A hierarchical deep learning approach for diagnosing impacted canine-induced root resorption via cone-beam computed tomography.

OBJECTIVES: Canine-induced root resorption (CIRR) is caused by impacted canines and CBCT images have shown to be more accurate in diagnosing CIRR than panoramic and periapical radiographs with the reported AUCs being 0.95, 0.49, and 0.57, respectively. The aim of this study was to use deep learning to automatically evaluate the diagnosis of CIRR in maxillary incisors using CBCT images. METHODS: A total of 50 cone beam computed tomography (CBCT) images and 176 incisors were selected for the present study. The maxillary incisors were manually segmented and labeled from the CBCT images by two independent radiologists as either healthy or affected by root resorption induced by the impacted canines. We used five different strategies for training the model: (A) classification using 3D ResNet50 (Baseline), (B) classification of the segmented masks using the outcome of a 3D U-Net pretrained on the 3D MNIST, (C) training a 3D U-Net for the segmentation task and use its outputs for classification, (D) pretraining a 3D U-Net for the segmentation and transfer of the model, and (E) pretraining a 3D U-Net for the segmentation and fine-tuning the model with only the model encoder. The segmentation models were evaluated using the mean intersection over union (mIoU) and Dice coefficient (DSC). The classification models were evaluated in terms of classification accuracy, precision, recall, and F1 score. RESULTS: The segmentation model achieved a mean intersection over union (mIoU) of 0.641 and a DSC of 0.901, indicating good performance in segmenting the tooth structures from the CBCT images. For the main classification task of detecting CIRR, Model C (classification of the segmented masks using 3D ResNet) and Model E (pretraining on segmentation followed by fine-tuning for classification) performed the best, both achieving 82% classification accuracy and 0.62 F1-scores on the test set. These results demonstrate the effectiveness of the proposed hierarchical, data-efficient deep learning approaches in improving the accuracy of automated CIRR diagnosis from limited CBCT data compared to the 3D ResNet baseline model. CONCLUSION: The proposed approaches are effective at improving the accuracy of classification tasks and are helpful when the diagnosis is based on the volume and boundaries of an object. While the study demonstrated promising results, future studies with larger sample size are required to validate the effectiveness of the proposed method in enhancing the medical image classification tasks.

Neurological Risks During Implant Placement in the Anterior Maxilla and Mandible: A Literature Review.

The placement of implants in the anterior maxillary and mandibular region requires esthetic proficiency and surgical finesse. It is important to consider the esthetic outcome while avoiding any type of nerve injury for the patient. In this literature review, anatomical structures of the anterior jaw were reviewed from a gross anatomical and radiographic interpretation. A discussion on the frequency of neurosensory complications for patients as a result of nerve damage in this region was evaluated. The purpose of this literature review was to educate the dental surgeon to consider the anterior jaw's neurological structures when performing procedures like implant surgery. The mandibular incisive canal (MIC) presents as an extension of the inferior alveolar canal that runs between the mental foramina. The MIC is a structure that is easily depicted in cone-beam computed tomography (CBCT) imaging and is present in most subjects in gross anatomical studies. The anterior loop of the mental nerve is another structure that is discussed in this paper. Although its structure is accurately depicted in CBCT images, its anatomical variations in patients can make implant treatment planning difficult. The maxilla contains 2 neurovascular structures that were discussed. First, the nasopalatine canal and its relation and impact on implant placement is evaluated. Case reports are reviewed that outline a prophylactic enucleation and bone grafting of the canal prior to implant placement. Second, the canalis sinuosus, which houses the anterior superior alveolar nerve, is of concern during implant placement in the lateral incisor region. Case reports involving nerve damage with follow-up are discussed.

Laser therapy for dentinal hypersensitivity.

