Accuracy of Age Estimation Using Three Dental Age Estimation Methods in a Young, Large, and Multiethnic Patient Sample.

European countries have become host countries for migrants and unaccompanied minors. However, many migrants arrive without identity documents. Many methods exist to estimate age; among them, several methods using dental age have been proposed. Our objective was to evaluate the accuracy of biological age determination in a multiethnic sample using dental age estimated using three methods: Nolla, Demirjian, and the London Atlas. Orthopantomograms collected for 324 patients of various ethnicities aged from 4 to 20 years old were included. Then, for each orthopantomogram, a blind trained examiner used the three methods of age estimation. For each method, the estimated mean age was greater than the real mean age (p < 0.0001). The accuracy after 18 years old with a 1-year margin was under 50%. Demirjian's method gave a less accurate estimated age than Nolla's method (p < 0.0001) or the London Atlas (p < 0.001). The most accurate methods were those of Nolla and the London Atlas, with average absolute deviations of 1.3 and 1.2 years, respectively. Demirjian's method was much less accurate, with a deviation of around 2 years. The evaluated methods are unable to provide reliable information to determine if an individual is a minor.

Management of a rare mandibular giant cell tumor of bone by neoadjuvant denosumab therapy and surgery: A 4-year follow-up case report.

INTRODUCTION: Giant cell tumor of bone (GCTB) is a very rare tumor encountered in the jaws and its histology is quite similar to the more common giant cell granuloma of the jaws (GCGJ). These two entities can be easily confused in maxillofacial region. They are classically managed surgically, but in some localizations and in specific medical-surgical contexts, neoadjuvant therapy with denosumab may be indicated. This report tends to reinforce existing evidence in favor of the use of a neoadjuvant approach, particularly for localization of GCTB in the orofacial region. PRESENTATION OF CASE: This is a 57-year-old female patient, an alcoholic smoker, in whom a voluminous mandibular radiolucent lesion was discovered during a routine X-ray by her dentist. After medical imaging assessment and incisional biopsy, diagnosis of GCTB was established. A neoadjuvant denosumab therapy was proposed first followed by a secondary surgical curettage. After 4 years' follow-up, complete healing was observed with no recurrence of the lesion. DISCUSSION: Surgical management of aggressive GCTB is risky particularly in localizations involving the sacrum, spine or craniofacial skeleton with a high residual recurrence rate. The use of denosumab to stop tumor progression and facilitate secondary excision surgery is a recent approach that is now well documented in the literature showing promising results with a low rate of side effects. CONCLUSION: This case of mandibular GCTB is to our knowledge the unique case described in this localization and treated by denosumab neoadjuvant therapy followed by surgery with a 4-year follow-up showing a complete healing.

Primary failure of eruption and tooth resorption / Défaut primaire d'éruption et résorption radiculaire externe

Introduction: The number of adult patients who seek an orthodontic treatment is increasing. These Primary failure of eruption (PFE) is defined as the partial or complete failure of eruption of at least one posterior tooth, without any mechanical obstacle. A better understanding of the biological mechanisms involved in PFE would enable to refine the diagnostic and prognostic criteria. This rare disease is currently related to PTHR1 gene variants. This gene codes for a transmembrane receptor involved in bone metabolism. However, there is few evidence associating PFE and bone remodeling abnormalities such as external root resorption. External root resorption is the loss of cementum and dentin tissues, resulting from the activation of clastic cells. Materials and Methods: Human teeth affected by PFE were extracted and histological sections were made after fixation of the tissues in 4% PFA. The observations were correlated with three-dimensional imaging by cone beam computed tomography (CBCT) carried out in the preoperative phase. Results: Histological and radiographic analysis confirm the presence of ankylosis area in patients with no history of orthodontic treatment. Large areas of resorption of external root replacement were detected. Discussion: The results call the causal link between the appearance of ankylosis areas and the establishment of orthodontic traction in patients with PFE into question. The installation of an orthodontic force in this context could be only an aggravating factor, accelerating the processes of ankylosis or triggering them more prematurely. Conclusion: With or without orthodontic treatment, teeth with PFE are likely to progress to ankylosis and resorption of replacement external root.

