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Introduction: Patients who receive ionizing radiation for diagnosis or treatment may suffer side effects in normal tissues. Radioprotective agents have the potential to decrease DNA damage and free radicals produced by ionizing radiation. Green tea is a natural product from the Camellia sinensis plant and have been shown to have antioxidant and radioprotective properties. The aim of the present study is assessing the protective effect of green tea on lymphocytes affected by radiation injury. Material and Methods: Blood samples was obtained from four adults healthy human and lymphocytes were extracted. Afterward, lymphocytes were exposed to X-radiation by OPG, CBCT, CT and radiotherapy instruments. The protective effects of the green tea polyphenol on Bcl-2 and Bax genes expression levels were evaluated in cultured lymphocytes obtained from treated cells (24 h and 1 h before and 1 h after exposure to ionizing radiation) and non-treated cells (Receiving X-radiation and non-receiving green tea). Results: The results of this investigation demonstrated Bax/Bcl-2 ratio, as an index of the radiation sensitivity, was significantly decreased in groups which had been received dose of 2 Gy in treated cells groups of 1 h before and 1 h after X-radiation (p<0.05). Conclusion: The results indicated different effects of green tea on low and high doses of X-radiation. Most protective effects of green tea as an apoptosis inhibitor were observed in high doses of ionizing radiation. Consequently, green tea may be useful as an adjunct to radiotherapy and medical imaging to diminish apoptosis and side effects in normal tissues. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to evaluate the association between temporomandibular joint (TMJ) structure and occlusal support status using computed tomography (CT) images. Methods: In this cross-sectional study, the computed tomography (CT) scans of 90 patients were categorized into six groups based on the number of posterior and anterior occlusal support areas (Eichner classification). In CT images, the articular eminence inclination, and glenoid fossa depth and angle were measured. Furthermore, condylar shape and position, and the presence of condyle-flattering or other pathologic changes were recorded. The TMJ variables were compared between different Eichner classification groups. The data were analyzed by paired samples T-tests, one-way ANOVA, and chi-square test (a=0.05). Results: The loss of posterior occlusal support was associated with TMJ flattening and a posterior condylar position (P<0.001). No significant difference was found in the inclination of the articular eminence and depth of the glenoid fossa between different Eichner groups (P>0.05). In patients with unilateral occlusal support, the TMJ on the edentulous side had a significantly lower articular eminence inclination, a greater angle of the glenoid fossa, and a decreased glenoid fossa depth (P<0.001). Conclusions: Loss of posterior occlusal support may lead to changes in the structure of the glenoid fossa, joint space, and condylar position and cause flattening of the condyle. These changes may predispose the joint to degenerative changes. [ABSTRACT FROM AUTHOR]

Background: Class II malocclusion is one of the most prevalent occlusion discrepancies. Knowledge of growth changes in craniofacial components can help clinicians plan orthodontic treatment, determine the proper timing to initiate the treatment, and predict the treatment outcome, especially in growth modification protocols. This study evaluates craniofacial skeleton changes in class II malocclusion subjects compared to class I malocclusion. Methods: In this cross-sectional study, cephalograms of 858 individuals aged between 7 and 23 were investigated. The samples were divided into the class I group (ANB angle 0–4) and class II group (ANB angle≥4 degrees), including 426 and 432 cephalograms, respectively, and each group was divided into seven subgroups considering age. Cephalometric analysis was performed using OnyxCeph software, and statistical analyses of variance, mean, paired t test, and independent samples t test were performed using SPSS software. Results: The results showed no significant differences between class I and class II groups in variables related to the cranial base and vertical facial height. In class II groups, the SNA angle was significantly greater. The total mandibular height (Co-Gn), facial angle (Npog-FH), and SNB angle were significantly greater in class I compared to the class II group. Conclusion: Protrusion of the maxilla affects the formation of class II malocclusion, but an underdeveloped mandible is the main component of Class II malocclusion formation. With increasing age, especially after puberty, the mandible may become more retruded in class II patients. [ABSTRACT FROM AUTHOR]

Statement of the Problem: Sex determination, using skeletal remains, is of paramount importance in forensic studies. The skull accounts for the most sexual dimorphism after the pelvis. Recent studies have shown that paranasal sinuses are valuable in sex determination and considering the location of the sphenoid sinus, the risk of traumatic injuries to this structure is low. Purpose: The present study aimed to evaluate the morphology of the sphenoid sinus and determine the validity of sphenoid sinus volume (SSV) in sex determination using cone beam computed tomography (CBCT) images. Materials and Method: In this cross-sectional retrospective study, CBCT images of 469 Iranian patients (186 male and 283 female), aged 24-45 years, were selected. The morphology of the sphenoid sinus was recorded. 3D Slicer software (4.10.0) was used to assess SSVs in coronal and axial planes. For data analysis, t-test, chi-square test, and discriminant function analysis (DFA) were performed using predictive analytics software (ver. 18.0). Results: The most common morphology of the sphenoid sinus in both genders was the sellar type (50.5%). SSV was significantly larger in males than in females (p< 0.001). DFA showed that the capability of SSV in sex identification was 86.0% and 92.9% in males and females, respectively. Conclusion: The findings of this study suggest that SSV is a reliable variable in gender discrimination in a northeast Iranian population. However, since the morphology of the sphenoid sinus and sex were independent of each other, the morphology of the sphenoid sinus is not a suitable indicator for sex determination. [ABSTRACT FROM AUTHOR]

