Surgical-orthodontic approach for correcting Vertical Maxillary Excess: Case report.

This report describes a patient with Vertical Maxillary Excess without open bite in whom surgical orthodontic treatment to reduce lower facial height remarkably improved function and facial esthetics. The patient was a 22-year-old male whose main concern was crowding and temporomandibular joint clicking sounds. The clinical and radiological findings led to the diagnosis of Vertical Maxillary Excess with a mild skeletal class II malocclusion. The proposed treatment plan comprised a bimaxillary surgery without premolar extractions. LeFort I osteotomy was planned to reposition the maxilla superiorly by 7-8 mm. This surgery was combined with a bilateral sagittal split osteotomy for mandibular anterior derotation to adjust the mandible to the occlusal and anteroposterior change. Postoperatively, the mandibular plane angle (GoGn-SN) was decreased by 4° and skeletal class I was achieved (ANB, 4°). In addition, lip incompetence was corrected and the excessive gingiva exposure upon smiling was significantly improved. The patient was satisfied with the treatment result and reported the temporomandibular joint clicking sounds disappearing after surgery.

Influence of orthodontic appliance type on salivary parameters during treatment.

OBJECTIVES: To evaluate the effect of orthodontic appliances on physicochemical, biochemical, and oxidative stress changes in salivary parameters during treatment. MATERIALS AND METHODS: A cohort study was conducted with 112 healthy patients. Salivary samples were taken at baseline, 1 month, and 9 months after placement of the orthodontic appliances used in treatment. RESULTS: A statistically significant difference was observed in certain examined salivary parameters, including enzymes, electrolytes, and oxidative stress markers. CONCLUSIONS: The use of aligners had a lower prevalence of disturbing salivary parameters. Orthodontist must consider these changes to prevent the occurrence of white spot lesions.

[Quality of finishing occlusion and long-term stability of orthodontic treatments with premolar extractions : A systematic review]. / La finition occlusale : un gage de pérennité des traitements orthodontiques avec extraction de prémolaires ? Revue systématique de la littérature.

Studies about orthodontic relapse have always confirmed the occurrence of some occlusal changes after orthodontic treatment. The reopening of premolar extraction spaces is one of the most frequently observed movements and would have several origins : gingival folds, root proximities, muscular imbalance... and particularly unstable end of treatment occlusion. The aim of this systematic review was to study the correlation between quality of the occlusal finishing after orthodontic treatment with premolars extraction and reopening of extraction spaces. The review was undertaken according to PRISMA recommendations from the Cochrane Handbook through an electronic consultation of the PubMed database to identify clinical trials that responded to the PICO research question. Five studies met all the inclusion criteria. Three studies used the Peer Assessment Rating (PAR) in assessing the quality of the occlusal finishing. For two of these studies, there is a correlation between poor occlusal finishing and reopening of extraction space. For the other three studies, no cause-and-effect relationship between these two factors has been proven. The divergence of the published results was explained by the fact that the stability of an orthodontic treatment depends on multiple parameters. Further controlled clinical studies should be conducted to objectively evaluate, without interfering with other parameters, the role of occlusal finishing in the long-term stability of orthodontic treatment.

Impact of adhesive system generation and light curing units on orthodontic bonding: In vitro study.

OBJECTIVE: We aimed to compare adhesive performance of fourth, fifth and seventh generation adhesive systems (GASs) and the effect of two different light curing units on shear bond strength (SBS). MATERIALS AND METHODS: One hundred and twenty extracted human upper premolars were divided in four groups. Bonds were assessed as following: group 1 using 4th GAS, group 2 using 5th GAS, group 3 and 4 using 7th GAS with two different light curing units (1500 and 800mw/cm2). Adhesive remnant index (ARI) scores were counted. RESULTS: Group 1 and 2 showed similar SBSs (P=0.7) which were significantly higher than group 3 (P=0.0002). Group 4 exhibited significantly the weakest SBS with mean=2.15±0.25. Applying shear forces less than 15MPa on group 3 bonds led to the release of almost all of the of brackets. Whereas, applying the same forces on group 2 bonds leads to the release of 66.7% of brackets. Notably, only 40% of brackets in group 1 were debonded. Group 4 brackets were totally debonded when applying shear forces less than 10MPa. While ARI=0 was the most frequent in group 1, ARI=3 was the most frequent in group 3. CONCLUSION: Fourth and fifth GASs showed similar SBS higher than seventh GAS. Fourth GAS bonds were able to resist longer against traction forces than those set up by fifth generation. Seventh GAS bonds offered the least efficient resistance. ARI=0 was the highest in group 1. However, Group 4 showed the highest ARI=1 and ARI=2 revealing cohesive failure. We also found that the adhesive power is proportional to the power of the lamp used. In fact, we concluded that 1500 mw/cm2 units light curing during 30seconds generated an ideal energy to enhance orthodontic bracket adhesion.

