Olivier Sorel

Le micro-sablage amélaire

Enamel conditioning (elimination of dental plaque and creation of an irregular surface) is an essential step before bonding of orthodontic brackets. The most popular procedure in our practice is bonding with resin which requires enamel etching in order to get enough shear bond strength. Many studies have tried to evaluate the effects of enamel bonding using the acid-etching procedure as well as the changes caused by detachment of brackets. Thanks to the development of other adhesives such as glass ionomer cements which chemically bind to the enamel, new enamel conditioning methods appeared, in particular sandblasting with aluminium oxide particles. This technique is a mechanical preparation of the tooth that avoids the harmful effects of acid products. By suitably choosing the parameters of sandblasting (pressure, time and quantity of powder), enamel loss is lower than with the acid-etch procedure and the surface of the enamel seems less affected. However the bond strength remains superior to the values required for treatment. The presented results indicate that enamel sandblasting can be considered as an alternative for the acid-etching technique currently used in orthodontic practice because it creates sufficient strength and respects enamel thickness better.

Relation entre la chirurgie orthognatique et les dysfonctionnements de l’appareil manducateur. Revue de la littérature

A painful and dysfunctional temporomandibular joint can be associated with a musculoskeletal anomaly. The multifactorial character of the etiology is now recognized. Among the etiologies, the role of orthognathic surgery is still debated. The analysis of the literature from 2000 to 2011 reveals for most authors a decrease in the frequency and intensity of signs and symptoms after surgery, especially pain and clicking. Risk factors may influence post-surgical results. Studies on patient risk factors such as age, sex, type of dysmorphia are inconclusive. Surgical techniques and the procedure used may have an influence on the development of post-surgical clinical signs and symptoms of temporomandibular disorders.

Laser Er:YAG en parodontologie et implication dans le plan de traitement orthodontique

The Er:YAG laser is used in periodontal surgery to remove excess tissue formations and to clean periodontal pockets. Combined with ultrasonic procedures lasers have significantly advanced the parameters of periodontal surgery. The goal of this article is to review the working mechanisms of the Er:YAG laser in the wide variety of its applications in complex treatment situations in both periodontics and orthodontics.

Traitement orthodontique sur un parodonte affaibli : apport de l'orthodontie

Orthodontics is the planned movement of teeth that can be carried thanks to the provoked resorption and apposition of osseous tissue. From the standpoint of the periodontium orthodontists should always be cognizant of the risk of iatrogenically weakening soft tissue status but at the same time they should consider that an improved character of the periodontium is one of the benefits that can be derived from mechano-therapy. These periodontal improvements, in the broadest sense of the term, can result from traditional overall therapy as well as treatment aimed solely at a local condition requiring extrusion of a tooth or, more rarely, alveolar distraction.

Periodontal diagnosis in orthodontics

Before any orthodontic treatment can begin, it is essential that the patients periodontium be in sound condition, capable of responding to the movement of teeth in a healthy fashion. Inspection of the dentition, palpation of tissues, and careful study of adequate X-Rays are all necessary for establishing a diagnosis, but review of the depth of gingival pockets with periodontal probes is the key procedure for avoiding blunders in treatment. After periodontal health has been validated, it is vital that orthodontists determine the patients periodontal biotype by clinical observation and periodontal probing and assess the quality of the gingival attachments of the teeth that will be affected by the expansion forces of treatment. The ensemble of these criteria will dictate what treatment paths and forces the orthodontist will employ.

[Bone-based anchorage failure].

The aim of this article is to list the circumstances likely to give rise to failure of orthodontic temporary bone-supported anchorage and, hence, to attempt to define criteria for correct miniscrew usage. Our study was based on a review of the literature and analyses of clinical cases. Our findings show that, with a sound knowledge of the indications for screw selection and positioning and of the insertion protocols combined with a clear understanding of orthodontic mechanics, bone-based anchorage can henceforth provide orthodontists with an essential tool to enable formerly unachievable dental movements and to stabilize unwanted movements, thus making treatment both more reliable and more effective.

Procédure de collage indirect

The indirect bonding technique is pivotal for success in lingual orthodontics. There are different laboratory techniques available for indirect positioning and bonding of lingual brackets. Different approaches are presented and described to perform a clinical application.

Specific bonding technics

Bonding is a major component of our therapeutic arsenal. We routinely bond attachments to enamel as well as to other surfaces including dentin, ceramic, acrylic, steel, amalgam, and gold, especially for adult patients. This procedure poses certain technical problems for which adapted and specific technical protocols can provide solutions.

Apport de la distraction osseuse dans le traitement du sens transversal chez l'adulte

Crowding and mal-positioning of teeth in the dental arch are problems frequently encountered with adult patients. These discrepancies are associated with a lack of development of basal bone, a shortcoming whose etiology is difficult to discern. Treating these problems with expansion assisted by surgery depends on osseous distraction, the separating of segments of bone to create new bone and the movement of whole groups of teeth and their periodontium, a technique that assures excellent stability. It is important to define precisely the indications for this technique as well as our therapeutic protocols, both in the maxilla and in the mandible. For an expander we use a single thread expansion screw welded to two molar bands. To be sure it works effectively; the surgeon first opens the maxillary suture to liberate the two portions of the maxilla. After a ten day wait, the expansion screw is opened daily for up to two weeks depending on how much expansion is required. When the desired point is attained, the expansion device is locked, and the patient returns for check-up visits every ten days. During this period the patient is outfitted with a false tooth to mask the large and unsightly diastema that has appeared between the central incisors. Three months after the original intervention the patient receives a full-banded strap-up. The orthodontist usually employs centripetal forces to level the teeth and to correct rotations in an effort to minimize the risk of periodontal complications. The results that we have obtained with this treatment have fulfilled our expectations with significant improvement in arch form, full respect for the periodontium, an improvement in facial balance, and the appearance of a generous and pleasing smile.

Prise en compte de la forme des dents dans un contexte d’hyperdivergence faciale

INTRODUCTION The study examines how the shape of the teeth is taken into account in the context of facial hyperdivergency. One aim was to check out the widely-held belief that the hyperdivergent patient has long teeth. DISCUSSION Our study found no link between the shape of the teeth and facial hyperdivergency, thus confirming the results in the literature. We examined the issue of how to characterize dental shapes. We found three diversely-appreciated types of shape: rectangular, triangular and ovoid. Individualized management of tooth shape harmony enables the clinician to envisage recontouring the shape of a patients teeth using interproximal enamel reduction. The anatomical demands of this type of tooth remodeling favor the less popular ovoid and triangular shapes. However, following treatment, they tend to adopt a more widely-accepted rectangular shape. MATERIALS AND METHODS Using a spreadsheet, we built a computational tool to perform the dimensional quantitative diagnosis and made drawings in order to approach the shapes from a qualitative point of view. This method enables us to determine the areas to be recontoured and to obtain a preview of our treatment objectives. The result is harmonious with respect to shapes, proportions and positions as well as from a functional and periodontal point of view.