[Contribution of 3D imaging using 3DNEO(®) software in surgical-orthodontic treatment of impacted teeth]. / Apport de la reconstruction tridimensionnelle à l'aide du logiciel 3DNEO(®) dans le traitement chirurgico-orthodontique des dents incluses.

OBJECTIVES: The aim of this investigation was to present and evaluate an original method of mini-invasive oral surgery and orthodontics based on 3D images from a computed tomography software (3DNEO(®), 3DNEOVISION). MATERIALS AND METHODS: Three patients with impacted teeth were examined and their data were analyzed with this software based on the "region growing" method. RESULTS: Several clinical interests emerge : locate and visualize precisely the relationships of the impacted tooth with the adjacent anatomical elements under the desired angle, associate/dissociate the different elements of the 3D scene, measure the distances, calculate the axes of traction, materialize the way of traction and the optimal point for bonding, prepare virtually the surgical exposure and orthodontic treatment plan. CONCLUSION: This 3D method might provide information for improved diagnosis and treatment plans in order to ultimately result in more successful treatment outcomes and better care for patients.

[One phase or two-phase orthodontic treatment: comparisons]. / Traitements orthodontiques en une ou deux phases : comparaisons.

INTRODUCTION: The optimal timing for starting an orthodontic treatment is discussed by many authors. This is even more difficult that there are different therapeutic approaches. In case of Class II, division 1 malocclusion, one approach consists of realising an early treatment during mixed dentition, then a surveillance phase and finally an alignment phase during adolescent dentition. The other approach consists of waiting for adolescent dentition to treat. MATERIAL AND METHODS: We made a study with 65 subjects with Class II, division 1 malocclusion: 33 were treated in one phase during adolescent dentition and 32 were treated in two phases, beginning in mixed dentition. In both groups the patients had the same age at the beginning of treatment and were treated with Distal Active Concept. RESULTS: Correction of offset bases bone, increase of the diagonal mandibular and over-jet stability are significantly better in the group treated in two phases. We guess that the functions estimated progressively more and more surely in this new environment.

[Accelerated tooth movement by alveolar corticotomy or piezocision]. / Le concept du déplacement dentaire accéléré par corticotomie ou par piézocision.

The relatively recent introduction of corticotomies and piezocision has made it possible for orthodontists to accelerate tooth movement and thereby to shorten the length of orthodontic treatment. Specialists emphasizing a mechanistic concept have been debating the underlying basic biological mechanics of these new therapeutic tools with opposing specialists who support a biological conception. Our analysis of different publications on the subject suggests that the biological explanation, with its emphasis on the Regional Acceleratory Phenomenon (RAP), is correct. However, the majority of studies in this field are not based on the principle of evidence based medicine (EBM).

[Dento-facial orthopedics and osteopathy]. / Orthopédie dento-faciale et ostéopathie.

Osteopathy has grown rapidly. Given their common action on children and adolescents, the collaboration between dentofacial orthopedics and osteopathy is increasingly common. It therefore becomes necessary and urgent to investigate whether, based on data acquired from science, there is evidence of possible interrelations between the two disciplines. After reviewing the literature, very few scientific publications demonstrate the utility of osteopathy and its relationships with other disciplines. However, the relationship between occlusion and posture seem relatively proven, especially in the sagittal direction. On the other hand, although the mobility of the cranial bones is established, the primary respiratory motion is still subject to controversy, even among osteopaths. This, even as orthodontics has long been accused of countering the primary respiratory motion of cranial bones (PRM). Today osteopaths do not reject orthodontics anymore, because the return to a physiological bite situation is considered beneficial. According to expert opinion (without proof, however), some orthodontic devices (like headgears) which block the sutures are still to be avoided and require appropriate monitoring osteopathy. The controversy over the adverse effects of orthodontic treatment is becoming more nuanced by osteopaths, and modern orthodontics claiming a «global¼ approach of patient, collaboration may be possible in future year.

[Aesthetic repercussions of the class II treatment on the profile: comparative study Distal Activ Concept (DAC)/Extra-Oral Force (EOF)]. / Conséquences esthétiques du traitement de la classe II : étude comparative Distal Active Concept (DAC)/Forces Extra-Buccales (FEB).

