Non-infectious granulomatous disorders of the upper lip: clinicopathological analysis of 11 patients.

BACKGROUND: Non-infectious granulomatous disorders of the upper lip represent a special chapter of oral and maxillofacial pathology. In this work we report a case-series of this process, to analyse its main clinicopathological features and find differential data that allow us improve its diagnosis and understand its pathogenesis. METHODS: We present 11 cases of non-infectious granulomatous disorders of the upper lip, 8 women and 3 men with an age range of 29-84 years, who have been attended at the Oral Medicine Department of the IUCT (France) and the Oral Medicine Unit of the UPV/EHU (Spain). All clinicopathological data were collected in a specific protocol. RESULTS: We recognized 4 different subtypes of non-infectious granulomatous disorders of the upper lip: (1) associated with Crohn's disease (1 case), (2) associated with foreign body (2 cases), (3) associated with gingivitis lichenoid-like (4 cases), (4) idiopathic (4 cases). CONCLUSIONS: Clinicopathological differences were identified between these subtypes. A good differential diagnosis is necessary in all cases to rule out the presence of local or systemic etiopathogenic factors.

Comparison of different machine learning approaches to predict dental age using Demirjian's staging approach.

CONTEXT: Dental age, one of the indicators of biological age, is inferred by radiological methods. Two of the most commonly used methods are using Demirjian's radiographic stages of permanent teeth excluding the third molar (Demirjian's and Willems' method). The major drawbacks of these methods are that they are based on population-specific conversion tables and may tend to over- or underestimate dental age in other populations. Machine learning (ML) methods make it possible to create complex data schemas more simply while keeping the same annotation system. The objectives of this study are to compare (1) the capacity of ten machine learning algorithms to predict dental age in children using the seven left permanent mandibular teeth compared to reference methods and (2) the capacity of ten machine learning algorithms to predict dental age from childhood to young adulthood using the seven left permanent mandibular teeth and the four third molars. METHODS: Using a large radiological database of 3605 orthopantomograms (1734 females and 1871 males) of healthy French patients aged between 2 and 24 years, seven left permanent mandibular teeth and the 4 third molars were assessed using Demirjian's stages. Dental age estimation was then performed using Demirjian's reference method and various ML regression methods. Two analyses were performed: with the 7 left mandibular teeth without third molars for the under 16 age group and with the third molars for the entire study population. The different methods were compared using mean error, mean absolute error, root mean square error as metrics, and the Bland-Altman graph. RESULTS: All ML methods had a mean absolute error (MAE) under 0.811 years. With Demirjian's and Willems' methods, the MAE was 1.107 and 0.927 years, respectively. Except for the Bayesian ridge regression that gives poorer accuracy, there was no statistical difference between all ML tested. CONCLUSION: Compared to the two reference methods, all the ML methods based on the maturation stages defined by Demirjian were more accurate in estimating dental age. These results support the use of ML algorithms instead of using standard population tables.

Knowledge and opinions of French dental students related to caries risk assessment and dental sealants (preventive and therapeutic).

OBJECTIVES: A national questionnaire study was performed to document knowledge and opinions of French dental students (FDSs) about minimal intervention (MI) in dentistry especially caries risk assessment (CRA) and dental sealants (DSs). MATERIALS AND METHODS: A questionnaire was administered to the fifth-year dental FDSs (n = 1370) from the 16 French dental schools. Descriptive and statistical analyses were performed. RESULTS: The response rate was 84.5%. A large majority of respondents (87.8%) linked MI with minimally invasive dentistry and 77.4% considered MI as a concept based on prevention. About 80% stated they use CRA in clinical practice, mostly without any specific form. If 80.4% of the respondents would base their treatment plans on CRA, only 55.1% would regularly plan preventive regimens according to individual risk level. However, while 96.6% declared they perform preventive DSs, only 44.3% considered therapeutic sealants as a routine treatment. Although 75.1% of FDSs stated that they had sufficient learning and training related to CRA, 55.9% thought that they need further education about preventive and therapeutic DSs. CONCLUSION: Although FDSs seem to be aware of the importance of CRA and preventive strategies, this study shows the need to harmonize the teaching in cariology according to the latest European recommendations. CLINICAL RELEVANCE: A national questionnaire study showed variability towards knowledge and opinions of FDSs related to MI in cariology. This may impact care provisions in their future professional life showing the urgent need to harmonize the teaching of MI in cariology in France.

Volume of unsupported peri-implant soft tissue over time: A cross-sectional observation study.

