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Background: Canine retraction has been successful with various force systems and retraction techniques. The appointment interval for force reactivation in canine retraction along the archwire is 4-8 weeks. Aims: The aim was to evaluate the effect of different reactivation intervals on the rate of space closure. Settings and Design: This split-mouth randomized clinical trial recruited 38 patients indicated for the first premolar extraction. Methods: Monthly digital models were acquired for 6 months. The first premolars were extracted, and temporary anchorage devices were placed for maximum anchorage control. The canines were retracted using elastomeric chains which were replaced every 2, 4, 6, or 8 weeks. The monthly rate of canine retraction was measured. The time to space closure was calculated. The secondary outcome was the mesial drift of the first molars. Statistical Analysis: The Kaplan-Meier survival analysis and the Friedman test evaluated and compared the groups. Results: There was no significant difference between the monthly canine retraction rate or the first molar mesial drift between the groups. The mean time to space closure was 5.74 months in the 2-week reactivation group, which was statistically less than the other groups. Conclusions: The 2-week reactivation interval may reduce time to space closure. Direct anchorage control with miniscrews limited anchorage loss significantly.

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Congenital missing second premolars in growing patients should be accurately evaluated in order to establish a suitable treatment plan. Concerning the decision of whether to close or maintain spaces in the dental arches, it shall also be based on biomechanical aspects and the aesthetic traits of individual patients. Accordingly, the option of closing tooth spaces requires an adequate application of biomechanical principles aimed at avoiding detrimental effects on dental arches and facial profile. An effective use of titanium miniscrews for immediate loading, associated with efficient sliding mechanics, can represent an elective way to successfully treat such cases. Herein, the objective is to describe the procedure and underscore the advantages of the mentioned approach by presenting a clinical case along with long-term follow-up.

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Background: Overtreatment design of clear aligner treatment (CAT) in extraction cases is currently primarily based on the clinical experience of orthodontists and is not supported by robust evidence on the underlying biomechanics. This study aimed to investigate the biomechanical effects of overtreatment strategies involving different maxillary anterior teeth intrusion patterns during anterior teeth retraction by CAT in extraction cases. Materials and methods: A finite element model of the maxillary dentition with the first premolar extracted was constructed. A loading method of clear aligners (CAs) based on the initial state field was proposed. The iterative method was used to simulate the long-term orthodontic tooth movement under the mechanical load exerted by the CAs. Three groups of CAs were utilized for anterior teeth retraction (G0: control group; G1: incisors intrusion group; G2: anterior teeth intrusion group). Tooth displacement and occlusal plane rotation tendency were analyzed. Results: In G0, CAT caused lingual tipping and extrusion of the incisors, distal tipping and extrusion of the canines, mesial tipping, and intrusion of the posterior teeth. In G1, the incisors showed minimal extrusion, whereas the canines showed increased extrusion and distal tipping tendency. G2 showed the smallest degree of posterior occlusal plane angle rotation, while the inclination tendency of the canines and second premolars decreased. Conclusion: 1. In CAT, tooth displacement tendency may change with increased wear time. 2. During anterior teeth retraction, the incisor intrusion pattern can provide effective vertical control for the lateral incisors but has little effect on the central incisors. Anterior teeth intrusion patterns can alleviate the inclination of canines and second premolars, resulting in partial relief of the roller-coaster effect.

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OBJECTIVES: To assess the success rate of spontaneous space closure after extraction of the first permanent molar (FPM) in the maxilla and the mandible, and to identify the factors that make spontaneous space closure most favorable in each. MATERIALS AND METHODS: A retrospective records-based cohort study was conducted through a search of the database of the Public Dental Service, Stockholm County Council, Stockholm, for young adults born between 2000 and 2001, who underwent extraction of one or more FPM between 2006 and 2016. A total of 995 extracted teeth were identified, of which 203 teeth in 155 patients met the inclusion criteria. RESULTS: Of the 203 extracted teeth, 166 (81.8%) did not receive any orthodontic treatment. The success rate for space closure in orthodontically treated patients was 91.9%. The success rate for spontaneous space closure was 84.3%. All unsuccessful spontaneous space closure in the maxilla occurred in patients older than 12 years. The dental developmental stage of the second permanent molar (SPM) had a statistically significant association with spontaneous space closure in the mandible (P < .001). CONCLUSIONS: The success rate of spontaneous space closure was high (84.3%) and was higher in the maxilla (94.1%) than the mandible (74.1%). Age at time of extraction and dental developmental stage of the SPM were significant factors for successful spontaneous space closure in the maxilla and mandible, respectively.

