Risk and prevalence of oral cancer in patients with different types of lupus erythematosus: a systematic review and meta-analysis.

OBJECTIVE: The objective of this study was to assess the risk and prevalence of oral cancer in patients with systemic lupus erythematosus (SLE) or discoid lupus erythematosus (DLE). STUDY DESIGN: The review included observational cohort and cross-sectional studies that investigated the incidence or prevalence of oral cancer in adults with confirmed diagnoses of SLE or DLE. Studies were selected based on predefined eligibility criteria, including the use of specific diagnostic criteria for SLE and DLE. After searches in PubMed/MEDLINE, EMBASE, Scopus, Web of Science, LILACS, and LIVIVO databases and gray literature for relevant studies, the selection process was conducted by independent reviewers. RESULTS: A total of 5,545 articles were identified. After screening, 8 studies met the inclusion criteria. The pooled risk estimate indicated a significantly increased risk of oral cancer in patients with SLE (risk ratio = 2.69; 95% confidence interval, 1.75 to 4.16; I2 = 0%; P = .78) compared with the general population. The pooled prevalence of oral cancer in patients with DLE was 10% (95% ci, 0.03 to 0.13; I2 = 59%; P = .12). CONCLUSIONS: This review provides evidence supporting an elevated risk for individuals with SLE or DLE developing oral cancer. The findings highlight the importance of monitoring oral mucosa in patients with these conditions.

The effect of the die material used in the indirect technique on the fracture resistance of a restored molar.

The aim of this study was to evaluate the effect of different die materials used in the indirect resin composite restorative technique on the fracture resistance and failure mode of restored molars and compare it with the direct resin composite restorative technique. Two flexible die silicone materials for dental models (Die Silicone - Voco and Scan die - Yller) and a type IV dental stone material (Fujirock EP - GC) were evaluated. Sixty third molars were selected and divided into four groups: indirect resin composite restoration - Die silicone (IRCR-DS); indirect resin composite restoration - Scan die (IRCR-SD); indirect resin composite restoration - Fujirock EP (IRCR-FR), and direct resin composite restoration (DRCR). Class II MOD cavities were prepared with 5 mm of buccolingual width and depth. The specimens were restored and subjected to an axial compression load until fracture, and the data were analyzed by one-way ANOVA and Tukey's HSD test (α=.05). The fracture mode was classified into restorable and unrestorable fractures. Fracture resistance values were influenced by the die material used for the IRCR fabrication and by the restorative technique (p<.001). Fracture resistance mean values and standard deviation were: IRCR-DS: 1835.5 ± 324.0 A; IRCR-SD: 1732.5 ± 384.1 AB; IRCR-FR: 1419.3 ± 318.8 BC; and DRCR: 1100.6 ± 224.9 C. Restorable fracture was more prevalent. IRCR with flexible die casts promoted higher fracture resistance and lower prevalence of unrestorable fractures.

The effect of pulp volume and impact direction on the stress and strain distribution during an impact.

BACKGROUND/AIM: Dentoalveolar trauma has a high incidence in different age groups, including the extremes, children, and older people. Mouth aging leads to some changes, one of them being the pulp volume reduction. The aim of this study was to evaluate the influence of different pulp cavity volumes and the impact direction on the stress and strain distribution of a maxillary central incisor. MATERIAL AND METHODS: Twenty cone beam computed tomography sets of images were selected and the pulp cavity volume was measured by ITK-SNAP software. The mean pulp cavity volume for age group of 10- to 12-year-olds was calculated to obtain the largest one. Subsequent reductions (25%, 50%, 75% and 100%) in the pulp volume values were made to simulate the aging process. The maxilla anterior segment was modeled in the Rhinoceros 5.0 software. The three-dimensional volumetric mesh was generated using the Patran software (MSC. Software), with isoparametrics, 4-noded tetrahedral elements, and exported to Marc/Mentat (MSC. Software) as element number 134. A non-linear dynamic impact analysis was performed in which a steel ball reached the central incisor at a speed of 5 m/s in the horizontal or vertical direction. The stresses were evaluated by modified von Mises stresses. The strains and the total displacement were also recorded. RESULTS: The pulp volume mean value for the age group of 10- to 12-year-olds was 65.05 mm3 . Stress concentrations were slightly different for the different pulp volumes. Impact directions resulted in different stress distribution. Higher stress values were present with the horizontal impact (range between 25.18 MPa and 24.08 MPa for enamel and 38.89 MPa and 37.03 for dentin) when compared to vertical impact (range between 15.30 MPa and 14.58 for enamel and 24.77 to 22.03 MPa for dentin). Total displacement was different for the two impact directions and higher for the horizontal impact. CONCLUSION: Pulp volume did not significantly affect the stress, strain, and total displacement during the impact but the impact direction did affect the evaluated parameters during impact.