STATEMENT OF PROBLEM: Supraimplant emergence profile changes have revealed that, when not supported, peri-implant soft tissue collapses. However, this phenomenon has not been described qualitatively and quantitatively in 3 dimensions. PURPOSE: The purpose of this cross-sectional clinical study was to analyze changes in the supraimplant emergence profile digitally over time when the peri-implant soft tissue was not supported. MATERIAL AND METHODS: A data set consisting of 16 participants with 16 implants was used. After removal of the healing abutment or the interim restoration, 4 intraoral optical impressions were made successively on the patient to record the supraimplant emergence profile at 4 different times: 0 second (T0), 30 seconds (T0.5 min), 2 minutes (T2 min), and 5 minutes (T5 min). The supraimplant emergence profile surfaces obtained were closed with a 3D meshing software program (Meshmixer) to obtain the volume of the supraimplant emergence profile at each time. The reference volume at T0 (Vol T0) corresponded to the volume created during the mucosal healing phase, which, theoretically, should be preserved for the fabrication of the definitive crown. The different volumes (Vol T0.5 min, Vol T2 min, and Vol T5 min) were compared with Vol T0 to analyze the volumetric changes, kinetics, and topography of this variation by using a 3D visualization and analysis software program (Avizo). A nonparametric Wilcoxon test for paired samples was used for comparison. RESULTS: The supraimplant emergence profile volume decreased by an average of 5% at 30 seconds (P<.001), 10% at 2 minutes (P<.001), and 14% at 5 minutes (P<.001). CONCLUSIONS: The supraimplant emergence profile collapsed significantly in 3D when unsupported for 30 seconds or more.

Sex estimation in the cranium and mandible: a multislice computed tomography (MSCT) study using anthropometric and geometric morphometry methods.

INTRODUCTION: The purpose of this study was to analyze the respective contribution of the skull and mandible to sex estimation in an entire cranium using metric and geometric morphometric methods and multislice computed tomography (MSCT) analysis. MATERIALS: The study sample comprised 120 individuals aged 23 to 84 years and divided into three groups (whole sample and over or under 40 years of age). METHODS: Forty-eight osteometric landmarks were positioned using Osirix®, 34 for the cranium and 14 for the mandible. The data were analyzed using univariate analyses and logistic regression using backward stepwise selection with cross-validation of the classification results. Generalized procrustes analysis (GPA) was used, and Goodall's F test and Mahalanobis D2 matrices allowed an assessment of statistical significance. RESULTS: The classification accuracy of cranium models ranged from 87% to 88.3%, and from 68% to 81.4% for the mandibular models. With geometric morphometry, accuracy was of 94-100% for the cranium and 84.2% for the mandible. DISCUSSION: We conclude that the mandible had a higher accuracy rate for individuals over 40 years than individuals under 40 years of age, although the accuracy of geometric morphometry did not differ significantly between the age groups. The cranium, however, presented greater predictability for all the parameters assessed.

Fetal age estimation using MSCT scans of the mandible.

The purpose of this study was to examine a documented fetal collection, to carry out morphometric analysis of femoral length and of the mandible, and to develop diagnostic standards for estimating fetal age at death based on multislice computed tomography (MSCT) reconstructions. The sample was composed of 81 fetuses, whose ages were recorded in weeks of amenorrhea (WA) between 20 to 40 WA. The measurements made were femoral length (FL) and six distances and four angles of the mandible. Femoral length was measured in 81 fetuses (39 females and 42 males). Morphometric study of the mandible was carried out in 65 fetuses (31 females and 34 males), as the mandible was missing in 16 fetuses. R software was used for statistical analyses. Coefficient correlation (R(2)) and linear regression formulas were calculated. Intra-observer and inter-observer variabilities were very satisfactory (intra-class correlation coefficient ≥0.95). Our method appears to be reliable and reproducible. Femoral length was most strongly correlated with age (R(2) = 0.9). The measurement of six distances and four mandible angles from four landmark positions showed a correlation similar to the femoral length correlation (R(2) ≥ 0.72). The results of this study agreed with those of the literature. We conclude that the mandible is a reliable indicator for estimating fetal age at death. Moreover, MSCT has been shown to be an innovative and reliable technology for this purpose.

Fetal age estimation using MSCT scans of deciduous tooth germs.