BACKGROUND: Dentinal hypersensitivity is characterized by short, sharp pain from exposed dentine that occurs in response to external stimuli such as cold, heat, osmotic, tactile or chemicals, and cannot be explained by any other form of dental defect or pathology. Laser therapy has become a commonly used intervention and might be effective for dentinal hypersensitivity. OBJECTIVES: To assess the effects of in-office employed lasers versus placebo laser, placebo agents or no treatment for relieving pain of dentinal hypersensitivity. SEARCH METHODS: Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 20 October 2020), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2020, Issue 9), MEDLINE Ovid (1946 to 20 October 2020), Embase Ovid (1980 to 20 October 2020), CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature; 1937 to 20 October 2020), and LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; from 1982 to 20 October 2020). Conference proceedings were searched via the ISI Web of Science and ZETOC, and OpenGrey was searched for grey literature. The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: Randomized controlled trials (RCTs) in which in-office lasers were compared to placebo or no treatment on patients aged above 12 years with tooth hypersensitivity. DATA COLLECTION AND ANALYSIS: Two review authors independently and in duplicate screened the search results, extracted data, and assessed the risk of bias of the included studies. Disagreement was resolved by discussion. For continuous outcomes, we used mean differences (MD) and 95% confidence intervals (CI). We conducted meta-analyses only with studies of similar comparisons reporting the same outcome measures. We assessed the overall certainty of the evidence using GRADE. MAIN RESULTS: We included a total of 23 studies with 936 participants and 2296 teeth. We assessed five studies at overall low risk of bias, 13 at unclear, and five at high risk of bias. 17 studies contributed data to the meta-analyses. We divided the studies into six subgroups based on the type of laser and the primary outcome measure. We assessed the change in intensity of pain using quantitative pain scale (visual analogue scale (VAS) of 0 to 10 (no pain to worst possible pain)) when tested through air blast and tactile stimuli in three categories of short (0 to 24 hours), medium (more than 24 hours to 2 months), and long term (more than 2 months). Results demonstrated that compared to placebo or no treatment the application of all types of lasers combined may reduce pain intensity when tested through air blast stimuli at short term (MD -2.24, 95% CI -3.55 to -0.93; P = 0.0008; 13 studies, 978 teeth; low-certainty evidence), medium term (MD -2.46, 95% CI -3.57 to -1.35; P < 0.0001; 11 studies, 1007 teeth; very low-certainty evidence), and long term (MD -2.60, 95% CI -4.47 to -0.73; P = 0.006; 5 studies, 564 teeth; very low-certainty evidence). Similarly, compared to placebo or no treatment the application of all types of lasers combined may reduce pain intensity when tested through tactile stimuli at short term (MD -0.67, 95% CI -1.31 to -0.03; P = 0.04; 8 studies, 506 teeth; low-certainty evidence) and medium term (MD -1.73, 95% CI -3.17 to -0.30; P = 0.02; 9 studies, 591 teeth; very low-certainty evidence). However, there was insufficient evidence of a difference in pain intensity for all types of lasers when tested through tactile stimuli in the long term (MD -3.52, 95% CI -10.37 to 3.33; P = 0.31; 2 studies, 184 teeth; very low-certainty evidence). Most included studies assessed adverse events and reported that no obvious adverse events were observed during the trials. No studies investigated the impact of laser treatment on participants' quality of life. AUTHORS' CONCLUSIONS: Limited and uncertain evidence from meta-analyses suggests that the application of laser overall may improve pain intensity when tested through air blast or tactile stimuli at short, medium, or long term when compared to placebo/no treatment. Overall, laser therapy appears to be safe. Future studies including well-designed double-blinded RCTs are necessary to further investigate the clinical efficacy of lasers as well as their cost-effectiveness.

The Effect of Composite Thickness on the Stress Distribution Pattern of Restored Premolar Teeth with Cusp Reduction.