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A agenesia dos incisivos laterais superiores compromete a função e a estética, prejudicando o desenvolvimento e autoestima do paciente. O tratamento pode se dar pela abertura dos espaços e reposição dos dentes ausentes por meio de implantes ou reposição mesial dos caninos, seguido pelo seu recontorno em incisivos laterais. A transformação dos caninos em laterais apresenta diversos desafios ao ortodontista devido às diferenças entre torque, volume e cor entre esses dentes, o que, se não devidamente corrigido, pode impactar negativamente no resultado do tratamento. A técnica MBT apresenta diversas versatilidades de bráquetes que podem ser utilizadas com a finalidade de otimizar a movimentação, compensar as diferenças anatômicas e facilitar o tratamento de diversos tipos de casos com arco reto. O caso clínico apresentado mostra o tratamento da agenesia dos incisivos laterais superiores por meio do fechamento de espaço em uma paciente padrão III, com mordida cruzada anterior seguindo a técnica MBT, fazendo uso das relatadas versatilidades de bráquetes de caninos e pré-molares para atingir um posicionamento ideal desses dentes, com as alterações de torque e angulações necessárias. O tratamento incluiu o fechamento de espaços, a extração de pré- -molares inferiores e transformação dos caninos em incisivos laterais, obtendo uma correta relação anterior, oclusão funcional e bom resultado estético.(AU)

Maxillary lateral incisors agenesis compromises the patient's function and aesthetics, impairing the development and self-esteem. Main treatment options are open space for future implant restoration or canine substitution. Canine substitution usually requires restorative treatment to ideally recreate maxillary lateral incisors torque, volume, and color to achieve treatment goals and satisfy the patient's expectations. MBT system presents versatilities that can be used to optimize orthodontic movements, compensate dental anatomic discrepancies, and facilitate some straight-wire cases. This case report describes the orthodontic management of a Class III with anterior cross-bite patient that presented maxillary lateral incisor agenesis. The patient was treated with canine substitution following the MBT technique. Versatilities for canine and premolars were used to achieve the best position, torque, and angulation. The treatment also included mandibular first premolar extraction, space closing, and restorative treatment to re-anatomize the canine into a lateral incisor, achieving proper anterior relation, functional occlusion, and best esthetic result (AU)

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BACKGROUND: This study aimed to assess the impact of aligner activation and power arm length and material on canine and aligner displacement, von Mises stress in the power arm, and principal stress in the periodontal ligament (PDL) during canine tooth distalization using finite element analysis (FEA). The effects of aligner activation and power arm length were primary outcomes, while the effect of the power arm material was a secondary outcome. METHODS: Aligner activation (0.1 mm or 0.2 mm) was applied without using a power arm in two models. The effects of aligner activation, power arm length (12, 13, or 14 mm) and power arm material (stainless steel [SS] or fiber-reinforced composite [FRC]) on canine distalization were investigated in 12 models by evaluating displacement and stress via ALTAIR OptiStruct analysis. RESULTS: Greater canine displacement was observed in all models with 0.2 mm than 0.1 mm of aligner activation. When models with the same aligner activation were compared, reduced mesiodistal tipping, increased palatal tipping, and increased extrusion of the canine cusp were observed with increasing power arm length. Moreover, the von Mises stress increased as the power arm length increased. Increasing the aligner activation and power arm length increased the maximum principal stress in the PDL. Power arms of the same length in both materials showed the same results in terms of canine displacement, clear aligner displacement, and maximum principal stress in the PDL. However, under conditions of equal length and aligner activation, the von Mises stress of the SS power arm was higher than that of the FRC power arm. CONCLUSION: Using a power arm in canine distalization reduced mesiodistal tipping but increased palatal tipping and extrusion of the canine cusp. Aligner activation and additional force increased tooth movement and principal stress in the canine PDL. FRC power arms exhibited less von Mises stress than SS power arms.

