Reabsorción radicular en premolares, posterior a ortodoncia de autoligado, utilizando tomografía computarizada / Root resorption in premolars after self-ligating orthodontic treatment, using computed tomography

Este Estudio tuvo por objetivo determinar la incidencia de reabsorción radicular externa en premolares superiores e inferiores permanentes al finalizar el tratamiento de ortodoncia. Esta investigación fue realizada en pacientes entre 18 y 35 años que recibieron tratamiento de ortodoncia, sin extracciones, con técnica de autoligado en la ciudad de Guadalajara. Se consideraron 120 premolares, realizando mediciones longitudinales en las tomografías computarizadas de haz cónico al inicio y término del tratamiento. Utilizando el software Implant Viewer 3. Los valores registrados en el primer y segundo premolar superior tanto del lado derecho como izquierdo al inicio y término del tratamiento fluctuaron entre -4.946 y -7.801; p ≤ 0.0005 encontrándose diferencias estadísticas significativas. Mientras que en el primer y segundo premolar inferior tanto del lado derecho como izquierdo, fluctuaron entre -4.864 y -5.28; p ≤ 0.0005 encontrándose diferencias estadísticas significativas. Se concluye en este estudio que los dientes sometidos a movimientos durante el tratamiento de ortodoncia sufren modificaciones en el contorno de la raíz, cambios con consecuencias mínimas que no comprometen la funcionalidad del diente. Los premolares superiores presentaron mayores rangos de reabsorción radicular que los premolares inferiores.

The aim of this study is to determine the incidence of root resorption in permanent upper and lower premolars at the end of an orthodontic treatment. This research was carried out in patients aged between 18 and 35 years old who received orthodontic treatment, without extractions, with a self-ligating technique in the city of Guadalajara, Mexico. In this study, 120 premolars were considered, making longitudinal measurements with cone beam computed tomography at the beginning and the end of the treatment, using the Implant Viewer 3 software. The values recorded in the upper first and second premolars on both the right and left sides at the beginning and the end of the treatment fluctuated between -4.946 and -7.801; p ≤ 0.0005, finding statistically significant differences. In the lower first and second premolars on both the right and left sides, they fluctuated between -4.864 and -5.28; p ≤ 0.0005, also finding statistically significant differences. It is concluded that teeth subjected to movements during orthodontic treatment suffer modifications in the contour of the root, changes with minimal consequences that do not compromise their functionality. The upper premolars showed higher ranges of root resorption than the lower premolars.

Características clínicas y radiográficas de reabsorciones radiculares externas / Clinical and radiographic characterization of external root resorption

INTRODUCCIÓN: La siguiente revisión bibliográfica se realizó con el propósito de reconocer las características clínicas y radiográficas que deben ser evaluadas para el diagnóstico de las reabsorciones radiculares externas incluyendo también sus tratamientos. METODOLOGÍA: Se llevó a cabo una búsqueda en las bases de datos MEDLINE/PubMed, Cochrane Library y Google Scholar bajo el término , incluyendo estudios experimentales y revisiones bibliográficas desde 2010 a 2022 en español e inglés, incluyendo finalmente 17 artículos. RESULTADOS: Los resultados obtenidos señalaron que cada tipo de reabsorción radicular externa presenta características clínicas específicas que las diferencian. Estas diferencias son: para la reabsorción externa inflamatoria la vitalidad pulpar negativa; para la reabsorción externa de reemplazo la ausencia de movilidad y percusión metálica; para la reabsorción externa cervical una coloración rosada de la corona; la reabsorción externa superficial no presenta ningún tipo de sintomatología clínica y la reabsorción de colapso apical transitorio presenta un cambio de coloración transitorio. CONCLUSIÓN: Las reabsorciones radiculares externas requieren un diagnóstico preciso y temprano. Se debe realizar un examen clínico con énfasis en sondaje, coloración, movilidad y pruebas de vitalidad.