PURPOSE: Different thicknesses of restorative material can alter the stress distribution pattern in remaining tooth structure. The assumption is that a thicker composite restoration will induce a higher fracture resistance. Therefore, the present study evaluated the effect of composite thickness on stress distribution in a restored premolar with cusp reduction. MATERIALS AND METHODS: A 3D solid model of a maxillary second premolar was prepared and meshed. MOD cavities were designed with different cusp reduction thicknesses (0, 0.5, 1, 1.5, 2.5 mm). Cavities were restored with Valux Plus composite. They were loaded with 200 N force on the occlusal surface in the direction of the long axis. Von Mises stresses were evaluated with Abaqus software. RESULTS: Stress increased from occlusal to gingival and was maximum in the cervical region. The stressed area in the palatal cusp was more than that of the buccal cusp. Increasing the thickness of composite altered the shear stress to compressive stress in the occlusal area of the teeth. CONCLUSION: The model with 2.5 mm cusp reduction exhibited the most even stress distribution.

Cone Beam CT Analysis of Tempora Bone Pneumatizatioi in Subjects with Unilateral Cleft Lip and Palate.

OBJECTIVES: To evaluate the pneumatization pattern in the temporal bone in patients with cleft lip and palate. METHODS: A retrospective observational analysis of cone beam computed tomography (CBCT) scans of patients with cleft lip and palate was done. The patients were referred for orthodontic treatment and had a unilateral cleft lip and palate and anterior maxillary constriction. Four reference structures were identified to evaluate the extension of pneumatization in the cleft vs non-cleft side temporal bones. RESULTS: Twenty patients had cleft on the left side and nine patients had cleft on the right side, This study found reduced temporal bone pneumatization on the side of the cleft. The mean score of temporal bone pneumatization on the cleft side was 4.7±1.47 while mean score of pneumatization on the non-cleft side was 6.7±1.80 (P<0.001). CONCLUSIONS: Pneumatization of the temporal bone was significantly lower on the side of the cleft and an identification of this change can help in early diagnosis and management of any ear-related conditions in this vulnerable group of patients to make appropriate referrals for specialized care.

Interventions for the management of external root resorption.

BACKGROUND: External root resorption is a pathological process, which tends to occur following a wide range of mechanical or chemical stimuli such as infection, pressure, trauma or orthodontic tooth movement. Although it is predominantly detected by radiography, in some cases root resorption may be identified by clinical symptoms such as pain, swelling and mobility of the tooth. Treatment alternatives are case-dependent and aim to address the cause of the resorption and aid the regeneration of the resorptive lesion. OBJECTIVES: To evaluate the effectiveness of any interventions that can be used in the management of external root resorption in permanent teeth. SEARCH METHODS: The following electronic databases were searched: the Cochrane Oral Health Group Trials Register (to 14 October 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2015, Issue 9), MEDLINE via OVID (1946 to 14 October 2015) and EMBASE via OVID (1980 to 14 October 2015). We searched the US National Institutes of Health Trials Register (http://clinicaltrials.gov) and the WHO Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: We included randomised controlled trials of permanent teeth with any type of external root resorption, which has been confirmed by clinical and radiological examination, comparing one type of intervention (root canal medications and canal filling, splinting or extraction of teeth or the surgical removal of any relevant pathology) with another, or with placebo or no treatment. DATA COLLECTION AND ANALYSIS: Two review authors screened search records independently. Full papers were obtained for potentially relevant trials. If data had been extracted, the statistical guidelines set out in the Cochrane Handbook would have been followed. MAIN RESULTS: No randomised controlled trials that met the inclusion criteria were identified. However, we identified one ongoing study that is potentially relevant to this review and will be assessed when it is published. AUTHORS' CONCLUSIONS: We were unable to identify any reports of randomised controlled trials regarding the efficacy of different interventions for the management of external root resorption. In view of the lack of reliable evidence on this topic, clinicians must decide on the most appropriate means of managing this condition according to their clinical experience with regard to patient-related factors. There is a need for well designed and conducted clinical trials on this topic, which conform to the CONSORT statement (www.consort-statement.org/).

Diagnostic accuracy of 2 cone-beam computed tomography protocols for detecting arthritic changes in temporomandibular joints.

