Search

Background and purpose: The anatomy of the great palatine canal is important for dentists and maxillofacial surgeons in terms of performing various surgical procedures such as local anesthesia, dental implant placement, and paranasal sinus surgery. In the axial view, the great palatal foramen (GPF) is usually seen in the alignment of the second molar and is hidden by the thick mucosa, which is important to determine its clinical position according to the anatomical signs. The present study aimed to investigate and evaluate the anatomical variations of the large palatine foramen and canal, the large and small palatine foramen, and the location of the large palatine foramen by CBCT technique. Materials and methods: In this retrospective cross-sectional study, 316 CBCT images related to the maxilla were analyzed to identify the large and small palatal foramen and the palatal canal and their positions. In this cross-sectional study, CBCT images obtained from patients were evaluated in terms of morphology and diameter of the large palatal foramen and large palatal canal. The anatomical shape of the large palatal canal in the sagittal plane and the position of the large palatal foramen in the axial plane relative to the second molar tooth in the upper jaw were investigated. The required information was collected in the checklist prepared for this purpose. With the help of two observers specializing in maxillofacial radiology, the CBCT images were examined and gave their opinion, and 20% of the data were repeated for the observer's error. In this study, the samples were divided into three age groups for statistical analysis. The relationship between age groups, GPF, and large palatal canal was investigated. After collecting the data and information, it was analyzed by SPSS V.23 software, and the data was described using number and percentage indicators and central and dispersion indicators. The significance level was considered to be P

Background and purpose: The anatomy of the great palatine canal is important for dentists and maxillofacial surgeons in terms of performing various surgical procedures such as local anesthesia, dental implant placement, and paranasal sinus surgery. In the axial view, the great palatal foramen (GPF) is usually seen in the alignment of the second molar and is hidden by the thick mucosa, which is important to determine its clinical position according to the anatomical signs. The present study aimed to investigate and evaluate the anatomical variations of the large palatine foramen and canal, the large and small palatine foramen, and the location of the large palatine foramen by CBCT technique. Materials and methods: In this retrospective cross-sectional study, 316 CBCT images related to the maxilla were analyzed to identify the large and small palatal foramen and the palatal canal and their positions. In this cross-sectional study, CBCT images obtained from patients were evaluated in terms of morphology and diameter of the large palatal foramen and large palatal canal. The anatomical shape of the large palatal canal in the sagittal plane and the position of the large palatal foramen in the axial plane relative to the second molar tooth in the upper jaw were investigated. The required information was collected in the checklist prepared for this purpose. With the help of two observers specializing in maxillofacial radiology, the CBCT images were examined and gave their opinion, and 20% of the data were repeated for the observer's error. In this study, the samples were divided into three age groups for statistical analysis. The relationship between age groups, GPF, and large palatal canal was investigated. After collecting the data and information, it was analyzed by SPSS V.23 software, and the data was described using number and percentage indicators and central and dispersion indicators. The significance level was considered to be P<0.05. Results: Results showed that large palatal holes are seen in 63.9% of the distal second molar and 36.1% flush with the second molar in CBCT images. In terms of foramen morphology, the most common shape was oval in 107 patients (33.9%). Also, according to the surveys, the most common morphology of the large palatal canal was cascade in 120 people (38%). Additionally, the results showed that there is a significant relationship between the morphology of the large palatal foramen and gender, so that the round and oval shapes are more common in men, and the round, split, and teardrop shapes are more common in women. The number of small palatal foramen was less than 3 in 88.8% of cases. According to statistical tests, there is a significant relationship between the diameter of the small palatal foramen with sex, age, and jaw direction (P=0.046). Conclusion: Considering that the large palatal foramen is located in the distal second molar in most cases a significant relationship was found between the shape of the GPF and its position. Therefore, to avoid surgical problems, it is necessary to evaluate the anatomical variations of the hole and the large palatal canal, especially before the maxillary wisdom tooth surgery. [ABSTRACT FROM AUTHOR]

Background: Antral exostosis in the maxillary sinus generally causes changes in the sinus, and its expansion may complicate planned sinus lift procedures before implant placement in the edentulous posterior maxilla. Therefore, before planning implant surgery, it is necessary to evaluate the presence of antral exostoses and other abnormalities, especially in the maxillary sinuses. The aim of the present study was to investigate the prevalence of exostoses in the maxillary sinus through cone beam computed tomography (CBCT) images in a population of northern Iran.Materials and Methods: In this descriptive analytical study, 1068 scans were examined. Several parameters such as the presence of exostosis, location, bilateral or unilateral, type of exostosis and type of bone were investigated. In the coronal, sagittal, and axial images, the presence of exostosis and its location in the maxillary sinus, and its appearance and symmetry were recorded. Then, the collected data were analyzed by SPSS version 20 software and the significance level was considered P

Background and Objective: One of the most important stages of root canal treatment is the correct and complete preparation of the root canal. This study aimed to compare the amount of canal transportation in two nickel titanium files, OneShape and Neolix. Materials and Methods: In this experimental study, 30 extracted mandibular first molar teeth with 25-35-degree curvature were selected for periodontal reasons and randomly divided into two groups (n=15 each). A cone beam computed tomography (CBCT) scan was obtained from the teeth before the intervention. Followingly, the teeth of each group were prepared by the desired file (OneShape and Neolix) according to the manufacturer's instructions. Another CBCT scan was obtained from the teeth at the same angle. The amount of transportation was analyzed from the mesiodistal aspect at two distances of 3 and 9 mm from the apex. The preparation time of each tooth was also recorded by a chronometer. Data were analyzed by independent t-tests (α=0.05). Results: The mean transport at a distance of 3 mm from the apex in the OneShape and Neolix groups was 0.19 and 0.1 mm, respectively. The mean transport at a distance of 9 mm from the apex was 0.2 and 0.1 mm in the OneShape and Neolix groups, respectively. Statistically, there was no significant difference in the amount of transportation between the two groups at the distance of 3 mm (P=0.055) and 9 mm (P=0.39). The mean preparation time was longer in the OneShape group than in the Neolix one; however, it did not show a statistically significant difference (P=0.73). Conclusion: Both Neolix and OneShape files can maintain the curvature of the canal and are suitable for curved canals in terms of shaping ability.

Background & Objective: Successful root canal therapy requires knowledge of the anatomy of the root canal system and complete clearance. Given the possibility of a second canal in mandibular incisors, it is important to find and completely debride this canal Therefore, in this study, we investigated the anatomy of the root canal of mandibular incisor teeth using CBCT.Material & Methods: In this descriptive analytical and cross-sectional study, CBCT images were evaluated from three sagittal dimensions (number of roots, channel type, apical foramen deviation from radiographic apex), coronal (apical foramen deviation from radiographic apex) and axial (channel type). Data were analyzed in SPSS software (Version 2016) through descriptive statistics using frequency distribution and Chi-square test. cases less than 0.05 were considered significant. Results: In this study, 606 mandibular incisor teeth were examined. The mean deviation of apical foramen from radiographic apex was 0.431 ± 0.296 mm. Only 1 double-rooted tooth was observed. 34.5% of the teeth were double-channel and 65.5% were single-channel. Class 1 and 3 Vertucci morphology was the most common and other classes included about 1.5% of the samples.Conclusion: According to the results, mandibular incisors in females and males are more single rooted and have a single canal. Regarding the Vertucci classification, the most prevalent type was type I.

Introduction: In recent years, CBCT imaging has found many applications in dentistry due to its advantages such as 3D images, ease of imaging and the possibility of data reconstruction. The aim of this study was to evaluate the knowledge and attitude of dental residents and students of Shahid Sadoughi University of Medical Sciences towards the need to prescribe CBCT in 2022-2023. Methods: the current study is a cross-sectional and descriptive study.146 general dentistry students and 24 dental residents participated in this study. 23 questions in the field of knowledge and attitude about the use of CBCT were used. The validity of the questionnaire was confirmed by using sources, valid scientific articles and by presenting and consulting radiology specialists. To determine the reliability, retest and Cronbach's alpha coefficient was used. Finally, the results were statistically analyzed by SPSS software version16 using chi-square, t-test and correlation tests. Results: The level of knowledge and attitude of general students was higher than dental residents. Moreover, there was a significant difference between the level of knowledge and attitude of students with their duration of study at the university, so the higher the academic year, the lower the knowledge and attitude. Conclusion: The results of the present study showed that dental students of Shahid Sadoughi University of Medical Sciences have a relatively moderate knowledge and attitude about the use of CBCT.

