Prevalence and predictive parameters of external root resorption caused by retained wisdom teeth.

OBJECTIVES: The aim of this study was to estimate the prevalence and severity of external root resorption (RR) caused by retained third molars (M3), to compare the sensitivity of panoramic radiography (PAN) and cone beam computed tomography (CBCT) and to determine predictive factors for root resorption. MATERIALS AND METHODS: In a retrospective cross-sectional analysis, we included patients (N = 367) who underwent PAN and CBCT imaging between December 2017 and July 2019. Previous orthodontic treatment, age, gender, superimposition of second molars (M2) and M3 on PAN, retention depth, inclination angle and vertical level of contact with the M2 were used as predictor variables. The outcome variable was RR of the M2, graded according to Ericson et al. [1]. Subgroup analyses compared patients with and without suspected resorption in the PAN. RESULTS: While less than 5% of PANs suggested RR associated with M3, CBCT showed RR in 20% of all M2 with adjacent retained M3. The angle of inclination of M3, patient age and vertical level of molar contact emerged as predictive parameters, with mesial inclination, older age and deeper retention associated with increased severity of M2. CONCLUSION: Within the limitations of our study, these data confirm the poor performance of PAN in the diagnosis of RR. CBCT may be helpful in detecting RR in mesioangulated and deeply retained M3 in elderly patients, even when PAN did not suggest pathology. CLINICAL RELEVANCE: Our study may help to decide whether CBCT should be considered prior to M3 surgery.

Survival analysis of primary molars following pulpectomy performed under dental general anesthesia: a five-year retrospective study.

BACKGROUND: Currently, the indications for pulpectomy of primary molars performed under dental general anesthesia vary across countries. Therefore, we retrospectively investigated the five-year survival rate of primary molars following pulpectomy performed under dental general anesthesia and the impact of this treatment on permanent successors, assessed the risk factors related to overall survival and clarified the indications for pulpectomy. METHODS: The medical records of children receiving pulpectomy of primary molars under dental general anesthesia from August 1, 2013, to November 30, 2023, were reviewed. Potential risk factors, including gender, age, general health, tooth type, tooth location, endodontic diagnosis and quality of root filling, were assessed via univariate and multivariate Cox proportional hazards regression models, and the survival rate was examined via the Kaplan‒Meier technique. Moreover, the rate of resorption of the root canal filling materials, degree of resorption of the overfilled/over-extended root canal filling materials and development of permanent successors were assessed by clinical and radiographic examination. RESULTS: The study included 320 teeth from 161 children (86 boys and 75 girls). The overall five-year survival rate was 38.2%, and the mean overall survival time was 54.2 months. Endodontic diagnosis was considered a significant risk factor (P < 0.05). In the first, second and third years, 57.4%, 81.8%, and 94.8%, respectively, of obturation materials in the root canals were resorbed at a faster rate than the roots. There was an altered eruption direction in 7 permanent teeth, and 4 permanent teeth were diagnosed with enamel hypoplasia. CONCLUSIONS: In this study, the 60-month survival rate of primary molars treated by pulpectomy under dental general anesthesia was 38.32%. Operators should have an accurate assessment of the status of the pulp, have a strict grasp of the preoperative indications and select the appropriate treatment method according to the guidelines. Individual cases suggest overfilling, overextension and periapical periodontitis in primary molars have an impact on enamel hypoplasia and altered eruption direction in permanent teeth.

A novel toothbrush with a thin-head, slender-neck and super-tapered bristles enhancing accessibility in hard-to-reach areas: a crossover randomized trial.

