Oro-maxillary, oro-nasal and oro-cutaneous fistulae formation
The presence of a food-containing nasal discharge following exodontia is indicative of an oro-nasal (Fig 8 ) or oro-maxillary (Fig 9 ) communication and likewise the presence of food at a repulsion site indicates the presence of an oro-cutaneous communication. By necessity, repulsion always damages the apical aspect of the alveolus and if the alveolar packing is lost before the damaged alveolar apex has healed, this causes oro-maxillary, oro-nasal or oro-cutaneous tracts that eventually may epithelialise and become fistulae. This is in total contrast to non-repulsion techniques that preserve the alveolus. Damage to the alveolar apex is especially marked when a traditional (large) dental punch is used, and one study showed an 11% prevalence of oro-maxillary or oro-nasal fistulation following repulsion (Carmelloet al . 2020). In contrast, the careful use of a fine punch (e.g., a 5mm diameter Steinmann pin) seldom causes fistulae, especially if inserted through a pre-existing apical draining tract.
When loosening maxillary cheek teeth using the MITT technique, care must be taken that the dental elevator is not punched too far in an apical direction, or at a later stage of MITT, that the drill bit does not penetrate the apex of the alveolus into the overlying sinus or nasal cavity. Greatly varying prevalences of oro-maxillary fistulae have been reported following MITT from 29% (Carmello et al. 2020), 26% (Reichert et al. 2014) to 2% Langeneckert et al. 2015).
For treatment, these tracts need to be lavaged of food and debrided of any epithelial lining. A more robust barrier e.g., an acrylic alveolar prosthesis, can be placed between adjacent teeth to prevent further alveolar food ingress into the alveolus until it heals (Dixon, 2020).