Background and Objective: Determining the exact position of the impacted maxillary canine during its orthodontic treatment using cone beam computed tomography (CBCT) can help select the most appropriate treatment plan. The present study aimed to compare the proposed treatment plan for impacted maxillary canines based on the factors affecting the degree of treatment difficulty in impacted maxillary canines with their definitive treatment plan using CBCT. Materials and Methods: In this retrospective cross-sectional study, 120 CBCT images were assessed. These images were taken from patients with impacted maxillary canines whose treatments were terminated. To investigate the severity of maxillary canine impaction factors, including the type of impaction, position of canine, distance to the occlusal plane, distance to the midline, and width of follicular space, were measured using CBCT. Ten orthodontists were asked to determine the type of treatment plan proposed for the patient. Then, they determined the degree of difficulty of each measured factors using numbers 1 to 10. Then, the relationship between the specified difficulty number for each factor and the proposed treatment plan was evaluated, and at the end, the relationship between the type of proposed treatment plan and the patient's actual treatment plan was measured. Results: A total of 26 men and 94 women with a mean age of 18.85 ± 6.5 participated in the present study. A significant relationship was observed between the variables of age, transverse to midline, and the type of impaction, with the type of treatment. Conclusion: Although the findings of this study showed a low inter-observer agreement on severity degree concerning the width of follicular space, the inter-observer agreement on severity degree with the other factors was high.

Background and Aim: Age estimation is an important issue in forensic medicine.Teeth are more resistant to changes than bones, so they are one of the main indicators for age estimation in forensic medicine. To determine the relationship between age and dental changes, the ratio of dental pulp/Tooth volume (PV/ TV) is one of the most appropriate indicators. The aim of this study was to determine the correlation between PV/TV ratio and chronological age in canine teeth using CBCT images. Materials and Methods: In this descriptive-analytical study, a total of 183 CBCT images were selected randomly from archive of images in an oral and maxillofacial radiology center. The images were imported into the 3D Slicer software as DICOM data. Pulp volume, tooth volume and their ratio were calculated. Data were introduced into SPSS 17. We used T-test, ANOVA, Pearson correlation coefficient and linear regression for data analysis. Results: The mean value of PV/TV ratio was not different significantly in relation to gender, teeth location (mandible and maxilla, right and left sides), but there was a significant difference in terms of age. Pearson correlation showed a significant negative relation between the age of the subjects and PV/TV ratio (R = -0.714). The results of regression analysis for all data and also for all of 6 age groups showed significant correlation only in the age groups of 15-19 and 50- 59 years old. Conclusion: The results of this study showed that there was an inverse and significant relationship between PV/TV ratio and chronological age. Also, in the age groups of 15-19 and 50-59 years, it seems that regression model can be considered a reliable method to estimate age in Iranian population.

Understanding maxillary sinus hypoplasia (MSH) and associated sinonasal variants is crucial for the success of diagnostic and therapeutic procedures in maxillary sinus and maxillary dental implant surgery. The aim of this study was to investigate a rare case of unilateral maxillary sinus hypoplasia associated with lower orbital floor displacement, without involving the Uncinate process. A 31-year-old woman presented to the Department of Oral and Maxillofacial Surgery at Babol Dental School for rhinoplasty without any complaints of headache or nasal congestion. She had no history of trauma, congenital or bone diseases/abnormalities. Cone Beam Computed Tomography (CBCT) images revealed left maxillary sinus hypoplasia, lower orbital floor, and increased thickening of the sinus mucosa. The patient's photograph also showed lower displacement of the orbital floor. The diagnosis of unilateral maxillary sinus hypoplasia in this study was based on clinical manifestations and coronal views of CBCT and CT scans. Symptoms of hypoplastic sinus include chronic headache, facial pain, voice problems, or may sometimes be asymptomatic. If the surgeon is not aware of the hypoplasticity of the sinus, complications during surgery may increase, including post-surgery complications such as visibility of the low orbital floor and resulting patient confusion. This study highlights the importance of using CBCT as a valuable diagnostic tool to identify anatomical variations and details of the hypoplastic sinus. This approach helps the surgeon to inform the patient and provide an appropriate treatment plan, especially in cases involving dental implants or sinus surgery.

Understanding maxillary sinus hypoplasia (MSH) and associated sinonasal variants is crucial for the success of diagnostic and therapeutic procedures in maxillary sinus and maxillary dental implant surgery. The aim of this study was to investigate a rare case of unilateral maxillary sinus hypoplasia associated with lower orbital floor displacement, without involving the Uncinate process. A 31-year-old woman presented to the Department of Oral and Maxillofacial Surgery at Babol Dental School for rhinoplasty without any complaints of headache or nasal congestion. She had no history of trauma, congenital or bone diseases/abnormalities. Cone Beam Computed Tomography (CBCT) images revealed left maxillary sinus hypoplasia, lower orbital floor, and increased thickening of the sinus mucosa. The patient's photograph also showed lower displacement of the orbital floor. The diagnosis of unilateral maxillary sinus hypoplasia in this study was based on clinical manifestations and coronal views of CBCT and CT scans. Symptoms of hypoplastic sinus include chronic headache, facial pain, voice problems, or may sometimes be asymptomatic. If the surgeon is not aware of the hypoplasticity of the sinus, complications during surgery may increase, including post-surgery complications such as visibility of the low orbital floor and resulting patient confusion. This study highlights the importance of using CBCT as a valuable diagnostic tool to identify anatomical variations and details of the hypoplastic sinus. This approach helps the surgeon to inform the patient and provide an appropriate treatment plan, especially in cases involving dental implants or sinus surgery. [ABSTRACT FROM AUTHOR]

External root resorption is a clinical problem that is difficult to diagnose, therefore radiographic examination is important for diagnose. The purpose of this study was comparing the diagnostic accuracy of 2 Cone Beam Computed Tomography in detecting of external root resorption, in vitro.Materials & Methods:This study was done on 48 single-rooted teeth. Cavities of 0.3, 0.2 and 0.15 mm in depth with round bur 0.3 mm were drilled on buccal and lingual surfaces in the cervical, middle and apical thirds of some of roots. Then CBCT were taken and 4 observers assessed the scans. Sensitivity, specificity and Kappa value were determined. The statistical analysis was performed with the Z-test (p value < 0.05).Results:In comparison of the accuracy, sensitivity and specificity of the two devices, there was no significant difference. In the apical, middle and cervical as well as at various depths there was no significant difference between the two devices, but in the numerical point of view, the sensitivity for both devices in the midsection, was in the highest amount. The highest value for the specificity is related to the apical region. For both devices, the sensitivity level GBJ, by increasing the depth. The lowest agreement between observers was 0.61. The highest agreement rate was in the middle section and the least amount of agreement was related to the apical region.Conclusion:CBCT brand type is not effective factor in the detection of external root resorption. The location and depth of external root resorption can be effective factors in diagnostic accuracy

Background and purpose: This study was conducted to investigate the relationship between the position of impacted canine and associated follicular width. Materials and methods: This cross-sectional descriptive study, included CBCT archival images (n=70) in a maxillofacial imaging center in Sari, Iran. The images were studied by Planmeca Romexis Viewer ver. 3.8.2. Variables were determined and any relationship was investigated. Data analysis was carried out in SPSS V22. Results: Findings showed that 61.43% of the canines were in palatal position, 28.57% were in central position of the alveolar process and 10% were in buccal position. Also, the frequencies of vertical position of the canine cusp tip impacted in coronal 1/3, apical 2/3, and cervical region of the lateral incisor root were 50.86%, 40%, and 7.14%, respectively, and there were mild and severe root resorption in 28.57% and 2.86% of the cases, respectively. Conclusion: Canine impaction often occurs in the palatal position relative to the bone crest and the risk of its occurrence increases with increase in the distance of the canine from the midline and increase in the size of the follicle. This phenomenon, which is reported more in women, can eventually lead to root resorption of the lateral incisor tooth.

