The relationship between pericoronitis, wisdom teeth, putative periodontal pathogens and the host response

To review the literature concerning pericoronitis, in particular the nature of the lesion and its aetiology, what factors may be used to predict if some patients would benefit from early removal of third molars, and if a scoring system can be developed for this purpose. A literature search using PubMed and the facilities of the Dublin Dental Hospital (DDH) library were used to gather the relevent information. PubMed lists all of the journals available in the DDH library and was used to identify relevent papers, which were then retrieved from the shelves and stacks with the help of library staff. The key word used was 'pericoronitis'. The studies reviewed assert that the bacteriology of pericoronitis is predominantly anaerobic in character, yet no causative species has been identified. Marker organisms for periodontitis were not generally isolated. Host factors examined in various studies were the inflammatory markers interleukin 1b and prostaglandin E2, and the immunological responses of neutrophils, macrophages, natural killer cells, T cells, helper T cells and suppressor/cytotoxic T cells. While all of these factors, with the exception of prostaglandin E2, tend to be elevated in cases of pericoronitis, both symptomatic and asymptomatic, no clearcut measurable entity has emerged that can be used as a predictive marker. A hypothesised scoring system to predict which patients would benefit from early removal of asymptomatic impacted lower third molars would be clinically advantageous in justifying prophylactic third molar surgery, but is not yet feasible or proven.