INTRODUCTION: The following bibliographic review was carried out with the purpose of recognizing the clinical and radiographic characteristics that must be considered in the diagnosis of external root resorption, including treatments. METHODS: A bibliographic search was carried out in PubMed/Medline, Cochrane Library and Google Scholar databases under the term "external root resorption", from 2010 to 2022 in Spanish and English. Experimental studies and bibliographic reviews were selected, and finally 17 articles were included. RESULTS: The results obtained indicated that each type of resorption presents specific clinical characteristics that differentiate them, these are: for external inflammatory resorption a negative pulp vitality; for replacement external resorption the absence of mobility and metallic percussion; for cervical external resorption a pink coloration of the crown; superficial external resorption does not present any type of clinical symptoms and transient apical collapse presents a transient change in color. CONCLUSION: External root resorptions require accurate and early diagnosis. A clinical examination should be performed with emphasis on the following: probing, coloration, mobility, and vitality tests.

The effects of invisible orthodontic appliances without brackets and labial fixed orthodontic appliances on periodontal status and root resorption in orthodontic patients / 中国医师杂志

Objective:To compare the effects of invisible orthodontic appliances without brackets and labial fixed orthodontic appliances on periodontal status and root resorption in orthodontic patients.Methods:A retrospective study was conducted on 102 orthodontic patients who visited the Affiliated Hospital of Jining Medical University from January 2019 to October 2022. According to different treatment methods, they were divided into group A ( n=52) and group B ( n=50). Group A was treated with invisible orthodontic appliances without brackets, while group B was treated with labial fixed orthodontic appliances. We compared two groups of treatment completion time, root resorption, and periodontal health indicators before and after treatment, including plaque index (PLI), gingival index (GI), gingival sulcus bleeding index (SBI), and levels of inflammatory factors in gingival crevicular fluid, including interleukin-1β (IL-1β) and soluble intercellular adhesion molecule-1 (sICAM-1). Results:The completion time of treatment in the Group A was longer than that in the group B [(34.62±4.28)months vs (28.93±3.11)months] ( P<0.01). After treatment, the incidence of root resorption in the group A was 50.96%, while in the group B it was 78.00%. The group A was significantly lower than the group B ( P<0.05), with no root resorption greater than 3 mm in the group A and 0.50% in the group B. After treatment, the levels of PLI, GI, SBI, and IL-1β and sICAM-1 in gingival crevicular fluid increased in both groups, with the group A being lower than group B [(1.26±0.39)points vs (1.73±0.54)points, (1.33±0.25)points vs (2.06±0.46)points, (1.73±0.40)points vs (2.48±0.50)points, (173.74±25.81)ng/ml vs (196.33±31.52)ng/ml, (42.28±5.16)μg/L vs (56.59±7.38)μg/L] (all P<0.05). Conclusions:Although invisible orthodontic appliances without brackets cannot shorten the completion time of treatment, they have advantages in inhibiting root resorption, improving periodontal health, and reducing inflammatory reactions. Clinically, appropriate appliances can be selected based on the specific situation of patients.

Clinical research progress on corticotomy and modified techniques for accelerating orthodontic tooth movement / 口腔疾病防治

@#Adjunctive interventions for accelerating orthodontic tooth movement have been a hot topic of interest in orthodontics. Prolonged orthodontic treatment is often associated with multiple potential complications, such as decalcification, caries, root resorption, and gingival inflammation. Therefore, applying adjunctive interventions that accelerate orthodontic tooth movement and reduce the duration of orthodontic treatment can provide patients with numerous benefits that are of profound clinical significance. Currently, adjunctive interventions for accelerating orthodontic tooth movement can be divided into two main categories: surgical and nonsurgical. Surgical interventions, represented by corticotomy and modified corticotomy procedures, are the most common in clinical practice and can minimize the treatment duration, augment alveolar bone, and expand the range of orthodontic tooth movement. However, these procedures are inevitably traumatic and have many risks and limitations that prevent them from being widely used in clinical practice. In recent years, multiple modified corticotomy techniques, such as corticision, piezocision, micro-osteoperforation, and discision, have been proposed; these techniques can reduce soft and hard tissue damage and the incidence of postoperative complications and are relatively easy to perform in the clinic. Corticotomy and other improved surgical techniques can shorten the duration of orthodontic treatment to a certain extent and promote the recovery of periodontal health with no adverse effects on periodontal, dental, or pulp tissues. However, in clinical application, several potential side effects (such as periodontal tissue damage, root resorption, loss of pulp vitality, etc) and shortcomings need further research with long-term follow-up.

