Bioglass 45S5, a relevant alternative to autogenous harvesting for secondary alveolar bone grafts in clefts? Retrospective study of one hundred surgeries.

The secondary alveolar bone grafting (SABG) step restores the continuity of the alveolar bone necessary for dentition. Faced with the complications of autografts, synthetic biomaterials such as Bioglass (BG) 45S5 have been proposed. The objective was to evaluate the success rate of SABG with the addition of BG 45S5 and to highlight the prognostic factors. Patients who underwent operation between 2015 and 2021 and had follow-up cone-beam computed tomography (CBCT) were analyzed. Multivariate analysis was performed to determine factors influencing radiographic success. A total of 102 SABG were analyzed. They were unilateral total cleft lip and palate (49, 48.0%). The mean age at surgery was 9.32 ± 3.09 years. Surgeries were performed mainly outside a syndromic context and without a family history after orthodontic preparation. The radiographic success rate at 1 year was 80.4%. Mixed dentition stage (odds ratio [OR] = 7.3, p = 0.024), absence of syndromic context (OR = 20.7, p = 0.024) and female sex (OR = 4.88, p = 0.021) were factors predictive of surgical success. The use of BG 45S5 instead of autograft is relevant for SABG, with a 1-year success rate of over 80%. The stage of mixed dentition, the absence of syndromic context, and female sex were factors for good prognosis.

Screening for the risk of canine impaction, what are the presumptive signs and how does it affect orthodontics? A cross-sectional study in France.

PURPOSE: The treatment of impacted canines is a challenge for orthodontists. The availability of suggestive clinical signs has become crucial for treatment before the potential for evolution ceases. The main objective was to evaluate the prevalence of the suspected displaced canine (SDC) and to highlight factors easily identifiable from the oral examination. METHODS: SDC was assessed on panoramic X-rays, on the basis of the angle with the median sagittal plane and the degree of overlap with the permanent lateral incisor. Its association with mesio-distal tooth and palate widths was assessed by univariate analysis. Next, the association of SDC with temporary tooth extraction, expansion and/or premolar extraction was considered using the same modality. RESULTS: In this retrospective study, the records of 292 patients aged 7 to 13 years were reviewed. SDC was detected in 39% of patients i.e., 28,8% of observed canines. Reduced coronal mesio-distal diameters of permanent maxillary central incisors, 8.7 ± 0.6 mm versus 8.8 ± 0.7 mm (p < .05), and first permanent molars, 10.0 ± 0.7 mm versus 10.2 ± 0.7 mm (p < .001), as well as reduced inter-molar width, 38.7 ± 2.7 mm versus 39.4 ± 2.9 mm (p < .01), were predictive factors. SDC led orthodontists to indicate extraction of maxillary primary canines, OR = 3,32 (p < .001) or even extraction of premolars, OR = 1,66 (p < .05). CONCLUSION: This study confirmed the interest of panoramic X-rays in detected canines at risk of SDC. Dental factors can be combined to make screening more reliable and predict impaction that makes orthodontics complex. TRIAL REGISTRATION NUMBER: Opinion n°21.131, dated 09.21.2021, retrospectively registered.

Spheroid Culture System, a Promising Method for Chondrogenic Differentiation of Dental Mesenchymal Stem Cells.

The objective of the present work was to develop a three-dimensional culture model to evaluate, in a short period of time, cartilage tissue engineering protocols. The spheroids were compared with the gold standard pellet culture. The dental mesenchymal stem cell lines were from pulp and periodontal ligament. The evaluation used RT-qPCR and Alcian Blue staining of the cartilage matrix. This study showed that the spheroid model allowed for obtaining greater fluctuations of the chondrogenesis markers than for the pellet one. The two cell lines, although originating from the same organ, led to different biological responses. Finally, biological changes were detectable for short periods of time. In summary, this work demonstrated that the spheroid model is a valuable tool for studying chondrogenesis and the mechanisms of osteoarthritis, and evaluating cartilage tissue engineering protocols.

Bioresorbable polylactic acid (PLA) and bioactive glasses (BG) composite: Influence of gold coated of BG powder on mechanical properties and chemical reactivity.

