Avaliação tridimensional de terceiros molares superiores impactados: um estudo tomográfico sobre a angulação, o nível de impacção e as alterações pós-operatórias na mucosa e na parede do seio maxilar

Abstract

One of the complications arising from the removal of impacted maxillary third molars (IMTM) is the injury of bone structures such as the perforation of maxillary sinus floor. Oroantral communication can lead maxillary sinus infection resulting in acute or chronic sinusitis. The aim of this study was to determine, throught CBCT images, the frequency of the angular position and the impaction level of IMTM based on a new classification, and to evaluate mucosa changes and the cortical bone of the maxillary sinus in CBCT post operative. Three hundred CBCT images of IMTM were assessed from the radiological database of FO/UFJF. Seventy out of the 300 IMTM undergoing dental extraction in Maxillofacial Surgery Clinic were evaluated by postoperative CBCT. The data were submitted to descriptive analysis and association tests. The average age was 23.74 years in the 300 sample. The most frequent positions were classified as low (n = 124), vertical (n = 184) and vestibular (n = 222). The comparison between ages showed significant difference for both classification of the level of impaction and classification of the mesiodistal angulation. For the association between each of the ratings there was a significant association between all intersections. A total of 70 extracted IMTM, the average age was 22.54 years. The most frequent positions were classified as buccal (n = 50), vertical (n = 44) and high (n = 35). The sinus mucosa presented alterations in 50% of the sample. A cortical disruption of the occurrence of the maxillary sinus in 30% of the sample was observed. The association between these events and classifications of IMTM was not significant and the association between changes in mucosa and the cortical disruption of the maxillary sinus was statistically significant (p = 0.014). CBCT provides exams that evaluates IMTM tridimensionally showing the real position of the tooth and helps in the diagnosis and planning of surgical removal of the IMTM. Despite of the low expectation of the occurance of severe adverse events during the removal of IMTM, some cases may have complicanting predictive variables and CBCT is the main tool for identifying factors that predispose surgical complications.