The « patient casting ¼: a key decision in orthognathic surgery / Le « casting du patient ¼: clé de décision en chirurgie orthognathique

Introduction: The surgical orthodontic patient is a patient whose management is specific. The success of this protocol goes beyond of the right indication and the control of the pre-surgical orthodontic preparation of the treatment. The coordination revolves around a multidisciplinary team, namely an orthodontist, a maxillofacial surgeon, a physiotherapist, a speech therapist, a general practitioner, etc. but also with the collaboration of a specialized psychotherapist. Material and Method: Does the ideal « patient ¼ exist in orthognathic surgery? The decision criteria are morphological (occlusal, aesthetic and cephalometric) but also psychosocial. Results: A new classification called « psychological ¼ is proposed in this article. Conclusion: This new classification can be considered as a key decision in the « casting ¼ of the surgical orthodontic patient and represents a first basis for further investigations in this field.

Introduction: Le patient orthodontique chirurgical est un patient dont la prise en charge est spécifique. La réussite de ce protocole va au-delà de la pose de la bonne indication et de la maîtrise de la préparation orthodontique pré-chirurgicale du traitement. La coordination s'articule autour d'une équipe pluridisciplinaire, à savoir un orthodontiste, un chirurgien maxillofacial, un kinésithérapeute, un orthophoniste, un omnipraticien, entre autres, mais également avec la collaboration d'un psychothérapeute spécialisé. Matériel et méthode: Le « patient idéal ¼ existe-t-il en chirurgie orthognathique ? Les critères de décisions sont morphologiques (occlusaux, esthétiques et céphalométriques), mais aussi psycho-sociaux. Résultats: Une nouvelle classification dite « psychologique ¼ est proposée dans cet article. Conclusion: Cette nouvelle classification peut être considérée comme une clé de décision dans le « casting ¼ du patient orthodontique chirurgical et représente une première base pour de plus amples investigations dans ce domaine.

Condylar repositioning according to digital bite registration method for virtual orthognathic surgery planning: A series of 49 consecutive patients.

INTRODUCTION: The accurate mandibular condylar positioning for orthognathic surgical planning is fundamental in obtaining a planned occlusal result. The differences between the position of condyles seen on computed tomography or cone-beam computed tomography (CBCT) scans and during surgery reduce the accuracy of the result. This study aimed to assess the differences between the condylar position recorded on CBCT and a numerical 3-dimensional (3D) model created after mandibular repositioning for orthognathic surgery planning. METHODS: This study retrospectively evaluated 49 patients who underwent virtual orthognathic surgery planning. The procedure involved recording a computed tomography or CBCT of the skull and dental surface using an intraoral digital scanner. The mandible was repositioned on the numerical 3D model according to the superimposed virtual bite registration in centric relation. Linear and angular measurements of the right and left condyles were recorded before and after mandibular repositioning. RESULTS: The positions of 98 condyles were compared. Linear measurements of the posterior and superior joint spaces revealed a significant difference. Subgroup analyses displayed statistically significant differences for patients with skeletal Class II malocclusion. CONCLUSION: According to the digital bite registration method, the difference between the mandibular position recorded on CBCT and on the numerical 3D model after repositioning may have clinical significance. Further studies are needed to validate this theory and test the accuracy of the clinical results.

Relevance of teleorthodontic tools: a systematic review of the literature / Pertinence des outils de téléorthodontie : une revue systématique de la littérature

Introduction: The concept of teleorthodontics was recently born; the Covid-19 crise has participated to the emergence and the amplification of this phenomenon. Objective: The main aim of the present systematic review was to evaluate the teleorthodontics relevance. Method: An electronic and manual search was performed in four databases (PubMed, Scopus, Embase and Cochrane Library) up to December 2021 according to PRISMA guidelines. Both prospective and retrospective studies, as well as case reports, case series and satisfaction surveys published in English or in French without time restriction were included. Two independant reviewers were involved in the selection of the studies and a third reviewer was required in case of disagreement. A bias assessment was performed using the Mixed Methods Appraisal Tools. Results: Out of 1757 articles, 22 articles published mainly between 2019 and 2021 and with varying levels of evidence, were included. Considering the results obtained, different concepts were discussed (time management, quality of communication, reliability and use of tools, satisfaction, quality of human relations, emergency management, compliance). Conclusions: Teleorthodontics is an interesting and complementary tool that is, in no way, a systematic alternative to face-to-face orthodontic appointments in the office. However, many essential aspects of telemedicine in orthodontics, such as data protection, still need to be investigated in order to fully analyze this tool.

