Ameliorating orthodontic relapse using laser bio-stimulation and mesenchymal stem cells in rats.

BACKGROUND: Orthodontic relapse is a frequent problem that many patients experience. Although orthodontic therapy has advanced, recurrence rates can still reach 90%. We undertook a study to look at the possibilities of laser bio-stimulation and stem cells because they have showed promising outcomes in lowering recurrence rates. OBJECTIVES: Our objective was to analyze the effects of Low-level laser therapy (LLLT) and Mesenchymal stem cells (MSC) alone and collectively on the rate of orthodontic relapse in rats radiographically and histologically. METHODS: Rat maxillary central incisors were moved distally for two weeks. One week later, the incisors were retained. Animals (n = 40) were split into four groups. Control group (C); laser treatment Group (L), Bone marrow mesenchymal stem cells Group (BMSCs) and combination of Stem cells and laser-irradiation group (BMSCs-L). Removed retainer permitted relapse. Before stem cell application or laser irradiation, each animal underwent two CBCT scans. Rat maxillae were stained with Hx&E, Masson trichrome, and tartrate-resistant acid phosphatase antibody for histology, histochemistry, and immunohistochemistry. RESULTS AND CONCLUSIONS: LLLT could reduce the relapse tendency, as shown by increased bone density and enhanced remodeling of hetero-formed periodontal ligament (PDL). Furthermore, the transfer of BMMSCs on the pressure side had positive effects on PDL remodeling and decreased, but did not inhibit, the relapse rate. Finally, the synergistic effects of the application of LLLT and BMMSC were better than the control but still moderate and long-lasting. CLINICAL SIGNIFICANCE: Based on the improved relapse rate as proven in the present study, the Application of both LLLT and stem cells can be adopted to reduce the relapse tendency either lonely or collectively.

Prevalence and factors influencing bullying among Egyptian schoolchildren.

OBJECTIVE: To evaluate the prevalence of bullying among schoolchildren and to study the correlation between bullying and a specific type of malocclusion, self-esteem, oral health-related quality of life (OHRQoL), the need for orthodontic treatment and socioeconomic status. DESIGN: A cross-sectional study. SETTING: Low, middle and high socioeconomic-class schools in the same educational district in Cairo, Egypt. PARTICIPANTS: A total of 324 Egyptian schoolchildren aged 11-14 years. METHODS: Validated questionnaires were used to assess self-reported bullying frequency and intensity, self-esteem and OHRQoL. The Index of Orthodontic Treatment Need (IOTN) was used to assess the orthodontic treatment need and the participants' occlusion was classified according to the British Standard Incisors (BSI) classification. RESULTS: Bullying was found to be prevalent in 61.7% of the sample. Regression analysis revealed that participants with a Class II division 1 incisor relationship had the highest odds ratio (OR) for predicting bullying (OR = 1.86, 95% confidence interval [CI] = 1.38-2.15). Being bullied was significantly associated with lower self-esteem (OR = 0.47, 95% CI = 0.13-0.78), worse OHRQoL (OR = 2.73, 95% CI = 1.95-3.15) and a high need for orthodontic treatment, as determined by the IOTN Dental Health Component score (OR = 1.33, 95% CI = 1.05-1.95) and IOTN Aesthetic Component score (OR = 1.52, 95% CI = 1.12-1.88). Moreover, participants in high and middle socioeconomic-class groups had a lower OR for predicting bullying than those in the low socioeconomic-class group (OR = 0.27, 95% CI = 0.13-0.54). CONCLUSION: The bullying prevalence among Egyptian schoolchildren aged 11-14 years was very high. The prevalence of bullying was higher in schoolchildren with higher orthodontic treatment need and Class II division 1 incisor relationship. Bullying was correlated to poor self-esteem as well as poor OHRQoL. In addition, low socioeconomic status was found to be a potential predictor for bullying.

Implant-supported canine retraction using different reactivation intervals of elastomeric chains: A CBCT-based split-mouth randomized controlled trial.

