BackgroundSocio-economic factors are considered as main determinants causing disparities in oral health across different countries. The aim of the present study was to investigate the associations of social and economic factors with dental caries experience among 6- and 12-year-old Iranian children.MethodsIn this cross-sectional study, a total of 31,146 students, aged 6 and 12 years old, were enrolled from all (31) provinces in Iran. Based on the standardized World Health Organization (WHO) criteria for oral health surveys, dental caries indices in primary and permanent teeth were assessed by clinical examination in schools. Data on socio-economic status was obtained from the modified WHO questionnaire and national data bank. The decayed, missing and filled teeth (dmft/DMFT) indices for primary and permanent dentition were compared at the individual and provincial levels using multilevel regression analysis. Poisson regression analysis was used to evaluate the association of social (demographic and behavioral) determinants with dental caries indices among individuals. To assess the causes of difference in dental caries indices across provinces, justifiable economic factors were also analyzed using poisson regression analysis.ResultsThe mean (SE) of dmft and DMFT were 5.84 (0.05) and 1.84 (0.03), for 6-and 12-year-old children, respectively. The differences of dental caries indices were statistically significant among provinces. Higher level of parental education was negatively related to dental caries indices of both age groups. Rural residency was positively and dental flossing was reversely associated with dmft index of 6-year-old children. Negative associations were found between frequency of tooth brushing and preventive dental utilization with dmft and DMFT indices. Gross Domestic Product (GDP) index had negative and Consumer Price Index (CPI) had positive associations with dmft and DMFT indices in both age groups. However, positive relationships were observed between Gini index with DMFT index among 12-year-old children; as well as between the number of dentists per capita with dmft index among 6-year-old children.ConclusionSocio-demographic and behavioral factors were found to be associated with dental caries experience. However, economic indicators had the greatest importance.

PurposeThis study assessed the accuracy of linear and angular measurements on panoramic radiographs taken at different positions in vitro.Materials and MethodsTwo acrylic models were fabricated from a cast with normal occlusion. Straight and 75° mesially and lingually angulated pins were placed, and standardized panoramic radiographs were taken at standard position, at an 8° downward tilt of the occlusal plane compared to the standard position, at an 8° upward tilt of the anterior occlusal plane, and at a 10° downward tilt of the right and left sides of the model. On the radiographs, the length of the pins above (crown) and below (root) the occlusal plane, total pin length, crown-to-root ratio, and angulation of pins relative to the occlusal plane were calculated. The data were subjected to repeated measures ANOVA and LSD multiple comparisons tests.ResultsSignificant differences were noted between the radiographic measurements and true values in different positions on both models with linear (P<0.001) and those with angulated pins (P<0.005). No statistically significant differences were observed between the angular measurements and baselines of the natural head posture at different positions for the linear and angulated pins.ConclusionAngular measurements on panoramic radiographs were sufficiently accurate and changes in the position of the occlusal plane equal to or less than 10° had no significant effect on them. Some variations could exist in the pin positioning (head positioning), and they were tolerable while taking panoramic radiographs. Linear measurements showed the least errors in the standard position and 8° upward tilt of the anterior part of the occlusal plane compared to other positions.

Background This study aimed to assess the diagnostic accuracy of cone beam computed tomography (CBCT) and quantitatively evaluate the morphology of mandibular first molars using CBCT. Material and Methods Twenty-four double-rooted mandibular first molars were evaluated by NewTom VGi CBCT. The distance from the furcation and apex to the cementoenamel junction (CEJ), diameter and thickness of canal walls, the buccolingual (BL) to mesiodistal (MD) ratio (ΔD), prevalence of oval canals at different sections and taper of the canals were all determined. In order to assess the diagnostic accuracy of CBCT, distance from the furcation and apex to the CEJ and thickness of canal walls at the CEJ and apex were compared with the gold standard values (caliper and stereomicroscope). Statistical analyses were carried out using intraclass correlation coefficient (ICC), paired t-test and repeated measures ANOVA. Results A high correlation existed between the CBCT and gold standard measurements (P<0.001). In dimensional measurements, length of mesial root was higher than the distal root and lingual furcation was farther from the CEJ than the buccal furcation (P<0.001). An important finding of this study was the mesiodistal taper of the mesiobuccal (MB) and mesiolingual (ML) canals; which was equal to 0.02. Conclusions CBCT has acceptable diagnostic accuracy for measurement of canal wall thickness. Cleaning and shaping of the canals should be performed based on the unique anatomy of the respective canal; which necessitates the use of advanced imaging techniques for thorough assessment of root canal anatomy in a clinical setting. Key words:Permanent mandibular first molar, accuracy, cone-beam computed tomography, dimensional measurement.

Background. The choice between reducing the bone height and inserting a shorter implant with a greater diameter or a longer and narrower implant without altering the bone height is a challenge in clinical practice. Objectives. The purpose of this finite element analysis (FEA) was to compare the pattern and level of stress around implants with different lengths and diameters and with different amounts of bone loss, which changes the implant-crown ratio over time, depending on the available bone and the treatment modality. Material and methods. The FEA was carried out to evaluate the stress distribution in bone around 3.25 × 13 mm and 4 × 11 mm 3i implants, and 3.3 × 12 mm and 4.1 × 10 mm Straumann ® implants. A 3D segment of the mandible was reconstructed from a computed tomography image of the posterior mandible. Occlusal force was simulated by applying 200 N vertical and 40 N horizontal loads to the occlusal node at the center of the abutment. The pattern of stress distribution in bone was evaluated in 10 models for each implant, representing 0-9 mm of bone resorption. Results. The results showed that along with decreasing the implant insertion depth, and consequently the implant-crown ratio, the amount of stress in bone increased. The amount of stress increased with an increase in depth of bone loss in all models, but there was no significant change in the amount of stress in the first several millimeters of bone loss. Conclusions. The results suggest that in terms of stress distribution, it is better to reduce the bone height and insert shorter implants with a greater diameter than longer implants with a smaller diameter.

