other standing teeth in the maxilla for 1 month usually results in union. This can be achieved sometimes with a wire and composite splint, but an alternative is to take an impression for a full-coverage palatal acrylic plate extending around the palatal surfaces of the affected teeth. This can be retained by Adams cribs, including one or more on the mobile segment.

If the tooth in the tuberosity fragment requires extraction it should be removed surgically by drilling away the surrounding bone after the tuberosity is firm. If the tooth is painful, this surgical extraction must be carried out earlier, but the chance of saving the tuberosity in such circumstances is greatly reduced.

Fractures extending to the alveolar floor of the maxillary sinus are treated in the same way, depending upon whether the alveolar fragment, together with any associated teeth, is completely detached from the periosteum.

If the alveolus and floor of the antrum are inadvertently removed during the extraction of a tooth a very careful soft-tissue repair of the defect must be carried out immediately, if necessary by advancing a buccal flap. The patient should be given nasal drops of ephedrine 0.5 per cent to help antral drainage and an antibiotic for 5 days to prevent infection leading to breakdown and development of an oro-antral fistula.

6. MATERIALS FOR SELF-CONTROL: