An interpretable machine learning approach to study the relationship beetwen retrognathia and skull anatomy.

Mandibular retrognathia (C2Rm) is one of the most common oral pathologies. Acquiring a better understanding of the points of impact of C2Rm on the entire skull is of major interest in the diagnosis, treatment, and management of this dysmorphism, but also permits us to contribute to the debate on the changes undergone by the shape of the skull during human evolution. However, conventional methods have some limits in meeting these challenges, insofar as they require defining in advance the structures to be studied, and identifying them using landmarks.

Estimation of Distances within Real and Virtual Dental Models as a Function of Task Complexity.

Orthodontists have seen their practices evolve from estimating distances on plaster models to estimating distances on non-immersive virtual models. However, if the estimation of distance using real models can generate errors (compared to the real distance measured using tools), which remains acceptable from a clinical point of view, is this also the case for distance estimation performed on digital models? To answer this question, 50 orthodontists (31 women and 19 men) with an average age of 36 years (σ = 12.84; min = 23; max = 63) participated in an experiment consisting of estimating 3 types of distances (mandibular crowding, inter-canine distance, and inter-molar distance) on 6 dental models, including 3 real and 3 virtual models.

[The digital workflow at the service of the practitioner's clinical learning].

Our relationship to digital technologies will be a determining factor in building our identity as 21 century orthodontists. The digital workflow used in orthodontics can be summarized in four successive phases: diagnosis, treatment planning, computer Aid Manufacturing, therapeutic follow-up. According to Professor Stanislas Dehaene, cognitive neuroscience has identified four criteria on which learning success depends.

[Autotransplantation of a maxillary incisor and orthodontic care: a case study].

Introduction: Severely impacted teeth with atypical root anatomy do not respond well to orthodontic traction after surgical exposure. Consequently, they are often removed, but replacing them with dental prostheses can prove difficult in patients who are still growing. Thus, autotransplantation seems to be the only way to preserve a natural tooth and the alveolar bone.

[Orthodontic approach to asymmetry].

From an orthodontic point of view, asymmetries can be gathered in three great clinical entities: mandibular lateral deviations, dental asymmetries without skeletal involvement, skeletal asymmetries. Once the therapeutic aims and the principles of the orthodontic approach of these dysmorphoses have been recalled, the authors present the various orthodontic means implemented in this type of treatment. Four cases treated illustrate those types of treatment.

[Etiopathogenic and clinical aspects of asymmetry].

Complex dysmorphies, asymmetries can affect the various elements of the stomatognathic system: cranial base, maxilla, mandible, musculature and dental arches, in the three dimensions of space. Their etiopathogenesis, as well as their clinical forms, vary considerably. Dysembryopathies, growth disorders, TMJ damages, postural or functional disorders and dental anomalies can create, according to their severity and their moment of appearance, severe or minor facial asymmetries, or asymmetries of the arches.