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Successful closure of edentulous spaces with clear aligners (CAs) is influenced by many factors. CAs are tailored orthodontic devices whose predictability may have relevant medico-legal implications. This study presents a scoping review about missing molar space closure (MMSC) with CAs and a clinical case. This study aims to highlight the feasibility of molar space closure by mesialization with CAs without hybrid supports. Following PRISMA Sc-review guidelines, English-written randomized/non-randomized/observational clinical studies on PubMed, Scopus, Cochrane and Lilacs were searched. An 18-year-old patient, with upper and lower edentulous spaces due to the loss of two first molars, was rehabilitated with CAs (Sorridi®, Sorridi srl, Latina, Italy) without hybrid supports and attachments. The therapy was carried out over 10 months. Currently, there are no studies documenting MMSC by mesialization with only CAs. Existing articles document the closure of premolar or incisor spaces. The upper and lower left second molars replaced the missing first molars, and erupting third molars replaced adjacent teeth. The biomechanical effects in space closure with CAs related to extraction cases appear as priorities of clinical/medico-legal interest. Our case turns attention to this movement of CAs without attachments/hybrid supports, indicating that even such a complex treatment can be comfortable for patients and safely predictable for specialists.

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INTRODUCTION: The alveolar bone loss (ABL) and external apical root resorption (EARR) depict the safety of mesialization of mandibular second molars into the extraction space of mandibular first molars. The aim of this study was to evaluate the ABL and EARR after closure of mandibular first molar extraction space by mesialization of second molar on extraction side (ES) as compared to the contralateral non-extraction side (NES). MATERIAL AND METHODS: A retrospective cross-sectional study was carried out using the pre and posttreatment orthodontic records of young adults with complete set of permanent dentitions treated with extraction of unilateral mandibular first molar and non-extraction treatment on the contralateral side. All patients underwent mini-implant supported mesialization of second molar on ES. The ABL and EARR of second molar on ES and contralateral NES were measured on digital orthopantomograms. The ABL and EARR of second molars on ES and contralateral NES were compared using independent sample t-test. RESULTS: A total of 36 subjects (14 males and 22 females) were included in the study. The mean treatment duration for molar mesialization was 28.75±8.05months. The mean crown and root movements of mandibular second molar on ES were 10.94±1.25mm and 9.04mm±1.14mm, as compared to 0.91±1.01mm and 0.77±0.83mm on contralateral NES, respectively. The mean ABL and EARR at mandibular second molar were found to be significantly greater on the ES than the contralateral NES (P<0.001 and<0.05, respectively). A total of seven patients (19.4%) experienced ABL≥1mm on ES as compared to none in the contralateral NES. EARR of>2mm of at least one root was found in seven patients (19.4%) in ES as compared to four (11%) in contralateral NES. CONCLUSION: There was small but statistically significant difference in the ABL and EARR of mesialized mandibular second molar at first molar ES as compared to the contralateral NES. For majority of patients this difference was small but few isolated cases experienced severe ABL and EARR.

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PURPOSE: Surgical techniques in orthodontics have received widespread attention in recent years. Meanwhile, biomaterials with high molecular content have been introduced, such as platelet concentrates (PCs), which may accelerate orthodontic tooth movement (OTM) and reduce periodontal damage. The present systematic review aimed to answer the following PICO question: "In patients in whom orthodontic surgical techniques are performed (P), what is the effectiveness of using PCs over the surgical site (I) when compared to not placing PCs (C) to achieve faster tooth movement (O)?" METHODS: A search was performed in 6 databases. The criteria employed were those described in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses declaration. The present review included studies with a control group that provided information about the influence of PCs on the rate of OTM. RESULTS: The electronic search identified 10 studies that met the established criteria. CONCLUSIONS: The included studies were very diverse, making it difficult to draw convincing conclusions. However, a tendency was observed for OTM to be accelerated when PCs were used as an adjuvant for canine distalization after premolar extraction when distalization was started in the same session. Likewise, studies seem to indicate an association between PC injection and the amount of canine retraction. However, it is not possible to affirm that the use of PCs in corticotomy shortens the overall treatment time, as this question has not been studied adequately. TRIAL REGISTRATION: PROSPERO Identifier: CRD42021278542.