BACKGROUND: Toothbrushing is the most commonly used method to physically remove dental plaque. However, there are many areas of the mouth that are difficult to reach with a toothbrush. The type of toothbrush is a critical factor influencing the effectiveness of oral care. The purpose of the study was to evaluate a toothbrush with a thin head, slender-neck and super-tapered bristles to target hard-to-reach areas in the oral cavity for reducing dental plaque and gingivitis. METHODS: This crossover study included 58 adults aged 20 years and older. All participants were randomly assigned to use test and control toothbrushes (the latter had a normal head and round bristles) for two 4-week phases. Participants brushed their teeth twice daily in their habitual manner. At the start and end of each phase the Silness-LÓ§e plaque index (PI), LÓ§e -Silness gingival index (GI) and bleeding-on-probing index (BOP) were assessed and performed plaque fluorescence tests using quantitative light-induced fluorescence technology. RESULTS: After using the test toothbrush, PI, GI and BOP decreased by 25%, 30% and 48%, respectively (P < 0.05). For the rearmost molars, PI, GI and BOP decreased by 18%, 26% and 47%, respectively (P < 0.05). For the implants, GI and BOP decreased by 31% and 57%, respectively (P < 0.05). The plaque fluorescence tests indicated that after using the test toothbrush, the dental plaque area for the anterior teeth and the simple plaque score for the rearmost molars decreased by 25% (P < 0.05) and 14% (P = 0.527), respectively. CONCLUSIONS: The test toothbrush was markedly better than the control toothbrush at reducing dental plaque and gingivitis. In particular, the test toothbrush produced an excellent reduction in dental plaque and gingivitis for the rearmost molars and the implants. TRIAL REGISTRATION: KCT0009669, retrospectively registered 02/08/2024.

Comparison of Three Management Approaches for Dental Caries in Primary Molars: A Two-Year Randomized Clinical Trial.

AIM: to compare two-year clinical success rates of caries management in children (Hall Technique HT, Nonrestorative caries treatment NRCT, Conventional restorations CR), and to evaluate pain perception, behaviour, technique acceptability by patients, parents and dentists. METHODS: 122, 3-8-year-olds were enrolled in 2-year parallel group randomised controlled trial (CR, n=52, HT, n=35, NRCT, n=35). Caries was recorded using Nyvad criteria to measure clinical success/ failure rates. Child's pain perception (Visual Analogue Scale of Faces), child behaviour (Frankl scale), parents' and dentists' treatment opinions (5-point Likert scale) were assessed. Statistical analysis included Chi-square, non-parametric Kruskal-Wallis, Bonferroni-corrected Mann-Whitney U tests (p<0.05), absolute risk reduction (ARR) and number needed to treat (NNT). RESULTS: After two years, with 116 participants, clinical success rates were: CR=60.8% (n=31), HT=93.8% (n=30), NRCT=42.5% (n=14) (p<0.001). Major/minor failure rates differed: CR=17.6% (n=9) / 21.6% (n=11); HT=6.2% (n=2)/ 0%, NRCT=33.3% (n=11)/ 24.2% (n=8), (p<0.05). When comparing HT to CR, ARR = 0.33; NNT= 3 (95% CI 0.02 -0.58); NRCT to CR, - no observed benefit from NRCT. More than 70% of children demonstrated "positive/definitely positive" behaviour during treatment. Pain intensity was "very low/low" in 92.3% CR, 88.6% HT, and 77.1% NRCT, respectively. NRCT was "very easy" to perform for 82.9%, compared to CR 42.3% and HT 17.1% (p<0.05). CR were reported to be longer than NRCT and HT (p<0.05). CONCLUSION: Clinical success rates of HT were superior to CR and NRCT. All treatment techniques were well tolerated by children, CR was more time-consuming and HT - technically more difficult to perform. CLINICAL SIGNIFICANCE: caries management in primary molars can be successfully performed using minimal intervention, particularly, sealing in caries lesions with Hall technique. NRCT can prevent caries progression when adequate access to mechanical plaque disruption and fluoride is provided. However, occasional fluoride application, and uncontrolled toothbrushing with fluoride toothpaste cannot replace restorative procedures.

Impacted third molar surgery in older patients-Is patient´s age really a risk factor for complications?

OBJECTIVES: The aim of this study was to analyze the influence of patients´ age on perioperative complications in impacted third molar surgery and how established risk factors are affected by age. MATERIALS AND METHODS: The clinical findings, digital panoramic radiographs and perioperative data of 200 patients (554 impacted third molars) that had been subjected to tooth extraction, from July 2023 until July 2024, were analyzed. Perioperative complications (Inferior alveolar nerve (IAN) hypesthesia, oroantral communication (OAC), lingual nerve (LN) hypesthesia, postoperative bleeding, postoperative infection) as well as impaction patterns and risk factors (angulation type, bone coverage, depth- and risk scores) were analyzed by age (cut-off 30 years). RESULTS: The population was divided into two groups by age (Group A = ≥ 30 years (n = 52) vs. Group B = < 30 years (n = 148)). Upper third molars showed significantly deeper bone coverage, higher depth scores, higher risk scores and different angulation types in patients aged < 30 years. Mandibular third molars showed significantly deeper bone coverage, higher depth scores, higher risk scores according and different angulation types in patients aged ≥ 30 years. However, IAN hypesthesia, LN hypesthesia, postoperative bleeding and postoperative infection did not show any significant differences regarding patients' age. CONCLUSION: The current findings suggest that age (cut-off 30 years) does not statistically correlate with a higher risk for postoperative complications in impacted third molar surgery in contrast to recent publications. CLINICAL RELEVANCE: In contrast to recent publications, the present study falsified a positive correlation between patients' age and the occurrence of postoperative complications in impacted third molar surgery. Therefore, other risk factors should be investigated in order to minimize these procedure specific complications.

