Introduction:The objective of this experimental study is to analyze the effect of artificial saliva on the mechanical properties of the Tera Harz TC-85 material (Graphy®) at different time intervals: day 0, day 7, and day 14, in order to observe over time the force delivered and the deformation of the direct-printed 3D aligners. Materials and Method:18 identical, Class I without DMD, Graphy® aligners were included in three groups (D0 unaged, D7, and D14) to undergo a continuous aging procedure in Fusayama/Meyer artificial saliva in a water bath at 37°C to reproduce the conditions of the oral cavity, before being placed on the traction bench with traction tests at D0, D7, and D14. Results:Deformation at D0 differed significantly (p < 0.001) from deformation at D7 and D14 in the incisors and molars. Conclusion:The stability of the mechanical properties of the Tera Harz TC-85 material (Graphy®) for direct 3D printing of aligners suggests that a weekly aligner replacement may be considered.
Introduction:Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disease with unknown cause, affecting one child out of 2,000. In more than a third of cases, the temporomandibular joints (TMJs) are involved. TMJ arthritis may cause significant functional disorders such as pain, reduced mouth opening, and malocclusion, as well as permanent aesthetic issues involving facial deformity. The purpose of this article is to describe the diagnosis and treatment of these children. Materials and Method:Based on a literature analysis of TMJ involvement in JIA and our own personal experience, we present the data obtained and the questions that remain. Results:Diagnosis of TMJ arthritis in JIA relies on clinical examination and MRI with injection. It is often made too late, when sequelae are already permanent, due to the asymptomatic nature of TMJ arthritis in many children and because deformities appear long after destructive lesions of one or both joints. Screening for TMJ inflammation in JIA should be routine. MRI with injection has been chosen as the best screening tool, but false positives are numerous. How to improve TMJ arthritis screening in JIA remains an unanswered question. Treatments of active TMJ arthritis are varied, including orthodontic procedures, maxillofacial surgery, and systemic therapies, but there is currently no unified strategy, and the use of intra-articular corticosteroid injections in children is increasingly being challenged. Discussion:Many aspects of the management of TMJ arthritis remain a matter of debate, from the early detection of inflammatory involvement of the TMJs, which may place the orthodontist on the front line, to the role of orthodontic and systemic treatments, as well as that of maxillofacial surgery. Conclusion:These unanswered questions could be addressed via a French multidisciplinary network involving orthodontists, maxillofacial surgeons, radiologists and pediatric rheumatologists.
Introduction:Ankyloglossia is a congenital condition characterized by limited tongue mobility due to an abnormality of the lingual frenulum. Long considered benign, it is now the subject of growing interest, with an increase in diagnoses and neonatal frenotomies, amid controversy stemming from the heterogeneity of diagnostic criteria and the limited level of evidence regarding long-term benefits. Objective:The objective of this study is to critically analyze the embryological basis of ankyloglossia, its clinical implications, the indications for frenotomy, and the medico-legal issues associated with this procedure in infants. Materials and Method:A critical narrative review of the international literature was conducted using major biomedical databases, including randomized trials, observational studies, meta-analyses, and institutional guidelines. Data analysis was performed using an integrative approach combining anatomy, pathophysiology, clinical findings, and ethical considerations. Results:The data suggest a short-term benefit of frenotomy, particularly regarding maternal pain and certain sucking parameters. However, evidence of a lasting effect on breastfeeding or the prevention of subsequent problems remains limited. Discussion:Interpretation of the results is limited by the heterogeneity of diagnostic criteria, variability in practices, and the small number of longitudinal studies. The increase in interventions raises a risk of overdiagnosis and overmedicalization, justifying an indication based on an objective functional impact and an approach consistent with evidence-based medicine. Conclusion:Neonatal frenotomy may be beneficial in the short term for selected indications, but it should not be performed routinely or prophylactically.
Introduction:While impaired eruption of permanent molars is a rare phenomenon, its prevalence appears to be increasing. Among these disorders, a distinction can be made between impactions, in which a tooth is blocked along its eruption path by a physical obstacle, and primary retention, in which eruption ceases in the absence of such a barrier. Within primary retention, primary failure of eruption (PFE) is a genetically determined condition that can severely affect one or more teeth and impact adjacent teeth. The clinical management of PFE is complex and multidisciplinary, and orthodontic traction is not recommended, as it often results in progressive ankylosis. Early identification of PFE is therefore essential to guide the therapeutic strategy. Materials and Method:Clinical and genetic analyses were conducted in a cohort of patients presenting with primary molar retention. The objective was to propose clinical and radiological criteria to differentiate PFE from primary retention of a single tooth (PRST), in order to guide clinicians in treatment planning prior to genetic confirmation. Results:Thirty-four patients treated at the Orthodontics Department of La Pitié-Salpêtrière Hospital (Paris, France) were included. PFE cases were characterized by involvement of several teeth, posterior predominance with possible anterior involvement, posterior infraclusion, reduced alveolar bone height in the affected area, eruption arrest that typically occurred at the supra-crestal level, a positive family history, and an absent, abnormal, or pathological response to orthodontic treatment. PRST cases were characterized by involvement of a single tooth in a given area, predominantly posterior location, eruption arrest that most often occurred intraosseously, apical root curvature in contact with the cortical bone, absence of family history, no initial ankylosis, and a favorable response to orthodontic traction. Discussion:In patients with PFE, orthodontic treatment does not correct eruption but may in fact worsen the condition, notably by causing intrusion of adjacent teeth. In contrast, patients with PRST generally achieve gradual and effective eruption correction with orthodontic traction. Establishing precise clinical and radiological diagnostic criteria is therefore essential to avoid inappropriate treatment and to promptly refer patients to appropriate care, including genetic confirmation if necessary.