Research progress on invasive cervical resorption / 口腔疾病防治

@#Tooth absorption can be divided into physiological absorption and pathological absorption. Root absorption of mature deciduous teeth is physiological absorption. Pathological absorption includes internal absorption and external absorption. Internal absorption, also known as intramedullary absorption, includes inflammatory absorption and alternative absorption. External tooth absorption originates from the outer surface of the root or the neck of the tooth and can be divided into inflammatory absorption, alternative absorption, pressure resorption and invasive cervical resorption. Invasive cervical resorption (ICR) is pathological damage caused by many factors, which usually begins in the cemento-enamel junction and extends peripherally or horizontally in the dentin. It hardly invades the pulp. Orthodontic devices, trauma, bleaching, systemic diseases, and the use of certain medications can all lead to invasive cervical resorption. The clinical manifestations of ICR are usually asymptomatic or not obvious, and most of which are found in imaging examinations. Because caries and internal absorption are often misdiagnosed through plain apical radiography, cone beam computed tomography (CBCT) can help to better understand the situation of invasive cervical resorption. Because the pathogenesis and etiology of invasive cervical resorption are not fully understood, clinical negligence and inadequate treatment of invasive cervical resorption can even cause unnecessary tooth loss. This article reviews the latest research progress on the histopathologic features, pathogenic mechanism, susceptibility factors, diagnosis and treatment of ICR, with special emphasis on susceptibility factors and their mechanisms.

Evaluation of different methods of calcium hydroxide removal from root canals with simulated internal resorptions / Avaliação de diferentes métodos de remoção de hidróxido de cálcio de canais radiculares com reabsorções internas simuladas

Objective: This study evaluated different methods of calcium hydroxide (CH) removal from root canals with simulated internal resorptions using microcomputed tomography (micro-CT). Material and Methods: Sixty acrylic resin blocks with simulated root canals and internal resorptions were prepared using a Reciproc R25 file and then filled with CH. The blocks were divided into five test groups (n=12) according to the method used for CH removal: hand files (HF), Easy Clean (EC), passive ultrasonic irrigation (PUI), XP-Endo Finisher (XP), XP-Endo Finisher + PUI (XP+PUI). The blocks were scanned using a SkyScan 1172 scanner before and after CH removal to measure the volume and percentage of CH removal. The OriginPro 2017 software was used for statistical analyses. The level of significance was set at p<0.05 for all tests. Results: No method under study removed all CH. All methods had similar results in the cervical third (P>0.05). The percentage of CH removal was significantly greater in the area of internal resorption and along the total length of the canal in the XP+PUI group (P<0.05). The best results of CH removal were found in the apical third of roots in the XP+PUI and PUI groups (P>0.05). Conclusion: No method removed all CH from the root canals, but the combined XP+PUI method removed more CH than the other methods, especially from the area of the internal resorption(AU)

Objetivo: Este estudo avaliou diferentes métodos de remoção de hidróxido de cálcio (CH) de canais radiculares com reabsorções internas simuladas por meio de microtomografia computadorizada (micro-CT). Material e Métodos: Sessenta blocos de resina acrílica com canais radiculares simulados e reabsorções internas foram preparados com lima Reciproc R25 e posteriormente preenchidos com CH. Os blocos foram divididos em cinco grupos de teste (n=12) de acordo com o método utilizado para remoção de CH: limas manuais (HF), Easy Clean (EC), irrigação ultrassônica passiva (PUI), XP-Endo Finisher (XP), XP -Endo Finalizador + PUI (XP + PUI). Os blocos foram escaneados usando um scanner SkyScan 1172 antes e depois da remoção do CH para medir o volume e a porcentagem de remoção do CH. O software OriginPro 2017 foi utilizado para análises estatísticas. O nível de significância foi estabelecido em p<0,05 para todos os testes. Resultados: Nenhum método em estudo removeu todos o CH. Todos os métodos tiveram resultados semelhantes no terço cervical (P>0,05). A porcentagem de remoção de CH foi significativamente maior na área de reabsorção interna e ao longo do comprimento total do canal no grupo XP+PUI (P<0,05). Os melhores resultados de remoção de CH foram encontrados no terço apical das raízes nos grupos XP+PUI e PUI (P>0,05). Conclusão: Nenhum método removeu todo o CH dos canais radiculares, mas o método combinado XP+PUI removeu significativamente mais CH do que os outros métodos, especialmente da área de reabsorção interna (AU)

