L'' Orthodontie française最新文献

Introduction: Various studies showed inconsistent and different results regarding the correlation between open bites and palate planes whether normal or abnormal. This study had for objective to investigate the correlation between dentoalveolar heights and palatal plane inclination in different vertical facial patterns.

Materials and methods: 120 lateral cephalometric radiographs (60 females and 60 males) were selected from the archives of the Faculty of Dentistry, Beirut Arab University. The sample consisted of three equal groups: hypodivergent (SN/MP<27°), normodivergent (SN/MP=27°-37°) and hyperdivergent (SN/MP>37°). The radiographs were digitally traced and cephalometric skeletal and dentoalveolar variables were measured. Statistical analysis was carried out with significance level at p<0.05.

Results: The palatal plane inclination showed statistically significant difference between hyperdivergent and both hypodivergent and normodivergent subjects with no statistically significant difference between hypodivergent and normodivergent subjects. A statistically significant difference in the upper anterior dentoalveolar height (UADAH) was found between hypodivergent and both hyperdivergent and normodivergent subjects. No statistically significant difference was found in the other dentoalveolar heights between the different vertical patterns. A negative moderate correlation was only observed between the palatal plane angle and UADAH in the hyperdivergent group. Multiregression analysis showed that the greatest contribution to overbite pooled across all groups other than the skeletal pattern was attributed to UADAH.

Conclusion: UADAH seems to influence the overbite depth compared to other dentoalveolar heights. It is possible that UADAH acts as a compensatory factor for palatal plane inclination in hyperdivergent subjects.

Introduction: Bisphosphonates are mainly used in the treatment of osteoporosis and in oncology. They bind to bone and inhibit the action of osteoclasts, leading to a decrease in bone remodeling and thus hindering tooth movement. The main objective was to present, through a review of the literature, the indications and therapeutic modalities for orthodontic treatment of patients who are or have been treated with bisphosphonates. The second objective was to propose a decisional organization chart for medical care.

Materials and methods: The search was done by keywords on PubMed.

Results: 189 articles were found, mostly case reports. 1) Intravenous treatment is a contraindication to ODF treatment. 2) Per os treatment is possible with precautions: to be in accordance with the prescribing practitioner, avoid major travels, avoid surgical procedures (extractions...) which must be as atraumatic as possible. A delay in healing is to be expected. The benefit-risk ratio must be taken into account. The risks - the patient must be informed of them - are slowed movement and osteonecrosis. Clinical and radiological follow-up is necessary and may warrant re-evaluation of treatment at any time: excessive tooth mobility, molar furcation damage, unusually persistent periodontal pain and symptoms, fistulas, exposed areas of necrotic bone.

Discussion: The articles are of low grade. Most of the articles are studies made on animals.

Conclusion: Research is ongoing to evaluate the value of bisphosphonates as anchorage reinforcement.

Introduction: The aim of the study was to assess the time factor and tooth type during premature debond of orthodontic brackets.

Material and method: A retrospective epidemiological study was carried out on adolescents who had benefited from a multi-metal vestibular attachment treatment, having all 6 to 6 teeth bonded to the arch on the day of installation.

Results: 333 patients were included. The detachment rate decreased as the treatment progresses. The teeth with most orthodontic debonding were the maxillary first molar, mandibular first molar, mandibular second premolar, and maxillary second premolar. Skeletal class II patients tended to take off more than class I patients. Detachments were significantly more frequent in the mandibular arch in deepbite compared to normalbite patterns, the mandibular second premolar being the tooth at risk. There seems to be a correlation between the quality of oral hygiene and the rate of detachment, regardless of the time of treatment.

Discussion: The type of orthodontic movement, the quality of the bonding, the failure to observe the precautions by the patient may affect the date of the detachment. The low coronary height, hygiene, the biting force, the divergence seems to intervene on the type of attachment debonded.

Conclusion: The brackets are more particularly debonded at the start of treatment and on the posterior teeth. Anteroposterior and especially vertical dysmorphosis could have an implication in debonding.

Introduction: The aim of this study was to evaluate the impact of nasomaxillary expansion using skeletally anchored transpalatal distraction (TPD) in children without transverse maxillary deficiency that were previously treated by rapid palatal expansion (RPE).