Due to the ageing of the population, the synthesis of biomaterials and the optimization of their physico-chemical characteristics are at the heart of many research projects in regenerative medicine. The emergence of 3D printing techniques has rapidly led to the manufacture PLA-BG composite scaffolds using the FFF (Fused Filament Fabrication) technique. However, this composite presents some problems including a lower mechanical strength than the two compounds alone, probably due to the ionic salting-out induced by the BG. This study aims to counter this phenomenon by coating the BG particles with a thin layer of gold. The 3D composite objects will then be characterized mechanically and biologically to ensure that the bioactive character of the composite is preserved.

Hyrax versus Leaf expander in growing patients, what about adverse dental effects? A retrospective study.

OBJECTIVES: Transverse discrepancy is a Common problem in young patients. Many devices are employed to expand the palatal dimension, with different characteristics and biomechanical aspects. The Leaf expander, a new-born appliance containing nickel-titanium springs, free from activation by parents. We compared the maxillary and mandibular dental effects of Leaf expander to conventional Hyrax in growing patients. METHODS: All patients who met the eligibility criteria between the period from January 2017 to December 2019 were included. The patients had transverse inter-arch discrepancy of at least 5mm and were treated with Hyrax expander (HEX) or Leaf expander (LEX). All patients had complete follow-up of expansion by remote monitoring. An algorithm established distances between the teeth. It was also used to measure the change in dental axes. RESULTS: In the maxilla, LEX caused more tipping on the canines and premolars but significantly less on the molars compared to HEX: -0.154̊ vs. 3.05̊ (P<0.001). In the mandible, LEX caused a greater increase in arch widths and tipping (P<0.02) in the molars and second premolars, but not in the other teeth. No correlation was demonstrated between mandibular dental movements and increased maxillary arch widths. Alternatively, for the two devices, expansion and tipping were correlated within each dental arch (r>0.4). CONCLUSIONS: The LEX produced more tooth movement on average than the HEX, except for the maxillary first molars. Several correlations exist between the movements within each arch for the two devices, most often between tipping and expansion.

Knowledge, attitudes and professional practices of ortho-periodontal care of adults: a cross-sectional survey in France.

BACKGROUND: Due to increasing numbers of adult patients, orthodontists are being confronted more and more with periodontal problems. Coordination amongst orthodontists, periodontists and general dentists is useful in preventing and stopping periodontal disease. The main objectives of this survey were to evaluate the technical knowledge, techniques and attitudes employed by French orthodontists, periodontists and general dentists in adult dental care. METHODS: A cross-sectional online survey was distributed to French dentists. The questionnaire, consisting of 30 questions, was divided into six sections covering treatment programs and the forensic environment. RESULTS: One thousand one hundred twenty-two complete answers were recorded. Adults undergoing orthodontic treatment represented 19.9% of the orthodontists' patients, but only 2.67% of the general dentists' patients. Communication between clinicians was rated as good, greater than 3 out of 5. Before treatment, orthodontists were less alarmed than generalists regarding bleeding, recessions, increased probing depths, halitosis and hyperplasia. During treatment, orthodontists never or only occasionally performed palpation or probing in 54.2% and 84.6% of cases. Gingivitis and recessions were the main reasons for consultations for 22.0% and 20.1% of general dentists and periodontists after orthodontic treatment. Of the practitioners surveyed, 43% felt that they experienced a setback in the ortho-periodontal treatment. CONCLUSIONS: This study revealed discrepancies in the knowledge and attitudes of practitioners. Therapeutic management remains one of the major challenges of multidisciplinary treatments. Continuing education needs to be further developed in this field.

The Challenge of 3D Bioprinting of Composite Natural Polymers PLA/Bioglass: Trends and Benefits in Cleft Palate Surgery.