Retrospective analysis of survival of avulsed and replanted permanent teeth according to 2012 or 2020 IADT Guidelines

Abstract This study aimed to compare the survival of replanted teeth that followed the 2012 or the 2020 International Association of Dental Traumatology (IADT) guidelines. Sixty-two permanent replanted teeth were retrospectively assessed (IADT 2012, n = 45; IADT 2020, n = 17). Five years after replantation (from January 2017 to December 2021), clinical and radiographic examinations were performed. A significance level of 95% was considered to evaluate the outcomes. Thirty-one teeth (50.0%) remained in their sockets and 31 (50.0%) were lost due to external root resorption. Of the 25 (40.3%) teeth replanted within one hour, 16 (64.0%) remained in their sockets, and 9 (36.0%) were lost. Twenty-two (71.0%) of all 31 lost teeth had an extra-alveolar time of more than one hour. Twelve teeth remained in their sockets without resorption: 8 (66.7%) were replanted within one hour, 2 (16.7%) followed the 2012 IADT, and 2 (16.7%) the 2020 IADT guidelines for late replantation. There was a significant difference (p <0.05) in the extra-alveolar time (< one hour), but without difference between the guidelines in late replantation (p > 0.05). Replanted teeth following both, 2012 or 2020 IADT guidelines, have similar clinical outcomes. The extra-alveolar time of less than one hour was demonstrated to be important to keep the permanent tooth in its socket.

Resumo Este estudo teve como objetivo comparar a sobrevida, por cinco anos, de dentes reimplantados que seguiram as diretrizes de 2012 ou 2020 da International Association of Dental Traumatology (IADT). Sessenta e dois dentes permanentes reimplantados foram avaliados retrospectivamente (IADT 2012, n = 45; IADT 2020, n = 17). Cinco anos após o reimplante, foram realizados exames clínicos e radiográficos. Foi considerado um nível de significância de 95% para avaliar os desfechos. Trinta e um dentes (50,0%) permaneceram em seus alvéolos e 31 (50,0%) foram perdidos por reabsorção radicular externa. Dos 25 (40,3%) dentes reimplantados em uma hora, 16 (64,0%) permaneceram em seus alvéolos e 9 (36,0%) foram perdidos. Vinte e dois (71,0%) de todos os 31 dentes perdidos tiveram um tempo extra-alveolar superior a uma hora. Doze dentes permaneceram em seus alvéolos sem reabsorção: 8 (66,7%) foram reimplantados em uma hora, 2 (16,7%) seguiram a IADT de 2012 e 2 (16,7%) as diretrizes da IADT de 2020 para reimplante tardio. Houve diferença significativa (p<0,05) no tempo extra-alveolar (< uma hora), mas sem diferença entre as diretrizes no reimplante tardio (p > 0,05). Dentes reimplantados seguindo as diretrizes de 2012 ou 2020 da IADT, tiveram taxas de sucesso semelhantes. O tempo extra-alveolar inferior a uma hora demonstrou ser importante para manter o dente permanente em seu alvéolo.