"Evaluation of Silver Diamine Fluoride Modified Atraumatic Restorative Treatment (SMART) on hypomineralized first permanent molar"- a randomized controlled clinical study.

BACKGROUND: Restoring first permanent molars affected with molar incisor hypomineralization (MIH) is challenging. Focusing on improving the quality of life for children affected by MIH, at least until the complete eruption of first permanent molars to receive full coverage, to decrease the hypersensitivity and to be able to perform proper oral hygiene measures, the purpose of this study was to compare silver modified atraumatic restorative technique (SMART) versus the conventional restoration and fluoride varnish application on moderate to severe hypomineralized molars. The comparison considered the restoration survival, hypersensitivity, and digital surface area changes after one year follow up. METHODS: Twenty-eight children were selected (20 girls and 8 boys) with at least 2 MIH molars with the same defect severity. The study comprised 2 groups; MOD group (moderate hypomineralized molar severity) and SEV group (Severe hypomineralized molar severity) (n = 28 tooth). Each group was further subdivided into 2 subgroups according to the technique of restoration: SMART subgroup and CONV subgroup (high viscosity glass ionomer restoration and fluoride varnish application) (each = 14 tooth). Evaluation was done in terms of the restoration survival (6 months and 12 months), hypersensitivity at 1 weak, 6 months and 12 months and occlusal surface area changes at 12 months). Professional Fluoride varnish application and home prophylaxis using MI paste were the protocol for each child patient. RESULTS: There was no significant difference between the 4 subgroups, regarding tooth restoration integrity at 6-months vs. 12-months. However, a statistically significant difference in tooth restoration integrity between the 4 subgroups at 12-months (P = .049). Also, the hypersensitivity score, there was a statistically significant difference between the 4-time intervals (P < .001) and a statistically significant difference in surface area changes between the 4 subgroups. CONCLUSIONS: Selective removal of carious tissue and SMART restoration, combined with dental home and professional preventive measures every 3 months maintained the integrity of restorations in severely and moderately affected permanent molars up to 1 year. TRIAL REGISTRATION: The study protocol was retrospectively registered on Clinical Trials (NCT05931822-05/ 07/2023).

Prevalence of radix accesoria dentis in a northern Peruvian population evaluated by cone-beam tomography.

Radix accessoria dentis are anatomical variations of the mandibular molars and identifying them radiographically can be challenging for the clinician, especially in specific areas such as endodontics. The objective this study was to determine the prevalence of radix accessoria dentis evaluated in cone-beam computed tomography in a northern Peruvian population. The study design was descriptive and cross-sectional. The sample consisted of 2640 permanent mandibular first and second molar teeth evaluated by cone beam tomography. Non-probabilistic convenience sampling was used. For the analysis of radix accesoria dentis, the axial and coronal views of the tomography were evaluated. Prevalence was evaluated according to sex and according to type of tooth and average length. The statistical analyses used were the chi-square test and Kruskal-Wallis H test to find the correlation of the variables. A prevalence of 2.5 % of radix accesoria dentis was determined. According to sex, radix accesoria dentis was present in 1.36 % in females and 1.14 % in males (p > 0.05). The tooth 4.6 obtained the highest prevalence with 1.33 % (p > 0.05) and the average length of radix accesoria dentis found was 9.27 mm (p > 0.05). The prevalence of the radix accesoria dentis evaluated in cone beam tomography in a northern Peruvian population is low. Sex does not influence its presentation. Mandibular first molars are the ones that present the greatest amount of this anatomical variation and the average length of the radix accesoria dentis is less than 10 mm.

