Inferior Alveolar Canal Research Articles

The Relationship between Impacted Mandibular Third Molar and Mandibular Canal on Orthopantomogram – A Retrospective Study

Background: Surgical removal of the impacted lower third molar teeth require thorough investigations and assessment, one of these very important investigations is orthopantomogram (OPG) which is the primary assessment method, to determine the relationship between impacted mandibular third molar and mandibular canal. The study aims to determine the relationship between impacted mandibular third molar and mandibular canal on orthopantomogram. Materials and methods: A retrospective of 300 OPGs out of 947 OPG were selected using simple random sampling method. Rood’s criteria was used in assessing the relationship between the apex of the roots and upper border of the inferior alveolar canal. Statistical analysis was performed to assess the relationship between the canal and the impacted lower third molar in relation to the age ,gender and type of impaction.Results: From 300 OPG, 473 impacted teeth were identified, the relation showed, the highest percentage was superimposed with 47.3%, followed by close contact (35.7%), and only 21.7% of the impacted teeth examined has distance between the roots and the upper border of mandibular canal.Conclussion:Mesioangular impaction has higher percentage of superimposition with the mandibular canal with the higher percentage of female58% to male42% ratio.

Fractal Analysis of Mandible in Panoramic Radiographs of Patients Received Radiotherapy for Nasopharyngeal Carcinoma

PurposeThis study aimed to assess the impact of radiotherapy on the internal structure complexity of mandibular cortical and trabecular bone and to determine the duration required for a return to healthy values post-radiotherapy. Materials and MethodsPanoramic radiographs from patients undergoing radiotherapy for nasopharyngeal carcinoma were analyzed before and after treatment. Four groups were formed based on post-radiotherapy radiography timing (0-6 months, 6-12 months, 12-24 months, and 24-36 months), comprising a total of 59 cases and 118 radiographs. Fractal analysis was conducted on four bilateral regions (ROI) in both trabecular and cortical bone on each radiograph. Additionally, measurements of inferior alveolar canal width and mandibular cortical width were performed. Mean and maximum radiation dose values to the mandible were measured, and their correlation with changes in fractal dimension, inferior alveolar canal width, and mandibular cortical width values was assessed. ResultsFractal dimension values in regions over trabecular bone showed a statistically significant decrease in all groups, although no significant difference was observed among the four groups. In ROI-4 from cortical bone, a significant fractal dimension decrease was noted in all groups except the 0-6 month group. The magnitude of fractal dimension decrease was higher in the 12-24 and 24-36 month groups compared to the 0-6 month group. inferior alveolar canal width and mandibular cortical width values significantly decreased post-radiotherapy in all groups, with a consistent decrease across the groups. ConclusionsRadiotherapy induces a reduction in the internal complexity of trabecular and cortical bone structures in the mandible. Osteoradionecrosis risk persists even three years post-radiotherapy, suggesting a cautious approach to interventional procedures on the bone.

Comparative Analysis of Impacted Mandibular Third Molar Root Proximity to the Mandibular Canal using Orthopantomography and Cone-beam Computed Tomography Imaging Modalities: A Pilot Study

Abstract Introduction: Fully detect risks of nerve damage, which can lead to temporary or permanent issues. Cone-beam computed tomography (CBCT) offers a three-dimensional (3D) view, providing more detailed visualisation of anatomical structures and their spatial relationships, which improves the accuracy of predicting nerve exposure. The study aims to evaluate and compare these imaging techniques’ effectiveness in categorising the relationship between third molars and the inferior alveolar canal, emphasising the importance of precise imaging for safer surgical outcomes. Materials and Methods: A pilot study involving 20 patients, representing 10% of the total sample size of 200, was conducted at Ahmedabad Dental College’s Department of Oral Medicine and Radiology. Investigators, trained to interpret radiological images from orthopantomography (OPG) and CBCT, compared their interpretations with those of two experts. A high inter-rater reliability was confirmed with a kappa statistic of 0.98. Following ethical approval, data were retrospectively collected from 20 cases, with digital OPG and CBCT images analysed and classified according to established criteria. Results: The results revealed a significant association between the results diagnosed through OPG and CBCT indicating similarity in their diagnosis. It was also seen that there was no bias towards the gender and the distribution was similar in case of diagnosis through OPG or CBCT. Conclusion: CBCT demands an in-depth understanding of anatomy and pathology, coupled with proficiency in operating imaging software and the ability to identify abnormalities in cross-sectional images. When executed and interpreted accurately, CBCT proves to be an exceptionally valuable tool in clinical dental practice. Its detailed 3D imaging capabilities enhance the assessment of complex cases, such as those involving intricate anatomical structures and pathologies. By providing comprehensive views that surpass traditional two-dimensional imaging, CBCT aids in precise diagnosis and treatment planning, making it an indispensable resource for addressing various dental conditions effectively.