Introduction: Gender determination can help establishing a biological profile of the human body remains. Since the pelvic and skull remains are the most unyielding parts of human skeleton, identifying the dead bodies from these two parts would be very useful. After coaxial bone, the skull is the most gender-discriminated portion of the human skeleton. Since no determination study have been reported in Iranian population, present study aimed to determine gender by measuring 12 craniomandibular parameters and provide specific discriminant function scores in a selected population in Mashhad, Iran. Methods: a total of 202 digital lateral cephalograms of healthy adults, (101 males and 101 females) in the age range of 18 to 50 years were selected. 14 cephalometric points were utilized, which enabled tracing of 11 linear measurements and an angle. All cephalometric points and measurements were traced by onyxceph® version 2.6 software. Results: Based on the analyses, among the chosen parameters, facial height (N-Me), mandibular ramus height (AR-Go), mandibular plane (Me-Go), frontal sinus width (FsWd) contributed the most for sexual dimorphism. The discrimination accuracy was 87.6% (84.2% in males and 91.1% in females). All the linear measurements were significantly larger in males except for angular variable which showed no significant difference between the two genders. Conclusion: According to the present findings, cephalometric craniomandibular parameters could be utilized to discriminate the gender of human remains using discriminant function analysis (DFA) in the selected Iranian population. [ABSTRACT FROM AUTHOR]

Objectives: Accurate localization of the inferior alveolar canal (IAC) is extremely important in some dental treatments. Anatomical variation of the canal means that it can be difficult to locate. The purpose of this study was to assess the relationship of the gonial angle (GA) size and IAC position using cone beam computed tomography (CBCT). Materials and Methods: In this in vitro study, 61 dry adult human hemi-mandibles were used. The CBCT scans were taken of all samples and GA was measured on all CBCT scans. The samples were divided into two groups of low angle (≤125°) and high angle (>125°). The canal dimensions, length and course were evaluated. On the sagittal view, the IAC path was classified as type A, B or C. On the axial view, canal course was defined as A1 or A2 according to the mental foramen angle. Results: The average GA size was 121.8±7.05° at the right side and 123.8±6.32° at the left side. On the sagittal view, there was a significant correlation between the GA size and the canal course (P=0.04). In the high-angle group, type A was dominant; whereas in the lowangle group, type B was more common. On the axial view of IAC course, type A1 was more common (73.43%). Conclusion: The results showed that GA size was associated with IAC course. In cases with a larger GA, the canal runs in a more straightforward path, and at the same level as the mental foramen. [ABSTRACT FROM AUTHOR]

Introduction: This study was conducted to determine the pattern of maxillofacial fractures in three age groups of adults, adolescents, and children, using CT scan images. Methods: In this cross-sectional study, CT scan images of 230 patients with maxillofacial trauma during one year were examined in terms of the number and site of fractures. The patients were divided into three age groups, children (0-14 years), adolescents (14-17 years), and adults (>17 years). The data collected from this group were analyzed using, Chi-square, independent t-test and ANOVA statistical tests. Results: The analysis showed that 85% of maxillofacial fractures occur in adults, 7% in adolescents, and 8% in children. The most prevalent causes of fractures in adults were accidents (70%) and fallings (16%). Accidents (73%) and quarrels (13%) were the most prevalent causes of fractures in adolescents. In children, falling (60%) as the most prevalent cause of fracture was significantly higher than that in other groups (P-value=0.001). The most prevalent sites of maxillofacial fracture in adults were nasal bones and zygomaticomaxillary complex. Nasal and orbital fractures in adolescents comprised the most prevalent sites of fracture. Mandibular bone was the most prevalent site of fracture in children. The variations in prevalent sites of fracture among the three groups were significant (P-value=0.002). Conclusion: Car accidents are the main risk factor for maxillofacial fractures. The prevalent causes and sites of maxillofacial fractures in adults, adolescents, and children are different from one another. [ABSTRACT FROM AUTHOR]

