[The Ball Abutment: new orthodontic applications for fixed and removable appliances. Case series]. / L'attachement boule : nouvelles applications orthodontiques pour dispositifs fixes ou amovibles. Une série de cas.

Widely used, especially for supra-implant solutions, the indication of attachments is now extended to orthodontics. The objective of this series of cases was to describe three clinical situations in which attachments on miniscrews have been adapted to orthodontics, leading to the development of a new connection: the ball attachment or Ball Abutment making it « semi removable ¼ anchoring devices which until now had to be fixed. A series of three cases is presented. For each case, the miniscrew(s) already in place during the active orthodontic treatment phase is (or are) used with a palatal device (palatal plate or palatal expander). In the latter case, the Ball Abutment, of relatively simple use, is fixed over the miniscrews allowing the device to offer controlled looseness. This attachment allows the clinician to put in place space-saving devices promoting the retention of the devices, at the border between the fixed and the removable device, sometimes less bulky and more discreet, particularly for adult patients. They could be part of lingual technique treatments. Tests are necessary to assess this orthodontic device in terms of materials, design and retention. This connection offers a new range of possibilities and design of semi-removable passive devices that increase the multifunctionality of miniscrews during treatment.

[Multipurpose miniscrews: combined canine disimpaction and malocclusion correction]. / Mini-vis polyvalentes : désinclusion de canine combinée à la correction de différentes malocclusions.

The objective of this case series was to show how only one miniscrew can be used to treat simultaneously or successively canine impaction and different malocclusions. Three patients aged of 13 years old who had malocclusions, such as Class II, overbite and canine impaction, were each one treated with the same miniscrew throughout the treatment period. Palatal miniscrews were placed mesially to the first molar and used as a direct or indirect anchorage depending on the moment of the treatment. In each case, satisfactory treatment was obtained with correction of overbite, class II malocclusion and canine impaction. The first steps of treatment were aesthetic for the patient and did not require patient cooperation.

[Multiple uses of skeletal anchorages: taking advantage of mini-screws to improve aesthetics with active and passive appliances]. / Usage multiple des ancrages squelettiques : mise à profit des mini-vis d'ancrage pour améliorer l'esthétique lors du traitement actif et lors de la contention.

INTRODUCTION: The main causes of failures in canine traction are anchorage defects, incorrect direction of force, uncontrolled forces. An adolescent female (10 years, 9 months) presents with two included canines on the maxillary arch, in a palatal position and her lateral incisors (12 and 22) are microdontic. Two mini-screws are inserted on the palate, in a mesial position to 16 and 26 to secure the traction of 13 and 23; in general, braces are bonded after this first step. After debonding, mini-screws remain to help stabilize the palatal plate during the retention period and to avoid unaesthetic metallic wires and hooks which sometimes cause occlusal interferences. DISCUSSION: The alternatives are discussed: Ballista spring, mini-screw inserted in the palatal suture, Nance appliance… Conclusion: The multi-use of temporary anchorage devices during traction of palatally impacted canine(s) (especially in the case of bilateral inclusions) offer new alternatives by securing the canine displacement, eliminating almost all of the patient's compliance (no loss of sagittal anchorage). This type of small appliance increases the patient's comfort and decreases the complexity of activations. The global duration of treatment with braces can be decreased if no braces are needed during the first steps, and then retention can be more effective and more aesthetic, especially during smiling.

[Increased susceptibility for white spot lesions by surplus orthodontic etching exceeding bracket base area]. / Prédisposition aux leucomes pré-carieux due à un excès de mordançage autour des attaches orthodontiques∗.