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ABSTRACT Objective: This study was designed to analyze and compare the cusp and apex movements of the maxillary canines and first molars during canine retraction in the first step of extraction space closure, and to evaluate if these teeth follow a curvilinear (acceleration and/or deceleration) movement rate. Material and Methods: Twenty-five patients (23.3 ± 5.1 years of age) were enrolled. The retraction of the maxillary canines was accomplished using nickel-titanium closed coil springs (100gf) on 0.020-in stainless steel archwire. Oblique cephalograms were traced and superimposed on the anatomic best fit of the maxilla (before the retraction [T0], and after one month [T1], three [T3], five [T5] and seven [T7] months). Statistics was based in a normally distributed data. Multilevel procedures were used to derive polynomials for each of the measurements. Student's t-test and one-way repeated measures ANOVA were conducted. The level of significance of 5% was adopted. Results: Canine cusps and apexes did not follow a quadratic curve regarding horizontal movement (neither accelerate nor decelerate). Canine and molar cusps showed more horizontal movement than apexes (4.80 mm vs. 2.78 mm, and 2.64 mm vs. 2.17 mm, respectively). Conclusions: Canine did not accelerate or decelerate overtime horizontally; the cusps and apexes of the canines and molars showed more horizontal movement and larger rate at the beginning of canine retraction, followed by significantly smaller and constant movement rate after the first month.

RESUMO Objetivo: O objetivo deste estudo foi analisar a movimentação das cúspides e dos ápices de caninos e primeiros molares superiores durante a retração de caninos na primeira fase do fechamento do espaço pós-extração, e avaliar se esses dentes apresentam mudança na taxa de movimentação (aceleração e/ou desaceleração). Material e Métodos: Vinte e cinco pacientes (idade = 23,3 ± 5,1 anos) foram incluídos. A retração dos caninos superiores foi realizada com molas helicoidais fechadas de níquel-titânio (100gf) em arco 0,020" de aço inoxidável. Foram feitos traçados cefalométricos de telerradiografias oblíquas e sobrepostos ao melhor ajuste anatômico da maxila (antes da retração [T0]; após um mês [T1], três meses [T3], cinco meses [T5] e sete meses [T7]). A estatística foi baseada em dados com distribuição normal. Procedimentos multiníveis foram usados para derivar polinômios para cada uma das medidas. Teste t de Student e ANOVA de uma via para medidas repetidas foram realizados, adotando-se um nível de significância de 5%. Resultados: As cúspides e os ápices dos caninos não seguiram uma curva quadrática em relação ao movimento horizontal (sem aceleração ou desaceleração). As cúspides dos caninos e molares apresentaram mais movimento horizontal do que os ápices (4,80 mm vs. 2,78 mm e 2,64 mm vs. 2,17mm, respectivamente). Conclusões: A movimentação horizontal dos caninos não acelerou ou desacelerou ao longo do tempo; as cúspides e os ápices dos caninos e molares apresentaram maior movimento horizontal e maior taxa de movimentação no início da retração dos caninos, seguida por uma taxa de movimentação significativamente menor e constante após o primeiro mês.

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Abstract The aim of study was to evaluate periodontal conditions of upper canines and second premolars with and without proximal contact of individuals undergoing orthodontic treatment associated to extractions of the upper first premolars. The study selected upper canines and premolars of individuals undergoing orthodontic treatment without extractions (30 hemiarches - control group), or with extraction of the upper first premolars and whose canines and second premolars had interproximal contact (16 hemiarches - group 1) or diastema (17 hemiarches - group 2). Clinical (plaque index, probing depth, gingival bleeding index, height of the gingival margin, clinical attachment loss and gingival clefts) and radiographic (crest height, bone height and bone-crest discrepancy) parameters of the distal surfaces of canines and mesial surfaces of premolars were evaluated. Group 1 had worse results when compared to the control group for the levels of plaque in canines and premolars and for probing depth in canines (distal and mean) and in premolars (lingual and mean), as well as increasing tendency of clinical attachment loss (lingual and mean) in premolars. Plaque level in canines in group 1 was also significantly higher than in group 2. There was no difference between group 2 and the control group. The lack of proximal contact between canines and second premolars did not significantly affect their periodontal characteristics.