Background and Aims: By using the image processing capability in Cone-Beam Computed Tomography (CBCT), obtained information can be improved. The aim of the present study was to investigate the effect of sharpen image processing filter in determining the external resorption of the root apical region in single-rooted teeth due to the proximity of the impacted tooth using CBCT. Materials and Methods: In this laboratory study, the lateral surfaces of the apical region of the root of 40 healthy extracted teeth were artificially cut by bur and the teeth were randomly divided into four groups: control, low, moderate, and high resorption. After preparing CBCT of the teeth, the samples were then processed with and without an image sharpening processing filter and examined by two observers. The results of this study were analyzed by SPSS22 and Medcalc Statistical Software version 14. The significance level was considered P≤0.05 for all the statistical tests. Results: Specificity (100%) and sensitivity (66%>) were either complete or very high for both modes without and with the sharpen filter. The overall accuracy (0.83>) was high in both cases and no significant difference was observed between the two overall accuracies (P>0.05). Statistical analysis of both image observations by two observers showed that the overall sensitivity and accuracy in the medium and high resorption groups was much higher than the low resorption group, but the specificity in all groups was 100%. Conclusion: The results showed that the images with a sharpening filter did not increase the detection power compared to the unfiltered images. However, as no loss of accuracy was observed with this filter, it could be used as a processing filter.

Background and purpose: Transverse problems in the maxilla (high arched- narrow hard plates) can cause respiratory disorders. Palatal expansion can be helpful in this way. The present study aimed at evaluating the effect of bone borne expansion and tooth borne palatal expansion on airway volume. Materials and methods: A review study was performed by search in Google Scholar, Scopus, PubMed, Embase, and Cochrane using the following keywords: maxillary expansion, palatal expansion, miniscrew-assisted palatal expansion, tooth borne, bone borne, rapid palatal expansion, airway dimension, and Cone beam computed tomography. The search was limited to articles published in January 2011-April 2021. Results: In the initial search, 343 articles were found. After reviewing the titles and abstracts only 20 papers were found that studied the effect of bone and tooth borne palatal expansion on airway dimensions and met the inclusion criteria. The studies indicated that both bone expansion and tooth borne palatal expansion could considerably increase airway volumes. However, only bone borne palatal expansion enabled more predictable and greater skeletal expansion and less teeth response. Conclusion: Both bone and tooth borne palatal expansion are efficient in increasing the airway volume. Further randomized clinical trials with large sample size and matched control groups, longer follow-up periods and measuring respiration index such as apnea-hypopnea index are suggested.

Introduction: Bifid mandibular canal is one of the types of mandibular canal. Considering that failure to identify the bifid mandibular canals can lead to various complications. In the present study, bifid mandibular canal was evaluated by CBCT (Cone beam Computed tomography) images in Rafsanjan City. Methods: In this descriptive cross sectional study, all the patients who underwent CBCT at a private oral and maxillofacial radiology clinic in Rafsanjan City during the May 2019 until May 2021 were evaluated. The mandibular canal and its different types were evaluated by an experienced radiologist, using CBCT images in reconstructed coronal, sagittal and panoramic planes for each quadrant. The bifid mandibular canal was identified and its type was determined based on Naitoh classification. After collecting the data, they were entered into SPSS version 16. Descriptive statistical methods (mean, standard deviation and frequency) were used to evaluate the data. Results: In the present study, 815 CBCT radiographs were examined and 62 (7.6%) cases consisting of 29 men (7.2%) and 33 (8%) women had bifid mandibular canal. The results declared there was no significant difference between the prevalence of bifid mandibular canal between the two sexes (P = 0.647). In addition, the type of bifid canal, canal side and canal branch location were not significantly different between the two sexes. Conclusion: The present study showed that the prevalence of Bifid mandibular canal in one sample of Iranian population is 7% and its identification before treatment can prevent further problems.

Background and purpose: This study was conducted to investigate the relationship between the position of impacted canine and associated follicular width. Materials and methods: This cross-sectional descriptive study, included CBCT archival images (n=70) in a maxillofacial imaging center in Sari, Iran. The images were studied by Planmeca Romexis Viewer ver. 3.8.2. Variables were determined and any relationship was investigated. Data analysis was carried out in SPSS V22. Results: Findings showed that 61.43% of the canines were in palatal position, 28.57% were in central position of the alveolar process and 10% were in buccal position. Also, the frequencies of vertical position of the canine cusp tip impacted in coronal 1/3, apical 2/3, and cervical region of the lateral incisor root were 50.86%, 40%, and 7.14%, respectively, and there were mild and severe root resorption in 28.57% and 2.86% of the cases, respectively. Conclusion: Canine impaction often occurs in the palatal position relative to the bone crest and the risk of its occurrence increases with increase in the distance of the canine from the midline and increase in the size of the follicle. This phenomenon, which is reported more in women, can eventually lead to root resorption of the lateral incisor tooth. [ABSTRACT FROM AUTHOR]

Background and Objective: Knowing the position of the inferior alveolar canal and mental foramen is very important in periapical surgeries, administration of local anesthesia and implantation. The aim of this study is to compare the position and view of the inferior alveolar canal and mental foramen in panoramic radiography and CBCT images. Methods: In this cross-sectional study, concurrent panoramic radiography and CBCT images of patients who visited a private radiology clinic for one year were examined. In panoramic radiographs, the indices of canal visibility, mental foramen visibility, proximity of mental foramen to mandibular premolar teeth, canal diameter, mental foramen diameter and distance from mental foramen to alveolar crest were examined. Then all these cases were evaluated and compared in CBCT radiographs (as gold standard). Findings: In this study, concurrent CBCT and panoramic radiographs of 41 patients including 23 men (56.1%) and 18 women (43.9%) with a mean age of 51±13 years were analyzed. The mean values of variables of inferior alveolar canal diameter and distance from mental foramen to alveolar crest in panoramic images were significantly higher than CBCT images (p

Background and purpose: Perforation impairs the prognosis of endodontic treatments, so, timely and accurate diagnosis is important. For this purpose, various radiographic diagnostic tools have been studied to select the method that has the least complications and helps in making the most accurate diagnosis. This study aimed to compare the accuracy of cone beam computed tomography (CBCT) and intra oral digital radiography phosphor storage plates (PSP) in detection of strip perforation in endodontically treated teeth. Materials and methods: In this experimental study, 124 extracted mandibular molar teeth were selected. Standard access cavities were prepared, then cleaning and shaping in mesiolingual canal were performed by Protaper Gold rotary instruments to size F2. Next, the teeth were randomly divided into four groups (n=31 per group). Control group was left with no perforation while distal wall of mesiolingual canal in other three groups were perforated using Gates Glidden #2 and 3 in 1-3 mm below the furcation region in three ranges; 0-0.5, 0.5-1, and 1-1.5 mm. Electronic Digital Caliper was used to confirm the accuracy of the size of perforations. Obturation was performed in mesiolingual canals employing sealer and gutta-percha by lateral condensation technique. The teeth were then randomly placed in bovin ribs. PSP and CBCT images of all samples were examined by two oral radiologists and data were analyzed in SPSS. Results: The sensitivity, specificity, and accuracy of PSP were 90.8%, 88.7%, and 90% and those of CBCT were 95.7%, 72.6%, and 90%, respectively. Sensitivity of CBCT was found to be significantly higher than that of PSP (P