Evaluation of Microleakage Using Different Luting Cements in Kedo Zirconia Crowns: An In Vitro Assessment.

Introduction A space between the prepared tooth and the cemented crown can cause microleakage, allowing microorganisms to enter, which in turn leads to the breakdown of the luting cement. To achieve an optimum fit, several factors should be considered, including the type of crown used, the taper of tooth preparation, and the type of cementing agent. Aim The purpose of the current study is to evaluate the microleakage of zirconia crowns cemented with glass ionomer cement (GIC), resin-modified GIC (RMGIC), and self-adhesive resin cement. Materials Forty-five primary mandibular molars were divided into three groups: Group I receiving GIC, Group II receiving RMGIC, and Group III receiving self-adhesive resin cement. These cements were used to lute the teeth with Kedo zirconia crowns. The restored samples underwent thermal cycling and were assessed for microleakage under a stereomicroscope. For the statistical analysis, SPSS version 23.0 was used. Descriptive statistics were presented as frequencies and percentages. Analytical statistics, including the Mann Whitney U test, were used to assess the differences in the level of microleakage between the groups at p < 0.05. Results The Mann Whitney U test revealed no significant difference in the level of microleakage between GIC and RMGIC (p = 0.072). However, self-adhesive resin cement showed significantly less microleakage than GIC (p = 0.000). Similarly, when comparing RMGIC and self-adhesive resin cement, the latter showed significantly less microleakage than the former (p = 0.001). Conclusion Microleakage of Kedo zirconia crowns on mandibular first molars was highest when luted with GIC, followed by RMGIC, and was least when luted with self-adhesive resin cement.

Cone beam computed tomography analysis of the root and canal morphology of the maxillary second molars in a Syrian subpopulation.

AIM: To investigate the root number and morphology of the maxillary second molars in the Syrian population besides bilateral symmetry, and the effect of gender. METHODS: 250 Cone Beam Computed Tomography (CBCT) images (140 females, 110 males) were examined by two endodontists. The detailed analysis included the number of roots, the number of canals and their configurations, bilateral symmetry, and relation to gender. The evaluation was made according to Vertucci classification by analyzing the CBCT images at all levels (Axial, Coronal, Sagittal, Oblique, and 3D). The Chi-square statistical analysis was performed to compare the canals' morphologies and bilateral symmetry in both genders via SPSS. RESULT: The most common shape of the upper second molars is three roots (90.4%). There were significant differences between males and females regarding the symmetry of the number of roots (P < 0.05). The root canal configuration was mainly Vertucci type I classification in the Distobuccally (93.4%) and palatal root (99.6%). The most common type in the mesial root was type I (29.5%), showing all varieties of Vertucci classifications (except VII, and VIII) percentage of MB2 of 70.5%. The ratio of symmetry was (59.6%) with no significant statistical difference between the genders (P = 0.708). CONCLUSION: Most maxillary second molars in the examined Syrian population were types (II) (associated with MB2 cases with three roots and four canals). In terms of symmetry, the number of roots surpassed the canal configuration. Males had a greater symmetrical tendency in the number of roots than females.

Cone-beam computed tomographic analysis of canal convolution in mesial root of mandibular second molars and a proposed new classification.

Aim: The aim is to evaluate the anatomical characteristics of mesiolingual and mesiobuccal canals in mandibular second molars particularly in terms of its exit direction, distance of confluence from the minor constriction, and the angle of confluence. Materials and Methods: The cone-beam computed tomography images of hundred mandibular second molars were analyzed. Endodontically treated teeth and those with anatomical variations such as C-shaped canal configuration were excluded from this study. The distance of the confluence from the minor constriction, angle of confluence, and the exit direction of the mesiobuccal and the mesiolingual canals were assessed. Data were analyzed using an independent t-test. Results: The course of the mesiobuccal and mesiolingual canals beyond the confluence was towards the center of the root. The average angle of confluence was 32.75°-35.28°. The average distance of confluence from the minor constriction was 2.19 to 2.68 mm. The mesiolingual canal was straighter whereas the mesiobuccal canal had a tortuous course. Considering the results of the present study, a new classification has been proposed for the root canal morphology of the mesial root of mandibular second molars. Conclusion: The variation in the morphology of mandibular second molars highlights that the mesiolingual canal presented a mild curvature through and beyond the confluence when compared to the mesiobuccal canal which exhibited a tortuous course through the confluence.