Integrative approach for supernumerary teeth: a single-center retrospective analysis.

This study aimed to provide a comprehensive case analysis from a single center, with the objective of clarifying the optimal timing and recommendations for a preferred treatment strategy customized to the specific presentation of each type of supernumerary tooth identified in the research. A retrospective study was conducted on patients who presented with a supernumerary tooth and were treated interdisciplinarily at the clinic. In total, 55 patients with 81 supernumerary teeth of the permanent dentition were analyzed, 30 males and 25 females. The dentition status of the patients was as follows: 31 patients with mixed dentition, no patients with primary dentition, and 24 patients with permanent dentition. The diagnosis of supernumerary tooth was primarily made by general or pediatric dental practitioners and/or orthodontists. Patients were then referred to maxillofacial surgeons for treatment decision. The timing of treatment was mainly determined by the oral surgeon, based on the recommendations of the other specialists involved. Cases involving maleruption or malalignment of permanent teeth required both surgical and orthodontic treatment. Patients over 9 years old were treated either under local anesthesia or sedation, whereas those under 9 years old were treated under deep sedation or general anesthesia. A comprehensive investigation of cases involved the utilization of CBCT at the supernumerary tooth site to facilitate treatment planning. There was a significant correlation between younger age and the preference for treatment under sedation or general anesthesia (P = .01, t test). Similarly, a strong association was found between younger age and the need for additional orthodontic treatment (P = .016, t test). Cases of surgical removal of a supernumerary tooth at a young age typically did not require orthodontic traction of the permanent tooth, in contrast to cases of late surgical intervention (patients over 11 years old), which often did necessitate such traction. There was a strong tendency for treating supernumerary teeth in the maxilla. The proximity of supernumerary teeth to vital anatomical landmarks significantly influenced treatment decisions. Patients with supernumerary teeth near the mental foramen or the inferior dental canal in the premolar area were exclusively placed under follow-up care (P = .002, Pearson chi-square test). However, in the maxilla, the proximity of supernumerary teeth to vital structures such as the floor of the nose and the incisive nerve did not affect the treatment approach, and those supernumerary teeth were mostly removed. A team approach for managing supernumerary teeth is recommended. The timing of treatment should carefully consider the advantages and disadvantages of early versus late intervention. Early surgical treatment in cases where eruption is disturbed might result in spontaneous eruption, eliminating the need for orthodontic traction of the permanent teeth.

Prevalence and topography of bifid and trifid mandibular canal in Turkish Western Anatolia Population: evaluation of the inferior alveolar canal with CBCT.

Various anatomical variations of the inferior alveolar canal increase the incidence of surgical complications; Therefore, this study aimed to evaluate the frequency and configuration of bifid and trifid mandibular canals using cone beam computed tomography (CBCT) in the Turkish subpopulation. The inferior alveolar canal was evaluated on 1014 hemi-mandibles in the CBCT (I-CAT 3D Imaging System) images of 513 patients. The frequency and configuration of the bifid and trifid mandibular canal (MC) were examined. The relationship between bifid MC configuration and dental status and age groups was analyzed. The distance of the accessory canal to the buccal and lingual walls and the alveolar crest was measured. The diameter of the main canal and accessory canal was measured and its relationship with dental status and age groups was evaluated. Bifid MC was found in 266 hemi-mandibles (24.7%) and 212 (41.3%) of 513 patients. The most common type of bifid MC was the retromolar canal (87 sides), followed by the forward canal without confluence (41; 4%) and the dental canal (34; 3.4%). 10 of the dental canals were opening to the 1st molar, 14 of the 2nd molars, and 10 of the 3rd molars. The number of retromolar foramina was 1 on 56 sides, 2 on 15 sides, and 3 on 4 sides. Forward canal without confluence was more common in edentulous patients than in dentulous patients, while the dental canal was more common in dentulous patients. The main canal diameter was 3.53 ± 0.97mm and the bifid MC diameter was 1.82 ± 0.70mm. Distance of the bifid MC to the lingual wall was higher in the > 64years group than in the 18-39years group (p = 0.022). Distance of the bifid MC to the alveolar crest was lower in the > 64years group compared to the 18-39years group and 40-64years group (p = 0.015). The main canal diameter was higher in the 40-64years group than in the 18-39years group (p = 0.012). Bifid MC has a high prevalence, occurring in almost one in two patients. Dental and retromolar types, which are close to the teeth, are more common, and this increases the possibility of complications. CBCT is the most accurate imaging technique used to detect and define these variations.