Introduction: Le concept de téléorthodontie a récemment vu le jour ; la crise de la Covid-19 a fortement participé à l'émergence et à l'amplification de ce phénomène. Objectif: L'objectif premier de cette revue systématique de la littérature était d'évaluer la pertinence de la téléorthodontie. Méthode: Une recherche électronique a été menée dans quatre bases de données (PubMed, Scopus, Embase et Cochrane Library), complétée par une recherche manuelle jusqu'à fin décembre 2021 conformément aux directives PRISMA. Tous types d'études cliniques, prospectives ou rétrospectives, y compris les rapports et les séries de cas ainsi que les enquêtes de satisfaction publiées en anglais ou en français sans restriction de temps, ont été inclus. Deux auteurs indépendants ont été impliqués dans la sélection des études et un troisième auteur a été sollicité en cas de désaccord. Une évaluation des biais a été réalisée à partir du Mixed Methods Appraisal Tools. Résultats: Sur les 1757 articles, 22 articles, publiés majoritairement entre 2019 et 2021 et de niveaux de preuve variables, ont été inclus. Tenant compte des résultats obtenus, différentes notions ont pu être discutées (gestion du temps, qualité de la communication, fiabilité des outils, facilité d'utilisation, satisfaction, qualité du rapport humain, gestion des urgences, observance). Conclusions: La téléorthodontie est un outil intéressant et complémentaire à une approche classique pour certaines indications. Cependant, elle ne constitue en aucun cas une alternative systématique aux rendez-vous orthodontiques en présentiel au cabinet. De nombreux aspects pourtant essentiels (protection des données, etc.) doivent être encore investigués pour analyser pleinement cet outil.

[Cranial Facial 3D Biometry: Statistical analysis of Class II disharmonies]. / Biométrie cranio-faciale 3D: analyse statistique des dysmorphies de classe II.

We could study Cone Beam documents of patients consulting in ORL with standard Angle Class I occlusion (45 ND), patients consulting in orthodontics with an orthodontic Class II (51 APNS) and patients with a surgical Class II (83 APS). The used 3D biometry calculates systematically a 164 set of parameters able to take into account all kinds of disharmonies; among which 38 parameters are specifically devoted to anterior-posterior "off asymmetry" pathologies. Then the specific Artificial Intelligence (AI) programs treat morphological data and give textual diagnoses. Analysis of the global sample aims to control the efficiency, separating different sub-samples one each other: t test appreciates efficiency of each parameter to recognize clinical sub-sample. The correlation coefficient, r, between each parameter and pseudo Angle molars Class II (GMMy-Gmmy) give the importance of its tie with Class II pathology. Presentation of parameters medium values in each sub-group gives the medium profiles. By direct comparison of patient's parameters values with medium profile, it is possible to locate patient's pathology. So we can take in account new parameters like arches upper/lower gap, anterior bases upper/lower gap, compensatingparameters... It is then possible to make more secure the clinical decision.

[Cranio-Facial 3D Biometry: Complete analysis of a case of class II "limit surgery"]. / Biométrie cranio-faciale 3D: analyse complète d'un cas de classe II « limite chirurgicale ¼.

With the conventional 2D exam of clinical cases, the diagnosis is penalized by the lack of data, not only for vertical or transverse or asymmetrical problems, but for classical cases of anteroposterior dysharmonies. In these cases, the effectively used parameter, ANB angle, seems insufficient. So the authors elaborated a 3D biometry tool. The program of morphological analysis is able to deliver a complete description of dysharmony, supported by Cone Beam data capture. In the first part of this article the authors present the foundation of the model: anatomical reference, skeletal landmarks, teeth location by inertia matrix calculus, parameters, diagnosis and aid to treatment plan. The second part is the presentation, step by step, of the program in function, analyzing a great case of Class II hyperdivergent, border line surgery. All along the diagnosis way, the authors make the assistant discover all the documents given by the computer about complete 3D diagnosis and aid to treatment plan.

[What is a malocclusion?] / Qu'est-ce qu'une malocclusion ?

Since 1907, the international community has used Angle's classification to assess the mesio-distal relationships of the dental arches. It is the basis of the diagnosis of malocclusion in the sagittal dimension and indicates or not an orthodontic correction treatment. This work was aimed to inventory the classification methods of malocclusions used today. Indices of treatment need were also presented because they are based on one or more occlusal anomalies to indicate treatment. The classifications were criticized and the contribution of a functional analysis based on the use of the trilogy setting, centering and guiding was detailed. The type of anomalies (skeletal and dental) must be completed by the analysis of the occlusal anomaly of setting (centering or guiding) and of the category of occlusion (functional occlusion, functional malocclusion or pathogenic malocclusion), ie its possible pathogenic impact on orofacial structures. A consensus on the classification of occlusal anomalies is necessary in order to better identify the anomalies and their global repercussions, and to better define the needs for orthodontic treatment.