Materials and methods: Twenty-nine consecutive children were treated by TPD. Twenty-five children, aged 10-16 years completed pre- and post-operative clinical evaluations, questionnaires (OSA-18), cone beam computed tomography (CBCT), and polysomnography (PSG). The pre- and post-operative CBCT data were used to reconstruct the 3-dimensional shape of the upper airway. Two measures of airflow function (pressure and velocity) were simulated by using computational fluid dynamics (CFD) at four different airway segments (nasal, nasopharyngeal, oropharyngeal and hypopharyngeal).

Results: Twenty-three patients (92%) experienced improvement based on PSG. The apnea hypopnea index (AHI) improved from 6.72±4.34 to 3.59±5.11 (p<0.001) events per hour. Clinical symptoms based on OSA-18 scores were improved in all patients. Twenty-five patients (100%) had successful expansion defined as separation of the midpalatal suture at least 1 mm from anterior nasal spine (ANS) to posterior nasal spine (PNS). The nasal sidewall widening was 2.59±1.54 mm at canine, 2.91±1.23 mm at first molar and 2.30±1.29 mm at PNS. The ratio of dental expansion to nasal expansion was 1.12:1 (2.90 mm:2.59 mm) at canine and 1.37:1 (3.98 mm:2.91 mm) at first molar. The nasal airflow pressure reduced by 76% (-275.73 to -67.28 Pa) and the nasal airflow velocity reduced by over 50% (18.60 to 8.56 m/s).

Conclusions: Nasomaxillary expansion by skeletally anchored TPD improves OSA in children without transverse maxillary deficiency that were previously treated by RPE. A nearly parallel anterior-posterior opening of the mid-palatal suture achieves enlargement of the entire nasal passage with improvement of the airflow characteristics in the nasal and pharyngeal airway. The improved airflow characteristic is significantly correlated with the improved polysomnographic findings, thus demonstrating that nasomaxillary expansion in previously expanded patients is a viable treatment option.

Objective: The focus of this report was to analyze the pattern of maxillary expansion and complications in patients following surgical and non-surgical maxillary expansion presented for evaluation and second opinion.

Materials and methods: During a 30-months period, 28 patients presented for second opinion following maxillary expansion performed elsewhere. The indication for treatment was obstructive sleep apnea (OSA). All patients reported a lack of symptomatic improvements and problems associated with the treatment. Clinical examination with pre- and post-expansion cone beam computed tomography (CBCT), and treatment photographs were analyzed.

Results: Complete clinical records and CBCT were available in 22 patients for analysis. Six patients had undergone surgical expansion with distraction osteogenesis maxillary expansion (DOME), and 16 patients had undergone a variety of non-surgical expansion with different appliances. All the DOME patients had anterior nasal spine (ANS) separation without posterior nasal spine (PNS) separation. Diastema ranging between 10-16 mm was noted in the DOME patients, and the ratio of anterior diastema to ANS separation was between 2:1 to 3:1. Bone defects existed between the central incisors at 18 months or beyond following DOME in all the patients despite bone grafting attempts in four patients. Anterior gingival recession occurred in two patients and four incisor teeth required endodontic therapy with long-term guarded prognosis. Sixteen patients underwent non-surgical maxillary expansion with four different appliances, including anterior growth guidance appliance (AGGA), daytime-nighttime appliance (DNA), advanced lightwire functionals appliance (ALF), and mini-screw assisted rapid palatal expansion (MARPE). The midpalatal suture did not separate in any of the 16 patients, and the expansion pattern was purely dental and dentoalveolar in nature. Lateral dental tipping, thinning of the labial/ buccal alveolar bone with gingival recession were noted in 10 patients. Significant mobility of the maxillary anterior teeth due to vertical and horizontal bone loss was noted in the five patients that underwent AGGA treatment.

Conclusions: Different maxillary expansion methods are currently being performed with varying outcomes. Critical analyses of these methods are needed to determine their impact and whether the desired outcomes are achieved.

Introduction: The prognostic improvement for dental auto-transplants is the result of a better understanding in the physiopathology of the periodontium and also of the refining of the technical operative procedure. This fact allows the use of third molars as donor site for the replacement of absent, or first or second badly decayed molars.

Discussion: This possible therapy is a supplement argument for the conservation of third molars and their extraction must be indicated only when the anatomic situation presents a pathological risk.