Statement of the Problem: Sex determination, using skeletal remains, is of paramount importance in forensic studies. The skull accounts for the most sexual dimorphism after the pelvis. Recent studies have shown that paranasal sinuses are valuable in sex determination and considering the location of the sphenoid sinus, the risk of traumatic injuries to this structure is low., Purpose: The present study aimed to evaluate the morphology of the sphenoid sinus and determine the validity of sphenoid sinus volume (SSV) in sex determination using cone beam computed tomography (CBCT) images., Materials and Method: In this cross-sectional retrospective study, CBCT images of 469 Iranian patients (186 male and 283 female), aged 24-45 years, were selected. The morphology of the sphenoid sinus was recorded. 3D Slicer software (4.10.0) was used to assess SSVs in coronal and axial planes. For data analysis, t-test, chi-square test, and discriminant function analysis (DFA) were performed using predictive analytics software (ver. 18.0)., Results: The most common morphology of the sphenoid sinus in both genders was the sellar type (50.5%). SSV was significantly larger in males than in females ( p < 0.001). DFA showed that the capability of SSV in sex identification was 86.0% and 92.9% in males and females, respectively., Conclusion: The findings of this study suggest that SSV is a reliable variable in gender discrimination in a northeast Iranian population. However, since the morphology of the sphenoid sinus and sex were independent of each other, the morphology of the sphenoid sinus is not a suitable indicator for sex determination., Competing Interests: The authors declare that they have no conflict of interest., (Copyright: © Journal of Dentistry.)

Background: Bilateral Sagittal Split Osteotomy (BSSO) is one of the treatment options for Class III maxillary deficiency which may affect the condylar position and the patient's occlusion. We aimed to evaluate the clinical and radiographic changes of temporomandibular joint (TMJ) following mandibular set back surgery by BSSO., Methods: In this retrospective study, All Class III patients, aged between 18-30 years old who underwent bimaxillary orthognathic surgery in the Oral and Maxillofacial Surgery Ward of Ghaem Hospital, Mashhad, Iran from January 2018- January 2020 were enrolled. Radiographic changes of joint space, condylar position and clinical changes for maximal mouth opening and joint sound were examined before and 6 months after surgery. Data were analyzed by SPSS16 software and the significance level of the data was set at P-value < 0.05., Results: Twenty-five patients were recruited. The axial angle of the left and right condyle and condylar inclination on both sides reduced but this reduction was not statistically significant. While the anterior joint space was reduced and posterior joint space was increased in both sides, the changes on the right side were only significant (P = 0.039). In clinical examinations maximum mouth opening, lateral and protrusive movements were also decreased but this reduction was not statistically significant., Conclusion: The mandibular set back with BSSO surgery in class III skeletal patients had no significant effect on the position of the condyle in the glenoid fossa as well as clinical symptoms., Competing Interests: The authors have no conflict of interests to declare.

Introduction: Maxillary sinuses are among the largest paranasal sinuses with various shapes and volumes. The dimensions and volumes of maxillary sinuses play an important role in the surgical treatment plan. The higher levels of pneumatization of alveolar bone lead to the increase of odontogenic sinusitis which cause problems in dental implantation. Therefore, this study aimed to evaluate the relationship between maxillary sinus volume and pneumatization and anatomical factors., Materials and Methods: In this cross-sectional study, computed tomography (CT) images of the healthy maxillary sinuses of 199 adult patients were reviewed. Amira software was used for the measurement of sinus volume. Sinus pneumatization of the alveolar bone in coronal CT scan images in the posterior teeth areas was measured. Moreover, anatomical variations of the sinonasal region, such as nasal septal deviation, and size of the ostium were measured and recorded. The Kolmogorov-Smirnov test, the t-test, and the Pearson's and Spearman's correlation coefficients were applied for data analysis., Results: According to the obtained results, the mean value of the maxillary sinus volume and the alveolar bone pneumatization were 15.54 mm 3 and 3.54 mm, respectively. The mean value of the maxillary sinus volume was statistically higher among males than females (P<0.001). The prevalence of nasal septal deviation, concha bullosa, and maxillary sinus septa were 14.6%, 14.6% and 6% respectively. There were no association between anatomical factors, including the nasal septal deviation, the size of the ostium, concha bullosa, and maxillary sinus septa and maxillary sinus volume and pneumatization. P-value less than 0.05 was statistically significant., Conclusion: No correlation was observed between the anatomical variations of the sinonasal region and maxillary sinus volume and pneumatization.

Objectives: Accurate localization of the inferior alveolar canal (IAC) is extremely important in some dental treatments. Anatomical variation of the canal means that it can be difficult to locate. The purpose of this study was to assess the relationship of the gonial angle (GA) size and IAC position using cone beam computed tomography (CBCT)., Materials and Methods: In this in vitro study, 61 dry adult human hemi-mandibles were used. The CBCT scans were taken of all samples and GA was measured on all CBCT scans. The samples were divided into two groups of low angle (≤125°) and high angle (>125°). The canal dimensions, length and course were evaluated. On the sagittal view, the IAC path was classified as type A, B or C. On the axial view, canal course was defined as A1 or A2 according to the mental foramen angle., Results: The average GA size was 121.8±7.05° at the right side and 123.8±6.32° at the left side. On the sagittal view, there was a significant correlation between the GA size and the canal course (P=0.04). In the high-angle group, type A was dominant; whereas in the low-angle group, type B was more common. On the axial view of IAC course, type A1 was more common (73.43%)., Conclusion: The results showed that GA size was associated with IAC course. In cases with a larger GA, the canal runs in a more straightforward path, and at the same level as the mental foramen.