[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.

[Influence of trigeminal nerve lesion on facial growth: study of two cases of Goldenhar syndrome]. / Influence de l'atteinte trigéminale sur la croissance faciale : étude de deux cas de syndrome de Goldenhar.

INTRODUCTION: This cases report confirms the hypothesis that embryonic and maxillofacial growth are influenced by the peripheral nervous system, including the trigeminal nerve (V). So, it's interesting to use the stigma of the trigeminal nerve as landmarks to analyze the maxillofacial volume and understand its growth. The aim of this study is to evaluate the validity of the three-dimensional cephalometric analysis of Treil based on trigeminal landmarks. CASE PRESENTATION: The first case is a caucasian female child with Goldenhar syndrome. The second case is a caucasian male adult affected by the same syndrome. In both cases, brain MRI showed an unilateral trigeminal nerve lesion, ipsilateral to the facial dysmorphia. CONCLUSION: The results of this radiological study tend to prove the primary role of the trigeminal nerve in craniofacial growth. These cases demonstrate the validity of the theory of Moss. They are one of anatomo-functional justifications of the three-dimensional cephalometric biometry of Treil based on trigeminal nerve landmarks.

[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.

[Three-dimensional imaging and cephalometry of cranio-facial asymmetry]. / Imagerie et céphalométrie tridimensionnelles des asymétries cranio-faciales.

The 75th meeting of the French Orthodontics Society will be held in Biarritz May 8-9-10-11 2002. The main topic for discussion will be: "facial asymmetry". During the meeting, authors will present study of facial asymmetries using a new innovative three-dimensional cephalometry. The method combines CT scans data, anatomical landmarks and mathematical tools to create, using the "Cepha" software, a 3D model of the human face. Balance and symmetry of the model are stable enough to define normality for each individual even with different ethnic and cultural origins. Unbalance and asymmetry characterize pathologies. Follow up shape and size of models allows growth prediction and modeling. The model is in the process of becoming the indispensable reference for all those who are interested in studying the human face: Orthodontics, Surgery, Anatomy, Anthropology, Plastic surgery, Forensic Medicine.

[Orthodontic approach to asymmetry]. / Approche orthodontique des asymétries.

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. Vertical non-surgical asymmetry may have an obvious local origin, for instance, a unilateral damage to a nerve. but usually, there is no evident origin. Frequently the occlusal slippage of a severe sagittal or a vertical malformation, which may evolve as a borderline surgery case, is suspected to be the real cause. In these cases, the diagnosis is always late, with the ending growth. The treatment needs peculiar strong asymmetric mechanics and, sometimes, unilateral mixed extractions. The post-treatment occlusion can be unstable; for this reason, the finishing steps must be carefully conducted. Four clinical case reports develop these points ov view. Multidisciplinary treatments prove very useful to solve three types of clinical situations. In the adult patient, facial esthetics are indicated in severe dentofacial asymmetries. Esthetic improvements of dental nature are still required in deviated smiles, or frontal tippings of the occlusal plane. In addition, asymmetrical intermaxillary relationships will lead to functional anomalies: TMJ disorders, dental wear or lingual dysfunctions. Finally, multidisciplinary treatments in the adult concern the occlusal transverse anomalies, the lateral crossbites, the Class II subdivisions, the deviations of the inter-incisor midlines or unilateral edentulousness. The various plans of treatment, as well as the orthodontic mechanics used, are illustrated in the following development by clinical cases.

[3-dimensional cephalometry in orthodontics. The current possibilities of Cepha 3DT software]. / Céphalométrie tridimensionnelle en orthopédie dento-faciale. Les possibilités actuelles du logiciel Cépha 3DT.

A 3D cephalometric analysis method from a scanner acquisition, has been developed thanks to a long collaboration between the CIRAD modeling Laboratory and Jacques Treil. The model of skeletal description is based on eight landmarks related to the neuromatrical axis of facial growth (heads of the mallei, supraorbital, suborbital, submental points); it has been abundantly described. The purpose of this work consists in presenting the dentoalveolar level of the analysis. The description and the marking of the arches and the teeth mainly rest on the systematic use of a mathematical tool, the calculation of the central matrix of inertia, and on three fundamental choices: the identification of the dental arches from their constituting teeth leaving aside any alveolar marking, the marking of each tooth relative to the arch, as it can be observed by the orthodontist's eye, and not relative to the craniofacial architecture, the definition of the position of each tooth by the orientation of its coronoradicular axis and not its sole buccal side, Their uses in orthodontics are numerous: diagnosis, choice of the mechanics, therapeutic simulation, therapeutic follow up, analysis of the findings... Clinical applications illustrate the theoretical presentation.