Cleft lip and palate is the fourth most common congenital malformation. Its prevalence is about 1 in 750 to 1 in 2000 live births. The consequences of this malformation are major: maxillary growth deficit, unaesthetic appearance, phonation disorders, difficulty in eating, and psycho-social disorders. Cleft palate repair establishes the division between the oral and nasal cavities. The alveolar bone graft is a key step. Different sites of autogenous bone harvesting are used, the most common being the iliac crest. Nevertheless, the large number of complications associated with harvesting has led to the use of substitute biomaterials. Bioactive glasses, discovered in 1969, are a group of synthetic silica-based materials with bone-bonding properties. Although 45S5 granular composition is commonly used in bone surgery to repair critical defects, it is only rarely used in the repair of cleft palates because this galenic form is only moderately adapted. However, advances in bone tissue engineering allow the shaping of three-dimensional scaffolds, which support colonization by host cells. Recent advances in computer-aided design/computer-aided manufacturing (CAD/CAM) have even led to the 3D printing of scaffolds combining 45S5 bioglass with a natural and biocompatible poly-lactic acid matrix. The shape of the parts is customized and adapted to the particular shape of the critical bone defects. The objective of this literature review is to highlight the particularities of alveolar defects subsequent to facial clefts, then to detail the characteristics of the materials and technologies used to elaborate 3D matrices by bioprinting. Finally, we will explore research directions regarding their use in reconstructive surgery of cleft palates.

How effective are three methods of teaching oral hygiene for adolescents undergoing orthodontic treatment? The MAHO protocol: an RCT comparing visual, auditory and kinesthetic methods.

BACKGROUND: Fixed orthodontic appliances hamper oral hygiene procedures. The consequences are gingivitis and white spot lesions. Fifty to 70% of patients treated with braces encounter these problems. Their care in the USA represents an annual cost of five hundred million dollars. Initial education and motivation for oral hygiene depend on two categories of factors: firstly, practical prophylactic measures (instruments and medication, professional care) and secondly, the educational component: choice of communication technique, frequency, and nature of hygiene instructions. This trial aims to study this last component. Its main objective is to compare three methods' effectiveness of oral hygiene education in adolescent patients treated with braces in terms of biofilm (plaque) control. The secondary objectives are the evaluation of these methods' effectiveness regarding gingival inflammation and the maintenance of hygiene during the first 6 months of treatment. METHODS: This study is a prospective randomized controlled trial of superiority. It evaluates the effectiveness of three hygiene education techniques. A total of 90 patients from the University Hospital Center of Rennes will be randomized into 3 parallel groups with a 1:1:1 ratio. Each will benefit from a different educational method: oral and/or practical. The main outcome will be the average plaque index for each group after 6 months of treatment. Additional outcomes will be the average gingival index for each group and the plaque and gingival indices over 6 months. DISCUSSION: The effectiveness of preventive procedures for optimizing oral hygiene during orthodontics is based on ambiguous literature. As a result, it is difficult to draw conclusions and to translate them into everyday practice. Sixty-eight percent of the orthodontists support the development of guidelines for education. The aim of this study is to standardize methods of oral hygiene education during orthodontic fixed treatment. The purpose of this study would be to provide practitioners with a concrete education program through guidelines dedicated to the method having the best results. TRIAL REGISTRATION: ClinicalTrials.gov NCT04444154 . Registered on 22 June 2020. SI CNRIPH ID 8011N° 20.04.27.58337. Registered on 29 July 2020.

[A new classif ication in Periodontology (Chicago 2017). Impact in Orthodontics]. / Une nouvelle classification en parodontologie (Chicago 2017). Impact en orthodontie.

In 2018, a new « Classification of Periodontal and Peri-implant Diseases and Conditions ¼ was adopted by the American Academy of Periodontology and the European Federation of Periodontology. Numerous studies in recent years have improved the understanding of periodontal diseases and their risk factors, leading to an update of the 1999 classification. Among the major changes is the development of a classification of periodontitis into different stages and grades and the notion of periodontal health, an essential prerequisite for orthodontic treatment. Based on the analysis of the 24 published articles, this work provides explanations regarding the main changes that orthodontists may face. The classification of Chicago precisely defines periodontal health and proposes a new system for characterizing periodontitis in stages and grades. It then becomes a valuable aid for the orthodontist in risk detection and periodontal screening. The knowledge of this new classification is essential for reliable communication between dentists, periodontists and orthodontists, in order to guarantee the success of orthodontic treatment.

Accuracy evaluation of bracket repositioning by indirect bonding: hard acrylic CAD/CAM versus soft one-layer silicone trays, an in vitro study.