Evaluation of alveolar bone thickness is crucial for proper implant placement and support and aesthetics of soft tissue around implant restorations. The aim of this study was to determine the relationship between skeletal protrusion of jaw and labiolingual inclination of teeth with maxillary and mandibular anterior alveolar bone thickness using computed beam computed tomography (CBCT).Materials & Methods:In this descriptive-analytical study, cone beam computed tomography images were obtained from 100 patients referred to the radiology department of Tabriz Dental School from 2013-2015 before implant insertion. Maxillary and mandibular protrusion was determined by measuring SNA (Sella-nasion-A point) and SNB (Sella-nasion-B point) angles and labiolingual inclination of maxillary and mandibular anterior teeth was determined by measuring U1-NA (Upper 1-Nasion A point) and L1-NB (Lower1-Nasion B point) angles. Then, thickness of buccal bone was measured at three levels: 3 mm below the CEJ (A), the middle part of the root (B) and the apex (C). Data were analyzed by using descriptive statistics (mean and standard deviation) and Pearson’s correlation coefficient and p value < 0.05 will be considered statistically significant.Results:Mean thickness of bone was higher at level C than other two levels and lower at level A than others. There is no statistically significant relation between mean maxillary bone thickness and SNA (p value > 0.05) except for B region on canine (Pearson correlation coefficient = 0.305 and p value < 0.05). There is no statistically significant relation between the mean maxillary bone thickness and U1-NA. There is no statistically significant relation between mean mandibular bone thickness and SNB and L1-NB. (p value > 0.05).Conclusion:There was no statistically significant relation between maxillary and mandibular protrusion and labiolingual inclination of upper and lower anterior teeth with alveolar bone thickness

Evaluating the dimensions of buccal and palatal alveolar bone in the anterior maxillary teeth is very important in patients who are candidates for immediate implant replacement. The aim of this study was Assessment of buccal and palatal alveolar bone thickness in maxillary anterior teeth on cone beam computed tomography (CBCT).Materials & Methods:In this descriptive-analytical study, 78 CBCT images of patients referred to Radiology Department of Khorasgan Dental Faculty were evaluated. The collected data included the measurement of the bone thickness of the alveolar buccal and palatal anterior maxillary teeth at three locations of the crest, the middle region of the root and apex with the Sidexis software. Then, the measurements were compared between males and females. The data were analyzed by T-test statistical methods.Results:The mean thickness of the buccal alveolar bone in the crest region and the middle region of the central, lateral and canine teeth was less than 1 mm. The mean thickness of the buccal alveolar bone at the apex site of the central, lateral and canine teeth was more than one mm. The mean thickness of the palatal alveolar bone in the crest region of the central, lateral and canine teeth was less than one millimeters. The mean thickness of the palatal alveolar bone in the middle region of the root and apex was more than one mm. There was no statistically significant difference between the sex and thickness of the buccal alveolar bone, except at the apex of the central and lateral teeth (p value > 0.05). Between sex and thickness of palatal alveolar bone, in the crest of lateral and canine teeth and in the middle root and apex area of all three central, lateral and canine teeth in men were significantly more than women (p value < 0.05).Conclusion:The buccal alveolar bone was present in most of the points examined at the crest and mid-root site, and the palatal alveolar bone was at the crest site at most checked points with a thickness of less than 1 mm.

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

Background and Aims: By using the image processing capability in Cone-Beam Computed Tomography (CBCT), obtained information can be improved. The aim of the present study was to investigate the effect of sharpen image processing filter in determining the external resorption of the root apical region in single-rooted teeth due to the proximity of the impacted tooth using CBCT. Materials and Methods: In this laboratory study, the lateral surfaces of the apical region of the root of 40 healthy extracted teeth were artificially cut by bur and the teeth were randomly divided into four groups: control, low, moderate, and high resorption. After preparing CBCT of the teeth, the samples were then processed with and without an image sharpening processing filter and examined by two observers. The results of this study were analyzed by SPSS22 and Medcalc Statistical Software version 14. The significance level was considered P≤0.05 for all the statistical tests. Results: Specificity (100%) and sensitivity (66%>) were either complete or very high for both modes without and with the sharpen filter. The overall accuracy (0.83>) was high in both cases and no significant difference was observed between the two overall accuracies (P>0.05). Statistical analysis of both image observations by two observers showed that the overall sensitivity and accuracy in the medium and high resorption groups was much higher than the low resorption group, but the specificity in all groups was 100%. Conclusion: The results showed that the images with a sharpening filter did not increase the detection power compared to the unfiltered images. However, as no loss of accuracy was observed with this filter, it could be used as a processing filter. [ABSTRACT FROM AUTHOR]

Background and purpose: Transverse problems in the maxilla (high arched- narrow hard plates) can cause respiratory disorders. Palatal expansion can be helpful in this way. The present study aimed at evaluating the effect of bone borne expansion and tooth borne palatal expansion on airway volume. Materials and methods: A review study was performed by search in Google Scholar, Scopus, PubMed, Embase, and Cochrane using the following keywords: maxillary expansion, palatal expansion, miniscrew-assisted palatal expansion, tooth borne, bone borne, rapid palatal expansion, airway dimension, and Cone beam computed tomography. The search was limited to articles published in January 2011-April 2021. Results: In the initial search, 343 articles were found. After reviewing the titles and abstracts only 20 papers were found that studied the effect of bone and tooth borne palatal expansion on airway dimensions and met the inclusion criteria. The studies indicated that both bone expansion and tooth borne palatal expansion could considerably increase airway volumes. However, only bone borne palatal expansion enabled more predictable and greater skeletal expansion and less teeth response. Conclusion: Both bone and tooth borne palatal expansion are efficient in increasing the airway volume. Further randomized clinical trials with large sample size and matched control groups, longer follow-up periods and measuring respiration index such as apnea-hypopnea index are suggested. [ABSTRACT FROM AUTHOR]

Introduction: Evaluating the dimensions of buccal and palatal alveolar bone in the anterior maxillary teeth is very important in patients who are candidates for immediate implant replacement. The aim of this study was Assessment of buccal and palatal alveolar bone thickness in maxillary anterior teeth on cone beam computed tomography (CBCT). Materials & Methods: In this descriptive-analytical study, 78 CBCT images of patients referred to Radiology Department of Khorasgan Dental Faculty were evaluated. The collected data included the measurement of the bone thickness of the alveolar buccal and palatal anterior maxillary teeth at three locations of the crest, the middle region of the root and apex with the Sidexis software. Then, the measurements were compared between males and females. The data were analyzed by T-test statistical methods. Results: The mean thickness of the buccal alveolar bone in the crest region and the middle region of the central, lateral and canine teeth was less than 1 mm. The mean thickness of the buccal alveolar bone at the apex site of the central, lateral and canine teeth was more than one mm. The mean thickness of the palatal alveolar bone in the crest region of the central, lateral and canine teeth was less than one millimeters. The mean thickness of the palatal alveolar bone in the middle region of the root and apex was more than one mm. There was no statistically significant difference between the sex and thickness of the buccal alveolar bone, except at the apex of the central and lateral teeth (p value > 0.05). Between sex and thickness of palatal alveolar bone, in the crest of lateral and canine teeth and in the middle root and apex area of all three central, lateral and canine teeth in men were significantly more than women (p value < 0.05). Conclusion: The buccal alveolar bone was present in most of the points examined at the crest and mid-root site, and the palatal alveolar bone was at the crest site at most checked points with a thickness of less than 1 mm. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction: Evaluation of alveolar bone thickness is crucial for proper implant placement and support and aesthetics of soft tissue around implant restorations. The aim of this study was to determine the relationship between skeletal protrusion of jaw and labiolingual inclination of teeth with maxillary and mandibular anterior alveolar bone thickness using computed beam computed tomography (CBCT). Materials & Methods: In this descriptive-analytical study, cone beam computed tomography images were obtained from 100 patients referred to the radiology department of Tabriz Dental School from 2013-2015 before implant insertion. Maxillary and mandibular protrusion was determined by measuring SNA (Sella-nasion-A point) and SNB (Sella-nasion-B point) angles and labiolingual inclination of maxillary and mandibular anterior teeth was determined by measuring U1-NA (Upper 1-Nasion A point) and L1-NB (Lower1-Nasion B point) angles. Then, thickness of buccal bone was measured at three levels: 3 mm below the CEJ (A), the middle part of the root (B) and the apex (C). Data were analyzed by using descriptive statistics (mean and standard deviation) and Pearson’s correlation coefficient and p value < 0.05 will be considered statistically significant. Results: Mean thickness of bone was higher at level C than other two levels and lower at level A than others. There is no statistically significant relation between mean maxillary bone thickness and SNA (p value > 0.05) except for B region on canine (Pearson correlation coefficient = 0.305 and p value < 0.05). There is no statistically significant relation between the mean maxillary bone thickness and U1-NA. There is no statistically significant relation between mean mandibular bone thickness and SNB and L1-NB. (p value > 0.05). Conclusion: There was no statistically significant relation between maxillary and mandibular protrusion and labiolingual inclination of upper and lower anterior teeth with alveolar bone thickness. [ABSTRACT FROM AUTHOR]