INTRODUCTION: The temporomandibular joint (TMJ) is a complex joint that often develops degenerative joint disease. Clinical examination alone cannot usually diagnose this accurately, and a radiographic examination complements and aids in diagnosis and treatment. The osseous components of the TMJ complex are best imaged using computed tomography. The evolution of cone-beam computed tomography (CBCT) offers a low radiation dose and a high spatial resolution alternative and is becoming the imaging modality of choice for the TMJ. To further reduce the dose and yet not compromise the diagnostic task at hand, some alternative rotation acquisition protocols are available but have not been adequately evaluated. The aim of this study was to evaluate the diagnostic efficacy of 2 CBCT acquisition protocols to detect degenerative changes associated with the TMJ complex. METHODS: Thirty-four TMJs, from 17 dry human skulls, were obtained from the anatomy department at the School of Dental Medicine of the University of Connecticut. The sample consisted of complete dentate and partially dentate skulls with no identifiable markers such as age, sex, or ethnicity. Small and large lesions simulating early and established arthritic changes were created on the mandibular condyle. Each defect was randomly created on the medial pole, articulating surface, or lateral pole. After simulating the articular disc with rubber dam material, the condyle and the glenoid fossa were articulated and positioned in place by a rubber band. The skulls were scanned by using an Accuitomo CBCT scanner (J. Morita Corp, Kyoto, Japan) with 180° and 360° rotation protocols. Two operators scored the lesions and compared the results to the gold standard, which was the master list of where the lesions were made on the condyles. RESULTS: On the 102 randomly selected sites, 39 large and 33 small lesions were made, and the rest of the sites had no lesions. The detection rates for areas with large lesions and areas with no lesions were 100% between the examiners. However, of the 33 small lesions, each examiner was able to identify 32 of them with the 360° scans: a 97.4% detection rate when compared with the gold standard. With the 180° scan, 94.9% of the small lesions were detected when compared with the gold standard, and 96.9% were detected with the 360° scan. The overall interexaminer reliability was over 90% for both imaging protocols (Cronbach's alpha, 92.4% for 180° and 97% for 360°). CONCLUSIONS: Based on the results of this study, the 180° CBCT acquisition protocol can detect small and large arthritic lesions with high reliability and is comparable with the 360° spin acquisition.

Evaluation of alveolar bone dimensions in unilateral palatally impacted canine: a cone-beam computed tomographic analyses.

INTRODUCTION: The purpose of this study was to evaluate the alveolar bone dimensions and arch perimeter discrepancy in unilateral palatally impacted canines. METHODS: This retrospective split-mouth study reviewed 207 cone-beam computed tomography (CBCT) scans of patients with unilateral or bilateral impacted canines referred for orthodontic treatment. Out of 207 CBCT scans, only 39 scans in which canines were unilaterally palatally impacted were approved for the study based on our inclusion and exclusion criteria. Two fiducial lines were used to orient the examiners and standardize the measurements. Arch perimeter, buccopalatal (BP) width, and alveolar height were measured both on the impacted and non-impacted side. Two different examiners measured all the parameters. A one-sample Kolmogorov-Smirnov test was used to examine normality of distribution of outcomes. Wilcoxon Signed Rank tests were used for comparing arch width and alveolar bone height between the impacted and non-impacted sides. For arch perimeter, the paired-sample t-test was used. RESULTS: The arch perimeter, BP width, and alveolar bone height was significantly decreased on the impacted side (P < 0.05). The mean arch perimeter on the impacted side was 41.7 ± 2.5mm compared to 43.5 ± 2.37 on the non-impacted side. Similarly, BP width and alveolar bone height on the impacted side was 6.87 ± 1.08 mm and 18.12 ± 2.28 mm, respectively, whereas on the non-impacted side was 8.70 ± 1.13 mm and 19.49 ± 2.09 mm, respectively. CONCLUSION: There was a significant decrease in the arch perimeter and alveolar bone dimensions (BP width and alveolar bone height) on the impacted side.

