The possible complications of wisdom-tooth removal must be considered, because it is the most common surgical intervention in dental practices. This retrospective study assessed the complications occurring during the removal of 1,562 maxillary wisdom teeth in 1,212 patients. A total of 543 cases of surgical removal and 1,019 cases of non-surgical removal were analyzed. In all cases, a pre-operative panoramic radiograph was taken. Anatomical and clinical parameters were included in the evaluation. 106 complications occurred in 92 patients (5.9%) of the total 1,562 operations. Of these complications, 5.1% were intra-operative and 0.8% postoperative. An oroantral fistula (OAF) was found in 38 cases (2.4%), and alveolar osteitis occurred post-operatively in 6 cases (0.4%). The risk of OAF correlated with increasing patient age (p = 0.0368). Root fractures also increased the risk of OAF. On the basis of the analysis of pre-operative panoramic radiographs, it was shown that radiological projection of the root tips to the sinus floor is a reliable criterion to assess the risk of OAF.