Objective:This study aimed to determine the cephalometric association of mandibular size/length to the surface area and dimensions of the frontal and maxillary sinuses.Materials and Methods:This descriptive study was conducted on 116 digital lateral cephalograms of 38 patients with skeletal Class I malocclusion (normal), 40 patients with skeletal Class II malocclusion with mandibular deficiency, and 38 patients with skeletal Class III malocclusion with mandibular excess. Both male and female patients were included. Using AutoCAD 2016 software, the anteroposterior dimension, height and surface area of the frontal and maxillary sinuses, mandibular body length and cephalometric indices including anterior and posterior cranial bases, and growth pattern indices were measured on lateral cephalograms.Results:Dimensions and surface area of the frontal and maxillary sinuses in skeletal Class III malocclusion were greater than those in other groups. These variables were significantly correlated with the mandibular body length. The coefficient for the correlation of height, width, and surface area of the frontal sinus with mandibular body length was 0.253, 0.284, and 0.490, respectively. The coefficient for the correlation of height, length, and surface area of the maxillary sinus with mandibular body length was 0.346, 0.657, and 0.661, respectively. These variables (except for the frontal sinus width) had a significant correlation with the anterior and posterior cranial bases. The frontal sinus width had a significant correlation with the anterior cranial base. These variables in males were greater than those in females.Conclusion:The dimensions and surface area of the frontal and maxillary sinuses in skeletal Class III malocclusion were greater than those in other groups. These variables (except for the frontal sinus width) had a significant correlation with the anterior and posterior cranial bases and mandibular body length.

Context:Better understanding of the anatomical location and course of the mandibular canal is necessary to avoid damaging inferior alveolar nerve.Aims:The aim of this study was to investigate the buccolingual course of the inferior alveolar canal (IAC) in different mental foramen locations, using cone beam computed tomography.Materials and Methods:Three hundred and twelve hemimandibular images were evaluated in this study. The location of mental foramen in relation to the apices of mandibular premolar and molar teeth were recorded. Nine measurements (in millimeters) were taken at the level of the IAC and posterior mandibular premolar and molar root apices. Relative distances of IAC to buccal and lingual mandibular cortex were calculated for different mental foramen types.Statistical Analysis Used:Data were analyzed by one-way analysis of variance and P < 0.05 was considered to be statistically significant.Results:The distribution of subjects according to the type of mental foramen includes: Type 1 = 50.3% (at the level of second premolar apex), Type 2 = 33% (between the apices of first and second premolars), and Type 3 = 16.7% (between the apices of second premolars and first molars). The buccolingual ratio of the IAC position was statistically significant in different mental foramen types (P = 0.00).Conclusion:The position of IAC was affected by the location of the mental foramen. The direction of IAC gradually changed from lingual to buccal and from posterior to anterior.

SummaryBackroundThe frequent anatomical variations of the inferior alveolar nerve (IAN) course should be considered prior to any treatment in this area. The aim of this study was to evaluate the course of the inferior alveolar canal (IAC) as it appears in the archived CBCT images of the mandible.Material/MethodThis cross- sectional study evaluated a sample of 156 CBCT examinations. The pattern of the IAC was evaluated and the prevalence of different patterns according to age and gender were recorded. In order to find the frequency of mandibular canal type among different ages, the patients were put into the three age groups (20–29, 30–44 and 45–59).The data were analyzed using Chi-square test and the significance level was set as p≤.05.ResultsOut of 156 patients, 52 canals was straight type, 52 had Catenary type and 52 of them were presented with Progressive descending type. There was not statistically significant difference between two genders (Pv=0.092). According to the type of the IAC course, there was a not statistically significant difference between the three age groups (Pv=0.32).ConclusionsCone beam computed tomography is a useful method for precise assessment of the IAC course.

The purpose of the present study was to determine the possible relationship between gonial angle size and three mandibular morphometric parameters, namely, panoramic mandibular index (PMI), mandibular cortical width (MCW), and antegonial notch depth (AD), in digital panoramic radiographs. Materials and methods: PMI, MCW, and AD were calculated in digital panoramic radiographs of 370 dentulous adult subjects with a mean age of 44.2 years and a mean number of remaining teeth of 23.49 ± 7.71. The differences between the mean values of measured parameters were compared between males and females, among various age groups, and between subjects with low and high gonial angles (gonial angle of ≤120 and ≥125, respectively). The correlation between gonial angle size, PMI, MCW, and AD was also evaluated. T-test, ANO-VA, and Pearson's correlation test were used for statistical analysis. A P<0.05 was considered as statistically significant. Results: PMI, AD, and MCW(Mandibular Cartical Width) were significantly higher in subjects with low gonial angle (LGA) than those with high gonial angle (HGA). PMI, AD, and MCW were also significantly higher in males than those in females. Significantly negative correlations between the gonial angle and PMI, AD, and MCW were also observed. Conclusion: The mandibular radiomorphometric parameters of PMI, AD, and ACW are related to sex and gonial angle size.