INTRODUCTION: There is a paucity of information with regard to the susceptibility of iatrogenic white spot lesion formation after inattentive, surplus orthodontic etching with 30% phosphoric acid and the subsequent provision or absence of adequate oral hygiene. METHODS: Ninety sound enamel specimens were randomly allocated to 6 trial groups (N = 15 each) for etching with 30% phosphoric acid for either 15 seconds and standardized daily enamel brushing or no brushing, etching for 30 seconds with daily brushing or no brushing, or nonetched controls with brushing or no brushing. Nutritive acidic assaults were simulated by demineralization cycles 3 times per day for 1 hour with interim storage in artificial saliva. Lesion depths in terms of percentage of fluorescence loss (delta F, delta Q) and lesion extension compared with the baseline were assessed by using quantitative light-induced fluorescence after 2, 7, 14, 21, and 42 days. Etching duration, trial time elapse, and oral hygiene, as well as the significance of factor interactions, were analyzed with 3-way analysis of variance (α=5%). RESULTS: The impact of the factors of enamel brushing, trial time elapse, and etching each had a comparably significant effect on lesion progression. The effect of surplus etching on white spot lesion formation was significantly enhanced by the simultaneous absence of enamel brushing and also the progression of trial time. The combination of 30 seconds of surplus etching with inadequate oral hygiene was especially detrimental. CONCLUSIONS: Excessive surplus orthodontic etching of the complete labial enamel surface, instead of the bracket bases only, must be avoided to prevent iatrogenic white spot lesions. Etching times not exceeding 15 seconds are favorable.

Brief communication: The size of the human frontal sinuses in adults presenting complete persistence of the metopic suture.

The notion of absence of the frontal sinuses in human individuals presenting a persistence of the metopic suture is considered as classical in many treatises of reference; however, precise studies are very rare and even controversial. The purpose of this study was thus to provide original data to confirm or refute this classical affirmation with the perspective of some original insights into biological significance of the frontal sinuses and the factors influencing their exceptional polymorphism. The material consisted of 143 dry skulls of adult individuals (European Homo sapiens), distributed in two groups: 80 skulls presenting a complete frontal closure with total disappearance of the metopic suture, and 63 skulls presenting a complete persistence of the metopic suture. Each skull was radiographed in oblique projection using the occipitomental view. A simple morphological quantification of the sinus size was defined with four categories: (1) aplasia, (2) hypoplasia, (3) medium size, (4) hyperplasia. Statistically significant difference in frontal sinusal size was found between both groups of skulls. Absent and small sinuses were considerably more frequent in skulls with persistence of the metopic suture (57.9 vs. 11.9%): small frontal sinuses (hypoplasia) were much more frequent (50.8 vs. 9.4%), although the frequency of absence of frontal sinuses (aplasia) was only slightly higher (7.1 vs. 2.5%).

[Combined use of Beneslider and lingual braces, mechanical aspects and procedures]. / Utilisation combinée du Beneslider et d'appareils multi-bagues linguaux, mécaniques et procédure clinique.

Over the last years, a tendency to prefer purely intra-oral appliances with minimal need for patient cooperation is noticed if upper molars should be distalized. Unfortunately, most of the conventional devices for non-compliance upper molar distalization produce unwanted side effects such as anchorage loss. To minimize or eliminate anchorage loss, mini-screws attracted a great attention in recent years because of minimal surgical invasiveness and low cost. Using the anterior palate as an insertion site, the failure rate is extremely low, there is no risk of root damage and the appliances are out of the path of tooth movement. Based on comprehensive clinical documentation, the rational and practical applications of the Beneslider in combination with lingual braces are presented. By this procedure, extractions in the upper arch and reactive forces in the lower arch resulting in a protrusion of the incisors can be avoided with an invisible treatment appliance.

[Improvement of mini-implant stability in orthodontics]. / Amélioration de la stabilité des mini-implants orthodontiques.

Orthodontists are continuing to increase the use of mini-implants as a source of skeletal anchorage. However, the relatively high 16.4% rate of their failures remains a problem. An analysis of articles in the literature on the loss of mini-implants shows that larger size anchorage screws and plates inserted in the anterior and median regions of the hard palate are highly stable and, accordingly, contribute to a high rate of optimum orthodontic outcomes. It is the reliability of the mini-implant/skeletal structure couple that is the principal factor in this success. With mini-implants whose heads possess internal threads, orthodontists can attach different types of stable, screwed-in abutments. And with long plates with specifically designed perforations splinting two mini-implants together, orthodontists can further increase the stability of this artificial anchorage. By employing a system with pre-fabricated components orthodontists can quickly create skeletal anchorage adaptable to the mechanics of different techniques.