Protocol for Diagnostic Test Accuracy Study: Evaluation of Cone Beam Computed Tomography (CBCT) in Prediction of Inferior Alveolar Nerve Injury as Compared to Orthopantomography (OPG) Secondary to Surgical Removal of Impacted Mandibular Third Molars.

Introduction Impairment of the inferior alveolar/dental nerve (IAN) is a relatively uncommon complication after lower wisdom tooth removal. Studies report varying incidences of IAN injury, with dysesthesia being noted as particularly distressing and 0-0.9% cases extending for a long duration. Neurosensory disruptions can severely impact speech, chewing, swallowing, and social interactions, leading to chronic pain and a lower quality of life. It also poses a risk of inadvertent injuries during meals. Although orthopantomogram (OPG) is primarily used for diagnosis, but when the lower wisdom tooth and nerve are in close approximation, cone beam computed tomography (CBCT) is recommended, despite its higher cost and radiation exposure. A white paper on third molar management necessitates further research on CBCT's role, citing conflicting evidence. Further in a multicentric trial, the difference between the OPG versus CBCT group was not statistically significant due to the low incidence of IAN injuries. They have emphasized the need for more well-designed studies to reach a statistically significant conclusion by meta-analyses. Hence, this study aims to provide additional evidence. Methods It is a two-arm, parallel, diagnostic study design involving individuals between the ages of 18 and 50 years, requiring lower wisdom tooth removal that is closely approximated with the nerve. Eligible adults, based on the specified inclusion/exclusion criteria, will be recruited into the study; informed consent will be obtained; then assigned randomly to the OPG or CBCT group using a random computer-generated sequence. Extractions will be done under local anesthesia using a standard surgical protocol with odontectomy. Surgical variables will include the experience of the surgeon, amongst others. The outcome variables will be recorded using patient interviews (subjective) and objective examinations from day one up to six months after surgery. The primary outcome will comprise the number of patients reporting abnormal sensations post-surgery. Secondary outcomes will include objectively confirmed IAN injuries and permanent IAN injuries (>6 months). Results will be analyzed statistically to look for significance and possible risk factors associated with it. Results If a statistically significant result is obtained, then we can deliberately reduce CBCT referrals and reserve them only for high-risk cases, wherein the risk of IAN injury cannot be predicted by OPG alone. If the experience of the surgeon proves to be an important risk factor, then it can also help refer high-risk patients to surgeons with more experience. Conclusion If CBCT proves to be statistically superior to OPG in the prediction of nerve injury, then we will be able to avoid significant morbidity and improve the quality of life of such patients by either modifying the surgical steps or by choosing other conservative treatment modalities. Further, this may reduce unnecessary CBCT referrals, thus reducing radiation exposure, the cost to patients, and, in turn, national healthcare expenditure. Besides, CBCT is not available at all centers, so a lot of low-risk patients can be managed safely at primary health centers, thus reducing the urban patient load.

Postoperative pain after total pulpotomy and root canal treatment in mature molars according to the new and traditional classifications of pulpitis: a prospective, randomized controlled trial.

BACKGROUND: The aim of this study was to compare postoperative pain following total pulpotomy (TP) and root canal treatment (RCT) in mature molar teeth with irreversible pulpitis. To compare the traditional pulpitis classification system with the Wolters system in evaluating postoperative pain. METHODS: Eighty mandibular molars with irreversible pulpitis were included and classified according to the Wolters (moderate/severe pulpitis). The teeth were randomly assigned to two groups (RCT or TP). RCT was performed following standardized protocols. TP was performed to the level of the canal orifices, and hemostasis was achieved with 2.5% sodium hypochlorite. A 3 mm layer of MTA was placed as the pulpotomy material. The teeth were restored with glass ionomer cement followed by composite. Pain scores were recorded preoperatively and, at 6, 12, 24, 48, and 72 h and 7 days after the interventions. The data were statistically analyzed using the Mann-Whitney U test, the Friedman test, the Wilcoxon signed-rank test, and the Spearman's correlation test. The significance level was set at 0.05. RESULTS: Sixty-four patients were analyzed at the one-week follow-up and all were diagnosed as irreversible pulpitis according to the AAE; 22 teeth were classified as moderate and 42 teeth were classified as severe pulpitis according to Wolters. There was no significant difference between TP and RCT in pain scores in moderate pulpitis patients (p > 0.05). There was a significant difference between TP and RCT at 24 and 72 h of severe pulpitis; higher pain scores were observed in the RCT (p < 0.05). CONCLUSIONS: In patients with moderate pulpitis, the TP procedure allowed symptom relief more quickly than RCT. In patients with severe pulpitis, TP provided for significantly lower pain scores compared to RCT at both 24 and 72 h. CLINICAL TRIAL REGISTRATION: The study was retrospectively registered with ClinicalTrials.gov (NCT05923619). Date of Registration: 06/16/23.