Resumo A extração de dentes para obtenção de espaço nos arcos dentários é uma estratégia rotineiramente utilizada em Ortodontia, porém a movimentação de dentes para os locais de extrações pode estar associada à falhas na estabilidade dos dentes e abertura do ponto de contato, gerando prejuízo aos tecidos periodontais. Objetivo: Avaliar a condição periodontal de caninos e segundos pré-molares superiores com e sem ponto de contato entre si de indivíduos submetidos ao tratamento ortodôntico associado à extração dos primeiros pré-molares superiores. Foram selecionados caninos, primeiros e segundos pré-molares superiores de indivíduos submetidos ao tratamento ortodôntico sem extração (30 hemiarcos - grupo controle) ou com extração dos primeiros pré-molares superiores cujos caninos e os segundos pré-molares apresentavam contato interproximal (16 hemiarcos - grupo 1) ou diastema (17 hemiarcos - grupo 2). Nas superfícies distal dos caninos e mesial dos pré-molares foram avaliados parâmetros clínicos e radiográficos para determinar o efeito da movimentação dos dentes para o local de extração e da ausência de ponto de contato interproximal nos tecidos periodontais. Os grupos não apresentaram diferença significativa para a idade e o tempo de pós-tratamento. O grupo 1 apresentou valores mais desfavoráveis em relação ao grupo controle para o índice de placa em caninos e pré-molares e para a profundidade de sondagem em caninos (distal e média) e em pré-molares (lingual e média), além de uma tendência de maior perda de inserção clínica (lingual e média) nos pré-molares. O índice de placa nos caninos do grupo 1 também foi significativamente maior do que no grupo 2. Os grupos 2 e controle não apresentaram diferença significativa. A ausência de ponto de contato entre os caninos e os segundos pré-molares superiores não afetou significativamente a situação periodontal desses dentes.

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AIM: The aim of this study was to evaluate clinical features that might be related to success rates of autotransplantation of molars with complete root formation. MATERIALS AND METHODS: A group of 60 patients with completely formed third molars autotransplanted to a different molar socket was followed for a medium period of 5 years and 5 months. Extreme care was used in order to preserve the vitality of the periodontal ligament cells. The same technique was applied for all teeth despite different anatomies. Descriptive statistics was performed. The association of the various factors with failures was assessed by using the Fisher's exact test and a p-value of 0.05 was considered as significance threshold. RESULTS: Autotransplantation was found to be a reliable method to replace extracted molar teeth with closed apices. The two major factors that positively influenced the outcomes were fixation with splint and a periodontal probing pocket depth less than 4 mm after the initial healing period. The technique resulted in a suitable well-conserved socket and donor tooth, after the extraction. CONCLUSION: An accurate case evaluation was critically important in order to identify the risks prior to surgery and to select the right patients for this procedure. Autotransplantation of third molar teeth is a feasible approach to replace compromised mature molars. Proper stabilization of the transplanted tooth is strategical for the success of this procedure. A conservative approach to unerupted wisdom teeth is also recommended. CLINICAL SIGNIFICANCE: Dental implants and fixed prostheses have been utilized to replace missing teeth, and orthodontic space closure can be sometimes an effective treatment option. Tooth autotransplantation can be a reliable and less invasive clinical alternative when an appropriate donor site is available.

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BACKGROUND: Maxillary frenectomy in children is a common procedure, but concerns about scar tissue affecting diastema closure prevent many clinicians from treating prior to orthodontics. OBJECTIVES: To determine if maxillary frenectomy is safe and if diastema size is affected by early treatment. MATERIALS AND METHODS: Paediatric patients with hypertrophic maxillary frena were treated under local anaesthesia with diode laser and CO2 laser. Diastema width was compared by calibrating and digitally measuring initial and postoperative intraoral photographs. RESULTS: In total, 109 patients were included: 95 patients with primary dentition (39% male; mean age 1.9 years±1.5 years) and 14 with mixed dentition (43% male; mean age 8.1±1.3 years) with a mean follow-up of 18.0±13.2 months. No adverse outcomes were noted other than minor pain and swelling. In the primary dentition, a decrease in diastema width was observed in 94.7% with a mean closure of -1.4±1.0mm (range +0.7 to -5.1mm). In the mixed dentition, a decrease in diastema width was observed in 92.9% with a mean closure of -1.8±0.8mm (range 0 to -3.5mm). 74.5% of patients in the primary dentition and 75% of patients in the mixed dentition with preoperative diastema>2mm improved to<2mm width postoperatively. CONCLUSIONS: Frenectomy is associated with cosmetic and oral hygiene benefits and when performed properly, does not impede diastema closure and may aid closure. Technique and case selection are critical to successful outcomes. IRB ethics approval was obtained from Solutions IRB protocol #2018/12/8, and this investigation was self-funded.