Introduction: Most dental traumas occur in the maxillary anterior region, and the related complications can be observed as root and crown fractures or luxation injuries. Root fracture indicates cementum, dentin, and pulp fractures that may be extended longitudinally or horizontally across the tooth root. This study aimed to investigate the accuracy of two different voxel sizes in cone beam computed tomography (CBCT) and the effect of filtration and artifact reductionalgorithm (AR) in the diagnosis of horizontal root fracture (HRF) in the presence and absence of intracanal metallic post (IMP). Methods and Materials: Artificial HRF was created randomly in 15 endodontically treated teeth at mid-root and coronal areas. Moreover, 15 intact teeth served as the control group. The cast posts were made for 30 teeth before fracture. The teeth were inserted in artificial casts for imaging and the images were prepared by CBCT system in 0.075 mm and 0.15 mm voxel sizes and were subjected to filtration and AR systems. An experienced radiologist analyzed the radiographic images. The sensitivity, specificity, and accuracy of the HRF diagnosis condition were calculated. Results: Sensitivity values ranged from 46.7% in 0.15 mm voxel size in the presence of IMP to 100% in 0.075 mm voxel size in the absence of IMP. The specificity rate for all the studied techniques was 100%. The most negative effect of IMP was observed in the diagnosis of one-third of the coronal root and cervical area fractures. Conclusion: The highest sensitivity and accuracy (100%) in the Promax 3DMax system was observed in 0.075mm voxel size in the absence of IMP. This result was in line with the results obtained with real samples. Filtration and AR systems were ineffective in the diagnose the HRF.

Background and Aims: In impacted third molar surgery, panoramic radiography is a preliminary technique for assessing the consequences associated with inferior alveolar nerve injury. However, this technique cannot provide enough information to determine the true risk in all cases. The aim of this study was to compare the accuracy of panoramic and CBCT radiographs in evaluating the relationship between the mandibular impacted third molars and the inferior alveolar nerve. Materials and Methods: In this cross-sectional study, the relationship between mandibular third molar and inferior alveolar nerve in 15 patients referred to the oral and maxillofacial radiology department of Birjand dental school including 20 mandibular third molars were evaluated using two panoramic and CBCT radiographs. Data were analyzed using descriptive statistics and chi-square test and sensitivity analysis in SPSS22. Results: In the evaluation of the teeth using panoramic radiography, the highest frequency was related to root darkening (65%) and root deflection (65%), and the lowest frequency was related to root narrowing (20%) and canal deviation (5%). The highest sensitivity of panoramic criteria was related to the root darkening with 100% sensitivity and the lowest sensitivity was related to the canal deviation with 17% sensitivity. On the other hand, the highest specificity of panoramic criteria between the mandibular third molars with the inferior alveolar nervewas was related to the two criteria of bifid apex and canal deviation with 100% specificity. The lowest specificity was related to the root deflection with 21% of specificity. Conclusion: According to the results of this study, the probability of observing relationship between the mandibular third molars with the inferior alveolar nerve in CBCT radiography was very high.

Background and purpose: Perforation impairs the prognosis of endodontic treatments, so, timely and accurate diagnosis is important. For this purpose, various radiographic diagnostic tools have been studied to select the method that has the least complications and helps in making the most accurate diagnosis. This study aimed to compare the accuracy of cone beam computed tomography (CBCT) and intra oral digital radiography phosphor storage plates (PSP) in detection of strip perforation in endodontically treated teeth. Materials and methods: In this experimental study, 124 extracted mandibular molar teeth were selected. Standard access cavities were prepared, then cleaning and shaping in mesiolingual canal were performed by Protaper Gold rotary instruments to size F2. Next, the teeth were randomly divided into four groups (n=31 per group). Control group was left with no perforation while distal wall of mesiolingual canal in other three groups were perforated using Gates Glidden #2 and 3 in 1-3 mm below the furcation region in three ranges; 0-0.5, 0.5-1, and 1-1.5 mm. Electronic Digital Caliper was used to confirm the accuracy of the size of perforations. Obturation was performed in mesiolingual canals employing sealer and gutta-percha by lateral condensation technique. The teeth were then randomly placed in bovin ribs. PSP and CBCT images of all samples were examined by two oral radiologists and data were analyzed in SPSS. Results: The sensitivity, specificity, and accuracy of PSP were 90.8%, 88.7%, and 90% and those of CBCT were 95.7%, 72.6%, and 90%, respectively. Sensitivity of CBCT was found to be significantly higher than that of PSP (P<0.01), while specificity of PSP was significantly higher than that of CBCT (P<0.01). Conclusion: CBCT is the most reliable technique when it is not possible to detect strip perforation in filled root canals by conventional periapical digital imaging systems. [ABSTRACT FROM AUTHOR]

Background and Objective: Dental implants are a reliable tool for the replacement of missing teeth, and the use of advanced imaging techniques for the examination of the location of implants is on the rise these days. The present study aimed to assess the frequency of different types of bone at the implant site in different age groups in Cone Beam Computed Tomography (CBCT) images. Materials and Methods: A number of 320 CBCT images (ProMax®) which were obtained for implant replacement were evaluated in this descriptive study. Patients were assigned to 10 groups according to age (5-year intervals) from 20-70 years old. The bone type was determined based on Zarb and Lekholm classifications. In order to determine the bone type, cross-sectional images with 1mm thickness were prepared in the most suitable place for implant placement, and the resulting images were evaluated by two observers. Results: Out of 1042 implant sites, 461 581 sites were in maxilla and mandible, respectively. According to Kappa statistical analysis, there was a significant inter-observers statistical correlation (82%). the most commonly observed bone types were D3, D2, D4, and D1, respectively. Bone type D3 and D1 were the most and least prevalent types in men, whereas in women, the most and least prevalent types were D3 and D1, respectively. The prevalence of D3 and D4 bone type increases with age. Moreover, D1 and D3 were the least and most prevalent bone types in younger ages, respectively. Conclusion: As evidenced by the obtained results, CBCT is a reliable tool for identifying the type of bone in the implant placement area and subsequently determining the prognosis of the treatment plan.

Background and Aims: Immediate implant placement following tooth extraction is a treatment with many advantages. Alveolar bone preservation after immediate implant, need minimum of 2 mm thickness in buccal bone plate. The aim of this study was to evaluate the thickness of buccal cortical bone of maxillary premolars by Cone Beam Computational Tomography (CBCT) technique. Materials and Methods: In this descriptive epidemiological study, Cone Beam Computed Tomography image was obtained from 29 patients (male and female) referred to the radiology department of Jundi Shapoor dental school of Ahvaz from 1393 (Mehr) to 1394 (Shahrivar) for implant insertion insertion. The thickness of buccal cortical bone was measured in 3 and 5 mm apical to the CEJ and root apex, perpendicular to the longitudinal axis. All the measurements were done by two oral and maxillofacial radiologists, separately. Data were analyzed by SPSS22 software, using descriptive statistics, and T-test. Results: The thickness of buccal cortical bone in second premolar was significantly more than 1 mm (P=0.001), but in first premolar, the thickness was close to 1 mm with a non-significant difference (P=0.29). Conclusion: The results of this study showed that immediate implant insertion could be done in the maxillary second premolar area with more predictability compared to the first premolar area.