Incidence and Pattern of Mandibular Impacted 3rd Molars and Their Relationship with the Mandibular Canal in Population of Jizan Province of Saudi Arabia: A Retrospective Radiographic Study.

Introduction: Impacted mandibular third molars pose challenges in dental practice, often requiring surgical intervention. This retrospective study aims to analyze the demographics, impaction patterns, and anatomical relationships of impacted mandibular third molars among Saudi patients. Methodology: Data from 722 patients visiting the Department of Maxillofacial Surgery and Diagnostic Sciences at Jizan University were retrospectively analyzed. Parameters including gender distribution, impaction types, relationship with the mandibular canal, and age demographics were evaluated based on panoramic radiographs. Results: Bilateral impaction predominated (57.59%), with mesioangular impaction being the most common (46.51%). Gender differences were noted in impaction types and relationships with the mandibular canal. Interruption of white lines of the canal was more frequent in males (70.00%). Early adulthood (20-25 years) exhibited the highest prevalence of impaction. Conclusion: The study provides insights into the demographics and characteristics of impacted mandibular third molars among Saudi patients. Gender-specific variations and age distribution underscore the importance of tailored treatment approaches and early intervention.

Comparison of Piezosurgery Devices and the Use of Rotatory Devices for the Extraction of Impacted Mandibular Third Molars.

The present study aimed to examine the extraction of impacted mandibular third molars by using rotatory and piezosurgery equipment. Twenty-five patients of both genders who required surgery to remove their third molars were split into two groups (control group and research group). In the surgical extraction of the impacted mandibular third molar, in the study group, a piezotome was used to remove the bone, while in the control group, a bur was used. Patients' acceptance of bone cutting, the length of the operation, discomfort and bleeding during the procedure, postoperative pain, swelling, trismus, and wound healing were evaluated. A statistically insignificant difference was observed for age and difficulty index. The intraoperative bleeding was similar in both groups. Both the groups tolerated the bone cutting well, with slightly better values for the piezo group. Based on Pederson's difficulty index, the scores of difficulty of extraction of the impacted tooth were measured between the groups. The slight difficulty was observed in 9 (36%) each in the study group and control group. The moderate difficulty in 14 (56%) of control group and 15 (60%) of study group. Severe difficulty was found among 2 (8%) in the control group and 1 (4%) in the study group. The difference was not significant (P > 0.05). Intraoral bleeding was moderately seen in 25 in both groups. Among the study and control groups respectively no intraoperative pain was seen in 14 and 16, mild intraoperative pain in 11 and 7, and moderate intraoperative pain in 0 and 2. Among group I and II acceptance to bone cutting was comfortably seen in 24 and 23, bearable in 1 and 2 respectively. The difference was not significant (P > 0.05). Piezosurgery and bur were comparable in evaluating patient acceptance, intraoperative duration, intraoperative bleeding and pain, postoperative pain, edema, trismus, and wound healing.

Orthodontic treatment for substitution of impacted mandibular second molars with their adjacent wisdom teeth.

A distinctive method for extraction of the bilateral impacted mandibular second molars (MM2s) and moving the bilateral mesioangularly impacted mandibular third molars (MM3s) to the MM2 positions with appropriate occlusion by orthodontic uprighting and protraction was demonstrated in a 24-year-old woman and a 20-year-old woman, respectively. Although the surgical procedures should be performed under general anesthesia, rapid orthodontic treatment after tooth extraction aided in the initial teeth movement of the bilateral MM3s. The proposed treatment could be implemented and completed in 2 years or less. After undergoing the orthodontic treatment, the patient achieved robust bone support no matter with or without bone grafting. With this less technique-sensitive method, the patient still achieved improved posterior occlusion and masticatory function. Oral and maxillofacial surgeons should be consulted before this treatment option was adopted.