Influence of the technical parameters of CBCT image acquisition on vertical root fracture diagnosis: a systematic review and meta-analysis.

OBJECTIVES: To evaluate the influence of image acquisition parameters (voxel, FOV, kVp, mA) on the accuracy of cone-beam computed tomography (CBCT) in detecting vertical root fracture (VRF). MATERIAL AND METHODS: Searches were performed in 6 main databases and the gray literature, without restrictions of language or date. Observational clinical studies (OCS) and in vitro-extracted teeth (IV) studies were considered eligible for inclusion when investigating the accuracy (sensitivity, specificity) of CBCT in detecting VRF in human teeth. The risk of bias was assessed using QUADAS-2, and a meta-analysis was performed using Review Manager v5.4 software and Jamovi software v1.6. RESULTS: A total of 60 out of 132 articles was included after fulfilling the eligibility criteria. Of these, 54 were IV studies while 6 were OCS. In the IV studies, it was seen that smaller FOV sizes tended to present higher accuracy values. The meta-analysis of the 6 OCS showed that the overall sensitivity and specificity values for 0.08 mm and 0.1 mm voxels were greater (0.84 and 0.79, respectively) than the sensitivity and specificity values for 0.125 mm and 0.2 mm voxels (0.70 and 0.55, respectively). CONCLUSIONS: Despite the uncertain risk of bias found for the IV and OCS studies, smaller voxel and FOV sizes seem to provide more accurate VRF detection values when using CBCT. CLINICAL RELEVANCE: This information is crucial for supporting the clinician when prescribing CBCT in cases of a clinical suspicion of VRF, and contributes to the personalization of the CBCT prescription, thereby ensuring greater accuracy in the VRF diagnosis. Registration This protocol was registered at the PROSPERO database (International Prospective Register of Systematic Review) under registration number CRD42020210118.

The effect of the die material used in the indirect technique on the fracture resistance of a restored molar

Abstract The aim of this study was to evaluate the effect of different die materials used in the indirect resin composite restorative technique on the fracture resistance and failure mode of restored molars and compare it with the direct resin composite restorative technique. Two flexible die silicone materials for dental models (Die Silicone - Voco and Scan die - Yller) and a type IV dental stone material (Fujirock EP - GC) were evaluated. Sixty third molars were selected and divided into four groups: indirect resin composite restoration - Die silicone (IRCR-DS); indirect resin composite restoration - Scan die (IRCR-SD); indirect resin composite restoration - Fujirock EP (IRCR-FR), and direct resin composite restoration (DRCR). Class II MOD cavities were prepared with 5 mm of buccolingual width and depth. The specimens were restored and subjected to an axial compression load until fracture, and the data were analyzed by one-way ANOVA and Tukey's HSD test (α=.05). The fracture mode was classified into restorable and unrestorable fractures. Fracture resistance values were influenced by the die material used for the IRCR fabrication and by the restorative technique (p<.001). Fracture resistance mean values and standard deviation were: IRCR-DS: 1835.5 ± 324.0 A; IRCR-SD: 1732.5 ± 384.1 AB; IRCR-FR: 1419.3 ± 318.8 BC; and DRCR: 1100.6 ± 224.9 C. Restorable fracture was more prevalent. IRCR with flexible die casts promoted higher fracture resistance and lower prevalence of unrestorable fractures.

Risk assessment of inferior alveolar nerve injury after wisdom tooth removal using 3D AI-driven models: A within-patient study.

