[Aesthetic rehabilitation of a case of maxillary fibrous dysplasia in a child]. / Réhabilitation esthétique d'un cas de dysplasie fibreuse maxillaire chez l'enfant.

Fibrous dysplasia (FD) is a rare, congenital, benign bone disorder in which healthy bone tissue is replaced by abnormal scar-like (fibrous) connective tissue. The lesions may affect one or more bones, including the jawbones. A 13-year-old girl visited the dentist for failed eruption of her left maxillary permanent teeth and facial asymmetry. Radiological analysis revealed impactions of the permanent teeth in hypertrophic, hyperdense, weakly trabeculated bone tissue. To restore the aesthetics of the smile, a treatment combining decoronation and bonded restorations was performed. FD enlargement would slow down after puberty, allowing for long-term therapies. But there is no information about implantology in this type of bone lesion. The aesthetic and functional consequences of a maxillary FD should be managed as soon as possible. Treatment involves a multidisciplinary team and follow-up care into adulthood.

Primary failure of eruption: From molecular diagnosis to therapeutic management.

Introduction: Primary Failure of Eruption (PFE) is a rare condition affecting posterior teeth eruption resulting in a posterior open bite malocclusion. Differential diagnosis like ankylosis or mechanical eruption failure should be considered. For non-syndromic forms, mutations in PTH1R, and recently in KMT2C genes are the known etiologies. The aim of this work was to describe the variability of clinical presentations of PFE associated with pathogenic variants of PTHR1. Material and methods: Diagnosis of non-syndromic PFE has been suggested for three members of a single family. Clinical and radiological features were collected, and genetic analyses were performed. Results: The clinical phenotype (type and number of involved teeth, depth of bone inclusions, functional consequences) is variable within the family. Severe tooth resorptions were detected. A heterozygous substitution in PTH1R (NM_000316.3): c.899T > C was identified as a class 4 likely pathogenic variant. The multidisciplinary management is described involving oral biology, pediatric dentistry, orthodontics, oral surgery, and prosthodontics. Conclusion: In this study, we report a new PTH1R variant involved in a familial form of PFE with variable expressivity. Therapeutic care is complex and difficult to systematize, hence the lack of evidence-based recommendations and clinical guidelines.

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.

[Representation of the oral sphere in medical comics, the child's perception]. / Représentation de la sphère buccale dans la bande dessinée médicale, la perception de l'enfant.

Medical comics are a suitable educational tool for paediatric populations. The emotions conveyed by the characters should not evoke negative feelings, which could then be associated with care or caregivers. The eyes and mouth are the first areas of the face to be analysed. One study attempted to assess the ability of children to perceive the emotions of one of the protagonists through the representation of their mouth.

Super-elasticity in vitro assessment of CuNiTi wires according to their Austenite finish temperature and the imposed displacement.

OBJECTIVES: To assess the super-elasticity of CuNiTi wires (Ormco, Glendora, Calif) according to their Austenite finish temperature (Af) and to the imposed displacement. The secondary objective was to compare the wire dimensions with the stated measurements and to study interbatch variability. MATERIALS AND METHODS: 10 types of CuNiTi wires (Ormco, Glendora, Calif) (n = 350) were investigated at 36 ± 1°C, with conventional brackets (Victory Series, 3M Unitek, Monrovia, Calif). Tensile test with coronoapical displacement ranging from 1 to 5 mm of the canine bracket was imposed. The wire dimensions were initially measured from two batches (n = 10). RESULTS: Dimensional heterogeneity varied by ± 2.00% compared to the manufacturer's data, and even up to 5.54% for 0.014-inch CuNiTi (P = .00069). However, all unloading forces were reproducible. In decreasing order, the forces delivered by a CuNiTi 27 were greater than those with CuNiTi 35 and 40. The super-elasticity was expressed only for displacements of 1 to 2 mm, at best up to 3 mm for 0.014-inch CuNiTi 27. CONCLUSIONS: The value of Af as well as the amount of imposed displacement seem to influence the expression of the super-elasticity of CuNiTi wires and the amount of corrected malocclusion. Among the tested wires, under these experimental conditions, 0.014-inch wire could be suitable as a first archwire. CuNiTi 35, therefore, seems to offer the best compromise among the force level, the expression of super-elasticity and the amount of malocclusion correction.