[Orthodontic intrusion using mini-screws]. / Ingression orthodontique sur mini-vis d'ancrage.

INTRODUCTION: Dental intrusion has long been considered one of the most difficult movements to induce in orthodontics. Using conventional mechanics, the main difficulty lies in the need to ensure anchorage control, which is highly complicated to achieve, so as to avoid parasitic movements. In this framework, mini-screws have proven to offer a very effective means of anchorage, allowing greater control over intrusion of the anterior and posterior teeth and a simpler biomechanical movement opening up new therapeutic perspectives for the orthodontist. OBJECTIVE: The aim of this study was to describe the clinical and biomechanical application of mini-screws for dental intrusion.

Agenesis of the upper lateral incisors: Study of an orthodontic population and clinical illustration.

In his daily practice, the orthodontist is regularly asked to treat patients with one or more missing teeth. Considering their functional and esthetic specificities, and the relatively high frequency of agenesia, our interest was to focus on the permanent lateral upper incisors. Our study, based on an orthodontic population including 1000 patients, shows that about 7.8% of these patients present agenesis of at least one permanent tooth (out of which 3.6% are agenesis of the upper lateral incisor). Treatment options for these cases are multiple with several decisional factors to consider: the solutions often lead to compromises, and require a multidisciplinary coordination. Therefore, the purpose of this article, was to describe the prevalence of these agenesia based on a retrospective study, and to present two clinical cases: the first case is a bilateral agenesis of the maxillary lateral incisors treated with space opening in order to place two implant-supported restorations. The second case is an agenesis of tooth 12 treated with space reopening and the placement of a cantilever bridge. These clinical cases are presented to illustrate the multidisciplinary approach involving orthodontics, prosthodontics, and periodontology, in order to achieve the most esthetic and functional results possible.

Antioxidant and antiproliferative potential of biosurfactants isolated from Lactobacillus casei and their anti-biofilm effect in oral Staphylococcus aureus strains.

Biosurfactants also called bioemulsifiers are amphipathic compounds produced by many microorganisms that allow them to exhibit a wide range of biological activities. The aim of this study was to determine the antioxidant and antiproliferative potential of biosurfactants isolated from Lactobacillus casei and to assess their anti-adhesive and anti-biofilm abilities against oral opportunistic Staphylococcus aureus strains. The antioxidant activity of biosurfactant was evaluated using the in vitro scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The antiproliferative activity was determined on epithelial cell line (HEp-2) by the Methylthiazole tetrazolium (MTT) reduction assay. The anti-adhesive and antibiofilm activity against S. aureus strains were achieved using crystal violet staining. Our results revealed that the DPPH scavenging activity of biosurfactants at 5.0 mg/mL concentration is between 74.6 and 77.3%. Furthermore, biosurfactants showed antiproliferative potency against studied epithelial cells as judged by IC50 and its value ranged from 109.1 ± 0.84 mg/mL to 129.7 ± 0.52 mg/mL. The results of the growth inhibition indicate that biosurfactant BS-LBl was more effective against oral S. aureus strains 9P and 29P with an IC50 of 1.92 ± 0.26 mg/mL and 2.16 ± 0.12 mg/mL respectively. Moreover, both biosurfactants displayed important antibiofilm activity with eradication percentages ranging from 80.22 ± 1.33% to 86.21 ± 2.94% for the BS-LBl, and from 53.38 ± 1.77% to 64.42 ± 2.09% for the BS-LZ9. Our findings demonstrate that biosurfactants from L. casei strains exhibited considerable antioxidant and antiproliferative potencies and were able to inhibit oral S. aureus strains with important antibiofilm efficacy. They could have a promising role in the prevention of oral diseases.

[Intramaxillary devices of molar distalization on fixed appliance and with aligners]. / Dispositifs intramaxillaires de distalisation des molaires en technique multi-attache et avec aligneurs.

