Variações anatômicas do canal mandibular e forame mentual avaliadas através de tomografia computadorizada de feixes cônicos / Anatomical variations of the mandibular canal and mental foramen measured by cone beam computed tomography

Este estudo investigou as variações anatômicas do canal mandibular (CM) e do forame mentual (FM) em uma população do sul do Brasil utilizando exames de tomografia computadorizada de feixes cônicos (TCFC). Exames de 99 pacientes (198 hemimandíbulas) foram avaliados quanto à presença e localização de canais mandibulares duplos (CMD), presença e extensão de alça anterior do CM, presença de forame mentual acessório (FMA), e a relação entre FMA e CM. Em adição às estatísticas descritivas, o teste de Qui-quadrado e o teste Exato de Fisher compararam a ocorrência de variações anatômicas para cada lado da mandíbula e para o gênero dos pacientes. CMD foram encontrados em 63 hemimandíbulas (32,48%) e a maioria foi classificada como canal vestíbulo-lingual. Alça anterior do CM foi detectada em 14 hemimandíbulas (7%) com comprimento médio de 1,87±0,56 mm. FMA foi encontrado em apenas duas hemimandíbulas (1,1%) e um FMA estava em relação com o CM. O teste de Qui-quadrado não mostrou relação entre variações anatômicas e lado da mandíbula. Entretanto, a presença de CMD foi relacionada de forma estatisticamente significativa com o gênero masculino. CMD foi observado em um percentual significativo da população estudada e ocorreu mais em homens. Entretanto, outras variações anatômicas avaliadas através de TCFC não foram associadas de forma significativa com nenhuma outra variável abordada, sugerindo que essas variações não são prevalentes na população estudada (AU).

This study investigated the anatomical variations of the mandibular canal (MC) and mental foramen (MF) in a southern Brazilian population using cone beam computed tomography (CBCT). Exams of 99 patients (198 hemimandibles) were evaluated for the presence and location of double mandibular canals (DMC), the presence and extent of MC anterior loops, the presence of an accessory mental foramen (AMF), and the relationship between the AMF and the MC. In addition to descriptive statistics, Chi-squared and Fisher's exact tests compared the occurrence of anatomical variations to each side of the mandible and the gender of patients. DMC was found in 63 hemimandibles (32.48%) and most was classified as buccolingual canals. Anterior loops were detected in 14 hemimandibles (7%) and they averaged 1.87±0.56 mm in length. AMFs were found in only 2 hemimandibles (1.1%) and one AMF was related to the MC. Chi-square tests showed no relationship between the anatomical variations and the side of the mandible. However, DMC was significantly more common in men. DMC was observed in a significant percentage of the population and they occurred more frequently in men. However, others anatomical variations evaluated by CBCT were not significantly associated with any characteristic of the study population, suggesting that these are not prevalent variations in southern Brazilians (AU).

Location and negotiability of second mesiobuccal canal in upper molar by tomographic and anatomical macroscopic analysis.

PURPOSE: The aim of this study was to assess the presence and negotiability of second mesiobuccal (MB2) canal at pulp chamber, cervical, medium and apical levels comparing the findings obtained by anatomical evaluation with cone-beam computed tomography (CBCT) images. METHODS: 56 and 43 human maxillary first and second upper molars, respectively, were assessed. The specimens were placed on an acrylic platform in a stationary position to identify the presence of MB2 canal at the pulp chamber floor, cervical, medium, and apical level. The samples were analyzed using two image acquisition softwares (XoranCat and DentalSlice) and subsequently by macroscopic anatomical analysis with a 4× magnifying glass. All data were summarized, and mean values, frequencies, and percentage values were calculated for each group of specimens. RESULTS: DentalSlice and XoranCat images of first molars showed a rate concordance index (CI) of present MB2 canals in comparison to anatomic evaluations of 65.2 and 70.1%, respectively. On the second molars, the rate of CI reached about 80 % in both sets of images. In the first molars, 29.9% of canals localized by XoranCat images did not display anatomical negotiability; 34.8% of canals localized by DentalSlice images did not display anatomical negotiability. Among second molars, 18.6% of canals localized by XoranCat did not display anatomical negotiability; 19.8% of canals localized by DentalSlice did not display anatomical negotiability. On the first molars with anatomical negotiability, errors not identified by XoranCat and DentalSlice reached rates of 22.3 and 25.4%, respectively. Among second molars, error rates were 8.7% (XoranCat) and 11.6% (DentalSlice). CONCLUSION: Our study indicated that (1) the tomographic image is an auxiliary way to detection and mapping of the MB2 canal in maxillary molars, (2) the tomographic image is ineffective in determining negotiability. Both image software packages used in this study showed similar results.