OBJECTIVE: To compare a three-dimensional (3D) artificial intelligence (AI)- driven model with panoramic radiography (PANO) and cone-beam computed tomography (CBCT) in assessing the risk of inferior alveolar nerve (IAN) injury after mandibular wisdom tooth (M3M) removal through a within-patient controlled trial. METHODS: From a database of 6,010 patients undergoing M3M surgery, 25 patients met the inclusion criteria of bilateral M3M removal with postoperative unilateral IAN injury. In this within-patient controlled trial, preoperative PANO and CBCT images were available, while 3D-AI models of the mandibular canal and teeth were generated from the CBCT images using the Virtual Patient Creator AI platform (Relu BV, Leuven, Belgium). Five examiners, who were blinded to surgical outcomes, assessed the imaging modalities and assigned scores indicating the risk level of IAN injury (high, medium, or low risk). Sensitivity, specificity, and area under receiver operating curve (AUC) for IAN risk assessment were calculated for each imaging modality. RESULTS: For IAN injury risk assessment after M3M removal, sensitivity was 0.87 for 3D-AI, 0.89 for CBCT versus 0.73 for PANO. Furthermore, the AUC and specificity values were 0.63 and 0.39 for 3D-AI, 0.58 and 0.28 for CBCT, and 0.57 and 0.41 for PANO, respectively. There was no statistically significant difference (p>0.05) among the imaging modalities for any diagnostic parameters. CONCLUSION: This within-patient controlled trial study revealed that risk assessment for IAN injury after M3M removal was rather similar for 3D-AI, PANO, and CBCT, with a sensitivity for injury prediction reaching up to 0.87 for 3D-AI and 0.89 for CBCT. CLINICAL SIGNIFICANCE: This within-patient trial is pioneering in exploring the application of 3D AI-driven models for assessing IAN injury risk after M3M removal. The present results indicate that AI-powered 3D models based on CBCT might facilitate IAN risk assessment of M3M removal.

Accuracy of artificial intelligence for tooth extraction decision-making in orthodontics: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to analyze the accuracy of artificial intelligence (AI) for orthodontic tooth extraction decision-making. MATERIALS AND METHODS: PubMed/MEDLINE, EMBASE, LILACS, Web of Science, Scopus, LIVIVO, Computers & Applied Science, ACM Digital Library, Compendex, and gray literature (OpenGrey, ProQuest, and Google Scholar) were electronically searched. Three independent reviewers selected the studies and extracted and analyzed the data. Risk of bias, methodological quality, and certainty of evidence were assessed by QUADAS-2, checklist for AI research, and GRADE, respectively. RESULTS: The search identified 1810 studies. After 2 phases of selection, six studies were included, showing an unclear risk of bias of patient selection. Two studies showed a high risk of bias in the index test, while two others presented an unclear risk of bias in the diagnostic test. Data were pooled in a random model and yielded an accuracy value of 0.87 (95% CI = 0.75-0.96) for all studies, 0.89 (95% CI = 0.70-1.00) for multilayer perceptron, and 0.88 (95% CI = 0.73-0.98) for back propagation models. Sensitivity, specificity, and area under the curve of the multilayer perceptron model yielded 0.84 (95% CI = 0.58-1.00), 0.89 (95% CI = 0.74-0.98), and 0.92 (95% CI = 0.72-1.00) scores, respectively. Sagittal discrepancy, upper crowding, and protrusion showed the highest ranks weighted in the models. CONCLUSIONS: Orthodontic tooth extraction decision-making using AI presented promising accuracy but should be considered with caution due to the very low certainty of evidence. CLINICAL RELEVANCE: AI models for tooth extraction decision in orthodontics cannot yet be considered a substitute for a final human decision.

Risk of oral cancer in patients with graft-vs-host disease: A systematic review and meta-analysis.