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.

Is there any difference between conventional, passive and active self-ligating brackets? A systematic review and network meta-analysis.

AIM: To test the null hypothesis that there was no difference in treatment efficiency between therapies undertaken with conventional (CBs), passive self-ligating (PSLBs) or active self-ligating (ASLBs) brackets. MATERIALS AND METHODS: An electronic search was performed in 3 data bases (Pubmed, Web of Science, Cochrane Library) from their origin up to January 2019. Additional references were hand searched. Search was strictly restricted to randomized controlled trials (RCTs) and split-mouth design studies (SMDs). RCTs and SMDs were initially processed separately and subsequently combined in a network meta-analysis. The following variables were evaluated: treatment duration, number of visits, occlusal outcomes, alignment rate, transverse arch dimensional changes, incisor position modification, rate of space closure, anchorage loss, bond failure, root resorption, perception of discomfort during the initial phase of alignment, time to ligate in or to untie an archwire, periodontal variables, quality of life. RESULTS: On 229 papers, 30 RCTs and 9 SMDs were finally included in this study. Out of 85 comparisons, 16 only revealed statistically significant differences. It was quicker to untie and ligate an 0.014 NiTi arch from/in 6 ASLBs anterior ceramic brackets compared to 6 ceramic CBs. It was also more painful to insert and remove an 0.019×0.025 SS wire in/from PSLB's brackets compared to CB's attachments. Compared to conventional brackets, there was less maxillary incisor proclination with PSLBs in non-extraction cases. Moreover, there was less bleeding on probing 4-5 weeks after bonding with PSLBs compared to CBs brackets. The only significant difference between ASLBs and PSLBs was that alignment was 10 days faster with active self-ligating braces compared with passive self-ligating braces even if treatment duration between ASLBs and PSLBs was not significantly different. The network meta-analysis revealed that IMPA was greater in extractions cases with CBs compared with both ASLBs (+2,5°) and PSLBs (+1,6°). CONCLUSIONS: The vast majority of the studied variables did not show any significant differences between the three types of brackets. The most significant findings were that it was quicker to insert and remove archwires from ASLBs compared to CBs, and it was more painful to insert and remove an 0.019×0.025" stainless steel wire in/from PSLBs compared to CBs. The major difference between ASLBs and PSLBs was that alignment was 10 days faster with active self-ligating braces compared with passive self-ligating braces even if treatment duration between ASLBs and PSLBs was not significantly different. Most of the claims put forward by the suppliers were not substantiated by our network meta-analysis.

[Surgical acceleration of tooth movement: a systematic review to optimize communication between the orthodontist, the oral surgeon and the patient]. / Accélération chirurgicale du déplacement dentaire : revue systématique pour optimiser les échanges entre l'orthodontiste, le chirurgien oral et le patient.

This systematic review aims to compare conventional corticotomy with minimally-invasive protocols (MIP). Electronic database, in MEDLINE and CENTRAL, and hand search were performed. Randomized controlled trials (RCTs) and randomized split-mouth designed studies (RSMSs) were selected for inclusion, reporting either the use of a corticotomy procedure or a MIP. The main outcomes were the rate/velocity of tooth movement, type of tooth movement observed, loss of anchorage, periodontal indexes, inflammatory mediators, root resorption, patient's pain experience, impact on the quality of life, and satisfaction. Twenty-two papers were included for the qualitative synthesis, from which ten RCTs and twelve RSMSs. Eighteen of them compared a conventional orthodontic treatment without and with a surgical adjunctive procedure, two with conventional corticotomy and sixteen with a MIP (piezocision, micro-osteoperforations (MOPs) or interseptal bone reduction). Four trials compared a surgical procedure to another one. Corticotomy, piezocision and MOPs are likely to accelerate tooth movement, in decreasing order. Pain is reported to be higher in experimental groups only on the first day after surgery. Patient satisfaction is high after surgical procedures. Loss of anchorage, periodontal indexes, or root resorption occurrence show no differences between groups. Corticotomy stands as the gold-standard procedure for surgically-assisted orthodontics, but piezocision appears as a good compromise solution as well as MOPs, in a lesser extent. MIP are known to accelerate tooth movement only during the first three months.