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OBJECTIVES: To assess the changes in alveolar bone of the mandibular second molars following molar protraction and investigate the factors associated with the alveolar bone changes. MATERIALS AND METHODS: Cone-beam computed tomography of 29 patients (mean age 22.0 ± 4.2 years) who had missing mandibular premolars or first molars and underwent molar protraction were reviewed. Alveolar bone level was measured as the distance from the cementoenamel junction at six points, buccal, lingual, mesiobuccal (MB), mesiolingual (ML), distobuccal (DB), and distolingual (DL), of the second molars at pretreatment (T0) and after molar protraction (T1). Factors associated with alveolar bone changes at the distal and mesial of the second molars were assessed. RESULTS: Mean alveolar bone changes ranged from -1.2 mm (bone apposition) to 0.8 mm (bone resorption). The presence of a third molar impaction at T0 (P < .001), third molar angulation at T0 (P < .001), and Nolla's stage of third molar at T0 (P = .005) were significantly associated with alveolar bone level changes distal to the second molars. Treatment duration (P = .028) was significantly associated with alveolar bone level changes mesial to the second molar. CONCLUSIONS: Patients with impacted third molars, third molars at an earlier stage of development, and mesially angulated third molars at pretreatment may have less alveolar bone resorption distal to the second molars following protraction. Patients with increased treatment time may have reduced alveolar bone resorption mesial to the second molars.

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OBJECTIVE: To investigate laypeople and dental professionals' opinions of the aesthetic outcome from implant therapy (IT) and orthodontic space closure (SC) for missing maxillary lateral incisors. MATERIAL AND METHODS: Evaluation was performed by three groups: laypeople 20-30 years of age (n = 26), laypeople 50-70 years of age (n = 26) and orthodontists (n = 25). The assessors viewed photographs of 44 different cases treated with IT or SC, and made an evaluation of the aesthetics. RESULTS: The gingival color adjacent to the replaced tooth was rated as having better aesthetics in the SC cases (p = 0.000). The orthodontists preferred the aesthetics of the dentition in the SC cases (p = 0.042). The young laypeople, compared to the older laypeople and orthodontists, were more dissatisfied with the color of the tooth replacing the missing lateral incisor in SC cases (p = 0.043). CONCLUSION: The color of the gingiva adjacent to the implant-supported crowns had a lower aesthetic rating than the SC group. Laypeople rated both treatments as equally good. The orthodontists had a slight preference for the aesthetics in the SC cases.

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OBJECTIVES: To evaluate the morphometric changes in maxillary and mandibular anterior alveolar bone after orthodontic treatment and retention for 18-24 months by cone-beam computed tomography (CBCT). SETTING AND SAMPLE POPULATION: Thirty-four adolescent patients (12 males and 22 females; mean age: 14.29 ± 1.24 years) diagnosed with bimaxillary dentoalveolar protrusion and with extractions of the 4 first premolars were included. MATERIALS AND METHODS: The labial and lingual (palatal) alveolar bone thickness, height and root length of the maxillary and mandibular anterior teeth were assessed using CBCT imaging at the pre-treatment (T1), post-treatment (T2) and retention phases (T3). Voxel-based superimpositions of the T2 and T3 images were performed, and the distances of incisal and apical movement between T2 and T3 were measured to determine whether relapses occurred. RESULTS: After orthodontic treatment, the labial and lingual (palatal) bone height decreased significantly (P < .05) and the labial thickness at the crestal (L1), midroot (L2), and apical levels (L3) had no significant change, while the lingual (palatal) bone thickness at all three levels decreased significantly (P < .05). After 18-24 months of retention, the lingual (palatal) height and the lingual (palatal) thickness at the crestal (L1) level increased significantly (P < .05). There were no obvious incisal and apical movements of the anterior teeth between T2 and T3 (P > .05), indicating that no relapses occurred. CONCLUSIONS: Even though lingual (palatal) alveolar loss occurred due to the orthodontic treatment, the cervical alveolar bone seemed to recover over time. Therefore, appropriate camouflage treatment can be used in patients with bimaxillary dentoalveolar protrusion, and this treatment will not irreversibly deteriorate periodontal health and affect the orthodontic treatment stability.