OBJECTIVE: This systematic review was undertaken to determine the risk of oral cancer in patients with chronic graft-vs-host disease (cGvHD). STUDY DESIGN: The search was conducted in 6 electronic databases (PubMed/MEDLINE, EMBASE, LILACS, Web of Science, Scopus, and LIVIVO) and gray literature (Google Scholar, Open Gray, and ProQuest) for studies published up to November 2021. RESULTS: Of the 13 cohorts included in qualitative synthesis, 9 were eligible for the quantitative analysis. The meta-analysis showed that the presence of cGvHD increased the risk of developing oral cancer (risk ratio [RR] = 2.78; 95% CI, 1.27-6.08; I2 = 46%; P = .01). A subgroup meta-analysis revealed a higher risk of oral cancer in Asian samples exposed to cGvHD (RR = 2.50; 95% CI, 1.54-4.04; I2 = 0%; P = .0002), which was not seen in the pooled analysis of European samples (P = .24). The overall methodological quality of most studies included was "good." The cumulative evidence (Grading of Recommendations Assessment, Development and Evaluation) was considered moderate and of very low confidence for Asian and European studies, respectively. CONCLUSIONS: Patients with cGvHD resulting from allogenic hematopoietic stem cell transplantation run an increased risk of developing oral cancer. Hence, it is recommended that patients with cGvHD be monitored to allow for the early detection and treatment of secondary malignant disease.

Prevalence of Bruxism in Brazilian Children: A Systematic Review and Meta-Analysis.

Purpose: The prevalence of bruxism in children varies considerably. The purpose of this study was to synthesize evidence of the prevalence of bruxism in Brazilian children and consider how proportions differ between genders, assessment approaches, and geographical regions. Methods: A search was conducted using five databases and in gray literature. Two independent investigators selected the studies and extracted data. The risk of bias was assessed via the Joanna Briggs Institute tool for studies on prevalence. The certainty of the evidence was evaluated using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Results: Twenty-two cross-sectional studies were included after a two-step selection. Overall, 13,076 children from all regions of the country were assessed. The risk of bias ranged from high to low. Data were pooled in a random-effect model and resulted in an overall prevalence of sleep and awake bruxism of 25.8 percent (95 percent confidence interval [95% CI] equals 22.2 to 29.4; I2 equals 96 percent; prediction interval equals 0.07 to 0.44) and 20.1 percent (95% CI equals 18.0 to 22.3; I2 equals 30 percent; prediction interval equals 0.18 to 0.22), respectively. Subgroup and sensibility analysis showed distribution similarity between genders (P=0.96), assessment approaches (P=0.88), and geographical regions (P=0.44). Conclusions: "Possible" and "probable" sleep bruxism affects one in four Brazilian children, and there is evidence with a low level of certainty that its prevalence does not vary between genders, assessment approaches, or geographical regions. The distribution of bruxism is still an unknown subject and presumably occurs because of individual rather than regional or collective factors.

Complications in intraoral versus external approach for surgical treatment of Eagle syndrome: A systematic review and meta-analysis.

OBJECTIVE: The surgical treatment of Eagle syndrome involves an intra- or extraoral approach. This systematic review set out to consolidate current knowledge on the prevalence of complications associated with intraoral and external approaches. METHODS: Seven main electronic and two gray literature databases were searched. Studies were blindly selected by two reviewers based on pre-defined eligibility criteria. Studies evaluating any type of complication in the treatment of Eagle syndrome were considered eligible. Risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for studies reporting prevalence data, case reports, and case series. The Comprehensive Meta-Analysis software (Software version 3.0 - Biostat, Englewood, NJ, USA) was used to perform all meta-analyses. RESULTS: Out of 1728 articles found on all databases, 36 were included for qualitative analysis. Twenty were included for quantitative analysis and meta-analysis. CONCLUSION: In this study, the highest rate of complications was found in the intraoral approach.

Prevalence of mandibular asymmetry in different skeletal sagittal patterns.