OBJECTIVES: Rapid development of digital technologies and 3D printing provide new tools for orthodontic indirect bonding. The purpose of this in vitro study is to evaluate the clinical acceptability of hard CAD/CAM indirect bonding tray. MATERIAL AND METHODS: Ten soft silicone transfer trays and ten hard CAD/CAM trays were produced, and 200 brackets were placed on them. The brackets were then transferred to twenty stereolithography -printed models by indirect bonding. These models were scanned and digitally compared with the reference model by three-dimensional superimpositions (GOM software). The linear and angular measurements were collected and analyzed. RESULTS: For the CAD/CAM trays, 100% of the mesiodistal, vertical, and transverse measurements of incisors were within the clinically acceptable range of the American Board of Orthodontists (ABO) standards. More specifically, the clinically acceptable linear measurements were between 97 and 100% for silicone trays while they were between 89 and 100% for CAD/CAM trays. The clinically acceptable angular measurements varied between 87 and 100% for the silicone trays and between 79 and 100% for the CAD/CAM trays. Silicone trays were more precise than CAD/CAM trays. The difference was significant for all linear and angular measurements. CONCLUSIONS: While the CAD/CAM group shows clinically acceptable results according to the ABO, silicone remains to be more precise than CAD/CAM for transfer trays and is therefore still the reference. CLINICAL RELEVANCE: We demonstrate here that the orthodontic indirect bondings, whether they are realized using silicone transfer trays or CAD/CAM trays, are clinically acceptable in terms of the repositioning accuracy of brackets.

Development of a 3D human osteoblast cell culture model for studying mechanobiology in orthodontics.

OBJECTIVES: Mechanobiology phenomena constitute a major element of the cellular and tissue response during orthodontic treatment and the implantation of a biomaterial. Better understanding these phenomena will improve the effectiveness of our treatments. The objective of this work is to validate a model of three-dimensional (3D) culture of osteoblasts to study mechanobiology. MATERIALS AND METHODS: The hFOB 1.19 cell line was cultured either traditionally on a flat surface or in aggregates called spheroids. They were embedded in 0.8% low-melting agarose type VII and placed in a polyethylene terephthalate transwell insert. Compressive forces of 1 and 4 g/cm2 were applied with an adjustable weight. Proliferation was evaluated by measuring diameters, monitoring glucose levels, and conducting Hoechst/propidium iodide staining. Enzyme-linked immunosorbent assays focusing on the pro-inflammatory mediators interleukin (IL)-6 and IL-8 and bone remodelling factor osteoprotegerin were performed to evaluate soluble factor synthesis. quantitative reverse transcription-polymerase chain reaction was performed to evaluate bone marker transcription. RESULTS: The 3D model shows good cell viability and permits IL dosing. Additionally, three gene expression profiles are analysable. LIMITATIONS: The model allows analysis of conventional markers; larger exploration is needed for better understanding osteoblast mechanobiology. However, it only allows an analysis over 3 days. CONCLUSION: The results obtained by applying constant compressive forces to 3D osteoblastic cultures validate this model system for exploring biomolecule release and analysing gene transcription. In particular, it highlights a disturbance in the expression of markers of osteogenesis.

[Bone mechanobiology, an emerging field: a review]. / La mécanobiologie osseuse, un domaine émergeant : revue de littérature.

INTRODUCTION: Mechanobiology, at the interface between biology and biophysics, studies the impact of mechanical forces on tissues, cells and biomolecules. The application of orthodontic forces, followed by induced tooth displacement, is a striking example of its clinical application. OBJECTIVE: The purpose of this article was to compile a review of the literature on the subject of mechanobiology; from its detection at bone level to the presentation of stimulated intracellular pathways. MATERIALS AND METHODS: The literature search was conducted on the Pubmed database in April 2018, with associations of the terms "mechanobiology", "orthodontics", "cell culture", "physiopathology". RESULTS: Three major areas of research were selected: highlighting of the phenomenon and its application in the field of bone biology; the cellular effectors of mechanobiology and its clinical applications. The use of mechanobiology in dentofacial orthopedics opens up a new field of reflection for clinicians regarding future advances in orthodontics.

[Treat or prevent the loss of inter-dental papillae]. / Traiter ou prévenir la perte des papilles inter-dentaires.

INTRODUCTION: Contemporary literature agrees that orthodontic results can no longer be limited to occluso-functional success. The integration of the teeth into a healthy periodontium is essential to good treatment finish and durability. MATERIALS AND METHODS: This article proposes to describe the orthodontic physiopathological and iatrogenic lesions leading to the opening of black triangles in place of the inter-dental papillae. It goes on to discuss different periodontal, prosthetic as well as orthodontic reconstruction protocols. RESULTS: This last point, supported by a biological rationale well-known to periodontologists, is described using clinical cases.

