RESUMO
The present study correlated the mineralization of third molars to chronological age using a modified classification based on Demirjian's stages in a Brazilian subpopulation and compared with the original classification. A total of 1082 patients with age ranging from 6 to 26 years were included in the sample, with at least one third molar on panoramic radiographs. The third molars were classified according to the original Demirjian classification (8 stages) and a new model based on the Demirjian method, where the original stages were grouped into four stages: AB-enamel mineralization; CD-crown dentin mineralization; EFG-root formation; and H-complete development. Statistical analyses were performed by Kruskal-Wallis/Dunn tests (α = 0.05) and the multinomial logistic regression model. Data were analyzed according to percentiles for the probability of an individual being over 18 years old. The mean ages of the stages in both classifications did not present a significant difference between superior and inferior arches (p < 0.05). The differences in mean ages between all the stages of mineralization were statistically significant (p < 0.001) only for the 4-stage classification. Males attained root formation and complete formation earlier than females (p < 0.05) in the 4-stage classification. The modified classification system showed dependence between chronological age and mineralization stages of third molars, simplifying the age estimation process. At stage H, females present a 95.7% chance of being over 18, while for males, this probability is 89.6%. This modified classification system simplifies the dental age estimation process based on third molars and can be used as a reference for future studies.
Assuntos
Determinação da Idade pelos Dentes/métodos , Dente Serotino/crescimento & desenvolvimento , Calcificação de Dente , Adolescente , Adulto , Brasil/epidemiologia , Criança , Fenômenos Fisiológicos Dentários , Feminino , Humanos , Masculino , Radiografia Panorâmica , Adulto JovemRESUMO
AIM: To assess the influence of artefacts generated by metal posts on the detection of simulated internal root resorption (IRR) in adjacent teeth using cone-beam computed tomography (CBCT) and to verify the impact of metal artefact reduction (MAR) on these cases. METHODOLOGY: CBCT images of 14 premolar teeth were acquired before and after IRR simulation using chemical and mechanical procedures, in an OP300 Maxio unit, with and without MAR. Each tooth was placed in the socket of a human mandible and scanned under three different conditions: (i) without adjacent teeth - control group; (ii) distal adjacent tooth restored with metal post; and (iii) with both adjacent teeth restored with metal post. Five oral radiologists scored the IRR detection using a 5-point scale. Diagnostic values were obtained for the tested groups and compared using two-way analysis of variance (α = 0.05). RESULTS: The presence of a single adjacent tooth restored with metal post did not significantly influence the diagnostic values for IRR detection (P > 0.05). The presence of both adjacent teeth with metal posts, without MAR application, was associated with a significantly lower area under the ROC curve (Az) compared to the control (P = 0.0182). In this case, the application of MAR increased Az, leading to nonsignificant differences from the control group and the group with one adjacent restored tooth (P > 0.05). Sensitivity decreased significantly when two adjacent restored teeth were present, regardless of MAR application (P = 0.0379). Specificity was not affected by the conditions tested (P > 0.05). CONCLUSION: CBCT detection of IRR was impaired by artefacts only when both adjacent teeth restored with metal posts were present. In such cases, activation of MAR improved the performance on this diagnostic task.
Assuntos
Reabsorção da Raiz , Tomografia Computadorizada de Feixe Cônico Espiral , Fraturas dos Dentes , Tomografia Computadorizada de Feixe Cônico , Humanos , Metais , Raiz DentáriaRESUMO
AIM: To assess the influence of artefacts, the metal artefact reduction (MAR) tool and kilovoltage (kVp) on the diagnosis of simulated external root resorption (ERR) in teeth close and distant to zirconium implants in cone beam computed tomography (CBCT) images. METHODOLOGY: Cavities (0.62 mm in diameter and 0.19 mm deep) were created in the apical thirds of 12 roots on the buccal, lingual, distal or mesial surface; ten roots served as controls. The roots were randomly positioned in the first and second right and left premolar sockets of a dry human mandible, and a zirconium implant was placed in the socket of the first right molar. A ProMax 3D unit varying kVp (70, 80, or 90 kVp) and with the MAR tool activated or not was used to obtain CBCT scans. Five examiners evaluated all images to determine the area under the receiver operating characteristic (ROC) curve, sensitivity and specificity. RESULTS: The ROC values and sensitivity were not affected by MAR or artefacts regardless of the distance to the implant (P > 0.05), whilst increasing kVp from 70 to 90 led to a significant increase in these values (P = 0.0202 and 0.0199, respectively). Specificity was not affected by the factors studied (P > 0.05). CONCLUSIONS: Amongst the factors studied, only kVp influenced the diagnosis of simulated external root resorption in CBCT images. Increasing kVp from 70 to 90 improved the accuracy in diagnosing the simulated lesions.
Assuntos
Reabsorção da Raiz , Artefatos , Tomografia Computadorizada de Feixe Cônico , Humanos , Mandíbula , Raiz Dentária , ZircônioRESUMO
BACKGROUND: Hepatic artery thrombosis (HAT) is a serious complication after orthotopic liver transplantation (OLT) and remains a significant cause of graft loss. HAT following OLT has been reported in 3% to 9% of patients. Among the surgical factors considered to be associated with HAT, arterial reconstruction might be the most important. The goal of this study was to compare the incidence of HAT between interrupted suture (IS) and continuous suture (CS) techniques during hepatic artery reconstruction in liver transplantation. METHODS: We performed a retrospective analysis of 200 consecutive liver transplantations occurring between May 2002 and December 2006, including medical records for: age, gender, cold ischemic time, warm ischemic time, type and number of arterial anastomosis. Hepatic artery anastomoses were performed using a 7-0 prolene with a running CS in the first 105 patients (CS group), and with an IS in the last 95 patients (IS group). RESULTS: Statistical analysis of age, gender, cold and warm ischemia time, and number of hepatic artery anastomoses was not different between the CS and IS groups. Eleven episodes of HAT were identified in the CS group (10%) and two episodes (2%) in the IS cohort, a significant difference (P = .0173). CONCLUSIONS: Our results suggested that IS might be a better choice for hepatic artery anastomosis with a lower incidence of HAT.