OBJECTIVES: To analyze the prevalence of mandibular asymmetry in skeletal sagittal malocclusions. MATERIALS AND METHODS: PubMed/MEDLINE, EMBASE, LILACS, Web of Science, Scopus, LIVIVO and gray literature (OpenGrey, ProQuest, and Google Scholar) were electronically searched. Two independent investigators selected the eligible studies, and assessed risk of bias and certainty of evidence (GRADE). One reviewer independently extracted the data and the second reviewer checked this information. Any disagreement between the reviewers in each phase was resolved by discussion between them and/or involved a third reviewer for final decision. RESULTS: Electronic search identified 5,132 studies, and 5 observational studies were included. Risk of bias was low in two studies, moderate in one, and high in two. The studies showed high heterogeneity. Mandibular asymmetry ranged from 17.43% to 72.95% in overall samples. Horizontal chin deviation showed a prevalence of 17.66% to 55.6% asymmetry in Class I malocclusions, and 68.98% in vertical asymmetry index. In Class II patients, prevalence of mandibular asymmetry varied from 10% to 25.5% in horizontal chin deviation, and 71.7% in vertical asymmetry index. The Class III sample showed a prevalence of mandibular asymmetry ranging from 22.93% to 78% in horizontal chin deviation and 80.4% in vertical asymmetry index. Patients seeking orthodontic or orthognathic surgery treatment showed greater prevalence of mandibular asymmetry. CONCLUSIONS: Skeletal Class III malocclusion showed the greatest prevalence of mandibular asymmetry. Mandibular vertical asymmetry showed a marked prevalence in all malocclusions. However, conclusions should be interpreted with caution due to use of convenience samples and low-quality study outcomes.

Orthodontists' criteria for prescribing cone-beam computed tomography-a multi-country survey.

OBJECTIVES: This study aimed to describe and compare CBCT imaging prescription in clinical practice among orthodontists from five countries in Europe and America. Additionally, it investigated factors associated with the prescribing and the use of guidelines for CBCT imaging. MATERIALS AND METHODS: A cross-sectional survey was carried out using an online questionnaire sent to all registered orthodontists in Belgium, Brazil, Canada, Romania, and the United States of America (USA). The data were analyzed by descriptive statistics, bivariate tests, and Poisson regression. RESULTS: The final sample consisted of 1284 participants. CBCT was prescribed by 84.4% of the participants for selected cases (84.9%), mainly for impacted teeth (92.4%), presurgical planning (54.1%), and root resorption (51.9%). High cost was most frequently the limiting factor for CBCT prescription (55.4%). Only 45.2% of those who were using CBCT imaging reported adhering to guidelines. CBCT imaging prescription was associated with the orthodontists' countries (p < .009, except for Belgium, p = .068), while the use of guidelines was associated with the respondents' country and additional training on CBCT imaging (p < .001). CONCLUSIONS: Orthodontists refer patients for CBCT for selected indications (impacted teeth, root resorption, presurgical planning, dentofacial deformities, as suggested by the international guidelines, and also for upper airway and temporomandibular joint evaluation). Many do not adhere to specific guidelines. There are substantial variations between the countries about the orthodontists' referral for CBCT and guideline usage, irrespective of gender. CBCT prescription may be limited by financial barriers, adhering to specific guidelines and prior CBCT training. CLINICAL RELEVANCE: CBCT prescription among orthodontists must be based on prescription criteria and current guidelines. It is advised to improve CBCT education and training to enhance CBCT selection, referral, analysis, and interpretation in orthodontic practice.

Malignant tumours mimicking periapical lesions: A report of three cases and literature review.

Apical periodontitis shows radiographic signs such as widening of the periodontal ligament and periapical radiolucency, which differ in extent depending on the stage of the lesion. However, other lesions can be associated with or coincidental to the apical region, representing developmental lesions and benign or malignant tumours. This article describes three cases of malignant tumours, a central mucoepidermoid carcinoma (CMEC), a chondroblast osteosarcoma and an osteosarcoma of the jaw (OSJ) that presented as periapical lesions. Endodontists must be aware of unsuccessful treatment, persistent pain, signs of paraesthesia, a rapid growth rate and delayed response to therapy associated with atypical features. Complementary examinations, such as biopsy and computed tomography, can allow the early diagnosis of malignant tumours, leading to a better prognosis and thus increased survival rates and improvement in quality of life.

Fatal necrotizing fasciitis following a non-treated mandibular fracture: case report / Fasciíte necrotizante fatal devido a fratura mandibular não tratada: relato de caso

ABSTRACT Necrotizing fasciitis is a rare and severe infection characterized by extensive and quickly progressing necrosis of the subcutaneous tissue and muscle fascia associated with high mortality rates in the head and neck region. We present a case of fatal necrotizing fasciitis due to an untreated mandibular fracture. Eight days after the trauma, the patient was admitted to the hospital and died on the sixth day of hospitalization.