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Introduction: The opening of the contact point can happen after orthodontic closure of the site of dental extraction and opened interproximal contacts are considered potential factors for periodontal diseases. Objective: To evaluate the condition of the alveolar bone crest of the interdental site between canines and upper premolars with or without contact points in individuals submitted to orthodontics associated with the extraction of the first premolars. Material and Methods: This cross-sectional observational study selected upper canines and premolars of individuals undergoing orthodontic treatment without extractions (12 hemiarches ­ control group), or with extraction of the upper first premolars and whose canines and second premolars had interproximal contact (11 hemiarches ­ group 1) or diastema (15 hemiarches ­ group 2). The height and the presence of lamina dura in the interproximal bone crest of the distal surfaces of canines and mesial surfaces of premolars were evaluated. Results: Groups 1 and 2 demonstrated the higher and smallest prevailing of the presence of lamina dura, respectively. The control group presented the bone crest positioned more crownly in relation to the others groups. Experimental groups did not present significant differences to the height of bone crest. Conclusion: The orthodontic allocation of teeth to extraction sites was associated with the significant reduction of the height of the marginal bone crest, regardless of the presence or absence of contact point between the teeth. The lack of contact point resulted in a minor prevalence of the continuity of the lamina dura of the alveolar bone crest in these regions.

Introdução: A abertura do ponto de contato pode ocorrer após o fechamento ortodôntico do sítio de extração dentária e os contatos interproximais abertos são considerados fatores potenciais para as doenças periodontais. Objetivo: Avaliar a condição da crista óssea alveolar do espaço interdentário entre caninos e pré-molares superiores com ou sem pontos de contato em indivíduos submetidos a tratamento ortodôntico associado à exodontia dos primeiros pré-molares. Material e Métodos: Este estudo transversal observacional selecionou caninos e pré-molares superiores de indivíduos submetidos a tratamento ortodôntico sem extrações (12 hemiarcos ­ grupo controle), ou com exodontia dos primeiros pré-molares superiores e cujos caninos e segundos pré-molares tiveram contato interproximal (11 hemiarcos ­ grupo 1) ou diastemas (15 hemiarcos ­ grupo 2). Foram avaliadas a altura e a presença da lâmina dura na crista óssea interproximal das superfícies distais dos caninos e mesiais dos pré-molares. Resultados: Os grupos 1 e 2 demonstraram a maior e a menor prevalência da presença de lâmina dura, respectivamente. O grupo controle apresentou a crista óssea posicionada mais coronalmente em relação aos demais grupos. Entre os grupos experimentais, não houve diferença significativa para a altura da crista óssea. Conclusão: Neste estudo preliminar, a movimentação ortodôntica dos dentes para os locais de exodontia foi associada à redução significativa da altura da crista óssea marginal, independentemente da presença ou ausência de ponto de contato entre os dentes. A falta de ponto de contato resultou em menor prevalência de continuidade da lâmina dura da crista óssea alveolar nessas regiões.

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Resumo Esta pesquisa busca demonstrar a utilização de sistemas de ancoragem absoluta focados na instalação extra-alveolar, principalmente, nas regiões conhecidas como prateleira bucal (buccal shelf-BC) e na crista infrazigomática (Infrazygomatic Crest-IZC). Através de pesquisas realizadas em portais especializados, como o Scielo e Google Scholar, selecionou-se uma série de artigos, periódicos, monografias e dissertações especializados na área. Verificando, principalmente através das pesquisas de Chang e Almeida, as principais áreas de instalação, o tamanho recomendado dos parafusos de acordo com o tipo de instalação, quais os métodos que proporcionam maior estabilidade ao parafuso, as principais indicações de uso, os benefícios incorridos no tratamento ortodôntico, assim como as contraindicações decorrentes do estado do paciente. Observando os diversos critérios elencados, pode-se verificar diversas vantagens dos miniparafusos extra-alveolares em relação aos intra-alveolares, principalmente, com relação à estabilidade decorrida pelo sistema extra-alveolar, permitindo o uso de parafusos com maior calibre sem afetar as raízes dentárias, podendo dessa maneira inclusive realizar a retração ou a mesialização de toda uma arcada, diminuindo sobremaneira as extrações dentárias e também corrigindo as divergências do plano oclusal. (AU)