In vitro comparison of the mechanical behaviour of archwires after computer-assisted and conventional bracket positioning protocols.

INTRODUCTION: The mechanical properties of orthodontic archwires can be defined using experimental setups incorporating brackets that provide conditions closer to those encountered in vivo. We aimed to compare a methodology based on computer-aided design with the gold standard protocol, performed when brackets are engaged to a full-size archwire to test the behaviour of wires in this condition. METHODS: Three models simulating a dental arch with an orthodontic fixed appliance (0.018-inch aesthetic conventional brackets) were designed. The brackets were positioned with a stainless-steel full-size wire on the first two models, with different interbracket distances. The setup 3, based on a computer-assisted design, allowed individualized placement of each bracket. Mean forces recorded and standard deviation were compared for a 0.016×0.022-inch copper-nickel-titanium wire deflected until 2mm. RESULTS: The inter-bracelet distances do not cause a statistical difference in the average maximum force recorded (12.6N and 11.4N; P=0.081) whereas the behaviour of the wires is affected. With setup 3, the recorded efforts (mean value: 8N) are statistically lower than with setup 1 and 2 respectively (P=0.018; P=0.012). CONCLUSION: An individualization of the housings by CAD-CAM dedicated to each bracket optimizes their placement. In our test conditions, the mechanical behaviour of the wires is more influenced by the positioning methods of the brackets than by the value of the interbracket distance. In perspective, our innovative methodology can be extended to other types of brackets.

Aesthetic and psychosocial impact of dentofacial appearance after primary rhinoplasty for cleft lip and palate.

The primary aim of this study was to demonstrate whether primary rhinoplasty shows aesthetic and psychosocial advantages for children with a complete unilateral cleft lip and palate. The second aim was to determine the satisfaction levels concerning the dentofacial appearance. Group A corresponded to patients from a center specialised in primary cheilo-rhinoplasty with 20 years' experience and Group B to patients who did not benefit from primary rhinoplasty. Children and their parents filled in a custom-designed satisfaction questionnaire on dentofacial appearance and its psychosocial impact. The variables studied were the main criterion (the nose) and secondary criteria (the upper lip, the smile, the profile and the face as a whole). 56 families consented to be involved in the study. The children did not rate statistically differently their social relationships if they had primary rhinoplasty or not. Parents however expressed very different views. They considered the nasal appearance of the children who had primary rhinoplasty as statistically more attractive and evaluated their psychosocial experience as significantly better. For the other parts of the face, in both groups, satisfaction levels of dentofacial appearance and psychosocial comfort were good (scores above 80/100). Yet, 44% of the families would go for further interventions, especially concerning the nose (13% of whom were in Group A and 42% in Group B). Within the limitations of this study, primary rhinoplasty seems to improve the patient's well-being and social life and, therefore, should be considered whenever appropriate.

[Are self-ligating brackets more efficient than conventional brackets ? A meta-analysis of randomized controlled and split-mouth trials]. / Les attaches auto-ligaturantes sont-elles plus efficaces que les attaches conventionnelles ? Méta-analyse d'essais contrôlés randomisés et d'études en bouche fractionnée.