INTRODUCTION: Orthodontists attempt to maximize treatment efficiency regarding time, tooth position and adverse effects. A new approach, not yet explored, is the activation frequency. OBJECTIVE: The aim of this split-mouth randomized controlled trial was to evaluate the effect of reactivation intervals on the efficiency of tooth movement. METHODS: Thirty eight patients having a Class I malocclusion with bimaxillary dentoalveolar protrusion or severe crowding, Class II with mandibular deficiency or Class III, requiring first premolar extraction and canine retraction were recruited. Elastomeric chains producing 150g were replaced every two, four, six or eight weeks. There were 36, 37, 36, and 36 quadrants randomly allocated to these groups, respectively. The canine retraction rate was the primary outcome. Canine tipping, rotation, and root resorption and pain were the secondary outcomes. Only the outcome assessors were blinded to group assignment. RESULTS: The average total movement for the 6 months was 5.14, 5.31, 2.79 and 3.85 mm for the two-week, four-week, six-week and eight-week reactivation intervals, respectively. Root resorption was significantly higher in the two-week and four-week groups. No adverse events were observed. CONCLUSION: The canine retraction rate, tipping, rotation and pain were similar in 2, 4, 6 and 8-week activation intervals groups. Longer reactivation intervals show less root resorption. The trial protocol was not pre-registered. The study was self-funded.

Implant-supported canine retraction using different reactivation intervals of elastomeric chains: A CBCT-based split-mouth randomized controlled trial

ABSTRACT Introduction: Orthodontists attempt to maximize treatment efficiency regarding time, tooth position and adverse effects. A new approach, not yet explored, is the activation frequency. Objective: The aim of this split-mouth randomized controlled trial was to evaluate the effect of reactivation intervals on the efficiency of tooth movement. Methods: Thirty eight patients having a Class I malocclusion with bimaxillary dentoalveolar protrusion or severe crowding, Class II with mandibular deficiency or Class III, requiring first premolar extraction and canine retraction were recruited. Elastomeric chains producing 150g were replaced every two, four, six or eight weeks. There were 36, 37, 36, and 36 quadrants randomly allocated to these groups, respectively. The canine retraction rate was the primary outcome. Canine tipping, rotation, and root resorption and pain were the secondary outcomes. Only the outcome assessors were blinded to group assignment. Results: The average total movement for the 6 months was 5.14, 5.31, 2.79 and 3.85 mm for the two-week, four-week, six-week and eight-week reactivation intervals, respectively. Root resorption was significantly higher in the two-week and four-week groups. No adverse events were observed. Conclusion: The canine retraction rate, tipping, rotation and pain were similar in 2, 4, 6 and 8-week activation intervals groups. Longer reactivation intervals show less root resorption. The trial protocol was not pre-registered. The study was self-funded.

RESUMO Introdução: Os ortodontistas buscam otimizar a eficiência do tratamento quanto ao tempo de duração, à posição dos dentes e aos efeitos adversos. Um aspecto ainda não avaliado são os diferentes intervalos entre as ativações. Objetivo: O objetivo desse estudo controlado e randomizado de boca dividida foi avaliar a influência de diferentes intervalos de reativação na eficiência da movimentação dentária. Métodos: Foram recrutados 38 pacientes com má oclusão de Classe I com biprotrusão dentoalveolar ou apinhamento severo, Classe II com deficiência mandibular ou Classe III, que necessitavam de extração do primeiro pré-molar e retração do canino. As cadeias elastoméricas gerando 150 g foram substituídas a cada duas, quatro, seis ou oito semanas, constando 36, 37, 36 e 36 quadrantes alocados aleatoriamente nesses grupos, respectivamente. O desfecho primário foi a taxa de retração do canino. Os desfechos secundários foram a inclinação, a rotação e a reabsorção radicular do canino, e a dor. Somente os avaliadores dos resultados não tinham conhecimento da alocação nos grupos. Resultados: O movimento total médio para os seis meses foi de 5,14; 5,31; 2,79 e 3,85 mm para os intervalos de reativação de duas semanas, quatro semanas, seis semanas e oito semanas, respectivamente. A reabsorção radicular foi significativamente maior nos grupos de duas e quatro semanas. Não foram observados eventos adversos. Conclusão: A taxa de retração, a inclinação e a rotação do canino e a dor foram semelhantes nos grupos com intervalos de ativação de duas, quatro, seis e oito semanas. Intervalos de reativação mais longos mostram menos reabsorção radicular. O protocolo do estudo não foi pré-registrado. O estudo foi autofinanciado.

Canine root/cortical bone relation (CRCR) and the orthodontic tooth movement.