Introduction: Les défauts primaires d'éruption (DPE) se caractérisent par l'échec total ou partiel de l'éruption d'une ou plusieurs dents postérieures, sans obstacle mécanique. Une meilleure compréhension des mécanismes biologiques impliqués dans les DPE permettrait d'affiner les critères diagnostiques et pronostiques. Cette pathologie rare est actuellement imputée à des variants du gène PTHR1. Ce gène code pour un récepteur transmembranaire impliqué dans le métabolisme osseux. Cependant, on trouve peu de données associant DPE et anomalies du remodelage osseux de type résorption radiculaire externe. La résorption radiculaire externe correspond à la perte de tissus cémentaire et dentinaire résultant de l'activation de cellules clastiques. Matériels et méthodes: Des dents d'origine humaine atteintes de DPE ont été avulsées et des coupes histologiques réalisées après fixation des tissus. Les observations ont été corrélées avec l'imagerie tridimensionnelle par tomographie volumique à faisceau conique (TVFC ou encore CBCT). Résultats: Les analyses histologiques et radiographiques montrent la présence de plage d'ankylose chez des patients sans antécédent de prise en charge orthodontique. De larges zones de résorptions radiculaires externes de remplacement ont été détectées. Discussion: Les résultats remettent en cause le lien de causalité entre l'apparition d'ankylose et la mise en place de traction orthodontique chez les patients atteints de DPE. La mise en place d'une force orthodontique dans ce contexte pourrait n'être qu'un facteur aggravant, accélérant les processus d'ankylose ou les déclenchant plus prématurément. Conclusion: Avec ou sans traitement orthodontique, les dents atteintes de DPE sont susceptibles d'évoluer vers l'ankylose et la résorption radiculaire externe de remplacement.

Apically Extruded Debris in Curved Root Canals Using a New Reciprocating Single-File Shaping System.

INTRODUCTION: The present study addresses the influence of 5 different shaping file systems on apical debris extrusion (AED) using 2 different irrigation protocols. METHODS: One hundred fifty mandibular first permanent molars were divided into 2 groups and 10 subgroups. The mesial root canals were shaped using One Reci (MicroMega), WaveOne Gold Primary (Dentsply Sirona, York, PA), and ProTaper Next (Dentsply Sirona) using reciprocating motion and One Curve (MicroMega) and ProTaper Next using continuous rotation. The first group and the second one were respectively irrigated with 10 and 5 mL distilled water. RESULTS: When the same instrumentation technique was used, the G10 mL subgroups showed statistically lower AED than the G5 mL subgroups (P < .05). The One Reci and One Curve subgroups, in both groups, produced statistically lower AED than the remaining subgroups. CONCLUSIONS: The cross section of the instrument could be the main parameter in determining the amount of AED. The irrigation volume used during the shaping procedure might affect the amount of AED.

Development of an innovative educational escape game to promote teamwork in dentistry.

BACKGROUND: Escape games have proven to be an innovative pedagogical tool that allows students to use the professional skills they acquired. The appeal of the game lies in the stimulation of the players' minds and in the diversity of the puzzles. PURPOSE/OBJECTIVES: To evaluate the effectiveness of an educational tool aimed at cultivating team spirit and group cohesion in dentistry students through a fun collaborative activity that mobilises their knowledge and skills. MATERIALS AND METHOD: Twenty-four students participated to the escape game over a one-day period. In order to win, they had to solve dentistry-related puzzles. RESULTS: Feedback was strongly positive. The balance between manipulations and theoretical questions stimulated them. Students did favour this type of activity which allows to increase interactions between students as well as with the teaching team. CONCLUSION: Escape games in dental schools foster a supportive learning environment and stimulated students' motivation and group cohesion.

Frequent, quantitative bone planar scintigraphy for determination of bone anabolism in growing mice.