The effect of occlusal loading on secondary tooth eruption: An experimental study using a rat model.

This study aimed to assess the impact of occlusal loading on secondary tooth eruption and to determine the extent to which altering the occlusal loading influences the magnitude of secondary eruption through an experimental rat model. The present sample consisted of 48 male Wistar rats. At the onset of the experiment, 24 rats were 4 weeks old (young rats) and 24 rats were 26 weeks old (adult). Within each age group, the rats were further divided into two equal subgroups (12 rats each), receiving either a soft- or hard-food diet for the 3-month duration of the experiment. The primary outcome was the tooth position changes relative to stable references in the coronal plane by evaluating the distance between the mandibular first molars and the inferior alveolar canal. Microcomputed tomography scans were taken from all rats at three standardized intervals over the 3-month study period. Descriptive statistics were calculated by age and diet over time, and the evolution of the outcomes were plotted by age and diet over time. Longitudinal data analysis via generalized estimating equations was performed to examine the effect of age, diet and time on the primary outcomes. Secondary tooth eruption was observed in all age groups (young and adult) regardless of diet consistency (soft or hard food). In young rats, the secondary eruption was greater in the animals fed a soft diet than those fed a hard diet. In adult rats, minimal difference in secondary tooth eruption were found between different diet consistencies. Occlusal loading influences secondary tooth eruption in teeth with an established occlusal contact. The quantity of eruption in growing rats is higher when occlusal loading is less, providing a certain amount of secondary tooth eruption occurs. This difference, however, is not evident in adult rats, at least during the given 3-month time frame.

Artificial Intelligence Application in a Case of Mandibular Third Molar Impaction: A Systematic Review of the Literature.

Objective: This systematic review aims to summarize the evidence on the use and applicability of AI in impacted mandibular third molars. Methods: Searches were performed in the following databases: PubMed, Scopus, and Google Scholar. The study protocol is registered at the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY202460081). The retrieved articles were subjected to an exhaustive review based on the inclusion and exclusion criteria for the study. Articles on the use of AI for diagnosis, treatment, and treatment planning in patients with impacted mandibular third molars were included. Results: Twenty-one articles were selected and evaluated using the Scottish Intercollegiate Guidelines Network (SIGN) evidence quality scale. Most of the analyzed studies dealt with using AI to determine the relationship between the mandibular canal and the impacted mandibular third molar. The average quality of the articles included in this review was 2+, which indicated that the level of evidence, according to the SIGN protocol, was B. Conclusions: Compared to human observers, AI models have demonstrated decent performance in determining the morphology, anatomy, and relationship of the impaction with the inferior alveolar nerve canal. However, the prediction of eruptions and future horizons of AI models are still in the early developmental stages. Additional studies estimating the eruption in mixed and permanent dentition are warranted to establish a comprehensive model for identifying, diagnosing, and predicting third molar eruptions and determining the treatment outcomes in the case of impacted teeth. This will help clinicians make better decisions and achieve better treatment outcomes.

Morphometric analysis of the inferior alveolar canal and its foramina in Egyptian children utilizing cone beam computed tomography: An observational retrospective study

Morphometric analysis of the inferior alveolar canal and its foramina in Egyptian children utilizing cone beam computed tomography: An observational retrospective study

Injury to Anatomic Structures Due to Fixation Device in Management of Mandibular Fracture.