Results: If, in adults, it is possible to compare the advantages and disadvantages with the classical implant or prosthetic techniques, it should however be considered as first choice therapy for adolescents and young adults. Indeed, in these cases, the lower risk of root ankylosis avoids passive intrusion and the osteogenic effect of the desmodontium allows normal alveolar bone formation.

Introduction: The use of fixed retainers at the end of a course of orthodontic treatment has become standard practice. The main complication that can occur with fixed retainers is the detachment of the wire from one or more teeth. A less common complication is unwanted tooth movement.

Method: This article presents a patient with extreme tooth movement associated with a mandibular fixed retainer. Ten years after orthodontic treatment, a 26-year-old male sought treatment for post-orthodontic movement of the mandibular anterior six teeth. Despite the fixed retainer still being attached to all teeth, the apex of the right canine was completed avulsed labially. Severe labial recession was also present on the left lateral incisor. The canine was extracted, and the fixed retainer was removed. Significant root resorption identified on a panoramic radiograph contraindicated any further extensive orthodontic intervention.

Discussion: This case highlights that clinicians and patients should be aware of this rare but serious complication.

Introduction: The aim of this in vitro study was to determine if there is a significant difference in the excess adhesive flash between the metallic APC™ Flash-Free adhesive system, the APC™ pre-coated adhesive system and a conventional uncoated system.

Materials and methods: One hundred eighty-six freshly extracted human premolars were randomly and blindly divided into three groups according to the type of brackets. Group A (control group n=60): The conventional uncoated metallic bracket (Victory, 3M Unitek®) with a Transbond XT™ Light Cure Adhesive Paste was used. Group B (n=60): The APC™ II metallic maxillary precoated premolar brackets was used. Group C (n=66) : The metallic APC™ Flash-Free adhesive system without flash clean up was used. Images were taken at 40 magnifications in a dental microscope (Leica M320 for dental, Wetzlar, Germany) then analyzed with the ImageJ software and the area of excess adhesive flash was measured.

Results: The mean percentage was significantly different between the three groups (p<0.001; ANOVA). It was significantly smaller for brackets in the APC Flash-Free group (p<0.001), and the difference was not significant between conventional brackets and APC (p=0.224).

Discussion: The new technique seems to reduce the amount of excessive adhesive around orthodontic brackets.

Introduction: The aim of this study was to analyze the skeletal, dental and airway changes with endoscopically assisted surgical expansion (EASE) to widen the nasomaxillary complex for the treatment of sleep apnea in adults.

Methods: One hundred and five consecutive patients underwent EASE. Cone beam computed tomography (CBCT) was conducted preoperatively and within four weeks after the completion of the expansion process. Computational fluid dynamic (CFD) analysis was performed on 20 randomly selected patients to assess airway flow changes.

Results: One hundred patients (67 males) with the mean age of 35.0±13.5 years (17-64 years) had completed pre- and post-expansion imaging. Ninety-six patients (96%) had successful expansion defined as separation of the midpalatal suture at least 1 mm from anterior nasal spine (ANS) to posterior nasal spine (PNS). The nasal cavity expansion was 3.12±1.11 mm at ANS, 3.64±1.06 mm at first molar and 2.39±1.15 mm at PNS. The zygoma expansion was 2.17±1.11 mm. The ratio of dental expansion to skeletal expansion was 1.23:1 (3.83 mm:3.12 mm) at canine and 1.31:1 (4.77 mm:3.64 mm) at first molar. CFD airway simulation showed a dynamic change following expansion throughout the airway. The mean negative pressure improved in the nasal airway (from -395.5±721.0 to -32.7±19.2 Pa), nasopharyngal airway (from -394.2±719.4 to -33.6±18.5 Pa), oropharyngeal airway (from -405.9±710.8 to -39.4±19.3 Pa) and hypopharyngeal airway (from -422.6±704.9 to -55.1±33.7 Pa). The mean airflow velocity within the nasal airway decreased from 18.8±15.9 to 7.6±2.0 m/s and the oropharyngeal airway decreased from 4.2±2.9 to 3.2±1.2 m/s. The velocity did not change significantly in the nasopharyngeal and hypopharyngeal regions.

Conclusions: EASE results in expansion of the midpalatal suture from the ANS to PNS with a nearly pure skeletal movement of minimal dental effect. The expansion of the nasomaxillary complex resulted in the widening of the nasal sidewall throughout the nasal cavity. The improved air flow dynamics was demonstrated by CFD simulation.