BACKGROUND: To provide insight into bone turnover, quantitative measurements of bone remodeling are required. Radionuclide studies are widely used in clinical care, but have been rarely used in the exploration of the bone in preclinical studies. We describe a bone planar scintigraphy method for frequent assessment of bone activity in mice across the growing period. Since repeated venous radiotracer injections are hardly feasible in mice, we investigated the subcutaneous route. METHODS: Repeated 99mTc-hydroxymethylene diphosphonate (HMDP) tracer bone planar scintigraphy studies of the knee region and µCT to measure femur growth rate were performed in eight mice between week 6 and week 27 of life, i.e., during their growth period. Three independent investigators assessed the regions of interest (ROI). An index was calculated based on the counts in knees ROI (normalized by pixels and seconds), corrected for the activity administered, the decay between administration and imaging, and individual weights. RESULTS: A total of 93 scintigraphy studies and 85 µCT were performed. Repeated subcutaneous tracer injections were well tolerated and allowed for adequate radionuclide studies. Mean scintigraphic indexes in the knees ROI decreased from 87.4 ± 2.6 × 10-6 counts s-1 pixel-1 MBq-1 g-1 at week 6 to 15.0 ± 3.3 × 10-6 counts s-1 pixel-1 MBq-1 g-1 at week 27. The time constant of the fitted exponential decay was equal to 23.5 days. As control mean femur length assessed by µCT increased from 12.2 ± 0.8 mm at week 6 to 15.8 ± 0.2 mm at week 22. The time constant of the fitted Gompertz law was equal to 26.7 days. A correlation index of -0.97 was found between femur growth and decrease of bone tracer activity count between week 6 and 24. CONCLUSION: This methodological study demonstrates the potential of repeated bone planar scintigraphy in growing mice, with subcutaneous route for tracer administration, for quantitative assessment of bone remodeling.

Microguided endodontics: Accuracy evaluation for access through intraroot fibre-post.

In this work, we intended to assess the reliability of guided endodontic technique to remove a bonded fibre-post when there are artefacts in the cone-beam computed tomography (CBCT) images caused by composite dental materials. We mounted natural posterior teeth on ten simulated models. Forty fibre-post and composite-core restorations were inserted in the teeth. We merged a pre-operative CBCT and optical surface scan on the BlueskyplanTM software to digitally design and subsequently 3D-printed the guides. Two operators initiated endodontic access into the fibre-post restorations using the template to guide the drill. Post-operative CBCT was taken and merged onto the pre-operative plan to measure the deviations at the coronal and apical segments. The mean deviation between the planned and actual drill paths were, respectively, of 0.39 ± 0.14 mm coronally and 0.40 ± 0.19 mm apically. Microguided endodontics is a predictable and accurate method to remove fibre-post restorations efficiently.

[Oral care and the Coronavirus COVID-19 epidemic]. / Soins bucco-dentaires et épidémie de Coronavirus COVID-19.

The COVID-19 Coronavirus epidemic started in December 2019 in China, and progressed very quickly in France. Its consequences were the implementation of national measures such as the containment of the population, but also a disorganization of the healthcare system, in particular concerning oral care. Indeed, dental procedures produce aerosols which can be loaded with viral particles, and as such, constitute a major contamination route by the virus. At the request of the Conference of Deans of the Faculties of Odontology, the National College of University Dentists in Public Health (CNCDUSP) set up a working group in order to issue recommendations for oral care in the context of the COVID-19 epidemic, given the specific risks faced by practitioners. Considering the lack of awareness of the specifics of dentistry in the medical world and among decision-makers, and given the speed with which national measures to fight the epidemic were implemented, the recommendations of the CNCDUSP had to be drawn up rigorously and quickly before being released to the profession. They take into account epidemiological data related to the virus, the specificities of oral care, and thus propose protective measures for dental surgery professionals.The necessary adaptation of the healthcare system during an epidemic will certainly make it possible to learn lessons from this health crisis.

[Oral care and the Coronavirus COVID-19 epidemic] / Soins bucco-dentaires et épidémie de Coronavirus COVID-19.

