Background and Objective: The aim of this study was to evaluate the diagnostic ability of CBCT to detect external root resorption.Subjects and Methods: External root resorption defects of different sizes and in different locations were simulated in 60 human mandibular incisors. Cavities simulating root resorption defects of small size (0.3´0.6 mm), medium (1.2´0.6 mm) and large (1.8´0.9 mm) were drilled in the cervical, medial and apical thirds of buccal surfaces. The teeth were divided in random groups and mounted in the mixture of acryle and dryed skull sheep powder. CBCT scan was used to evaluate external root resorption in 180 root thirds by two blinded observer. Statistical analysis was done with Kappa test.Results: Sensitivity of CBCT to detect external root resorption was 89% and the specificity was 99 %.The most defects that was detected were on the medial root thirds and the lowest defects that were detected were on the apical root. The percentage of small defects detection was 80%.Conclusion: CBCT technique is a very good method to evaluate external root resorption with high sensitivity and excellent specificity. It can detect the defects as small as 0.3mm.

In this paper we introduce the CONE bounded linear mapping and show that the CONE norm is continuous. Among other things, we prove the open mapping theorem and the closed graph theorem in TVS-CONE normed spaces. We also show that under some restrictions on the CONE, two TVS-CONE norms are equivalent if and only if they induce equivalent topologies. In the sequel, the notion of algebraic CONE metric is introduced and it is shown that every algebraic CONE metric space has a topology and the Banach fixed point theorem for contraction mappings on algebraic CONE metric spaces is proved.

Introduction: The inferior alveolar canal is an important anatomical structure in the field of dentistry implants and CONE beam computed tomography (CBCT) is an important diagnostic technique. The aim of this study was to evaluate the prevalence of anatomical variations of the mandibular canal observed in CBCT images. Materials & Methods: In this descriptive-analytic study 384 inferior alveolar canals were evaluated in 192 patients, who were referred to the radiology department of Isfahan Azad University in 1396 for a CONE-beam computed tomography. Radiographs were performed to assess the frequency of different left and right mandibular canal segregations by sex in terms of upper and lower position, baccolingual position, shape of the general canal. The frequency and different types of existing mandibular plug canals were also evaluated. Data were analyzed by Chi Square, independent T Test, paired t-test. (p value < 0. 05). Results: The mandibular canal was 2. 1% of the lower position, 11. 9% of the upper position and 86% of the middle position. Statistically significant differences were observed between the frequency distributions of canal positions and gender (p value = 0. 004). The prevalence of Bifid mandibular canals was 14. 8%. There was no significant relationship between the shape of the general channel path and gender. There was no significant difference between the mean distance between the mandibular canal and the buccal cortex in both Molar and Ramus with the sex of the subjects and the side of the canal (p value < 0. 05). Conclusion: The highest frequency of mandibular canal in most subjects was on the right in the intermediate position. The mean distance between mandibular canal and buccal cortex in Ramos and Molars area on both right and left sides was not significantly different between men and women.

Introduction & Objective: The mental foramen is a part of lower jaw which has neurovascular bundles and also is important in biology. 3D imaging of this area by CONE beam computed tomography (CBCT) before surgery can prevent some problems. This study aims to evaluate the anatomic position and geometrical shape of the mental foramen by CBCT images.Materials & Methods: In this research, the CBCT images (by NewTom and Planmeca promax 3D set) of 85 patients referred to dentistry school clinic or other clinics in Hamadan city were studied. These patients did not have their first and second premolar teeth extracted in both right and left sides. The geometrical shape of mental foramen, the canal angle connecting to mental foramen compared to the buccal plate of lower jaw, distance from the lower border of mental foramen to the lower border of lower jaw, position of mental foramen relating to the root of adjacent tooth and the incidence of accessory mental foramen were studied.Results: The means of canal angle connecting to mental foramen in the right side in men and women were 123.3 and 130.1 and in the left side were 123.8 and 133.7, respectively. The mean distance from the lower border of mental foramen to the lower border of lower jaw in the right side in men and women were: 12.4 and 13.3 mm and in the left side were: 12.7 and 13.6 mm, respectively. Also, there is a meaningful statistical relation between gender and the angle of canal of mental foramen, regarding to the buccal plate in both sides.Conclusion: Regarding to the variations in the position and shape of mental foramen and the angle connecting to the mental foramen related to the buccal plate and accessory mental foramen, investigation of CBCT images before placement of implants is necessary.

Please click on PDF to view the abstract.

Background and Objective: Many surgeries are performed on anterior region of mandible. Incisive branch of the inferior alveolar nerve is located in the anterior region of mandible. The identification of various form of nerve is important for diagnosis and treatment plan. This study was carried out to the assessment of visibility and extension rate of incisive branch of the inferior alveolar nerve in CONE beam computed tomography (CBCT) imagings.Methods: This descriptive- analytic study was performed on 105 CBCT images. The presences or absence of incisive branch of the inferior alveolar nerve and assessment of visibility and extension rate of mandibular incisive canal were studied.Results: In 79% extension of the incisive branch of the inferior alveolar nerve were observed. 18.07% of extensions were observed in one-side and 78.31% were bilateral. Extension of the incisive branch of the inferior alveolar nerve was observed to central, lateral and canine tooth in 59%, 26.5% and 14.5% respectively. There was no significant relation beween gender and age of subjects with extension of the incisive branch of the inferior alveolar nerve.Conclusion: Regarding the high visibility of the incisive nerve branches in the lower dental CBCT images this method can be used to evaluate the anterior region of mandible.

CONE penetrometers are devices to determine the soil penetration resistance at different depths and the results can be used in many varied applications such as construction, military and agriculture. In this research, CONE index - depth measurements of a developed tractor mounted and a hand push (model SP1000) CONE penetrometers were compared and evaluated. In both systems, a cantilever beam transducer and a photocell sensor were used to measure the soil resistance and depth, respectively. The penetration tests were conducted on two type soils at two plots. On each plot, 10 points were randomly selected and both systems were tested. The hand push penetrometer data were collected in a digital memory and was given to a computer. However, the results of tractor mounted CONE penetrometer were recorded by an x-t recorder. The results of experiments indicated that coefficient of correlation for plowed and stubbly soils were R2=0.97 and R2=0.96, respectively. Based on t-test results, there was no significant difference between CONE indexes for both systems at 5% level of confidence. Therefore, with respect to advantages of tractor mounted CONE penetrometer, it is suggested to use in soil strength researches.