In the past orthodontists frequently used extra-oral force to slow down skeletal growth in their treatment of Class II malocclusions; more modern practice relies less on applying distal force to the maxilla than on stimulating forward growth of the mandible. Does this change in therapeutic design have any repercussions in facial esthetics? To evaluate the impact of treatment on the appearance of the profile, we conducted a study with 64 patients in the adolescent dentition stage with a Class II, division 1 malocclusions. None had teeth extracted or preliminary orthodontic treatment. We divided them into two sections; we treated the first group of 33 patients with the Distal Active Concept (DAC), which encourages forward movement and growth of the mandible, and we treated the second group of 31 patients with Extra-Oral Force (EOF) in combination with a full-banded appliance. Comparing the results with cephalometric profile analyses, we found that the soft tissue contour of the lower part of the face showed considerably more sagittal development in the children treated by DAC than those treated by EOF.

[Early treatment of Class III: a long-term cohort study]. / Traitement interceptif de classe III: une étude de cohorte à long terme.

The aim of this comparative retrospective short- and long-term study was to evaluate the interceptive treatment in Class III malocclusion in daily orthodontic practice. The sample was composed of 69 children divided into two groups according to the interceptive treatment applied: 31 children in group F (facial mask) and 38 in group M (interceptive fixed appliance). A Pancherz cephalometric analysis was carried out on the lateral head films at the start of the study (t(0), after the active treatment (t(1) and 29 months after t(1) (t(2). The two groups were compared at the beginning of the study by t-test and chi-squared test: there were no difference between groups M and F except for facial divergence, which was greater in group M. Long-term comparison (interceptive and post-interceptive stage i.e. six years) showed that (i) overjet was corrected in each group: molar discrepancy was stable in both groups, (ii) alveolar discrepancy was stable and (iii) antero-posterior discrepancy was not improved in either group. At t(2) there were no differences, either qualitative or quantitative between groups M and F. In the end, more than 80% of the children did not need an orthognathic surgery.

[Can orthodontic treatment generate temporomandibular disorders and pain? A review]. / Le traitement orthodontique peut-il générer des algies et/ou dysfonctionnements articulaires ou musculaires (ADAM) ? Une revue de littérature.

While considered for years to play the primary role in the etiology of temporo-mandibular joint disturbances (TMD), occlusal discrepancies are now considered to be just one causative factor among many. Recent studies, literature reviews or meta-analyses, and longitudinal studies with follow-up of children treated for many years all conclude that there is no risk of orthodontic treatment giving rise to episodes of temporo-mandibular disorders. The signs of TMD appearing during the course of orthodontic treatment should be considered in the context of the epidemiology of the disorder, which is characterized by a strong increase in its occurrence during adolescence. In conclusion, it should be stated that if orthodontic treatment can no longer be considered as one of the etiopathogenic factors in the TMD complex, there are no scientific arguments to justify the converse, that there are indications for orthodontic treatment whose sole goal would be the treatment of TMD.

[Is retention justified after interceptive treatment of Class II malocclusion?]. / La contention est-elle justifiée après traitement interceptif de classe II ?

Indication of intermediate retention after early treatment of class II malocclusion has not been yet assessed by comparative studies. Therefore, it is up to the practitioner to analyse the need for retention in the time period between the two phases. Does wearing a retainer indeed decrease the chance of relapse between phase one and phase two? We performed a retrospective comparative study consisting of 90 subjects in mixed dentition with class II molar relationships with an increased overjet (> or = 5 mm) treated in the J.-J. Aknin office with DAC appliance. The sample was divided into two groups: 31 patients wearing retention represented by a removable Hawley plate and 59 children in supervision without retention. Three lateral head-films were made at the beginning and the end of early treatment and before the resumption of the second phase treatment. Studied cephalometrics parameters were assessed according to superimposing Pancherz's analysis. A statistical analysis was performed. Results showed a significantly lower relapse of incisor's protrusion in the group wearing an upper retainer. Results' interpretation was in accordance with the assessment of confusion's factors and selection's criteria. Besides, this study was carried out in intention-to-treat and retention's effectiveness in proportion with patient's compliance. Nevertheless, the study was performed in real conditions. In conclusion, and without randomised trial, results show that retention seems to decrease maxillary incisor movements. It is therefore justified in cases presenting with important class II especially with procumbent incisors.