RESUMO Fasciite necrosante é uma infecção rara e grave caracterizada por necrose extensa e de rápida progressão do tecido subcutâneo e fáscia muscular associada a altas taxas de mortalidade na região da cabeça e pescoço. Apresentamos um caso de fasciite necrosante fatal devido a uma fratura mandibular não tratada. Oito dias após o trauma, o paciente deu entrada no hospital e faleceu no sexto dia de internação.

Is Zirconia Better Than Titanium Abutments for Soft Tissue Color? A Systematic Review and Meta-analysis of Spectrophotometric Evaluation.

PURPOSE: The aim of this systematic review was to evaluate the influence of zirconia and titanium as abutment materials on peri-implant soft tissue color. MATERIALS AND METHODS: The searched electronic databases included MEDLINE/PubMed, LILACS, Web of Science, Scopus, and LIVIVO. Two types of studies were included: randomized clinical trials (RCTs) and controlled clinical trials (CCTs) that compared zirconia (Zr) and titanium (Ti) abutments. The outcomes measured were as follows: implant crown esthetic index, visual analog scale, esthetic index, gingiva discoloration index-spectrophotometry, papilla index, recession index, and pink esthetic score. Two reviewers selected the records, assessed quality, and extracted data of included studies independently. RESULTS: A total of 323 patients enrolled in 13 studies were included in this analysis with 11 RCTs and 2 CCTs. Due to the wide variety of methodologies used, meta-analysis was only possible for RCTs that performed spectrophotometric analysis. The use of zirconia or titanium for implant abutments does not seem to be the principal factor for influencing peri-implant soft tissue color. The meta-analysis showed no difference between zirconia and titanium abutments. CONCLUSION: This study does not support any better advantage of the use of zirconia in comparison to the use of titanium related to peri-implant tissue color.

Factors associated with the morphology of the mandibular symphysis and soft tissue chin.

OBJECTIVES: This study aimed to (I) assess the morphology of the symphysis and soft tissue chin associated with sex, age and sagittal/vertical skeletal patterns, and (II) identify the individual and combined contributions of these variables to different portions of the symphysis. METHODS: This cross-sectional study included 195 lateral cephalometric radiographs from untreated adults. Alveolar, basal, and soft tissue of the symphysis were measured by an X/Y cranial base coordinate system, and divided in accordance to four predictor variables: sex, age, and sagittal/vertical skeletal patterns. Parametric tests were conducted for comparison and correlation purposes, while multiple regression analysis was performed to explore combined interactions. RESULTS: Alveolar inclination is related to sagittal and vertical patterns, and both explained 71.4% of the variations. Alveolar thickness is weakly predicted and poorly influenced by age. Symphysis height was 10% higher in males, and associated with a vertical skeletal pattern and sex, and both explained 43.6% of variations. Basal symphyseal shows an individual thickness, is larger in males, and vertically short-positioned with age. Soft tissue chin is not necessarily related to the size of the underling skeletal pattern, and enlarges with age, even in adulthood. CONCLUSIONS: The symphysis and surrounding tissues are influenced by sex, age, and sagittal and vertical patterns, acting differently on the alveolar, basal and soft tissue portions. Sagittal and vertical skeletal patterns are the strongest association on alveolar symphysis inclination, whereas sex and age acts on the vertical symphysis position and soft tissues thickness.

Binary and WHO dysplasia grading systems for the prediction of malignant transformation of oral leukoplakia and erythroplakia: a systematic review and meta-analysis.