Orthokeratinized Odontogenic Cyst: Case of a Rare Peripheral Counterpart.

In this paper, we describe a case of a 57-year-old male with an orthokeratinized odontogenic cyst (OOC), which presented as a diffuse, asymptomatic swelling located on the left posterior aspect of the mandible that together with radiographic and histopathologic findings was diagnosed as a peripheral OOC.

Calcification of the stylohyoid ligament in panoramic radiography and cone beam computed tomography among patients referred for dental implant treatment planning.

BACKGROUND: Calcification of the stylohyoid ligament (SHL) is a common condition noted as an incidental finding in routine radiographic examination. Due to proximity with important neurovascular structures, elongation and calcification may sometimes lead to dysphagia and pain. The objective of this study was to evaluate the incidence of calcified SHL detected on cone beam computed tomography (CBCT) scans and panoramic radiographs (PR) in patients referred for dental implant therapy. METHODS: Retrospective analysis of 30 patients referred for dental implants to the Department of Oral and Maxillofacial Radiology at the University of Connecticut School of Dental Medicine was done. Patients were imaged using Hitachi CB MercuRay CBCT machine, and PRs were obtained using Planmeca panoramic machine. CBCT reconstructions and panoramic images were evaluated for the incidence and pattern of SHL calcification. RESULTS: Nineteen patients (63.3%) had calcified SHLs, 16 of whom were reported to have bilateral involvement. PR was unable to show complete calcification of the ligament in any of the cases, whereas CBCT showed evidence of complete calcification when present (14 cases). CONCLUSION: CBCT was more accurate in determining the pattern and extent of calcification of the SHL in patients undergoing implant treatment planning.

Applications of artificial intelligence in dentomaxillofacial imaging: a systematic review.

BACKGROUND: Artificial intelligence (AI) technology has been increasingly developed in oral and maxillofacial imaging. The aim of this systematic review was to assess the applications and performance of the developed algorithms in different dentomaxillofacial imaging modalities. STUDY DESIGN: A systematic search of PubMed and Scopus databases was performed. The search strategy was set as a combination of the following keywords: "Artificial Intelligence," "Machine Learning," "Deep Learning," "Neural Networks," "Head and Neck Imaging," and "Maxillofacial Imaging." Full-text screening and data extraction were independently conducted by two independent reviewers; any mismatch was resolved by discussion. The risk of bias was assessed by one reviewer and validated by another. RESULTS: The search returned a total of 3,392 articles. After careful evaluation of the titles, abstracts, and full texts, a total number of 194 articles were included. Most studies focused on AI applications for tooth and implant classification and identification, 3-dimensional cephalometric landmark detection, lesion detection (periapical, jaws, and bone), and osteoporosis detection. CONCLUSION: Despite the AI models' limitations, they showed promising results. Further studies are needed to explore specific applications and real-world scenarios before confidently integrating these models into dental practice.

Deep learning for tooth identification and numbering on dental radiography: a systematic review and meta-analysis.

OBJECTIVES: Improved tools based on deep learning can be used to accurately number and identify teeth. This study aims to review the use of deep learning in tooth numbering and identification. METHODS: An electronic search was performed through October 2023 on PubMed, Scopus, Cochrane, Google Scholar, IEEE, arXiv, and medRxiv. Studies that used deep learning models with segmentation, object detection, or classification tasks for teeth identification and numbering of human dental radiographs were included. For risk of bias assessment, included studies were critically analysed using quality assessment of diagnostic accuracy studies (QUADAS-2). To generate plots for meta-analysis, MetaDiSc and STATA 17 (StataCorp LP, College Station, TX, USA) were used. Pooled outcome diagnostic odds ratios (DORs) were determined through calculation. RESULTS: The initial search yielded 1618 studies, of which 29 were eligible based on the inclusion criteria. Five studies were found to have low bias across all domains of the QUADAS-2 tool. Deep learning has been reported to have an accuracy range of 81.8%-99% in tooth identification and numbering and a precision range of 84.5%-99.94%. Furthermore, sensitivity was reported as 82.7%-98% and F1-scores ranged from 87% to 98%. Sensitivity was 75.5%-98% and specificity was 79.9%-99%. Only 6 studies found the deep learning model to be less than 90% accurate. The average DOR of the pooled data set was 1612, the sensitivity was 89%, the specificity was 99%, and the area under the curve was 96%. CONCLUSION: Deep learning models successfully can detect, identify, and number teeth on dental radiographs. Deep learning-powered tooth numbering systems can enhance complex automated processes, such as accurately reporting which teeth have caries, thus aiding clinicians in making informed decisions during clinical practice.