Abstract This research aims to demonstrate the use of absolute anchoring systems focused on extra-alveolar installation, especially in regions known as buccal shelf-BC and infrazygomatic crest (IZC). Through research carried out in specialized portals, such as Scielo and Google Scholar, a series of articles, journals, monographs, and dissertations specialized in the area were selected. Checking, mainly through research of Chang and Almeida, the main installation areas, the recommended size of the screws according to the type of installation, which methods provide greater stability to the screw, the main indications of use, the benefits incurred to orthodontic treatment, as well as the contraindications resulting from the patient's condition. Observing the various criteria listed, several advantages of extra-alveolar mini-screws can be verified in relation to intra-alveolar screws, especially in relation to the stability eluded by the extra-alveolar system, allowing the use of screws with greater caliber without affecting the dental roots, thus being able to perform the retraction or mesyalization of an entire arch, reducing dental extractions in the way and also correcting the divergences of the occlusal plane.(AU)

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INTRODUCTION: This randomized controlled clinical trial aimed to assess the effect of LED5 and LLLT6 in a three-arm parallel setting. METHODS: Sixty patients who needed the maxillary first premolar extraction were allocated to three groups using the stratified block randomization method. In the LED group, a custom-made device with a wavelength of 640nm and a power density of 40 mW/cm2 was used 5min/day. In the laser group, Ga Al As7 laser with a wavelength of 810nm and a power of 100 mW was used on days 0, 3, 30, and 60 each time for 18seconds. Patients in the control group received placebo treatment as the laser group protocol, using a coated light cure device. Models were made at baseline and monthly until the end of the retraction. The rate of canine retraction was the primary outcome, while canine rotation and pain were secondary outcomes. The final data were anonymous for the outcome assessor and statistical consultant. Data were analyzed per protocol using a linear mixed model. RESULTS: The rate of canine retraction significantly increased by 60.8% in the laser group, while it increased not significantly by 26% in the LED group compared with the control group. There was no significant difference among the groups in terms of tooth rotation and pain. CONCLUSIONS: LLLT can accelerate orthodontic tooth movement (OTM). LED with the present setting couldn't increase the rate of OTM. LLLT and LED did not affect canine rotation or pain. TRIAL REGISTRATION: IRCT20120220009086N4. On 1 June 2019 was retrospectively registered.

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Decreasing orthodontic treatment duration is at the forefront of innovation for clinical orthodontics. This network meta-analysis aimed to determine the relative efficacy and safety of treatments for accelerated orthodontic tooth movement (OTM) in patients undergoing extraction of maxillary first premolars followed by canine retraction in any orthodontic setting. MEDLINE, EMBASE, Cochrane CENTRAL, CINAHL and SCOPUS were searched (from inception to 20 April 2020). Study selection and data extraction were performed in duplicate. Eligible randomized controlled trials (RCTs) were meta-analysed to estimate the rate of tooth movement, 95% credible interval and surface under the cumulative ranking curve (SUCRA) in the first 3 months following the application of the adjunctive accelerative method. Eligible RCTs were assessed by Cochrane risk of bias tool, and quality of evidence was assessed by GRADE approach, obtained from CINeMA web application. Interventions were ranked for efficacy and reviewed for safety. Nineteen studies pertaining to eight interventions, with data from 415 patients were included. Quality of evidence was very low to moderate. Very low-to low-quality evidence suggests that corticotomy is an efficacious and safe adjunctive treatment to accelerate OTM in comparison with conventional treatment in the first 2 months of treatment. Low-quality evidence suggests that piezocision and micro-osteoperforations (MOP) are efficacious and safe adjunctive treatments only in the first month of treatment. Frequent MOP in conjunction with low-level laser therapy appeared to be an efficacious and safe adjunctive treatment only in the first month following its initial application but not thereafter.

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