[Are extraoral forces justified in the early treatment of Class II malocclusions?]. / Les forces extra-buccales sont-elles justifiées dans le traitement précoce des classes II?

First phase class II early treatments are able to restore a correct growth. DAC (Distal Active Concept) is an early fixed treatment using class II elastics, coils and springs. The aim of this retrospective study was to evaluate short and long term dental and skeletal effects of head-gear applied on upper first molars associated to class II elastics and to compare our results to a sample treated with early DAC. Headgear group included 37 subjects. DAC group included 100 subjects. Cephalometric values came from Pancherz's and Tweed's analysis. Lateral head-films were analysed at t1 (before early active treatment), at t1' (after early active treatment) and at t2 (before second stage in permanent dentition). T-tests were performed to compare the groups. Results were quite similar for these two types of treatment showing nevertheless greater mandibular answer in DAC group. Only a prospective randomised study would be able to precise these observations.

[Is hyperdivergence a contraindication in the early treatment of Class II malocclusion?]. / L'hyperdivergence est-elle une contre-indication dans le traitement précoce des classes II?

Vertical growth pattern is supposed to have adverse effects on sagittal growth and is considered as a contra-indication for early treatment. The aim of this retrospective cohort study was to analyse whether early treatment of children with Class II malocclusion was able to achieve as an important sagittal correction on subjects with growth vertical pattern as on subjects without vertical pattern without modification of vertical growth. The study was composed of 123 children (110 months old in average), with Class II division 1 malocclusion : 34 children with excessive vertical growth pattern and 74 children without excessive vertical growth pattern, both treated with DAC appliance, and 15 not treated subjects with excessive vertical growth pattern. Data were collected at the start of the study (t(1)), after the active treatment (t(1')) and 29 months after t(1) (t(2)). A Pancherz cephalometric analysis was applied on the lateral roentgenograms. Differences were evaluated with t-test. Results show that DAC appliance may be an orthopedic appliance indicated to achieve correction in class II skeletal pattern by mandibular growth without augmentation of vertical dimension.

[Not Available]. / Evolution des dents de sagesse dans les traitements de classe II division 1 avec et sans extractions.

UNLABELLED: Various factors participate to lower third molar eruption included premolar extractions. In Class II division 1 malocclusion, premolar extractions are sometimes decided to correct antero-posterior malocclusion. Alternative therapies without extractions exist such as DAC appliance. What is the influence on third molar eruption of extractions and non extractions in Class II division 1 malocclusion? MATERIAL AND METHODS: We made a study with 60 subjects with Class II division 1 malocclusion: 30 were treated without extractions and 30 were treated with 4 extractions (included second lower premolars). We observed the evolution rate of third lower molars, the movement in the mandible and the modifications on lower arch. RESULTS: Extractions of second lower premolars increase the possibilities of third lower molars eruption (that increase from 10% to 50%). DISCUSSION: Like in others publications, extractions of second lower premolars, more than the first, may increase significantly the evolution rate of third molars. Nevertheless, inclusion risk is not reduced and is still important (50% in our study) with the probability that the treatment leads at the end to extractions of a quart of dental capital of the patients.

[Not Available]. / Distraction symphysaire et orthodontie.