The effect of He-Ne and Ga-Al-As laser light on the healing of hard palate mucosa of mice.

Low-level laser therapy (LLLT) has been used to accelerate wound healing, yet questions remain concerning its therapeutic applications. This study aimed to compare the healing efficacy of helium-neon (He-Ne) red light (laser) and gallium aluminum arsenide (Ga-Al-As) infrared lasers at two different doses on hard palate wounds. In a randomized controlled study, 75 adult male mice were divided into five groups of 15 each, after undergoing identical surgical procedures; a control group, with no laser irradiation; HD1 and HD2 groups, treated with He-Ne laser (wavelengths 632.8 nm, power 5 mW, and spot size 0.02 cm(2)) at doses of 4 J/cm(2) and 7.5 J/cm(2) respectively; and GD1 and GD2 groups, treated with Ga-Al-As laser (wavelengths 830 nm, peak power 25 mW, and spot size 0.10 cm(2)) at the doses of 4 J/cm(2) and 7.5 J/cm(2), respectively. Five animals from each group were killed on the third, seventh, and 14 days after surgery, and biopsies were made for histological analysis. On the 3rd and 7th day after the surgery, the number of polymorphonuclear cells (PMN) in HD1, HD2, GD1, and GD2 groups was significantly lower than that of the control group. On the 7th and 14th day, the fibroblasts and new blood vessels counts and collagen density fibers in HD1, HD2, GD1, and GD2 groups were also significantly higher than that of the control groups, and the fibroblast counts and collagen density fibers in HD1 and HD2 groups were higher than that of the GD1 and GD2 groups. LLLT with He-Ne laser compared to Ga-Al-As laser has a positive healing effect on hard palate gingival wounds in mice regardless of the radiation dose.

Artificial Intelligence (AI) for Detection and Localization of Unobturated Second Mesial Buccal (MB2) Canals in Cone-Beam Computed Tomography (CBCT).

The aim of this study was to develop a deep learning model to automatically detect and segment unobturated mesial buccal 2 (MB2) canals on endodontically obturated maxillary molars depicted in CBCT studies. Fifty-seven deidentified CBCT studies of maxillary molars with clinically confirmed unobturated MB2 canals were retrieved from a dental institution radiology database. One-hundred and two maxillary molar roots with and without unobturated MB2 canals were segmented using ITK-SNAP. The data were split into training and testing samples designated to train and evaluate the performance, respectively, of a convolutional neural network (CNN), U-Net. The detection performance revealed a sensitivity of 0.8, a specificity of 1, a high PPV of 1, and a NPV of 0.83 for the testing set, along with an accuracy of 0.9. The segmentation performance of unobturated MB2 canals, assessed using the custom metric, rendered a mean value of 0.3018 for the testing set. The current AI algorithm has the potential to identify obturated and unobturated canals in endodontically treated teeth. However, the AI algorithm is still somewhat affected by metallic artifacts, variations in canal calcifications, and the applied configuration. Thus, further development is needed to improve the algorithm and validate the accuracy using external validation data sets.

Metal artifact reduction using common dental materials.