ORIF is the gold standard for the management of mandibular fractures. The chances of postoperative complications are due to infection, damage of the inferior alveolar nerve canal, or tooth root during the fixation of the fracture fragments. Fixation hardware placed in the vicinity of the vital structures may encroach on the anatomic structures, leading to postoperative complications. The aim of this study is to evaluate the injury to the anatomic structures in the proximity of the fracture line due to the fixation device. This retrospective study was conducted in a tertiary care teaching hospital from July 2021 to June 2023. The cases of maxillofacial trauma reported and referred from peripheral centers were considered duly, applying the inclusion and exclusion criteria. Patients having mandibular fractures from one mandibular foramen to another with or without associated other facial fractures were treated by ORIF under general anesthesia. The patient was followed up at 1 week, 1 month, 3 months, and 6 months. The cases of postoperative complications were further investigated by CBCT. There were 67 patients (56 males and 11 females) with 86 fracture lines in the age group of 18-55 years with an average age of 35.2 years. Postoperatively 7 patients presented with unilateral paresthesia of the lower lip and chin region. CBCT revealed that the mean distance of the screw from the inferior alveolar nerve canal was 3.02mm. None of these cases had injury to the nerve canal or roots of teeth. All the patients recovered from paresthesia within 6 months. Complications like injury to the inferior alveolar nerve (IAN) with sensory disturbances to the lower lip and chin, as well as tooth/tooth root fractures, may occur due to mandibular fracture, surgical manipulation, and fixation devices. The anatomic structures in the vicinity of the fracture line can be damaged during the fixation of the fracture fragments by the bone plates and screws. In the present study, it was found that 7 out of 67 patients presented with unilateral paresthesia of the lower lip and chin. CBCT analysis showed a considerable distance of 3.02mm from the inferior alveolar nerve canal to the screws. There was no evidence of hardware encroachment on the IAN or tooth roots. Selection and placement of appropriate fixation devices, particularly the length of the bone screws, are crucial to avoid injury to the anatomic structures.

Comparison of quantitative radiomorphometric predictors of healthy and MRONJ-affected bone using panoramic radiography and cone-beam CT.

To determine the most distinctive quantitative radiomorphometric parameter(s) for the detection of MRONJ-affected bone changes in panoramic radiography (PR) and cone-beam CT (CBCT). PR and sagittal CBCT slices of 24 MRONJ patients and 22 healthy controls were used for the measurements of mandibular cortical thickness (MCT), fractal dimension (FD), lacunarity, mean gray value (MGV), bone area fraction (BA/TA), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular number (Tb.N). MCT was measured in the mental foramen region. While FD and lacunarity were measured on mandibular trabecular and cortical regions-of-interest (ROIs), the remaining parameters were measured on trabecular ROIs. The independent samples t-test was used to compare the measurements between the MRONJ and control groups for both imaging modalities (P = .05). MCT was the only parameter that differentiated MRONJ-affected bone in both PR and CBCT (P < .05). None of the remaining parameters revealed any difference for MRONJ-affected bone in CBCT (P > .05). FD, lacunarity, MGV, BA/TA, and Tb.Sp could distinguish MRONJ-affected trabecular bone in PR (P < .05). The correspondent ROI for both imaging methods that was reliable for detecting MRONJ-affected bone was the trabecular bone distal to the mental foramen above the inferior alveolar canal (ROI-3). MCT is a reliable parameter for the discrimination of MRONJ-affected bone in both PR and CBCT images. PR may be used to detect MRONJ-affected trabecular bone using FD, lacunarity, MGV, BA/TA, and Tb.Sp measurements as well.

Radiographic Recognition of Mental Nerve for Secured Dental Implant Placement by Cone-Beam Computed Tomography in Mosul City Population.

The study aims to estimate precisely the different levels of mental loop and foramina in the Mosul population of Nineveh governorate in Iraq. It is a cross-sectional study of a previously saved database in the cone-beam computed tomography device. The study sample was 357 patients selected randomly from the database of patients at the Oral Radiology Unit at the Maxillofacial Department in Al-Salam Teaching Hospital. The study variables are mental foramen (MF) position, shape, radiograph appearance, and mental loop presence and direction. The results show that the age group from 19 to 30 years shows the highest percentage (40.1%). Females show more than half of the cases (59.7%). The MF position's highest percentage is shown in 2 areas with the slight differences. These are the long axis of first premolar and the area between first premolar and second premolar (42.6%, 40.9). According to shape variation round shapes are the uppermost percent (53.8%). More than 60% of cases (66.1%) show continuity with the inferior alveolar canal and 50% show no loop presence, and the mental nerve leaves the foramen in a perpendicular direction. In conclusion localization of the MF, nerve, and its loop precisely in both horizontal and vertical directions, both hard and soft tissues in a continuous view. Before arranging any surgical procedure, anatomic markers are crucial. To reduce the danger of harm to the foramen region, the authors thus advised cone-beam computed tomography before scheduling implant surgery, particularly in the mental region of the jaw.