Comparison of Faster R-CNN, YOLO, and SSD for Third Molar Angle Detection in Dental Panoramic X-rays.

The use of artificial intelligence algorithms (AI) has gained importance for dental applications in recent years. Analyzing AI information from different sensor data such as images or panoramic radiographs (panoramic X-rays) can help to improve medical decisions and achieve early diagnosis of different dental pathologies. In particular, the use of deep learning (DL) techniques based on convolutional neural networks (CNNs) has obtained promising results in dental applications based on images, in which approaches based on classification, detection, and segmentation are being studied with growing interest. However, there are still several challenges to be tackled, such as the data quality and quantity, the variability among categories, and the analysis of the possible bias and variance associated with each dataset distribution. This study aims to compare the performance of three deep learning object detection models-Faster R-CNN, YOLO V2, and SSD-using different ResNet architectures (ResNet-18, ResNet-50, and ResNet-101) as feature extractors for detecting and classifying third molar angles in panoramic X-rays according to Winter's classification criterion. Each object detection architecture was trained, calibrated, validated, and tested with three different feature extraction CNNs which are ResNet-18, ResNet-50, and ResNet-101, which were the networks that best fit our dataset distribution. Based on such detection networks, we detect four different categories of angles in third molars using panoramic X-rays by using Winter's classification criterion. This criterion characterizes the third molar's position relative to the second molar's longitudinal axis. The detected categories for the third molars are distoangular, vertical, mesioangular, and horizontal. For training, we used a total of 644 panoramic X-rays. The results obtained in the testing dataset reached up to 99% mean average accuracy performance, demonstrating the YOLOV2 obtained higher effectiveness in solving the third molar angle detection problem. These results demonstrate that the use of CNNs for object detection in panoramic radiographs represents a promising solution in dental applications.

Estimating the Extraction Time of an Upper Third Molar: Proposal and Validation of Results.

Background: Numerous studies in the literature have aimed to evaluate the difficulty level of removing third molars. However, most of these studies have focused on the lower third molars, which can lead to complications. There is a lack of a method to determine the complexity of upper third molar extraction. Therefore, this study's objective was to develop an equation using multiple linear regression to estimate the extraction time of an upper third molar based on its complexity. Methods: This study involved patients enrolled in the Master of Oral Surgery program at the University of Seville. To determine their relationship with surgical time, the researchers analyzed various factors, such as depth, root morphology, and the need for odontosection. They then validated their findings by studying patients treated at Palmaplanas Hospital in Mallorca. Results: The cohort analysis from the University of Seville revealed significant associations between surgical time and the identified factors. A regression equation design was performed to predict the total duration of surgical intervention for wisdom teeth extraction. This equation incorporates several independent variables, represented by Xi, together with a constant term, C, and the corresponding coefficients, Bi, which weight the impact of each variable on the intervention time. The results are as follows: -0.312 (spatial relationship), 0.651 (depth), -0.443 (bone and mucosa integrity), 0.214 (roots), -0.745 (ostectomy), 0.713 (odontosection), and -0.426 (suture). Upon application of the statistical methodology to the Palmaplanas Hospital cohort, a regression coefficient of 0.770 was determined. This indicates a strong correlation between the input data and the estimated surgical time. Conclusions: In conclusion, the proposed formula demonstrates notable validity in predicting the surgical time required to extract upper third molars.

Micro-Computed Tomographic Analysis of Radicular Dentin Thickness in Mandibular Second Molars Across Diverse Anatomic Root Variations: Identifying Potential Danger Zones.