The COVID-19 Coronavirus epidemic started in December 2019 in China, and progressed very quickly in France. Its consequences were the implementation of national measures such as the containment of the population, but also a disorganization of the healthcare system, in particular concerning oral care. Indeed, dental procedures produce aerosols which can be loaded with viral particles, and as such, constitute a major contamination route by the virus. At the request of the Conference of Deans of the Faculties of Odontology, the National College of University Dentists in Public Health (CNCDUSP) set up a working group in order to issue recommendations for oral care in the context of the COVID-19 epidemic, given the specific risks faced by practitioners. Considering the lack of awareness of the specifics of dentistry in the medical world and among decision-makers, and given the speed with which national measures to fight the epidemic were implemented, the recommendations of the CNCDUSP had to be drawn up rigorously and quickly before being released to the profession. They take into account epidemiological data related to the virus, the specificities of oral care, and thus propose protective measures for dental surgery professionals.The necessary adaptation of the healthcare system during an epidemic will certainly make it possible to learn lessons from this health crisis.

Soins bucco-dentaires et épidémie de Coronavirus COVID-19.

The COVID-19 Coronavirus epidemic started in December 2019 in China, and progressed very quickly in France. Its consequences were the implementation of national measures such as the containment of the population, but also a disorganization of the healthcare system, in particular concerning oral care. Indeed, dental procedures produce aerosols which can be loaded with viral particles, and as such, constitute a major contamination route by the virus. At the request of the Conference of Deans of the Faculties of Odontology, the National College of University Dentists in Public Health (CNCDUSP) set up a working group in order to issue recommendations for oral care in the context of the COVID-19 epidemic, given the specific risks faced by practitioners. Considering the lack of awareness of the specifics of dentistry in the medical world and among decision-makers, and given the speed with which national measures to fight the epidemic were implemented, the recommendations of the CNCDUSP had to be drawn up rigorously and quickly before being released to the profession. They take into account epidemiological data related to the virus, the specificities of oral care, and thus propose protective measures for dental surgery professionals.The necessary adaptation of the healthcare system during an epidemic will certainly make it possible to learn lessons from this health crisis.

Hidden intra-mandibular carcinoma cuniculatum appearing in a patient with metastatic prostate cancer: a case report.

BACKGROUND: Whereas the incidence of cancers increases, overall survival of cancerous patients improves. Preventing the onset of second primary cancer is a new public health challenge and requires a special attention from organ specialists. We report a rare case of carcinoma cuniculatum in a context of metastatic prostate cancer. No case was previously described. Diagnosis delay of carcinoma cuniculatum is frequent and particularly in case of endophytic intra-osseous topography. The aim of this case report is to remind that persistent pain requires medical evaluation to rule out any possibility of second primary cancer. CASE PRESENTATION: A 78-year-old patient followed for a metastatic prostate cancer had been describing neuralgic dental pain in the lower posterior left quadrant for several months. Healing delay of tooth #37 (second left mandibular molar) extraction socket in the painful region led to an intra-alveolar incisional biopsy, which showed a tumor widely invading the mandibular body. Radiologic, histopathologic and clinical elements finally concluded to an intra-osseous carcinoma cuniculatum. Duration of total treatment (oral biopsy to hemimandibulectomy) and follow up were about five months and one year respectively. Patient died before reconstruction. CONCLUSION: This case recalls that any persistent tooth pain affecting cancer patients requires a thorough review to exclude any secondary primary cancers or any metastasis of the oral cavity and more specifically in jawbones.

Prevalence and risk factors of root resorption of adjacent teeth in maxillary canine impaction, among untreated children and adolescents.

OBJECTIVES: The aim of this retrospective study was to assess in maxillary canine impaction cases both the prevalence of root resorption of adjacent teeth among untreated children and adolescents, and its associated risk factors. SUBJECTS AND METHODS: Sixty subjects (mean age 12.2 years; SD 1.9; range 8-17 years) with 83 displaced maxillary canines and without any past or ongoing orthodontic treatment were included in this study. The presence of root resorption was evaluated on images from a single cone beam computed tomography (CBCT) unit. Potential risk factors were measured on the CBCT images and on panoramic reconstructions of the 3D data sets. The sample was characterized by descriptive statistics and multiple logistic regressions were performed to predict root resorption. RESULTS: Root resorption of at least one adjacent tooth was detected in 67.5 per cent of the affected quadrants. It was found that 55.7 per cent of the lateral incisors, 8.4 per cent of the central incisors, and 19.5 per cent of first premolars were resorbed. Of the detected resorptions, 71.7 per cent were considered slight, 14.9 per cent moderate, and 13.4 per cent severe. Contact between the displaced canine(s) and the adjacent teeth roots was the only identified statistically significant risk factor, all teeth being considered (odds ratio [OR] = 18.7, 95% confidence interval: 2.26-756, P < 0.01). An enlarged canine dental follicle, a peg upper lateral, or an upper lateral agenesis were not significantly associated with root resorption of adjacent teeth, nor were age nor gender. CONCLUSIONS: Root resorption of adjacent teeth was detected in more than two-thirds of a sample of sixty untreated children and adolescents.

