Incidence and predictive factors for perforation of the maxillary antrum in operations to remove upper wisdom teeth: prospective multicentre study.

BACKGROUND Our aim was to evaluate the incidence of perforations of the sinuses and their related treatment after the removal of upper wisdom teeth depending on various anatomical and clinical variables. MATERIAL AND METHODS A total of 1057 upper wisdom teeth were removed under local anaesthetic in the departments of oral surgery at the Universities of Bonn, Düsseldorf, Frankfurt and Mainz, Germany. Data were collected with the help of an anonymised questionnaire dealing with information about the patients, and the position and stage of the development of teeth, as well as the occurrence and size of an oro-antral communication and its treatment. RESULTS Of 465 extractions and 592 osteotomies of the upper third molars, 134 interventions (13%) were related directly to the diagnosis of a perforated maxillary sinus. Acute oro-antral communication occurred as a result of the removal of completely impacted teeth in 88 of 370, (24%) by removal of partially impacted teeth in 23 of 222 (10%) and in fully erupted third molars in 23 of 465 (5%) of all cases. These differences are significant (p<0.001). In 111 (83%), the diameter of the oro-antral perforation was less than 3mm. In 25 (19%) of all sinus openings, a buccal sliding flap was used to close the extraction wound. We conclude that intraoperative fracture of the root, higher degree of impaction and higher age of the patient are associated with a greater likelihood of oro-antral perforation.