OBJECTIVES: The aim of this systematic review was to examine the evidence of the binary histologic grading system capacity for predicting malignant transformation and to compare it with that of the WHO systems. MATERIAL AND METHODS: A systematic review was conducted, using PubMed, EMBASE, LILACS, Web of Science, Scopus, and LIVIVO databases without any language or timeframe restrictions. Studies were included if they compared the binary and the WHO histologic grading systems in the prediction of malignant transformation of oral epithelial dysplasia (OED). RESULTS: The capacity of the WHO and binary grading systems to predict malignant transformation ranged from 16 to 80% and from 5 to 80%, respectively. The pooled malignant transformation rate of lesions classified as severe dysplasia or carcinoma in situ by the WHO grading was 40% (95% confidence interval (CI), 0.02-0.87; I2 = 92%; P = 0.00), while the corresponding value for lesions classified as high-risk by the binary grading system was 31% (95% CI, 0.00-0.84; I2 = 97%; P = 0.00). Overall, there was no significant difference in prognostication accuracy between the WHO and the binary systems (odds ratio = 2.02; 95% CI, 0.88-4.64). CONCLUSIONS: Although some studies suggest that the binary system is associated with lower inter-rater variability when grading OED, the evidence remains inconclusive on whether this system is superior to that of the WHO at predicting malignant transformation. CLINICAL RELEVANCE: The reproducibility of the binary system has the potential to be better for prognostic purposes. However, there is no high-quality evidence to confirm if this advantage may assist clinicians in decision-making.

Directions of mandibular canal displacement in ameloblastoma: A computed tomography mirrored-method analysis.

PURPOSE: This study was performed to investigate mandibular canal displacement in patients with ameloblastoma using a 3-dimensional mirrored-model analysis. MATERIALS AND METHODS: The sample consisted of computed tomographic scans of patients with ameloblastoma (n=10) and healthy controls (n=20). The amount of mandibular canal asymmetry was recorded as a continuous variable, while the buccolingual (yaw) and supero-inferior (pitch) directions of displacement were classified as categorical variables. The t-test for independent samples and the Fisher exact test were used to compare groups in terms of differences between sides and the presence of asymmetric inclinations, respectively (P<0.05). RESULTS: The length of the mandibular canal was similar on both sides in both groups. The ameloblastoma group presented more lateral (2.40±4.16 mm) and inferior (-1.97±1.92 mm) positions of the mental foramen, and a more buccal (1.09±2.75 mm) position of the middle canal point on the lesion side. Displacement of the mandibular canal tended to be found in the anterior region in patients with ameloblastoma, occurring toward the buccal and inferior directions in 60% and 70% of ameloblastoma patients, respectively. CONCLUSION: Mandibular canal displacement due to ameloblastoma could be detected by this superimposed mirrored method, and displacement was more prevalent toward the inferior and buccal directions. This displacement affected the mental foramen position, but did not lead to a change in the length of the mandibular canal. The control group presented no mandibular canal displacement.

Influence of CBCT metal artifact reduction on vertical radicular fracture detection.

PURPOSE: This study evaluated the influence of a metal artifact reduction (MAR) tool in a cone-beam computed tomography (CBCT) device on the diagnosis of vertical root fractures (VRFs) in teeth with different root filling materials. MATERIALS AND METHODS: Forty-five extracted human premolars were classified into three subgroups; 1) no filling; 2) gutta-percha; and 3) metallic post. CBCT images were acquired using an Orthopantomograph 300 unit with and without a MAR tool. Subsequently, the same teeth were fractured, and new CBCT scans were obtained with and without MAR. Two oral radiologists evaluated the images regarding the presence or absence of VRF. Receiver operating characteristic (ROC) curves and diagnostic tests were performed. RESULTS: The overall area under the curve values were 0.695 for CBCT with MAR and 0.789 for CBCT without MAR. The MAR tool negatively influenced the overall diagnosis of VRFs in all tested subgroups, with lower accuracy (0.45-0.72), sensitivity (0.6-0.67), and specificity (0.23-0.8) than were found for the images without MAR. In the latter group, the accuracy, sensitivity, and specificity values were 0.68-0.77, 0.67-083, and 0.53-087, respectively. However, no significant difference was found between images with and without MAR for the no filling and gutta-percha subgroups (P>0.05). In the metallic post subgroup, CBCT showed a significant difference according to MAR use (P<0.05). CONCLUSION: The OP 300 MAR tool negatively influenced the detection of VRFs in teeth with no root canal filling, gutta-percha, or metallic posts. Teeth with metallic posts suffered the most from the negative impact of MAR.