Diagnosis and Innovative Multidisciplinary Management of Hallermann-Streiff Syndrome: 20-Year Follow-Up of a Patient.

Hallermann-Streiff syndrome (HSS) is a rare congenital disorder that mainly affects head and face development. We described the different patterns of the disease throughout the whole growth period and provided innovative treatment steps. Indeed, early genioplasty and dental implantation before growth completion were performed. These steps allowed to improve facial growth and to provide orthodontic anchorage, respectively. Complementary orthognathic surgery achieved satisfactory occlusion and refined aesthetics. We believe such an approach could be considered as a relevant treatment modality to complete multidisciplinary care in patients with HSS.

Image quality evaluation of small FOV and large FOV CBCT devices for oral and maxillofacial radiology.

OBJECTIVES: Quantitative and qualitative image quality evaluation of two different dental CBCT scanners. METHODS: Two CBCT systems were evaluated in this study: one small field-of-view (FOV) (50-mm diameter) system that also allows two-dimensional (2D) dental panoramic imaging and one large FOV CBCT system (60-180-mm diameter). These devices were all tested with installed acquisition default modes and proprietary reconstruction software, enabling high-resolution bone imaging. Quantitative analyses were carried out to measure spatial resolution, linearity and homogeneity. Small-size phantoms and a human dry skull were used to evaluate intrinsic performances. Visual qualitative analyses of specific anatomical parts were blindly performed by 10 operators. RESULTS: Concerning spatial resolution, small-voxel size protocols provide equivalent results on the two apparatus. In terms of linearity, all systems are highly linear (0.98 < r2 < 0.99) over the range of signal intensities encountered. Our results, coming from either phantoms or the dry skull, demonstrate that the small FOV CBCT suffers from a lack of homogeneity. CONCLUSIONS: For limited oral and maxillofacial volume imaging (diameter < 50 mm), the polyvalent small FOV CBCT (2D and three-dimensional imaging) system used in this study could reach performances similar to those of the large FOV CBCT.

MSCT versus CBCT: evaluation of high-resolution acquisition modes for dento-maxillary and skull-base imaging.

OBJECTIVES: Our aim was to conduct a quantitative and qualitative evaluation of high-resolution skull-bone imaging for dentistry and otolaryngology using different architectures of recent X-ray computed tomography systems. MATERIAL AND METHODS: Three multi-slice computed tomography (MSCT) systems and one Cone-beam computed tomography (CBCT) system were used in this study. All apparatuses were tested with installed acquisition modes and proprietary reconstruction software enabling high-resolution bone imaging. Quantitative analyses were performed with small fields of view with the preclinical vmCT phantom, which permits to measure spatial resolution, geometrical accuracy, linearity and homogeneity. Ten operators performed visual qualitative analyses on the vmCT phantom images, and on dry human skull images. RESULTS: Quantitative analysis showed no significant differences between protocols in terms of linearity and geometric accuracy. All MSCT systems present a better homogeneity than the CBCT. Both quantitative and visual analyses demonstrate that CBCT acquisitions are not better than the collimated helical MSCT mode. CONCLUSION: Our results demonstrate that current high-resolution MSCT protocols could exceed the performance of a previous generation CBCT system for spatial resolution and image homogeneity. KEY POINTS: • Quantitative evaluation is a prerequisite for comparison of imaging equipment. • Bone imaging quality could be objectively assessed with a phantom and dry skull. • The current MSCT shows better image quality than a dental CBCT system. • CBCT remains a work-in-progress technology.