[Evaluation of the knowledge, attitude and practices of orthodontists in relation to nickel allergy during orthodontic treatment]. / Evaluation des connaissances, attitudes et pratiques des orthodontistes sur les réactions allergiques au nickel provoquées par les matériaux orthodontiques.

INTRODUCTION: The aim of this study was to evaluate knowledge, attitudes and practices (KAP) of Moroccan dentists about allergy to Nickel (Ni) during orthodontic treatment. POPULATION AND METHODS: Dentists of two Moroccan cities (n = 553) were contacted and a questionnaire was distributed to those who have certified of partial or exclusive practice of orthodontics (N = 202). They were asked to specify the adverse reactions observed and the alloys frequently used. KAP about etiology, prevention and therapeutic management of allergic patients were also addressed. RESULTS: Twenty-two percent of the dentists have reported at least one allergic patient reaction with more implication of fixed appliances. Eleven percent of adverse effects locations reported were mucosal area and facial skin near contact area and less than 5% was systemic eruption outside contact site. Only 34% of the respondents knew the Nickel allergy etiology. CONCLUSION: Nickel-containing orthodontic alloys are generally used even in patient with suspected nickel allergy. It is very important to minimize corrosion factors and use nickel-free appliances in clinical practice.

[Early treatment of mandibular incisor-canine crowding]. / Traitement précoce de l'encombrement incisivo-canin mandibulaire.

In the mixed dentition, lower incisor crowding can exist. He may be transitory or increase with dental arch evolution because of reduction of arch length by loss of leeway space. Early diagnosis allows the instauration of interceptive therapy, to ovoid extractions. Preserve or loss leeway space will depend of orthodontic space management. The clinical case presented in this article shows the interest of early treatment of incisor crowding to preserve arch length and make the leeway space available to resolve the crowding.

[The effect of autoclave sterilization on the surface properties of orthodontic brackets after fitting in the mouth]. / Effet de la stérilisation par autoclave sur l'état de surface des bagues orthodontiques après essayage en bouche.

Repeated sterilizations of the orthodontic bands, after fitting in mouth, are likely to involve modifications of their surface properties. Through this study we have tried to observe the effect of sterilization by autoclave on the surface of the orthodontic bands, as well as the contribution of the use of ultrasound in the chain of sterilization. The sample was composed of 30 orthodontic bands divided into 5 groups: a group of new bands (witnesses) and 4 groups having undergone respectively 1 cycle, 3 cycles, 5 cycles and 7 cycles of autoclave sterilization according to the World Health Organization recommendations. For half of each group bands, ultrasonic cleaning has not been provided. The scanning electron microscopy with the elementary microanalysis by X-rays was used for the investigation of surface. At the exam, new bands showed surface irregularities probably due to manufacturing procedures. And the bands, without ultrasonic cleaning, showed the presence of contamination and discolourations. Moreover, there were no modifications on the surface of the bands cleaned by ultrasounds before sterilization. The presence of surface irregularities associated with deposits observed on the bands surface, may be the site of bio corrosion by contributing bio film accumulation. The stay duration of the orthodontic bands in mouth, during orthodontic treatment, is important. So the effect of sterilization on the surface of the orthodontic bands must encourage other scientific research to determine the long term effects of sterilization which remains an essential process in our daily practice.

[Loss of molar anchorage: quantitative evaluation with a method of structural superposition]. / Perte d'ancrage molaire: évaluation quantitative avec une méthode de superpositions structurales.

The goal of this study is to analyze using structural cephalometric superimpositions the quantity of mesial molar drift in the maximum anchorage cases, with mainly extractions of the first four premolars. Molar anchorage is appreciated in cases treated with or without use of directional forces. The influence of various parameters: age, facial divergence, discrepancy and incisor repositioning, on the loss of anchorage is also evaluated. The statistical study called upon the test of Student for independent groups. A value of the risk of first species p<0.05 was considered as significant. The loss of anchorage seems less important with the use of the directional forces. On the other hand it is raised in teenagers and the cases of important incisor repositioning.

Traitement d'un cas de classe II avec extraction : cas clinique

Le choix des extractions est une etape importante dans le plan de traitement orthodontique. Ce choix peut changer d'une hemiarcade a l'autre et peut se faire pour des besoins occlusaux et dentaires. Le but de cet article est de mettre le doigt; a travers un cas clinique; sur une decision d'extraction qui peut trouver son indication dans certaines situations mais qui peut poser des problemes d'ordre occlusal et esthetique a cause de l'asymetrie de l'arcade; mais aussi des difficultes therapeutiques vue la necessite d'individualiser les arcs de finition pour chaque hemiarcade a part; sans nuire a l'harmonie occlusale de l'ensemble