Carpal tunnel syndrome (CTS) is one of the reasons for labor abandonment due to inability and pain. The aim of this study was to evaluate the effectiveness of gabapentin and exercise training in the treatment of CTS and compare their effects. This single-blind clinical trial was conducted on patients referred to the Imam Hossein hospital’s electrodiagnostic (EDX) unit. The patients randomly assigned into four groups: using nocturnal splint as an approved treatment in the control group; taking 300-mg gabapentin per night and using nocturnal splint; nerve and tendon gliding exercises and using nocturnal splint; and taking 300-mg gabapentin per night, performing same exercise as group 3 and using nocturnal splint. At baseline, four indicators were assessed in all patients, including the Boston carpal tunnel questionnaire, visual analogue scale (VAS), pinch and grip strength of the affected hand. One month after the beginning of intervention, participants were reassessed and compared for each of the four indicators. Using nocturnal splint along with exercise and gabapentin significantly improved VAS, pinch and grip strength in moderate CTS compared to control group that only used nocturnal splint. However in mild CTS, grip strength was not significantly higher compared to control group (P=0.048). Results of this study showed that use of splint alone in mild CTS is an appropriate and sufficient treatment; however, in moderate CTS, receiving gabapentin along with exercise and splinting showed better treatment results compared to splinting alone.

Objective: The aim was to evaluate the survival time and success rates of dental implants in warfare victims and factors that affect implant success. Subjects and Methods: This retrospective study involved 250 Iranian warfare victims who received dental implants from 2003 to 2013. Patients' demographic characteristics, as well as the brand, diameter, length, location and failure rate of the implants were retrieved from patients' dental records and radiographs. The associations between these data and the survival rate were analyzed. Statistical analysis was carried out with χ² and log-rank tests. Results: Overall, out of the 1,533 dental implants, 61 (4%) failed. The maxillary canine area had the highest failure rate [9 of 132 implants (6.8%)], while the mandibular incisor region had the least number of failures [3 of 147 implants (2.0%)] and the longest survival time (approximately 3,182 days). Maxillary canine areas had the shortest survival (about 2,996 days). The longest survival time was observed in implants with 11 mm length (3,179.72 ± 30.139 days) and 3.75-4 mm diameter (3,131.161 ± 35.96 days), and the shortest survival was found in implants with 11.5 mm length (2,317.79 ± 18.71 days) and 6.5 mm diameter (2,241.45 ± 182.21 days). Moreover, implants with 10 mm length (10.7%) and 5.5-6 mm diameter (22.2%) had the highest failure rate; however, the least failure rate occurred when the implants were 11.5 mm in length (1.9%) and 3-3.5 mm in diameter (3.1%). Conclusions: The brand, length and diameter of implants affected the survival time, failure rate and time to failure. The location of the implant was not statistically significant regarding the mentioned factors, although it has clinical significance.

This study conducted to assess the factors related to skin lesions in bilateral lower limb war-amputees. This is a clinical based, cross-sectional study of 335 bilateral amputees who injured during Iran-Iraq War. Their demographics and injuries detail, amputation, prosthesis and gait-aid characteristics, stump hygiene and skin problems, have been investigated. Through logistic regression analysis, the three factors of the shape of the stumps, the length of the stumps and excessive perspiration were recognized to have an independent association in skin lesions development, among the population studied. The results suggest that most of stump skin disorders in war-injured amputees are due to intensity of injury and awkwardness of the stump. The quality of surgical, medical and rehabilitative care, improve their quality of life by functional ambulation with prosthesis.

Purpose This study aimed to identify the prevalence and extension of the anterior loop (AL) of the mental nerve in different populations and according to different cone-beam computed tomography (CBCT) imaging settings. Materials and Methods Medline/PubMed, Embase, Scopus, Web of Science, and ProQuest were searched. The main inclusion criterion was ALs evaluated in CBCT images. The quality of studies was assessed with the Joanna Briggs Institute risk of bias checklist. Subgroup analyses were conducted for sex, side, continent, voxel size, field of view, and type of CBCT-reconstruction images with a random-effects model. Results Sixty-three studies with 13,743 participants (27,075 hemimandibles) were included. An AL was found in 40.6% (95% CI: 32.8%-48.9%, P <0.05) of participants and 36.0% (95% CI: 27.5%-45.5%, P <0.05) of hemimandibles, in 34.9% (95% CI: 25.1%-46.2%, P <0.05) of males and 34.5% (95% CI: 23.5%-47.4%, P <0.05) of females. The average length of ALs was 2.39 mm (95% CI: 2.07-2.70 mm, P <0.05). Their extension was 2.13 mm (95% CI: 1.54-2.73 mm, P <0.05) in males and 1.85 mm (95% CI: 1.35-2.36 mm, P <0.05) in females. Significant differences were observed regarding the prevalence and length of ALs among continents and for its measured length on different CBCT-reconstruction images, but not between other subgroups. Conclusion AL was a relatively common finding. The voxel size and fields of view of CBCT devices were adequate for assessing AL; however, a 2-mm safety margin from anatomical structures (such as the AL) could be recommended to be considered when using CBCT imaging.