Facing a dental crowding, the orthodontist has several therapeutic options. If maxillary expansion is often used, mandibular orthodontic expansion is proscribed because of its tendency of inefficiency and relapse. Mandibular symphyseal distraction osteogenesis allows to remove this proscription. This therapeutic protocol consists in a pre-surgery orthodontic preparation phase followed by surgery (symphyseal osteotomy and placement of the distraction device), a latency period (five to seven days), then an activation period (most of the time 1 mm/day in two steps) followed by a consolidation period (three months) during which the orthodontic treatment can be resumed. Skeletal and alveolar expansion corrects dental crowding. This surgical technique is versatile, minimally invasive, and stable with time. Major indications are hypoplastic symphysis, anterior crowding, relapse of orthodontic treatments and some syndromes. This method can also be an answer to aesthetic concerns or an alternative for treatment of dental crowding. Face à un encombrement dentaire, l'orthodontiste dispose de plusieurs options thérapeutiques. Si au maxillaire, l'expansion est fréquemment utilisée, l'expansion mandibulaire orthodontique est proscrite, car inefficace et récidivante. La distraction symphysaire permet de lever cet interdit. Ce protocole thérapeutique comprend : une préparation orthodontique pré-chirurgicale, une chirurgie (ostéotomie symphysaire et pose du distracteur), une période de latence (cinq à sept jours), puis une période d'activation (le plus souvent 1 mm/j en deux fois) suivie d'une période de consolidation (trois mois) pendant laquelle le traitement orthodontique peut être repris. L'expansion basale et alvéolaire corrige l'encombrement dentaire. Cette technique est polyvalente, peu invasive et stable dans le temps. Ses indications majeures sont l'hyposymphysie, l'encombrement incisif, la récidive de traitements orthodontiques et certains grands syndromes. Cette méthode peut aussi être proposée pour répondre à des préoccupations esthétiques ou comme alternative aux traitements classiques de l'encombrement dentaire.

[Interceptive treatment with the DAC appliance: structural analysis]. / Traitement interceptif DAC: analyse structurale.

The aim of this retrospective short and middle term study was to evaluate dental and skeletal effects during early class II treatment. Thirty subjects were treated with DAC appliance, 32 children were not treated. Data were collected at the start of the study (t(1)), after the active treatment (t(1')) and 28 months after t(1) (t(2)). L.D.V. and Tweed cephalometric analyses were applied on the lateral roentgenograms of the three groups. Differences for all the variables from t(1) to t(1') and t(2) were calculated and compared by t-test. Results suggested that DAC appliance was able to achieve twice more mandibular growth in the treated group than in the non treated group. Anterior total skeletal and matricial rotations were similar to control group. Early DAC appliance achieved overjet correction thanks to major skeletal participation (89%) and little dental participation (11%). During following-up stage, overjet relapsed partially as shown in other articles with other appliances. As a conclusion, DAC appliance may be an orthopedic appliance indicated to achieve correction in class II skeletal pattern without maxillary prognathism and with mandibular retrognathism.

Cleidocranial dysplasia: molecular genetic analysis and phenotypic-based description of a Middle European patient group.

Cleidocranial dysplasia (CCD) (OMIM 119600) is a rare dysplasia of osseous and dental tissue. Characteristic features are typical facial and dental appearance plus morphologic anomalies. RUNX2 (OMIM 600211), the responsible gene for CCD, is considered to be a master gene for bone development and bone homeostasis. This study describes the genotype-phenotype correlation based on craniofacial features involving an interdisciplinary approach. Our patient cohort consisted of 31 CCD patients from 20 families; five patients from two families were unavailable for clinical examination. Since CCD mostly affects the craniofacial region, phenotypic characterization of each individual focused on craniofacial and dental aspects. After recording patient medical and family history, the phenotypic data was analyzed using homogeneity analysis (HOMALS), a statistical procedure for data reduction in categorical data analysis. The coding sequence of the RUNX2 gene was analyzed using PCR, direct sequencing, and restriction endonuclease digestion. Eight unpublished and four known heterozygous mutations in a total of 14/20 index patients (70%) were identified. In total, we detected 7 missense mutations, 5 frameshift mutations, and 2 nonsense mutations in 14 index patients (35%, 25%, 10%, respectively). The overall CCD phenotype varied from mild to fullblown expression. Using HOMALS, we were able to discriminate four groups of patients showing significant differences in phenotypic expressivity, thereby simplifying the grouping of our large patient cohort into clear distinguishable entities. Analysis of the mutation patterns revealed that mutational frequency and types of mutations found can be attributed to the gene's structure and function.