INTRODUCTION: This study aimed to investigate radicular dentin thicknesses in mandibular second molars (MSMs), considering variations in root configuration and the morphology of the pulp chamber floor (PCF). The types of radicular grooves and potential danger zones were also identified. METHODS: A total of 149 MSMs were scanned with micro-computed tomographic imaging and classified into 4 groups according to root fusion and PCF morphology as follows: (1) 45 with fused roots and C-shaped PCFs, (2) 45 with fused roots and non-C-shaped PCFs, (3) 14 with a single canal, and (4) 45 with separated roots. The first 2 groups were subdivided into Ω-shaped, U-shaped, and V-shaped radicular groove subgroups. Measurements included minimum and mean dentin thickness from the start of the radicular groove or root bifurcation extending 5 mm apically, the ratio of outer to inner dentin thickness, and the distribution of dentin thickness. RESULTS: Ω-shaped and U-shaped subgroups showed significant thinner minimum inner wall thickness than V-shaped subgroups at 2-5 mm from the starting point of the radicular groove in both C-shaped and non-C-shaped pulp floor categories (P < .05). The mesial roots of separated rooted MSMs showed significant thinner dentin than a non-C-shaped floor regarding minimum and mean inner thickness and mean outer thickness (P < .05). Teeth with a single canal had significantly thicker walls compared with the other 3 groups. CONCLUSIONS: In MSMs, caution must be exercised, especially in the presence of Ω-shaped and U-shaped grooves in C-shaped roots and around the root furcation of separated roots.

A retrospective study on the outcome of pulpotomy with iRoot BP plus in primary molars and its relationship with hemostasis time.

BACKGROUND: Pulpotomy is a crucial method to preserve primary teeth until natural exfoliation. This study aimed to evaluate the clinical and radiographic outcomes of pulpotomy with iRoot BP Plus in primary molars and to explore the association between hemostasis time and these outcomes. METHODS: Primary molars that underwent iRoot BP Plus pulpotomy and were followed for at least 12 months were selected for this study. Clinical and radiographic data were collected, and the success rate was analyzed in relation to factors such as hemostasis time, tooth type, and arch type. The tests of significance used were the chi-square test, Fisher's exact test, or Kruskal-Wallis test. Statistical significance was set at P < 0.05. RESULTS: A total of 183 teeth in 106 patients were included in the analysis. The follow-up period fell into a range of 1-3 years, with a mean of 1.6 years. The clinical and radiographic success rates were 96.7% and 92.9%, respectively. The earliest time to observe the radiographic failures was half a year after the treatment, and the latest time was two years after the treatment. Among all the teeth, 130 were recorded with hemostasis time before the application of iRoot BP Plus. Compared to teeth with a hemostasis time of 5 min or less, teeth with a hemostasis time exceeding 5 min showed no significant differences in clinical and radiographic success (P = 1.000 and 0.879). Additionally, neither arch nor teeth type showed a relationship with the pulpotomy success rate (P > 0.05). CONCLUSIONS: Pulpotomy using iRoot BP Plus in primary molars achieved favorable results. The hemostasis time may not significantly impact the outcomes of pulpotomy using iRoot BP Plus in primary molars.

Eruption and caries status of first permanent molars in children aged 6-7 years in Shijingshan District, Beijing, China.

BACKGROUND: Dental caries is still a major disease that affect the oral health of people in China. First permanent molars (FPMs) are the most caries-susceptible teeth among school-aged children. The aim of this study was to investigate the eruption and caries status of first permanent molars in children aged 6-7 years in Shijingshan District, Beijing, China, to provide information for oral health promotion. METHODS: The study was a cross-sectional survey conducted in 6-7-year-old first grade children from public elementary schools in Shijingshan District, Beijing. Participants were invited to receive a clinical oral examination. The eruption status and caries experience of FPMs were recorded. Questionnaires assessing children's sociodemographic information and oral health-related behaviors were completed by the children's parents or guardians. RESULTS: A total of 3,176 children, including 1,644 boys (51.8%) and 1,532 girls (48.2%) were included in the oral examination and questionnaire. Eruption status of FPMs was as follows: 37.5% fully erupted, 28.3% partially erupted, 34.2% not erupted. Girls had more erupted FPMs than boys (70.1% VS 61.8%, P < 0.001). The prevalence of dental caries in FPMs was 5.5% (174/3,176) in studied children. The mean decayed missing filled teeth score of FPMs was 0.11 and the mean decayed missing filled surface score of FPMs was 0.19. Binary Logistic regression analysis demonstrated that girls had more tooth decay than boys and father's educational background also associated with the caries experience of the studied children (P < 0.05). CONCLUSIONS: Around two-thirds of FPMs were fully erupted or partially erupted among children aged 6-7 years old in Shijingshan District, Beijing. Approximately 5% of the newly erupted FPM established dental caries. Effective intervention should be applied in this age group for oral health promotion.