Inferior alveolar nerve injury resulting from different implant rotary instruments: An ex vivo comparative study in human cadaveric mandibles

The present study aimed to evaluate the degree of nerve injury on inferior alveolar nerve (IAN) by different implant drills resulting from direct canal intrusion into inferior alveolar canal (IAC). A cadaveric study involving 7 human mandibles was performed to evaluate mechanical injury of canal enclosed IAN resulting from different drills. In group 1, osteotomies were created using different drills with 1 mm of intracanal intrusion, simulating accidental drill intrusion into canal. In group 2, drilling was stopped when the tip has breached into IAC, limited by tactile feedback of operator. The depth and width of nerve defects were assessed using optical coherence tomography. A significant difference in defect depth was found (p < 0.001) in group 1. A sinus lift reamer inflicted the least damage (0.068 ± 0.022 mm). It was also found that the mean defect depth was significantly different when a twist drill was used (p = 0.016). Sinus lift reamer can be used safely for osteotomy preparation in mandible when bone height is limited or when radiographic visualization of canal is poor. Bone corticalization around IAC does not provide adequate protection for IAN in the event of accidental intracanal intrusion.

Assessment of Impaction Pattern of Mandibular Third Molars in an Iranian Subpopulation: a Retrospective Cross-sectional Study

Background: Impacted teeth are teeth that cannot be indicated in their physiological position in the expected period. Impacted mandibular third molar (IMTM)is the most common tooth to be impacted. Impaction of the tooth may be accompanied by complications such as pain, swelling, caries, bone loss, and inferior alveolar canal pathology. Because of possible complications of the IMTMs,a surgical extraction may be necessary. Moreover, knowing the pattern of IMTMs can lower the possibility of complications after the surgery.This research aims to evaluate the impaction pattern of the IMTMs in the population of patients referring to the Dentistry faculty of the Guilan University of medical sciences clinic. Methods: In this retrospective analytic cross-sectional study 98 radiographs were gathered and the angulation, depth, and side of impactions, inferior alveolar canal pathology, and decay existence were evaluated. Then each factor was assessed based on age and gender. Analyzing data was done using IBM Statistical Package for the Social Sciences (SPSS) Statistics for Windows, version 21 (IBM Corp., Armonk, N.Y., USA). Conclusion: Mesioangular pattern and level B of impaction depth were the most prevalent position of the IMTMs. Most cases had unilateral impaction and right-sided impaction was more frequent than left-sided.

The alveolar canals and foramina in the first edition of Terminologia Oroanatomica: a preview.

Anatomy was initially developed out of necessity to decrease surgery complications. Over time, anatomists and surgeons have sometimes used different terms for the same anatomical structures, thus resulting in numerous discrepancies in terminology between anatomy and surgery. To avoid any confusion or misunderstanding and to better elucidate the oral anatomy terms, the Federative International Programme for Anatomical Terminology (FIPAT) organized a group of specialists on oral anatomy, Terminologia Oroanatomica (ToA) working group, composed of dentists, anatomy researchers, anatomy educators, oral and maxillofacial surgeons, and oral and maxillofacial radiologists. Within the ToA working group, major anatomical structures in the mandible, such as the mandibular canal, were focused and discussed to determine the most appropriate term, i.e., inferior alveolar canal. Although yet to be approved by the International Federation of Associations of Anatomists (IFAA), this article will preview some changes suggested by the ToA.

Morphological and quantitative study of the inferior alveolar nerve canal in hemifacial microsomia.