This observational study evaluates three-dimensionally the relation between the root of maxillary canine and overlying labial cortical plate of bone during orthodontic canine retraction. Eighty-four bilateral maxillary canines in 42 patients were retracted in the extraction space of first premolars, using conventional orthodontic NiTi retraction spring delivering 150gm. Three-dimensional evaluation at the cusp tip, root apex, and the overlying cortical bone was done based on Classification of Root/Cortical bone relation (CRCR) before and after canine retraction. 168 observations of the canines pre- and post-retraction showed a mean distal movement of the canine cusp tip of 3.78(± 2.05) mm, while the canine root apex was almost stationary. Scarcely, 5.4% of the canine roots and root apices persisted in the medullary bone during retraction, while 16.1% contacted the overlying cortical bone. Fenestration of the overlying cortical bone by the canine roots or root apices occurred in 78.6% of the sample. The unembellished intimacy between the canine root and apex to the overlying thick dense cortical bone might have the decelerating effect on the maxillary canine retraction. The natural bone plate labial to the maxillary canine root did not yield infront nor enlarge due to canine retraction, but else defeated the current orthodontic biomechanical implementation.

Root resorption associated with maxillary buccal segment intrusion using variable force magnitudes.

OBJECTIVES: To compare the root resorption resulting from miniscrew-supported maxillary posterior dentoalveolar intrusion using two different force magnitudes. MATERIALS AND METHODS: Adult patients with skeletal open bite, indicated for maxillary posterior dentoalveolar intrusion, were recruited and randomly assigned to the comparison or intervention groups. The comparison group involved applying 200 g of intrusive force per segment, which measured 20 g per root, while this force was 400 g per segment in the intervention group, measuring 40 g per root. RESULTS: Twenty participants were included in the final analysis after 2 patients dropped out, 1 in each group, to end up with 10 subjects (200 roots) per group. There was statistically significant root resorption of 0.84 ± 0.96 mm and 0.93 ± 1.00 mm in the comparison and the intervention groups, respectively. However, there was no statistically significant difference between the groups. CONCLUSIONS: Root resorption inevitably took place in association with orthodontic intrusion. However, increasing the magnitude of the intrusive force did not increase the amount of root resorption, either statistically or clinically.

Force magnitude as a variable in maxillary buccal segment intrusion in adult patients with skeletal open bite.

OBJECTIVES: To compare the effects of two different force magnitudes on maxillary posterior segment intrusion using mini-screws. The null hypothesis was that there would be no difference between the two force magnitudes. MATERIALS AND METHODS: Adult patients with skeletal open bite and a dental open bite ranging from 3 to 8 mm were recruited for this trial. The comparator group had 200 g of intrusive force applied for posterior segment intrusion, whereas 400 g of force was applied in the intervention group. Primary outcomes were the amount of posterior teeth intrusion and anterior open bite closure. RESULTS: Twenty-two subjects were randomized to include 11 participants in each group. One participant dropped out in each group, leaving us with 10 subjects to be analyzed per group. There was statistically significant posterior teeth intrusion of 2.42 ± 2.06 and 2.26 ± 1.87 mm for the comparator and intervention groups, respectively, with no difference between them. Statistically significant open bite closure was achieved in both groups, measuring 2.24 ± 1.18 and 3.15 ± 1.06 mm in the comparator and intervention groups, respectively, with no difference between them. CONCLUSIONS: Both the 200 g and 400 g intrusive forces yielded similar outcomes in terms of posterior teeth intrusion and anterior open bite closure.

Virtual techniques for designing and fabricating a retainer.

The purpose of this article was to report a procedure for using 3-dimensional cone-beam computed tomography imaging, computer-aided design, computer-aided manufacturing, and rapid prototyping to design and produce a retainer.

Three dimensional approach for realistic simulation of facial soft tissue response: a pilot study.

Facial attractiveness is ranked as a principal priority among patients seeking orthodontic treatment or combined surgical orthodontic therapy. A successful treatment planning process necessitates an accurate prediction of the postoperative facial profile. In this manuscript, the simulation procedure on a real clinical case using virtual volumetric 3D mesh through different scenarios of orthognathic procedures was done. Results depict several facial soft tissue outcomes, with the likelihood of sharing with the patient the most esthetically pleasing end result prior to carrying out the surgical procedure.