Influence of orthodontic premolar extraction therapy on the eruption of the third molars: A systematic review of the literature.

BACKGROUND: Through a systematic literature review, the authors assess the effect of premolar extractions on third-molar (M3) eruption considering eruption rate, retromolar space, and molar angulation. TYPES OF STUDIES REVIEWED: The authors performed a systematic search using MEDLINE and Web of Science databases up through April 2017 to identify quality studies available comparing M3 eruption between a group with premolar extraction and a group without premolar extraction. RESULTS: Twelve comparative retrospective cohort studies met all the inclusion criteria. The authors found in 5 studies comparing the rate of M3 eruption that there were significantly higher results in the group with extractions. They found in 5 studies comparing the evolution of the retromolar space significantly higher results in the group with extractions. Lastly, concerning the uprighting of the M3 during treatment, the authors found only 2 studies showing significant differences between the 2 groups, each time in favor of the group with extractions. CONCLUSIONS AND PRACTICAL IMPLICATIONS: The dental literature on premolar extraction related to the eruption of the M3 is composed of average-quality retrospective studies. Premolar extraction significantly improves the chances of M3 eruption, but the level of evidence of comparative retrospective cohort studies is low. Clinicians must continue to rely on their judgment regarding premolar extraction on a case-by-case basis until the evidence is stronger. Retrospective studies with standardized protocols and more detailed methodologies are required to obtain higher levels of evidence.

[Effectiveness of selective alveolar decortication in accelerating orthodontic treatment: a systematic review]. / Efficacité des techniques de décortication alvéolaire sélective dans l'accélération du traitement orthodontique : une revue systématique de la littérature.

INTRODUCTION: The number of scientific publications on accelerating orthodontic treatment, and especially surgical alveolar corticotomies techniques, has grown exponentially over the years. The objective of this systematic literature review was to assess the effectiveness of these corticotomies basing on human studies. MATERIAL AND METHOD: The review was conducted from Medline and Web of Science Core Collection to identify prospective controlled clinical trials with duration of orthodontic treatment or the tooth movement rate for primary endpoint. RESULTS: Eleven studies respected all inclusion criteria. Six investigated the duration of treatment and found shorter values in experimental group than in control group, with a gain of 8 to 34 weeks. Five investigated the tooth movement rate and found 2.3 times higher values on average during the first month in experimental groups, 1.9 times during the second and third months, and 1.3 times during the fourth month. The technique also seemed to decrease the risk of root resorption and improve molar anchorage. Moreover, it exhibited good periodontal tolerance. CONCLUSION: Current literature highlights the effectiveness of surgical decortications during the first three to four months after surgery. Longer prospective studies are needed to assess their long term effects.

[Consideration of the shape of the teeth in facial hyperdivergency]. / 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 patient's 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.

A Protocol for Treatment of Minor Orthodontic Relapse During Retention.

OBJECTIVES: Successful orthodontic treatment presupposes that the esthetic and functional outcomes are maintained. Bonded retainers on the incisors and canines provide this stability. Failure of one or two units exposes the teeth to a relapse. This article describes the use of a retainer wire and an elastic device to provide rapid, effective and esthetic correction of incipient crowding. CLINICAL ASPECTS: After removing the retainer, a fixed appliance comprising a replacement retainer and a clear elastic are positioned. This device exerts a free tipping force on malpositioned teeth. The space required to realign the contact points is obtained by stripping. When the misaligned teeth are corrected, they are bonded to the retainer and the height of the incisal edges is equalized. CONCLUSIONS: The combination of a new elastic-activated retainer and stripping makes it possible to ensure rapid and effective correction of moderate relapsed crowding. CLINICAL SIGNIFICANCE: This article demonstrates the efficacy of a retainer used to correct incipient relapsing crowding. The esthetics of the anterior alignment is restored by means of an almost invisible device. This solution also permits functional guidance to be restored with minimal intervention on the dental tissues while avoiding conventional esthetic techniques involving lingual brackets. (J Esthet Restor Dent 28:359-366,2016).

[Bone-based anchorage failure]. / Échecs des ancrages osseux.

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.