Spheroid Culture System, a Promising Method for Chondrogenic Differentiation of Dental Mesenchymal Stem Cells.

The objective of the present work was to develop a three-dimensional culture model to evaluate, in a short period of time, cartilage tissue engineering protocols. The spheroids were compared with the gold standard pellet culture. The dental mesenchymal stem cell lines were from pulp and periodontal ligament. The evaluation used RT-qPCR and Alcian Blue staining of the cartilage matrix. This study showed that the spheroid model allowed for obtaining greater fluctuations of the chondrogenesis markers than for the pellet one. The two cell lines, although originating from the same organ, led to different biological responses. Finally, biological changes were detectable for short periods of time. In summary, this work demonstrated that the spheroid model is a valuable tool for studying chondrogenesis and the mechanisms of osteoarthritis, and evaluating cartilage tissue engineering protocols.

Osteoarthritis of the Temporomandibular Joint: A Narrative Overview.

Background and Objectives: This study reviewed the literature to summarize the current and recent knowledge of temporomandibular joint osteoarthritis (TMJOA). Methods: Through a literature review, this work summarizes many concepts related to TMJOA. Results: Although many signaling pathways have been investigated, the etiopathogenesis of TMJOA remains unclear. Some clinical signs are suggestive of TMJOA; however, diagnosis is mainly based on radiological findings. Treatment options include noninvasive, minimally invasive, and surgical techniques. Several study models have been used in TMJOA studies because there is no gold standard model. Conclusion: More research is needed to develop curative treatments for TMJOA, which could be tested with reliable in vitro models, and to explore tissue engineering to regenerate damaged temporomandibular joints.

[Ehlers-Danlos syndrome: Role of the dentist]. / Le syndrome d'Ehlers-Danlos : rôle du chirurgien-dentiste.

The Ehlers-Danlos syndrome (EDS) is a group of genetic connective tissue disorder due to abnormal collagen synthesis. EDS is characterized by the triad: joint hypermobility - skin hyperextensibility - connective tissue friability leading to vascular and skin fragility. Thirteen forms exist including three main ones: the hypermobile, classical and vascular forms. Given the diversity of clinical manifestations, the diagnosis of EDS is difficult. The management of this syndrome is multidisciplinary and includes the dental surgeon, because EDS can have many oral and dental manifestations. This syndrome can lead to dental, periodontal, mucosal damage and also to joint damage to the manducatory apparatus. The authors, after describing the symptoms of EDS, their manifestations and their detection, will explain the implications in odontostomatology. EDS must be known to the dentist because it can lead to precautions during dental care, and because patients with EDS are more prone to temporomandibular disorders. At the last, the many oral and dental manifestations of EDS give the dentist an important role in screening for this syndrome.

Relationship between natural or iatrogenic malocclusions and temporomandibular disorders: A case control study.

OBJECTIVE: To investigate the link between malocclusions and temporomandibular disorders (TMD) with a focus on iatrogenic malocclusion. Other etiologies of TMD (oral parafunctions) were also assessed. METHODS: The prevalence of malocclusions was correlated in two groups: patients with TMD (case group) and patients without TMD (control group). Malocclusions involving dental care were specified. Parafunctions in the case group were assessed. RESULTS: A statistically significant association between TMD and overbite >4 mm, interferences in laterotrusion, and absence of Angle Class I was shown. A potential deleterious effect of iatrogenic malocclusions was highlighted. CONCLUSION: The multifactorial etiology of TMD was confirmed because an association between TMD and three malocclusions was found, and all case patients had parafunction(s). Current recommendations advising first a reversible treatment, TMD care should start with a behavioral re-education to remove parafunctions. However, it is essential to avoid creating iatrogenic malocclusion during dental care.