OBJECTIVES: To determine the effect of different dental lab materials on cone beam computed tomography (CBCT) metal artifact at different resolutions. METHODS: A total of seven common dental lab materials were molded to a dental sextant of four extracted, restored teeth. In addition to base alone (control), each material was scanned using the Carestream 9600 CBCT unit at three resolutions - 0.3 mm, 0.15 mm, and 0.075 mm - at manufacturer established exposure parameters. A single, representative axial view of each trial was evaluated for metal artifact both quantitatively by histogram analysis and qualitatively by profile plot analysis in ImageJ. RESULTS: No statistically significant differences between the control and the dental materials were found; however, post-hoc tests showed significance between Blu-mousse® and polyvinyl siloxane with dental materials and control, predominantly in lower resolutions. CONCLUSIONS: The current study provides initial evidence on the influence of dental materials have on CBCT metal artifact as described by beam hardening, photon starvation, scatter, and noise, especially at lower resolutions. Blu-Mousse® and polyvinyl siloxane reduced the perceived beam hardening and photon starvation artifact the greatest, relative to other materials, at all three resolutions and lower resolutions, respectively.

The relationship between diabetes and carotid artery calcifications detected via dental cone-beam computed tomography in patients undergoing implant treatment planning.

BACKGROUND: The authors investigated the association between carotid artery calcifications (CACs) detected incidentally on dental cone-beam computed tomographic scans and positive diabetes status. METHODS: Two patient groups were identified retrospectively from a patient database: positive for CACs based on cone-beam computed tomographic scans and positive diabetes status. In addition to demographic characteristics, data including diabetes status and presence, type, and absence of CACs were obtained. A χ2 statistical analysis was completed by means of dividing the data into sets of known CAC and known history of diabetes; significance level was P < .05. RESULTS: To satisfy the a priori power analysis, records from 2010 through 2021 were used. For the positive CAC group, data were obtained from 288 patients (171 men, 117 women) and 68 patients (24%) had a positive diabetes status at the time of cone-beam computed tomography (P < .001). There were significantly more male patients (n = 47) than female patients (n = 21) with diabetes (χ2 = 9.9; P = .002). For the positive diabetes group, data were obtained from 225 patients (149 men, 76 women), and 100 patients (44%) had an identifiable CAC. There were significantly more male patients (n = 73) than female patients (n = 27) with CAC (χ2 = 21.2; P < .001). CONCLUSIONS: There was a significant relationship to diabetes for patients with CACs, indicating potential undiagnosed diabetes. Male patients with diabetes are significantly more at risk of developing CACs. PRACTICAL IMPLICATIONS: People with CAC may be at risk of having undiagnosed diabetes and require heightened awareness during implant treatment planning.

Supernumerary teeth amongst Iranian orthodontic patients. A retrospective radiographic and clinical survey.

OBJECTIVE: To investigate the prevalence, characteristics (malocclusion, location, type) and gender distribution of supernumerary teeth (ST) in an Iranian orthodontic population. MATERIAL AND METHODS: A retrospective study was carried out using radiographs (periapicals, panoramic) and study models of 1751 subjects (870 girls, 881 boys; age range 9-27 years). The Pearson chi-square test was used to determine differences in the distribution of ST when stratified by gender and malocclusion type. RESULTS: Fourteen ST were found in 13 patients (six males, seven females), giving a prevalence rate of 0.74%. The prevalence rate of ST was higher in Class III malocclusions (5.2%) and was a rare finding among Class II malocclusions (0.1%). The occurrence rate of ST was higher in maxilla (78.5%) than in mandible (21.5%). The most common type of ST was the conical form (43%). We did not observe any late-developing paramolar or distomolar ST. CONCLUSION: The prevalence rate of ST in our study was 0.74% and ST were more common among Class III malocclusions.

Comparative assessment of the sealing ability of Nd:YAG laser versus a new desensitizing agent in human dentinal tubules: a pilot study.