Background and purpose: The purpose of mechanical cleaning of the root canal is to clean the canal walls, create a conical shape to facilitate access, effective washing, and filling all areas of the root canal. Errors such as root canal transportation are cuased by excessive dentin removal from the canal. The objective of this study was to investigate root canal transportation by a BT Race rotary and manual file with Cone Beam Computed Tomography (CBCT). Materials and methods: An Ex-vivo study was conducted in 54 extracted first molars. Root curvature was measured by Schneider's method. Preparation was performed in two groups (n= 27 per group) with manual and rotary files. CBCT images were prepared pre and post instrumentation of the canals. SPSS 18 Software was used to measure the amount of canal transportation. Results: The mean differences of canal transportation between the two groups were 0.24 ± 0.16, 0.19 ± 0.13mm, and 0.17± 0.12mm at T1 (1 mm from apical foramen), T2 (2 mm from apical foramen), and T3 (3 mm from the apical foramen), respectively. The total deviation was 0.022mm in this study. The rotary and manual files at T1 (P=0.51) and T3 (P=0.57) were not significantly different in causing transportation but T2 was found to cause significant canal transportation (P=0.027). Conclusion: The average canal transportation in 2mm canal from the apical foramen by manual files was lesser than the rotary files. BT race and K-flexo file instruments can preserve the curvature of the root canals. Therefore, both systems can be used in clinical settings with minimal apical transportation.

Background and Aims: Accurate diagnosis of vertical root fracture (VRF) is a fundamental importance in endodontics. Because of poor prognosis of VRF, digital radiographs with two horizontal angles have limitations in VRF detection. Also, Gutta-percha can produce artifacts that impair CBCT scan accuracy. The aim of this study was to compare accuracy of CBCT and digital radiography system in vertical root fracture in endodentically treated teeth. Materials and Methods: In this study, 60 endodentically treated single teeth were selected and randomly coded. The teeth were divided into two groups: 30 with induced root fracture and 30 with no fracture. CBCT scan and digital radiographs with two horizontal angles with a difference of fifteen degrees for all teeth were performed. Two observers assessed the CBCT images and digital radiographies for presence of VRF. The statistical analysis used in this study was Weighted Kappa. Results: CBCT had the highest sensivity (75.8) and specificity (90). Digital radiography with 68.3 sensitivity and 79.1 specificity were not as efficient as CBCT (P

Background and Aims: In impacted third molar surgery, panoramic radiography is a preliminary technique for assessing the consequences associated with inferior alveolar nerve injury. However, this technique cannot provide enough information to determine the true risk in all cases. The aim of this study was to compare the accuracy of panoramic and CBCT radiographs in evaluating the relationship between the mandibular impacted third molars and the inferior alveolar nerve. Materials and Methods: In this cross-sectional study, the relationship between mandibular third molar and inferior alveolar nerve in 15 patients referred to the oral and maxillofacial radiology department of Birjand dental school including 20 mandibular third molars were evaluated using two panoramic and CBCT radiographs. Data were analyzed using descriptive statistics and chi-square test and sensitivity analysis in SPSS22. Results: In the evaluation of the teeth using panoramic radiography, the highest frequency was related to root darkening (65%) and root deflection (65%), and the lowest frequency was related to root narrowing (20%) and canal deviation (5%). The highest sensitivity of panoramic criteria was related to the root darkening with 100% sensitivity and the lowest sensitivity was related to the canal deviation with 17% sensitivity. On the other hand, the highest specificity of panoramic criteria between the mandibular third molars with the inferior alveolar nervewas was related to the two criteria of bifid apex and canal deviation with 100% specificity. The lowest specificity was related to the root deflection with 21% of specificity. Conclusion: According to the results of this study, the probability of observing relationship between the mandibular third molars with the inferior alveolar nerve in CBCT radiography was very high. [ABSTRACT FROM AUTHOR]

Background and Objective: Between 0.5 to 7% of injuries in permanent teeth include root fractures. If left without diagnosis, tooth will become non-vital and subsequent necrotic pulp leads to loss of the tooth. Diagnosis is based on radiography (a radiolucent line /lines) and mobility of coronal segment of tooth. In this study accuracy of cone beam computed tomography (CBCT) was compared with periapical direct digital radiography (CCD) in evaluation of horizontal root fracture in single root teeth. Materials and Methods: This in vitro study was performed on 90 recently extracted single root teeth. In study group horizontal fractures (45 teeth) were done by applying mechanical force of hammer and the each two broken segment were stuck together by glue and then imaging performed by CCD and CBCT. The images were evaluated by two radiologists as a single blind study. Results were analyzed by SPSS software version 22. To comparing sensitivity, specificity, positive and negative predictive value using Wilcoxon and MC Nemar analysis and Spearman’s correlation coefficient were calculated. Results: Sensitivity, specificity, positive and negative predictive value in CBCT were 97.8%, 95.6%, 93% 92% respectively and CCD were 86.7%, 66.7%, 80% and 85% respectively. Accuracy of CBCT was 93% and that of CCD was 60%. Conclusion: Add conclussion. The above statement is results. [ABSTRACT FROM AUTHOR]

Background and Objective: The preparation of the root canal (i.e., cleaning and shaping) is the main step in the endodontic treatment. The nickel-titanium rotary files result in fewer errors during the preparation of curved canals. This study aimed to compare the transportation of Neolix and Reciproc rotary systems in curved canals using cone beam computed tomography (CBCT). Materials and Methods: In this experimental study, 70 extracted curved premolar teeth from patients referred to dentistry faculty were assigned into two groups (n=35). The preparation of the canals was performed by the Neolix and Reciproc rotary systems. Remaining dentin thickness, transportation, and canal-centering ratio were evaluated and compared using CBCT images before and after the instrumentation. The data were analyzed in SPSS software (version.19) through ANOVA, independent t-test, and paired t-test. Results: There was a significant difference in terms of remaining dentin thickness in three sections of 3, 5, and 7 mm from the apex, before and after the instrumentation regarding the level of mesiodistal and buccolingual. However, no significant difference was observed in terms of the transportation in three sections of 3, 5, and 7 mm from the apex in both Neolix and Reciproc systems. Conclusion: According to the results, both Neolix and Reciproc rotary systems showed high efficacy in root canal shaping. The amount of transportation in these systems during preparation of curved canals was very low leading to the protection of canal-centering ratio.

Introduction: The facial oral pain and symptoms of sinusitis is one of the concerns of patients especially dentists which can be associated with Haller cells. The aim of this study was to evaluate the prevalence of Haller cells of an Iranian population and its relationship with inflammatory sinus disease using CBCT images. Materials & Methods: In this descriptive- analytical research (in 2018) samples were selected from all available CBCT images of patients referring to Tabriz school of dentistry. Haller cells cases were selected and the samples were examined for the presence of inflammatory sinus disease in the coronal and axial sections. The data from CBCT images were entered in NNT viewer version 2.17 and the images were reviewed by two oral and maxillofacial radiologists. Then agreement between the two observers was measured by Kappa coefficient. Data were analyzed using SPSS 20 and Chi-Square test and p value < 0.05 was considered. Results: For total sinuses, the prevalence of Haller cells was 44.5% and it was 70.3% for chronic sinusitis. Haller cells were 48.4% unilateral and 52.6% bilateral. There was no significant difference in the frequency of Haller cells between men and women. Statistical analysis showed there was significant correlation between Haller cells presence and sinusitis (p value < 0.05). Conclusion: According the results of this study, people with Haller cells are more likely to develop inflammatory sinus disease. [ABSTRACT FROM AUTHOR]

