Prevalence and Predisposing Factors of Periapical Osteoperiostitis: A Retrospective Cross-Sectional Study.

Periapical Osteoperiostitis (PO) is an inflammatory reaction of the periosteum located on the maxillary sinus floor, characterised by reactionary deposition of bone caused by periradicular disease of the maxillary posterior teeth. Radiographically, PO presents as a radiopaque 'halo' over the involved root(s). There is a gap in the literature regarding the prevalence and predisposing factors of PO. This study aims (1) to evaluate the prevalence of PO in maxillary posterior teeth amongst patients at NYU College of Dentistry, Department of Endodontics, and (2) to identify predisposing factors associated with PO. A chart review and cone-beam computed tomography (CBCT) evaluation were conducted at NYU College of Dentistry from 2016 to 2021. Initially, 586 scans were screened, and 335 scans were included. The presence of PO, mucositis, sinus perforation, age, sex, pulpal and periapical diagnosis, size of the lesion, the vertical and horizontal distance between the sinus floor and roots, number of roots with apical lesions, type of tooth, and iatrogenic errors during treatment were recorded. Data were analysed using chi-square, Fisher's tests and logistic regression. Of the 335 CBCT scans included, 98 scans (29.3%) presented with PO. The presence of mucositis was associated with 3.37 times higher odds of PO than those without mucositis. Each incremental increase in the size of the lesion (CBCTPAI) was associated with a 2.51 increase in the odds of PO occurrence, and the vertical distance between the sinus and roots was statistically significant (p < 0.001). The prevalence of PO in this study was higher than previously reported. Three factors were significantly associated with PO: the presence of mucositis, the size of the lesion, and the vertical distance between the sinus and roots.