The aim of this systematic review and meta-analysis was to compare self-ligating brackets (SLBs) considered as a whole to conventional brackets (CBs). An electronic search was performed in three databases (PubMed, MEDLINE via Web of Science, Cochrane Library) from their origin up to June 2017. Additional articles were hand searched from January 2006 to June 2017. This meta-analysis was restricted to randomized controlled trials (RCTs) and split mouth design studies (SMDs). No distinction was made between active and passive SLBs. The following variables were investigated : treatment duration, number of visits, alignment rate, rate of space closure, perception of discomfort during the initial phase of treatment, pain experience during wire insertion or removal, bond failure rate, time to ligate in or to untie an archwire, periodontal indices, occlusal outcomes, transverse arch dimensional changes and root resorption. 25 RCTs and 9 SMDs were finally selected. It was more painful to insert or remove a 0.019× 0.025 SS archwire in/from SLBs. It was significantly quicker to insert or remove an archwire from SLBs. There was less bleeding on probing with SLBs 4 or 5 weeks after bonding. All other variables did not exhibit any significant difference between SLBs and CBs. Out of the 31 comparisons between self-ligating and conventional brackets, 9 only revealed statistically significant differences. This meta-analysis contradicts most of the promotional statements put forward by the distributors.

[Primary failure of eruption: a French prospective survey among the orthodontists from the Grand Est and Bourgogne-Franche-Comté regions]. / Défauts primaires d'éruption : état des lieux auprès des spécialistes en orthopédie dento-faciale des régions Grand Est et Bourgogne-Franche-Comté.

INTRODUCTION:  Primary failure of eruption (PFE) can be defined as the partial or complete failure of eruption of at least one posterior tooth, without any mechanical obstacle; isolated and syndromic forms exist. PFE results from an abnormal dental eruption process that can affect temporary teeth and / or permanent teeth. Molars are the main affected teeth, inducing posterior infraclusions. Orthodontists are the specialists most often concerned by this rare pathology. Unsuccessful orthodontic-surgical traction therapies are commonly reported. MATERIALS AND METHODS:  The aim of our study using a prospective survey was to evaluate the level of knowledge reported by the orthodontists and the therapeutic difficulties they reported. An anonymous questionnaire was submitted to practitioners practicing in north-eastern France (Grand Est and Bourgogne-Franche-Comté regions). RESULTS:  The participation rate was 33.5%. In France, until 2015, specialization in orthodontics was obtained thanks to a local qualification, the Certificat d'Etudes Cliniques Spéciales - Mention Orthodontie (CECSMO), which has now been replaced by specialization following a national ranking competition. Most respondents obtained their qualification between 1980 and 2009 (80%), via the CECSMO (87%). Eighty-six per cent were aware of PFE but only 20% of them knew that PTHR1 (Parathyroid Hormone Receptor 1) gene could be involved in this pathology. The wide range of proposed therapies and the variable satisfaction rates highlight the difficulties encountered by practitioners. DISCUSSION:  Phenotypic variability complicates the diagnosis and makes any therapeutic systematization uncertain. CONCLUSION:  New clinical research projects, particularly in the field of molecular diagnosis, may improve understanding of genotype-phenotype correlations, and may potentially pilot therapeutic management.

A five-year follow-up of a root fracture in a ten-year-old boy.

The management of horizontal root fracture still presents a challenge to clinicians. The case of a 10-year-old boy with a horizontal root fracture in the left maxillary central incisor (tooth number 21) is described here. The fracture was present at the junction of the apical and the middle thirds. We report both the emergency care and the 5-year follow-up. At the same time, an orthodontic treatment was planned for a retained maxillary cuspid (tooth number 23), first composed of a high-pull headgear and then by a fixed multi-bracket appliance. Today, the tooth number 21 remains vital and symptomless. This report highlights the successful management of a horizontally fractured tooth requiring orthodontic treatment. Our work also underlines the advantages of 3D images [cone-beam computed tomography (CBCT)] in positive and differential diagnosis especially in the event of a suspicion of post-traumatic complication.

