Implementation of orthodontic extraction for pre-implant soft tissue management: A systematic review.

OBJECTIVE: This systematic review aims to define the recommendations allowing an optimized clinical implementation for orthodontic extraction as a pre-implant soft tissue management procedure. MATERIALS AND METHODS: A digital search was performed in the Cochrane Library, PubMed, Scopus, and DOSS databases; a pre-screening was conducted according to the title and summary of the articles. After a complete reading, only the articles meeting all of our inclusion criteria were selected, and a second search, this time manual, was performed within their references. The selected articles were then analysed according to twelve parameters. RESULTS: Thirty-nine articles were included. Despite low statistical evidence in the available literature, some principal guidelines, which seem generally accepted by the scientific community, could be highlighted based on this analysis. However, no ideal clinical protocol could be established. CONCLUSIONS: Orthodontic extraction is an efficient procedure for pre-implant soft tissue management, however, further studies are needed to establish full clinical recommendations and optimize its clinical implementation.

Bond strength of pre-coated flash-free adhesive ceramic brackets. An in vitro comparative study on the second mandibular premolars.

CONTEXT/OBJECTIVES: Clinical studies show a mean bond failure rate of orthodontic brackets, which ranges between 6% and 8%, with a predominance for the second mandibular premolars. The pre-coated flash-free adhesive ceramic brackets allow to obtain, according to their manufacturer, a low bond failure rate, while ensuring a simplified implementation. The aim of this study was to measure the shear bond strength of ceramic brackets bonded with the direct method using a pre-coated flash-free adhesive system, and to compare it with the shear bond strength of the old generation precoated brackets and that of operator coated brackets to the buccal surface of the second mandibular premolars. MATERIEL AND METHODS: 45-second mandibular premolars extracted for orthodontic purposes were randomly distributed into 3 groups of 15 teeth each. In the first group, the brackets were precoated with the APC™ Flash-Free® system (3M Unitek; in the second group, with the APC Plus® system (3M Unitek), and in the third group, the brackets were bonded manually with the Transbond XT® composite (3M Unitek). The enamel surface was prepared in the same way for the 3 groups: etching using 36% orthophosphoric acid, followed by the application of the Transbond XT® primer adhesive (3M Unitek). Each sample was submitted to shear bond strength forces using a Universal Testing Machine LRX® (Lloyd Instruments LTD., Fareham, UK) in shear mode with a crosshead speed of 1.0mm/min. The bond strength values of the brackets were recorded in megapascals (MPa) for each tooth. The mean values were then compared using the one-way ANOVA test. RESULTS: Although the mean shear bond strength value for the APC Flash-Free® group was lower than those of the two other groups, this difference was not statistically significant (P=0.276). CONCLUSION: Given the experimental conditions of this in vitro study, the shear bond strength of the brackets precoated with the APC Flash-Free® system is comparable to the two other conventional systems.

[Etiopathogenic and clinical aspects of asymmetry]. / Approche étiopathogénique et clinique des asymétries.

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. An exo- and endobuccal clinical examination endeavors to specify the localization and the severity of the damage, and to evaluate the importance of the possible alveolar compensations. Consolidated by additional examinations, it enables the clinician to differentiate the various forms of asymmetries.

[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.