[Maxillo-facial surgery in skeletal Class II: repercussions on the temporo-mandibular joints]. / La chirurgie des cas de classe II et ses répercussions sur les articulations temporo-mandibulaires.

These interventions usually aimed at the correction of the skeletal discrepancy by mandibular retrognatism with an advancement of the distal portion of the mandible after mandibular osteotomy. The position of the condyle is determined during the osteosynthesis with miniplates. Condyles are set back in relation with the supine position of the patient and the weakness of his (her) curarized muscle. All studies show that surgery of mandibular advancement causes a lateral, torque and backward movement of the condyles, all harmful to the condyles. Factors that predispose to condylar resorption are "the patient": a woman, young (between 15 and 40), high mandibular angle, with a history of temporo-mandibular disorders and surgical overload applied to the condyles. What are the possible solutions to avoid failures? Patient preparation before surgery and surgery simulation with an articulator, condylar position control during surgery, working with surgeons to achieve a condylar portion stabilization system (with the CAD), quickly set up a mobilization of the mandible by physiotherapy.

[Study of asymmetries in the severe antero-posterior disharmonies]. / Etude des asymétries dans les grandes dysmorphies antéro-postérieures.

Using the Treil 14 points cephalometric model orthodontists can prepare a complete cranio-facial anatomic assessment at three analytic levels: the framework or envelope, the basal bone and the alveolo-dental arcade. The assessment of border-line surgical antero-posterior dysmorphosis can elucidate interesting depictions of asymmetries, their relation to other malformities, and their genesis. Asymmetry arises from over-growth of one side of the face in all three dimensions of space even if, clinically, it often appears that one dimension is predominately affected. The ortho-morphic cases of Angle Class I present a little right excess or "natural" asymmetry. The Class III cases present a severe excess on the right side, while the Class II cases present an excess on the left side comparing with reference sample.

Posterior growth and forecasting the development of mandibular third molars.

The inter-dependence of overall orthodontic treatment and the development of the third molars requires the entire dentition to be taken into consideration ab initio and for the patient to be fully informed as to the extractions involved. The anatomical conditions in which the development of the wisdom teeth can occur are studied using comparative samples, with and without third molar retention, followed up to the age of 20 years. Posterior growth observed between the beginning of multiband treatment and adulthood amounted to 11/16mm (girls/boys). The initial difference in forecasting the space between the groups with retained third molars and without was slight (5.5mm). However, this difference was maintained throughout the growth period and was sufficient to guide the final choice whether to extract these teeth or allow them to erupt.

[Three-dimensional 14 point-cephalometric analysis: compensation of maxillofacial dysmorphisms]. / Analyse céphalométrique tridimensionnelle à 14 points: compensations des dysmorphies maxillo-faciales.

The eight points cephalometric Treil model and the alveolodental parameters already allows an initial description of the maxillofacial framework and the teeth. Added six points allows taking into consideration an intermediate level: the maxillary and mandibular skeletal basis. So, the 14 points complete model allows a complete craniofacial anatomy description in three analysis levels: the framework or envelope, the osseous bases, the alveolodental arch. The correlation study between the 3D parameters at different levels defines the compensation notion. It allows understanding how skeletal disharmony may be distributed among the different levels. Only vertical direction compensations are analysed here.

[Three-dimensional cephalometry: applications in clinical practice and research]. / Céphalométrie tridimensionnelle: applications en clinique et en recherche.

A 3D cephalometric analysis method from scanner acquisition has been developed thanks to a long collaboration between Dr Treil and the Department of Orthodontics in Toulouse III University. It allows a perfect knowledge of maxillo-facial architecture using fourteen landmarks related to the neuromatricial axis of facial growth. These landmarks can be identified without ambiguity. The marking of each tooth relative to dental arches (gravity centre coordinates and torque and tipping of each tooth), and the location of arches relative to maxillo-facial frame are given by the analysis. Description and reconstruction of dental and maxillo-facial anatomy are possible with three levels: maxillo-facial frame, maxillar and mandibular bases and dentoalveolar level. The method not only gives more precise information than conventional cephalometrics in anteroposterior and vertical directions, but it allows transversal analysis and asymmetry measurement. Applications are numerous in research as well as in clinical medicine: analyses of cases border line surgery, surgical set-up, facial asymmetry, analysis of dentoalveolar compensations, definition of therapeutic aims, occlusal analysis and set-up, study of evolution in anthropology-primatology, study of growth etc. This method of description using a pattern of landmarks is perfectly adapted to the last developments of modern research techniques: morphometric geometry with Procustes superimpositions, EDMA, TPS, FEM.