Introduction: Although using panoramic images of the third impacted molars and assessing their proximity to mandibular canal, this technique has limitations such as two-dimensional nature and magnifications occurred which calls to use a three-dimensional radiographic modalities such as CBCT. This study compared the location of the mandibular third molar’s roots regarding the inferior alveolar canal using panoramic radiography and CBCT techniques. Materials & Methods: In a descriptive-analytical trial, 103 radiographic images of the patients’ impacted mandibular third molars were selected from the archives of Radiology Department of Tehran Dental School and assessed by means of panoramic and CBCT techniques. Three oral & maxillofacial radiologists assessed the positions of the mandibular third molars’ roots regarding the inferior alveolar canal in the panoramic and CBCT images at 2 time intervals. The assessments were repeated for next 2 weeks again. And then they were done on CBCT images. Frequency and percent of panoramic signs indicating the proximity of the mandibular third molars regarding buccal, lingual and medial positions of the teeth were obtained among the observers and 2 time intervals and the results were statistically analyzed by chi-square test. Significance level was considered to be 0.05 (p value = 0.05). Results: Of total 103 impacted mandibular third molars, 56 (54.4%) had lingual location, 25 (24.3%) had medial location and 22 (21.3%) shoed buccal locations of the roots towards mandibular canal (p value < 0.002). The frequency of the root deflections (p value < 0.003), diversion of canals (p value < 0.03), narrowings of the roots (p value < 0.005), interruption of the borders (p value < 0.006) and narrowing of the canals (p value < 0.04) were higher in the buccal positions of the third molar roots towards the mandibular canal compared to other positions. The differences were statisticaly significant in some cases. However, the frequency of darkening of the roots (p value < 0.04) was higher in the lingual positions of the third molars than other positions. The agreements of the obervers was acceptable when assessing the images regarding indices of the proximity of third molars’ roots and mandibular canal. Conclusion: Then, CBCT technique is a valuable tool to assess the location of the mandibular impacted third molars regarding the inferior alveolar canal. Using CBCT images of impacted third molars, the risk of damage to the alveolar nerve can be reduced. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVE: Anatomical variations of ostiomeatal complex have an imperative role in pathologies of sinonasal complex, ventilation obstruction and success of surgical treatments. The purpose of this study was to evaluate the anatomical variations of osteomeatal complex in cone beam computed tomography images in North of Iran. METHODS: In this cross-sectional retrospective study, 159 CBCT images were analyzed. Anatomical variations evaluated included Concha bullosa, Paradoxical middle turbinate, Uncinate process hypertrophy and pneumatization, hypertrophied Bulla ethmoidalis, Agger nasi cell, Maxilo-ethmoidal cell (Haller's cell) which were assessed based on the frequency, gender, unilateral/bilateral appearance and the involved side in unilateral cases (left/right). Also, two observers evaluated the data simultaneously and the result of final agreement was recorded on the checklists.The data were analyzed descriptively and analytically. FINDINGS: From among 159 subjects, 76 (47.8%) were female and 83 (52.2%) were male. The patients were 18-80 years old (mean: 34.96±14.50 years). Agger nasi cell and concha bullosa which were observed in 143 (98.9%) and 151 (95%) cases, respectively, were the most common findings and often appeared bilaterally. The least frequency belonged to hypertrophied bulla ethmoidalis which was 9 (5.7%) and uncinate process hypertrophy which was 12 (7.5%). Paradoxical middle turbinate, uncinate process pneumatization, and Haller's cell were observed in 28 (17.6%), 57 (35.8%), and 61 (38.4%) cases, respectively. No significant relationship was found between gender and the anatomical variations. (p > 0.05) CONCLUSION: In the present study, Concha Bullosa and Agger Nasi Cell were the most common anatomical variations in CBCT images of paranasal sinuses, which were reported bilaterally

Background and Objectives: The anatomy of maxillary molars is very complicated and root canal therapy for this specific group of teeth is a major challenge for dentists. Given the limitations of conventional techniques for finding the second mesiobuccal canal (MB-2) and anatomical differences observed in different ethnicities, this study aimed to determine the anatomy of mesiobuccal root canal in maxillary first permanent molars using CBCT (Cone-beam computed tomography) in Rafsanjan city. Materials and Methods: In this descriptive study, 41 promax 3D CBCT radiographs of patients in Rafsanjan in 2018 were studied. To investigate the root morphology, after obtaining multiple planar reformation (MPR) images in sagittal and axial planes, evaluation was done by Vertucci classification. Data were analyzed using chi-square test or Fisher's exact test. Results: Of the 41 studied films, one canal was observed in mesiobuccal root in 15 (36.6%) films and two canals in the others 26 (63.4%) films. Among the roots containing two canals, second type of Vertucci classification was the most common type observed. It should be noted that there was no significant relationship between the number of canals and also the type of canals and gender (p=0.495 and p=0.583, respectively) and with quadrant of the tooth (respectively p=0.133 and p=0.669). Conclusion: According to the results of the present study and the amount of two-canal mesiobuccal roots, it can be said that the preparation of CBCT film before root canal therapy in maxillary first molar is necessary to verify the existence and type of MB-2 canal. [ABSTRACT FROM AUTHOR]

Background and purpose: The purpose of mechanical cleaning of the root canal is to clean the canal walls, create a conical shape to facilitate access, effective washing, and filling all areas of the root canal. Errors such as root canal transportation are cuased by excessive dentin removal from the canal. The objective of this study was to investigate root canal transportation by a BT Race rotary and manual file with Cone Beam Computed Tomography (CBCT). Materials and methods: An Ex-vivo study was conducted in 54 extracted first molars. Root curvature was measured by Schneider's method. Preparation was performed in two groups (n= 27 per group) with manual and rotary files. CBCT images were prepared pre and post instrumentation of the canals. SPSS 18 Software was used to measure the amount of canal transportation. Results: The mean differences of canal transportation between the two groups were 0.24 ± 0.16, 0.19 ± 0.13mm, and 0.17± 0.12mm at T1 (1 mm from apical foramen), T2 (2 mm from apical foramen), and T3 (3 mm from the apical foramen), respectively. The total deviation was 0.022mm in this study. The rotary and manual files at T1 (P=0.51) and T3 (P=0.57) were not significantly different in causing transportation but T2 was found to cause significant canal transportation (P=0.027). Conclusion: The average canal transportation in 2mm canal from the apical foramen by manual files was lesser than the rotary files. BT race and K-flexo file instruments can preserve the curvature of the root canals. Therefore, both systems can be used in clinical settings with minimal apical transportation. [ABSTRACT FROM AUTHOR]

Background and Aims: Immediate implant placement following tooth extraction is a treatment with many advantages. Alveolar bone preservation after immediate implant, need minimum of 2 mm thickness in buccal bone plate. The aim of this study was to evaluate the thickness of buccal cortical bone of maxillary premolars by Cone Beam Computational Tomography (CBCT) technique. Materials and Methods: In this descriptive epidemiological study, Cone Beam Computed Tomography image was obtained from 29 patients (male and female) referred to the radiology department of Jundi Shapoor dental school of Ahvaz from 1393 (Mehr) to 1394 (Shahrivar) for implant insertion insertion. The thickness of buccal cortical bone was measured in 3 and 5 mm apical to the CEJ and root apex, perpendicular to the longitudinal axis. All the measurements were done by two oral and maxillofacial radiologists, separately. Data were analyzed by SPSS22 software, using descriptive statistics, and T-test. Results: The thickness of buccal cortical bone in second premolar was significantly more than 1 mm (P=0.001), but in first premolar, the thickness was close to 1 mm with a non-significant difference (P=0.29). Conclusion: The results of this study showed that immediate implant insertion could be done in the maxillary second premolar area with more predictability compared to the first premolar area. [ABSTRACT FROM AUTHOR]

Introduction: Aging increases the probability of the concurrent incidence of osteoporosis and hypertension. It is demonstrated that antihypertensive drugs can affect bone metabolism. The object of this study was to evaluate the effects of antihypertensive medication on bone mineral density of maxilla and mandible in males over 50 years old using CBCT. Methods: In this analytical cross-sectional study, 174 CBCT images belong to males over 50 years old were selected according to inclusion and exclusion criteria. According to the history of using antihypertensive drugs by the patients, these images set into three groups: control group who did not have any history of hypertension, beta blocker users group (at least 5 years) and calcium-channel blocker users group (at least 5 years). Bone mineral density in each jaw was obtained in four regions using CBCT and the mean of these four values in each jaw was taken as the mean mineral density of that jaw. One-way ANOVA analysis and Tukey post hoc test were used to compare the mean values. Results: In beta blocker group, the mean of mineral density of all regions of maxilla except for incisor region was significantly greater than that for the control group. The difference between these two groups in mandible was statistically significant only at the mean of lower jaw. There was no statistically significant difference between the control group and the calcium-channel blocker group at all regions of maxilla and mandible. Conclusion: It may be preferred to use beta blockers instead of calcium channel blockers to control hypertension in the patients at risk for osteoporosis.