INTRODUCTION: Class II malocclusion is a dysmorphosis that can result from different skeletal and/or alveolar components of maxillary and/or mandibular origin. In dental class II cases due to mesial drift of the maxillary molars, it is sometimes interesting to retract the maxillary molars, in order to avoid in certain situations extractions of premolars. To this end, several devices have been described in the literature. The most recent intraoral devices allow a more controlled correction, and no longer require cooperation from the patient. In addition, in a number of cases of distalization, aligners now offer a useful therapeutic option since they are both esthetic and easy-to-use. MATERIALS AND METHODS: In this study, we carried out a review of the various studies in the literature describing intra-oral distalization of the maxillary molars in the multi-bracket technique as well as using aligners, with a clinical illustration of a Class II case treated by aligners.

Adhesiveness of opportunistic Staphylococcus aureus to materials used in dental office: In vitro study.

Staphylococcus aureus (S. aureus) is one of several opportunistic microbial pathogens associated with many healthcare problems. In the present study, S. aureus was assessed for its biofilm-forming ability on materials routinely used in dental offices, including stainless steel (SS), polyethylene (PE), and polyvinyl chloride (PVC). Materials that were tested were characterized for roughness (Ra) and surface free energy (SFE). The adhesion forces exerted by S. aureus to each substratum were investigated using atomic force microscopy (AFM), and biofilm formation was quantitatively assessed by crystal violet staining assay. AFM measurements demonstrated that the strongest adhesion forces (20 nN) were exerted on the PE surfaces (P < 0.05) and depended more on Ra. In addition, the results of biofilm formation capability indicated that S. aureus exhibited more affinity to SS materials when compared to the other materials (P < 0.05). This ability of biofilm formation seems to be more correlated to SFE (R = 0.65). Hence, control of the surface properties of materials used in dental practices is of crucial importance for preventing biofilm formation on dental materials to be used for patients' dental care.

High potential of adhesion to biotic and abiotic surfaces by opportunistic Staphylococcus aureus strains isolated from orthodontic appliances.

Orthodontic and other oral appliances act as reservoir of opportunistic pathogens that can easily become resistant to antibiotics and cause systemic infections. The aim of this study was to investigate the ability of Staphylococcus aureus strains isolated from healthy patients with orthodontic appliances, to adhere to biotic (HeLa cells) and abiotic surfaces (polystyrene and dental alloy). Adhesive ability to polystyrene was tested by crystal violet staining and quantitative biofilm production on dental alloy surfaces was evaluated by MTT reduction assay. In addition, the presence of icaA and icaD genes was achieved by polymerase chain reaction (PCR). Qualitative biofilm production revealed that 70.6% of strains were slime producers. The metabolic activity of S. aureus biofilms on dental alloy surfaces was high and did not differ between tested strains. Moreover, all the isolates were adhesive to HeLa cells and 94% of them harbor icaA and icaD genes. Considerable adhesion and internalization capacity to the epithelial HeLa cells and strong biofilm production abilities together, with a high genotypic expression of icaA/icaD genes are an important equipment of S. aureus to colonize orthodontic appliances and eventually to disseminate towards other body areas.

[Incisor repositioning: a new approach in orthodontics]. / Le repositionnement incisif : une nouvelle approche en orthodontie.

Lower incisors axis has a "key" position in different cephalometric analysis. However, several critics are directed towards the cephalometric profile and cephalometric landmarks (point, line and angle). The published norms and the cephalometric standards recommended for the optimal positioning of incisors could only be used as general clinical guidelines. Incisor repositioning to achieve optimal facial aesthetics requires taking into consideration the hard and soft tissues of the face, the profile, the muscular dynamics as well as the facial growth. In this work, we propose a new approach of incisor repositioning taking into account the variability of periodontal, functional and aesthetic factors.

[Brackets and friction in orthodontics: experimental study]. / Brackets et frottement en orthodonti : étude expérimentale.

Many authors have been involved in developing brackets in order to improve the quality, stability, speed and efficiency of orthodontic treatment. In order to reduce friction between bracket and archwire, new therapeutic approaches have been devised based on novel technologies. Among these innovative techniques, self-ligating brackets are increasingly popular. SLBs can be classified into several categories according to their mode of action and their materials. We performed an experimental study to compare the friction forces generated during the sliding of orthodontic archwires made from various alloys through conventional and self-ligating brackets. Results show the favorable influence of SLBs, compared to conventional systems using elastomeric or metal ligatures, on the level of friction, particularly when shape-memory Ni-Ti archwires are used.