Evaluation of fetal age is an essential element in many fields such as anthropology, odontology, paleopathology, and forensic sciences. This study examines the correlation between fetal age, femoral diaphyseal length (considered as the gold standard), and deciduous tooth germs of fetuses aged 22 to 40 weeks amenorrhea (WA) based on computed tomography (MSCT) reconstructions. Qualitative and quantitative studies of femoral and deciduous tooth germ lengths were performed on 81 fetuses (39 females and 42 males). R software was used for statistical analyses. Intra-observer and inter-observer variabilities and the interclass correlation coefficient (ICC) were calculated. Correlation coefficients (R (2)) and linear regression equations were calculated. Intra- and inter-observer variabilities were very satisfactory (intra-observer ICC ≥ 0.96, inter-observer ICC ≥ 0.95). Femoral length was significantly correlated with age (R (2) = 0.9). The correlation coefficient between age and height, width, and dental volume was R (2) ≥ 0.73. Tooth germs were good indicators of fetal age. Our method appears to be reliable and reproducible, and the results of this study agreed with those of the literature. The dental formula provided a precise estimation of fetal age between 25 and 32 WA. Tooth germs were reliable indicators of fetal age, and multislice computed tomography was shown to be an innovative and reliable technology for this purpose.

The dental microscope in endodontic education: A feasibility study of a distance learning course.

This study aimed to evaluate the feasibility of preclinical training, specifically in root canal preparation, using a virtual educational system equipped with an operating microscope. Ten postgraduate general dentistry trainees and practitioners undergoing postgraduate training in endodontics participated. The telesimulation course included three steps: theory, demonstration of practical work by the teacher and lastly practical training by the participants. The digital environment including the dental microscope was presented, and the feedback was collected with a questionnaire. The majority of participants considered that the online video conference format allowed them to acquire theoretical content but also practical knowledge and skills, owing to the contribution of the operating microscope. The technical feasibility of endodontic telesimulation was demonstrated. The operating microscope has a potential role in distance education, enabling teaching to occur synchronously and collaboratively. This allows learners to interact with each other and demonstrators in real time.

Machine Learning Analysis of the Anatomical Parameters of the Upper Airway Morphology: A Retrospective Study from Cone-Beam CT Examinations in a French Population.

The objective of this study is to assess, using cone-beam CT (CBCT) examinations, the correlation between hard and soft anatomical parameters and their impact on the characteristics of the upper airway using symbolic regression as a machine learning strategy. Methods: On each CBCT, the upper airway was segmented, and 24 anatomical landmarks were positioned to obtain six angles and 19 distances. Some anatomical landmarks were related to soft tissues and others were related to hard tissues. To explore which variables were the most influential to explain the morphology of the upper airway, principal component and symbolic regression analyses were conducted. Results: In total, 60 CBCT were analyzed from subjects with a mean age of 39.5 ± 13.5 years. The intra-observer reproducibility for each variable was between good and excellent. The horizontal soft palate measure mostly contributed to the reduction of the airway volume and minimal section area with a variable importance of around 50%. The tongue and the position of the hyoid bone were also linked to the upper airway morphology. For hard anatomical structures, the anteroposterior position of the mandible and the maxilla had some influence. Conclusions: Although the volume of the airway is not accessible on all CBCT scans performed by dental practitioners, this study demonstrates that a small number of anatomical elements may be markers of the reduction of the upper airway with, potentially, an increased risk of obstructive sleep apnea. This could help the dentist refer the patient to a suitable physician.

Sexual dimorphism of the mandibular conformational changes in aging human adults: A multislice computed tomographic study by geometric morphometrics.

The aging process has an impact on mandibular bone morphology and can therefore affect shape sexual dimorphism. Understanding the effect of senescence on mandibular shape changes is particularly important to correctly estimate the sex of an individual and predict age-related conformational modifications. The purpose of this study was to assess age-related changes in mandibular shape and sexual dimorphism. The study sample comprised 160 Multi Slice Computed Tomography examinations of individuals aged 40 to 79 years. Geometric morphometric analysis of fourteen osteometric landmarks was used to examine sexual dimorphism and patterns of mandibular shape variation with age. Results showed that mandibular sexual dimorphism of shape remained significant with aging. Conformational changes occurred between 50 and 70 years and were different for male and female individuals. Females presented earlier and more marked age-related shape changes than males. These observations suggest that mandibular senescence is a sexually dimorphic process since its onset, rate, and the areas subjected to conformational changes differ from male to female individuals. Senescence-related changes present substantial variability, and further investigation is required to determine precisely the age that marks their onset.

Smartphone oral self-photography in teledentistry: Recommendations for the patient.

In the current context of the coronavirus disease 2019 pandemic, the deployment of telemedicine has accelerated considerably. Like telemedicine, teledentistry involves the use of telecommunication technologies to provide medical information and services. Teledentistry can contribute to remote assessment (teletriage) and continuity of care (telemonitoring). This evaluation at a distance can be done by sending photos taken by the patient with a smartphone. Providing patients with a simple and reproducible protocol and explaining how to take a photo is important for sufficient image quality. The aim of this technical note is to help clinicians advise their patients on how to take photographs of their oral cavity simply and with sufficient quality to be reproducible.

Knowledge and Opinions of French Dental Students Toward Occlusal and Proximal Restorative Thresholds.