This study aimed to probe into the anatomic course of inferior alveolar nerve canal (IANC) in hemifacial microsomia (HFM) on a large scale, morphological observations and further quantitative study were performed. Patients were classified by Pruzansky-Kaban classification. The anatomic course of IANC was analyzed morphologically with three-dimensional (3D) imaging software among 248 patients. Seven distances between fixed landmarks on both sides were measured for 236 patients. The differences between affected and unaffected sides were compared. Significant differences were found in the entrance (P < 0.001), route (P < 0.001), and exit (P < 0.05) of IANC in type IIb and III HFM. The higher the degree of mandibular deformity was, the higher the incidence of IANC variation was (P < 0.05). The distances in the horizontal aspect of IANC including from mandibular foramen to mental foramen (P < 0.05) and from mental foramen to gonion (P < 0.05) were significantly shorter on the affected side. Abnormalities of the anatomical course of IANC exist in patients with Pruzansky-Kaban type IIb and type III HFM. The reduction of IANC on the affected side in the horizontal distance is more obvious. Three-dimensional imaging assessment is recommended before surgery.

Do metal artifact reduction algorithms influence the detection of implant-related injuries to the inferior alveolar canal in CBCT images?

BackgroundThe routine application of dental implants for replacing missing teeth has revolutionized restorative and prosthetic dentistry. However, cone beam computed tomography (CBCT) evaluations of structures adjacent to the implants are limited by metal artifacts. There are several methods for reducing metal artifacts, but this remains a challenging task. This study aimed to examine the effectiveness of metal artifact reduction (MAR) algorithms in identifying injuries of implants to the inferior alveolar canal in CBCT images.MethodIn this in vitro study, mono-cortical bone windows were created and the inferior alveolar canal was revealed. Using 36 implants, pilot drill and penetration damage of the implant tip into the canal was simulated and compared to the control implants with distance from the canal. CBCT images were evaluated by four experienced observers with and without the MAR algorithm and compared to direct vision as the gold standard. The values of accuracy, sensitivity, and specificity were obtained and compared by receiver operating characteristic (ROC) curve (α = 0.05).ResultThe area under the ROC curve values for detection of pilot drill injuries varied between 0.840–0.917 and 0.639–0.854 in the active and inactive MAR conditions, respectively. The increase in ROC area was only significant for one of the observers (P = 0.010). For diagnosing penetrative injuries, the area under the ROC curve values was between 0.990–1.000 and 0.722–1.000 in the active and inactive MAR conditions, respectively. The improvement of ROC curve values in active MAR mode was only significant for one of the observers (P = 0.006).ConclusionActivation of MAR improved the diagnostic values of CBCT images in detecting both types of implant-related injuries to the inferior alveolar canal. However, for most observers, this increase was not statistically significant.

Immediate implant placement in the posterior mandibular region was assisted by dynamic real-time navigation: a retrospective study

BackgroundEfficient utilization of residual bone volume and the prevention of inferior alveolar nerve injury are critical considerations in immediate implant placement (IIP) within the posterior mandibular region. Addressing these challenges, this study focuses on the clinical efficacy and implant accuracy of dynamic real-time navigation, an emerging technology designed to enhance precision in implantation procedures.MethodsThis study included 84 patients with 130 implants undergoing immediate placement in the posterior mandibular region. Stratified into dynamic navigation, static guide plate, and freehand implant groups, clinical indicators, including initial stability, distance to the inferior alveolar nerve canal, depth of implant placement, and various deviations, were systematically recorded. Statistical analysis, employing 1- or 2-way ANOVA and Student’s t-test, allowed for a comprehensive evaluation of the efficacy of each technique.ResultsAll 130 implants were successfully placed with an average torque of 22.53 ± 5.93 N.cm. In the navigation group, the distance to the inferior alveolar nerve and the depth of implant placement were significantly greater compared to the guide plate and freehand groups (P < 0.05). Implant deviation was significantly smaller in both the navigation and guide plate groups compared to the freehand group(P < 0.05). Additionally, the navigation group exhibited significantly reduced root and angle deviations compared to the guide plate group(P < 0.05), highlighting the superior precision of navigation-assisted immediate implant placement.ConclusionsIt is more advantageous to use dynamic navigation rather than a static guide plate and free-hand implant insertion for immediate posterior mandibular implant implantation.