Introduction: Presence of external root resorption in second molars associated with impacted mandibular third molars was not rare. The neglect of this issue may leads to penetration of the pulp and loss of the second molars. The aim of this study was to investigate the incidence and risk factors affecting the external root resorption in second molars associated with mandibular impacted third molars were inclined mesially and horizontally by Cone Beam Computer Tomography (CBCT) images. Methods: In this cross sectional study the samples consisted of 231 scans with mesially and horizontally impacted mandibular third molars. Incidence of external root resorption of second molars and the effects of age, gender and clinical parameters such as location and intensity of external root resorption were considered. Moreover, depth and inclination of impacted mandibular third molar were evaluated by CBCT. The data were analyzed by Chi-square test. Results: The overall incidence of external root resorption in the second molars was 22.08%. Incidence of external root resorption in second molars was significantly related to gender and inclination of third molar. The relations between external root resorption and impaction depth of third molar or the patient's age was not statistically significant. However, the relationship between external root resorption and the intensity or depth of impacted third molar and location of root resorption was statistically meaningful. Conclusion: Patient’s gender and horizontal inclination of third molars are the most important factors affecting the presence of external root resorption in the second molars associated with mesially and horizontally impacted mandibular third molars.

BACKGROUND AND OBJECTIVE: Iatrogenic injury to the inferior alveolar nerve is one of the possible complications in surgical procedures such as implant placement. Considering the anatomic variety in nerve placement, the present study aims to assess the exact position of mandibular canal in the posterior mandibular body using cone beam computed tomography (CBCT). METHODS: CBCT mandible images of 150 patients with mean age of 45 years were used in this cross-sectional study. The cross-sectional profiles of each patient were measured at intervals of 5 mm, starting from 1 mm before mental foramen to the anterior border of the ramus in two age groups, below 50 and above 50. In each profile, the distances from the walls of the mandibular canal to the cranial nerve (CN), inferior nerve (IN), buccal nerve (BN) and lingual nerve (LN) were measured. FINDINGS: 70 men with mean age of 48.91±13.46 years and 80 women with mean age of 41.56±14.41 years participated in this study. The mean distances (mm) on the right and the left were respectively as follows: CN: 10.67±3.83, 10.38±3.73, BN: 4.44±1.42, 4.31±1.37, LN: 2.23±1.15, 2.42±1.23, and IN: 5.75±1.86, 5.63±1.86. According to the separate analysis of the profiles, the mandibular canal in men was more inclined to lingual nerve in buccolingual dimension and was more inclined to the top of the alveolar ridge in the inferior alveolar dimension. In terms of age, the bone in the cranial nerve (CN) in patients under 50 years in all profiles was significantly more than patients above 50 years (p

Background and Aims: Accurate diagnosis of vertical root fracture (VRF) is a fundamental importance in endodontics. Because of poor prognosis of VRF, digital radiographs with two horizontal angles have limitations in VRF detection. Also, Gutta-percha can produce artifacts that impair CBCT scan accuracy. The aim of this study was to compare accuracy of CBCT and digital radiography system in vertical root fracture in endodentically treated teeth. Materials and Methods: In this study, 60 endodentically treated single teeth were selected and randomly coded. The teeth were divided into two groups: 30 with induced root fracture and 30 with no fracture. CBCT scan and digital radiographs with two horizontal angles with a difference of fifteen degrees for all teeth were performed. Two observers assessed the CBCT images and digital radiographies for presence of VRF. The statistical analysis used in this study was Weighted Kappa. Results: CBCT had the highest sensivity (75.8) and specificity (90). Digital radiography with 68.3 sensitivity and 79.1 specificity were not as efficient as CBCT (P<0.05). Conclusion: According to this study, the accuracy of CBCT seems to be higher than that of digital radiography in detecting VRF and provides the most reliable data in comparison of digital radiography. [ABSTRACT FROM AUTHOR]

Introduction: The existing bone is regarded as an important criteria in dental implants. In this regard, the radiographic modality is of great significance in quantifying the remaining bone, and CBCT accurately represents height and width of the existing bone. Therefore, this study aimed to evaluate the frequency distribution of the edentulous posterior mandibular ridge types using cone beam computed tomography in an Iranian population. Methods: In this cross-sectional descriptive study, CBCT scans of 127 patients with full edentulous mandible with an average age of 61.15 were evaluated who referred to a radiology clinic in Tehran. The images were analyzed applying OnDemand3D application and bone height and width of each area were determined. To analyze the collected data, SPSS software (ver,17) was employed applying Fisher's exact test. Results: The ridges were classified in 4 different groups (A,B+,B-w,C-w). The frequency of ridge types A and B + in male and ridge types B-w and C-w in females were demonstrated to be higher. An increase in age led to a reduction in the frequency of type A and a rise in the frequency of type C-w. The mean bone height was higher in males in all areas. In addition, the mean bone width was higher in males in all areas except for the first molar area. Conclusions: The study results indicated that as the age increases, the height of edentulous mandible reduces, while no significant relationship was detected between the bone width and aging. As a result, with aging the evolution of bone was held to be from type A to type C-W.

Background and Aims: Considering importance of recognizing the position of incisive canal before inserting intraosseous implants and bone harvesting from the symphysis and to preventing from adverse effects after these surgeries, using appropriate imaging method is essential and necessary. Due to the high accuracy measurement and high quality of CBCT and also low received dose to patient ̦ the aim of this study was to evaluate and recognize the position of incisive canal using cone beam computed tomography (CBCT). Materials and Methods: In this study, good quality CBCT mandible image of 60 patients including 32 women and 28 men with average ages of 41.3±2.5 were observed for diagnosing and recognizing the position of mandibular incisive canal using three observers separately. Data were statistically analyzed using SPSS software (version 20.0 for Windows, Chicago, IL, USA) and Chi-square and Fisher's exact tests. Results: Horizontal and vertical assessment was independent from the sex of patients. The incisive canal was recognizable in 89.8 percent of specimens. In vertical dimension, in 57.5 percent of specimens the canal was observed in the inferior one third and in 32.25 percent in the medial one third. In horizontal dimension, in 14.75 percent of specimens the canal was observed in the buccal one third, 52.75 percent in the medial one third and 22.25 percent in the lingual one third. Conclusion: The quality of CBCT imaging and its accuracy and resolution can play an important role in the differentiation and determination of the position of incisive canal.

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.

Introduction: Sutures are important intermediaries in the skeletal growth and biomechanical treatments, by changing their morphology during normal growth. The aim of this study was to observe and assess the changes in the morphology of mid-palatal suture in the age group of 8 to 25 years by using cone beam computed tomography (CBCT) images in an Iranian population living in Guilan province. Materials & Methods: This cross-sectional study done based on 128 CBCT images of the patients who referred to an Oral and maxillofacial radiology center in the city of Rasht at 1393 to 1394. Three line status of (1)vast distinct lucent,(2) slim distinct lucent and (3)indistinct and six marginal status of (A)smooth, (B)opened scallop, (C)closed scallop, (D)smooth to open scallop, (E)opened to closed scallop and (F)smooth to closed scallop identified and defined. Data analysis was done by Chi-square, Fisher's exact and one way ANOVA tests with the level of significance less than 0.05. Results: Vast distinct lucent and slim distinct lucent with frequency of %71.1 and %26.6 was the most common Line status of mid-palatal suture, in age range of 16-20 and 11-15 respectively. The most common marginal status was smooth (%57.0) in age range of 16-20, second was opened scallop (%25.0) in age range of 21-25, and closed scallop (%12.5) was the third common status that was in the age range of 11-15. From the point of view of the most marginal status in combination with line status smooth margin in connection with vast and slim distinct lucent was the common status with frequency of %64.68 and %41.2 that we observed subsequently, and the only indistinct line status was connected with closed scallop. There was no significant difference between sex, among mean age levels and totally among different age groups about form and marginal status of the midpalatal suture. Conclusion: It seems that chronological age and gender could not be appropriate standard criteria for determining of developmental status of suture’s line and margin during growth. [ABSTRACT FROM AUTHOR]