PURPOSE: To investigate the practices, knowledge and opinions of French dental students (FDSs) in various domains of minimal intervention (MI) in cariology. MATERIALS AND METHODS: A cross-sectional, questionnaire-based study was conducted in spring 2018 among all fifth-year French dental students (FDSs) from the 16 French dental schools. The present article focuses on restorative management. Statistical analyses (descriptive, chi-squared) were performed. RESULTS: The response rate was 84.5%. Overall, 97.4% of respondents would have operatively intervened for proximal and 83% for occlusal carious lesions, respectively, while non-or micro-invasive intervention would have been possible. Interestingly, 15% would completely open the occlusal fissures. For both occlusal and proximal lesions requiring a restoration, composite resin was indicated by over 95% of the respondents. In a clinical case, 51.6% of FDSs who rightly diagnosed an enamel carious lesion would operatively intervene. When FDSs could not diagnose the type of carious lesions, a high proportion of invasive actions were also reported (40%). FDSs who read scientific articles were more likely to consider the high importance of not filling sound teeth unnecessarily (p = 0.033). CONCLUSION: FDSs do not have sufficient awareness of MI guidelines regarding occlusal and proximal restorative thresholds. Efforts are required in dental schools to teach FDSs to postpone invasive/restorative strategies to later stages of carious progression. There is a need to strengthen prevention techniques and non-invasive options in the teaching of MI in cariology.

Knowledge and Opinions of French Dental Students in Operative Dentistry - Management of Deep Carious Lesions.

PURPOSE: A questionnaire survey was recently undertaken among French dental students (FDSs) to investigate their practices, knowledge and opinions in various domains of minimal intervention (MI) in cariology. The present work focuses on management of deep carious lesions (DCLs). MATERIALS AND METHODS: The questionnaire was administered (Spring 2018) to all the fifth-year students of the 16 French dental schools. Descriptive analyses were performed. RESULTS: Among 1370 FDSs (response rate: 84.5%), hardness was the most commonly reported criterion for assessing the endpoint of carious tissue removal (53.9%), followed by firm dentin (40.0%). Regarding FDSs' opinion of leaving carious dentine under a restoration, 41.9% of the respondents agreed that carious tissues should always be removed completely. For an asymptomatic tooth with DCLs and exposed pulp, direct pulp capping was mainly chosen (93.9%). In a clinical case correctly diagnosed as a reversible pulpitis by 79.7% of respondents, nearly half of FDSs chose a one-step complete excavation (48.3%) followed by selective excavation (25.1%), then two-step complete excavation (20.9%) and a minority (5.7%) opted for pulpal therapy (biopulpotomy or endodontic treatment). CONCLUSION: The present results suggest an inadequate dissemination of MI concepts among FDSs towards DCL management. The present results show the need for a harmonisation and a reinforcement of teaching evidence-based MI according to the latest European recommendations.

Ethics in systematic reviews.

Since its introduction by the Nuremberg Code and the Declaration of Helsinki, the place held by ethics in biomedical research has been continuously increasing in importance. The past 30 years have also seen exponential growth in the number of biomedical articles published. A systematic review of the literature is the scientific way of synthesising a plethora of information, by exhaustively searching out and objectively analysing the studies dealing with a given issue. However, the question of ethics in systematic reviews is rarely touched upon. This could lead to some drawbacks, as systematic reviews may contain studies with ethical insufficiencies, may be a possible way to publish unethical research and may also be prone to conflict of interest. Finally, informed consent given for an original study is not necessarily still valid at the systematic review level. There is no doubt that routine ethical assessment in systematic reviews would help to improve the ethical and methodological quality of studies in general. However, ethical issues change so much with time and location, and are so broad in scope and in context that it appears illusory to search for a universal, internationally accepted standard for ethical assessment in systematic reviews. Some simple suggestions could nevertheless be drawn from the present reflection and are discussed in the paper.

Brain Abscess Secondary to a Dental Infection.

The risk of a brain abscess is a complication of odontogenic infection that is rarely considered by physicians and little spoken of, yet treating dental infections may avoid a potentially life-threatening condition. We report a case of 7-year-old boy with a brain abscess secondary to a dental infection. He was immediately taken to the operating theatre for drainage and cleaning of the abscess. A dental examination revealed root abscesses on temporary molars, which were extracted under general anaesthetic. Two months after his admission, the child was switched to oral antibiotherapy and could return home. A brain abscess represents a life-threatening disease. Childhood brain abscess is uncommon but may be encountered by all physicians and students as a clinical emergency. It is indispensable that physicians finding symptoms similar to those in this case study refer the patient for emergency care and that possible dental foci of infection be assessed, whether or not the patient is being followed for dental care.