[Effects of maxillary disjunction on canine impaction in patients presenting a maxillary transverse skeletal deficiency]. / Effets de la disjonction maxillaire rapide sur la rétention des canines chez les patients présentant un déficit squelettique transversal maxillaire.

INTRODUCTION: This study focuses on the effects of rapid maxillary disjunction on the tendency to canine impaction in patients displaying a maxillary transverse skeletal deficiency. MATERIALS AND METHODS: Using the segmentation method described by Ericson and Kurol and modified by Lindauer, et al., a series of panoramic views taken before and after disjunction was studied to compare changes in the position of the tip of the maxillary canine depending on whether it was covered or not by the homolateral lateral incisor, according to the side and patient's sex. The cohort consisted of 193 patients, all treated using a palatal expander welded to bands. RESULTS: A statistically significant improvement was observed in all categories regarding the position of the maxillary canine. Disjunction was successful in 87% of cases in our sample. No significant differences were found according to side or sex.

[Preventive and therapeutic advantages of sugar-free chewing gums in orthodontics. A study conducted on practitioners and patients]. / Intérêt prophylactique et thérapeutique des chewing-gums sans sucre en orthodontie. Une étude menée auprès de professionnels de santé et de patients.

OBJECTIVE: The objective of this study is to assess the level of knowledge in a cohort of oral health professionals and patients about preventive and therapeutic actions of sugar-free chewing gums. MATERIALS AND METHODS: A forward-looking monocentric study of perception regarding the level of information about the effects of sugar-free chewing gums consumption was conducted on 135 young patients, from 11 to 17 years old, carriers of fixed orthodontic appliances and treated in the Department of Orthodontics in the Oral Medicine and Surgery Center of the University Hospitals of Strasbourg. Besides, 34 practitioners in the Department of Orthodontics and Pediatric Dentistry were also included. Data were collected between May 2016 and July 2016. A specific questionnaire, using the adapted terminology and dealing with the same items was developed for each studied population. RESULTS: The majority of the individuals of both studied populations believe that the consumption of sugar-free chewing gum leads to a greater risk of orthodontic device unsticking or fracture and that it is not associated to a decrease of the orthodontic pain. DISCUSSION: Our results confirm the fact that the knowledge, mainly acquired in an empirical way, is against the data of the current literature. The evaluation of the level of knowledge demonstrated that there is a real lack of information about the preventive interests of the consumption of sugar-free chewing gums during orthodontic treatment. CONCLUSIONS: This study highlights the need for information campaigns and oral prevention in general population, as well as in healthcare professionals, concerning the preventive and analgesic interests of sugar-free chewing gums during orthodontic treatments.

Mechanical equilibrium of forces and moments applied on orthodontic brackets of a dental arch: Correlation with literature data on two and three adjacent teeth.

Although orthodontics have greatly improved over the years, understanding of its associated biomechanics remains incomplete and is mainly based on two dimensional (2D) mechanical equilibrium and long-time clinical experience. Little experimental information exists in three dimensions (3D) about the forces and moments developed on orthodontic brackets over more than two or three adjacent teeth. We define here a simplified methodology to quantify 3D forces and moments applied on orthodontic brackets fixed on a dental arch and validate our methodology using existing results from the literature by means of simplified hypotheses.

Experimental quantification of the mechanical forces and moments applied on three adjacent orthodontic brackets.

Orthodontic appliances deliver forces and moments that will determine movement of teeth. To analyze this latter, we developed an experimental setup to measure the mechanical forces applied on the teeth and to calculate, through a simplified theoretical analysis, the reactive forces and corresponding moments onto the brackets of three adjacent teeth. To validate the theoretical and experimental results, we use a simplified clinical situation of a maxillary canine in infraclusion and surrounded by its corresponding upper lateral incisor and first premolar. Forces are then measured experimentally and compared with the calculated results. From this, we show the specific dissymmetry of the mechanical forces on each side of the maxillary canine due to the applied mechanical forces and the undesirable induced generated moments occurring on each tooth that will directly impact the bone remodeling process and the final tooth repositioning.