Dentinal hypersensitivity is a painful condition that occurs following periodontal treatment. Many treatment alternatives have been considered for this problem, including treatments with laser and dentinal adhesives. This study compared the sealing ability of Nd:YAG laser versus a new resin in scanning electron microscopy (SEM) micrographs. Ten human premolars were sectioned yielding 30 specimens of each premolar, which were randomly divided into three groups. The laser group was irradiated by Nd:YAG laser (1 W, 10 Hz, 60 s), the resin group was treated with the new Seal & Protect resin according to the manufacturer's instructions, and the third group served as the control group and did not receive any interventions. After preparation and gold coating of the samples, they were photographed by SEM at two magnifications (1500× and 4000×). The number and diameter (µm) of the dentinal tubules were recorded in selected fields, and analysis of variance (ANOVA) and Tukey tests were used to determine significant differences between groups. The ANOVA results revealed significant differences in both the mean number (P < 0.001) and diameter (P < 0.05) among the three groups. Further statistical analysis showed a significant difference between the laser group and the resin group in both outcome measures (P < 0.05). Thus, both Nd:YAG laser and the new resin reduced the number and diameter of open dentinal tubules, a result that also explains the desensitization mechanism of these interventions. We further conclude that application of the new resin is more effective than Nd:YAG laser in minimizing the number and diameter of exposed dentinal tubules.

An unusual presentation of osteoblastoma of the maxilla: A case report.

This report presents a rare case of maxillary osteoblastoma in a 17-year-old female. The patient presented with dull pain and facial asymmetry inferior to the left zygoma. An intraoral examination found a painless swelling on the buccal gingival tissue in the left posterior maxilla. Panoramic radiographs and multidetector computed tomographic images revealed an ill-defined, non-corticated, mixed attenuating entity of osseous density located within the left posterior maxilla apical to the left maxillary molars. The entity exhibited a heterogeneous internal structure with a fine granular appearance, and the periphery showed a partial hypo-attenuating rim along the antero-medial aspect. Expansion of the left posterior maxilla accompanied with displacement of the left maxillary sinus floor was noted. External root resorption of the first and second molars was noted, as well as postero-superior displacement of the third molar. The histopathologic diagnosis of the biopsy was osteoblastoma. Complete excision of the tumor was performed.

Interventions for the management of external root resorption.

BACKGROUND: External root resorption is a pathological process which tends to occur following a wide range of mechanical or chemical stimuli such as infection, pressure, trauma or orthodontic tooth movement. Although it is predominantly detected by radiography, in some cases, root resorption may be identified by clinical symptoms i.e. pain, swelling and mobility of the tooth. Treatment alternatives are case-dependant and aim at the removal of the cause and the regeneration of the resorptive lesion. OBJECTIVES: To evaluate the effectiveness of any interventions that can be used in the management of external root resorption in permanent teeth. SEARCH STRATEGY: We searched the following databases in April 2010: The Cochrane Oral Health Group's Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 3); MEDLINE (via OVID) (1950 to April 2010); and EMBASE (via OVID) (1980 to April 2010). We also searched two regional bibliographic databases (IndMED and Iranmedex) and handsearched five Iranian dental journals using free text terms appropriate for this review. SELECTION CRITERIA: Randomised controlled trials comparing any type of intervention including root canal medications and canal filling, splinting or extraction of teeth or the surgical removal of any relevant pathology with each other, or placebo or no treatment applied to permanent teeth with any type of external root resorption which had been confirmed by clinical and radiological examination. DATA COLLECTION AND ANALYSIS: Two review authors conducted screening of studies in duplicate and independently. The Cochrane Collaboration statistical guidelines were to be followed. MAIN RESULTS: 66 trials were identified in our searches none of which matched our inclusion criteria. However, we identified one ongoing study which is potentially relevant to this review and will be assessed when it is published. AUTHORS' CONCLUSIONS: We were unable to identify any reports of randomised controlled trials regarding the efficacy of different interventions for the management of external root resorption. In view of the lack of any high level evidence on this topic, it is suggested that clinicians decide on the most appropriate means of managing this condition according to their clinical experience with regard to patient related factors. Future research should consist of robust clinical trials which conform to the CONSORT statement (www.consort-statement.org/).