Fully automated deep learning model for detecting proximity of mandibular third molar root to inferior alveolar canal using panoramic radiographs

ObjectiveThis study endeavored to develop a novel fully-automated deep learning model to determine the topographic relationship between mandibular third molar (MM3) roots and inferior alveolar canal (IAC) using panoramic radiographs (PR). Study DesignA total of 1570 eligible patients with MM3s who had paired PR and cone-beam computed tomography (CBCT) from January 2019 to December 2020 were retrospectively collected and randomly grouped into training (80%), validation (10%), and testing (10%) cohorts. Spatial relationship of MM3/IAC was assessed by CBCT and set as the ground truth. MM3-IACnet, a modified deep learning network based on YOLOv5 (You only look once) was trained to detect MM3/IAC proximity using PR. Its diagnostic performance was further compared with dentists, AlexNet, GoogleNet, VGG-16, ResNet-50, and YOLOv5 in another independent cohort with 100 high-risk MM3 defined as root overlapping with IAC on PR. ResultsThe MM3-IACnet performed best in predicting the MM3/IAC proximity as evidenced by the highest accuracy (0.885), precision (0.899), AUC value (0.95) and minimal time-spending compared to other models. Moreover, our MM3-IACnet outperformed other models in MM3/IAC risk prediction in high-risk cases. ConclusionMM3-IACnet model can assist clinicians in MM3s risk assessment and treatment planning by detecting MM3/IAC topographic relationship using PR.

Mandibular changes in a patient suspected with Thalassemia trait: A case report by radiograph finding

Thalassemia is an inherited hemolytic anemia characterized by abnormal synthesis the hemoglobin globin component. A forty-year-old woman presented to a private dentist complaining of a left-sided facial pain and headache that occurred out of the blue. Panoramic radiograph showed severe caries on several teeth, generalized reduction in the alveolar crest, thin lamina dura and changes in trabecular pattern of mandible and the inferior alveolar canal on each side was partially absent. Unmanaged anemia caused ineffective erythropoiesis resulting extensive bone marrow with sparse coarse trabecular. As the mean hemoglobin falls, enhanced osteoclastic bone resorption thus thinning lamina dura, reducing alveolar crest and lacking radiopaque line of inferior alveolar canal. Panoramic is widely used in dentistry, this case report presents a case of patient discovered thalassemia through radiological findings.

The Patterns of Impacted Third Molars and Their Associated Pathologies: A Retrospective Observational Study of 704 Patients.

Background: The study aims to investigate parameters in patients attending Fujairah Dental Center, including assessing the prevalence of impacted teeth, determining the frequency of associated pathological conditions, and evaluating the patterns and angulations of impacted third molars. Methods: It is a retrospective descriptive study of the panoramic radiographs of patients who attended Fujairah Dental Center for dental care between January 2011 and December 2017. The minimum age for inclusion was 17 years. Clinical records were used to obtain the demographic details of patients, such as age, gender, nationality, medical history, and smoking history. Seven hundred and four panoramic radiographs and clinical records of patients were analyzed. The age range was between 17 and 112 years old, with a mean age of 34 years (S.D 13.5). Results: Of the 704 panoramic radiographs evaluated, 236 (33.6%) X-rays showed teeth impaction with a total of 562 impacted teeth in the upper and lower jaws. Five hundred and twenty-five (93.4%) were impacted third molars, and 37 (6.5%) teeth were other kinds of impacted teeth. Females showed a higher frequency of impacted teeth (62.6%) compared to males (37.4%). The highest prevalence of impacted teeth was found in the 17-25 year age group (61%), and the prevalence declined with advancing age. Impacted third molars were more likely to occur in the mandible (57.3%) than in the maxilla (42.7%). Most of the impacted third molars were in the mesioangular position, followed by the vertical position. The evaluation of the depth of impacted third molars demonstrated that level C impaction was the most frequently seen, followed by level B impaction. Impacted third-molar teeth often presented with two roots (60.7%), followed by a single root (31.3%). An evaluation of the relationship between lower third molars and the inferior dental canal (IDC) revealed that the most frequently observed relation was interrupted (61.5%), followed by a distant relation to the ID canal, and 13% were superimposed. The most common morphological pattern of roots of the impacted third molars was either straight-type or curved and dilacerated roots (5.7%). Additionally, the most noticed pathological conditions associated with impacted teeth were carious second molars adjacent to impacted third molars (42%), which was more likely to be seen in the 17-25-year age group, with females having a higher prevalence than males.