Multiple idiopathic root resorption: a case report and literature review / 口腔疾病防治

Objective @#To explore the etiology, clinical manifestations, diagnosis and treatment of multiple idiopathic root resorption to provide a reference for clinical diagnosis and treatment. @*Methods@# The clinical data of a case of multiple idiopathic root resorption were analyzed retrospectively, and the related literature was reviewed.@*Results@#The patient had no history of orthodontic correction, occlusal trauma, trauma history or other causes of root resorption. Clinical examination revealed full-mouth gingival congestion, redness, a loose texture, and variable degrees of destruction of the alveolar bone. Imaging examination showed that teeth 13, 16, 26, 36, 46 had idiopathic root resorption. The diagnoses were multiple idiopathic root resorption and periodontitis. The pathology tests showed that a large number of osteoclasts were present in the soft tissue surrounding the teeth. Whole-exome sequencing showed that there was a strong correlation between gene mutations (WNT7a and HSPG2) and the present phenotype. Root resorption of teeth without periodontitis was stopped after periodontal treatment during the 19-month follow-up. Tooth 13 was removed, and extraction socket preservation was performed. The etiology of idiopathic root resorption may be related to gene mutations, but it is not clear. At present, there is no effective treatment. @* Conclusion @#Multiple idiopathic root resorption has an unknown etiology, but it may be related to WNT7A and HSPG2 gene mutations. The rate of root resorption can be slowed by controlling periodontal inflammation.

Comparison of panoramic radiography and cone-beam computed tomography images for detecting external root resorption of mandibular second molar associated with third molar impaction / 口腔医学

Objective@# To compare the diagnostic performance between panoramic radiography(PR)and cone beam computed tomography(CBCT)in the assessment of external root resorption(ERR)of mandibular second molars associated with impacted third molars. @*Methods@# A total number of 832 patients with 1 074 mesially and horizontally impacted mandibular third molars treated at our institution from January 2019 to December 2020 were retrospectively analyzed. Presence of ERR on the adjacent second molar was investigated with PR and CBCT. Factors affecting the diagnostic accuracy of PR were determined. @*Results@# The overall incidence of ERR in second molars was 33.15%(356/1 074)as detected by CBCT images. The accuracy of PR was 66.39%. Multivariate Logistic regression analyses further revealed that middle and Class Ⅲ impaction, crown contact or overlap with the root of adjacent tooth were risk factors for inaccurate diagnosis of PR(P<0.05). @*Conclusion@#The accuracy of detection on ERR of mandibular second molar associated with impacted third molar using panoramic radiography is lower. CBCT is recommended for this clinical scenario.

Combined micro-apical surgery and vital pulp therapy in mandibular second molars with external root resorption caused by impacted teeth / 华西口腔医学杂志

OBJECTIVES@#This study aimed to establish a new treatment of the mandibular second molars with external root resorption caused by impacted teeth to preserve the affected teeth and their vital pulps.@*METHODS@#For mandibular second molars clinically diagnosed as external root resorption caused by impacted teeth, debridement and removal of the root at the resorption site via micro-apical surgery and direct capping of the pulp with bioactive material on the surface of the root amputation via vital pulp therapy were performed immediately after the impacted teeth were extracted.@*RESULTS@#The external root resorption of the affected tooth was ceased. It was asymptomatic with intact crown, normal pulp, periapical alveolar bone reconstruction, normal periodontal ligament, continuous bone sclerosis, and no periapical translucency in radiographic examination at the 1-year postoperative follow-up, thus showing good prognosis.@*CONCLUSIONS@#Simultaneous combination of micro-apical surgery and vital pulp therapy after extraction of impacted teeth could successfully preserve mandibular second molars with ERR caused by impacted teeth and their vital pulps.

Experimental study of subcutaneous adipose-derived stem cells inhibiting orthodontic root resorption / 中国修复重建外科杂志

OBJECTIVE@#To investigate the effect of human subcutaneous adipose-derived stem cells (hADSCs) local transplantation on orthodontically induced root resorption (OIRR) and provide theoretical and experimental basis for the clinical application of hADSCs to inhibit OIRR.@*METHODS@#Forty 8-week-old male Sprague Dawley rats were randomly divided into experimental group and control group, with 20 rats in each group, to establish the first molar mesial orthodontic tooth movement (OTM) model of rat right maxillary. The rats in the experimental group were injected with 25 μL of cell suspension containing 2.5×10 5 hADSCs on the 1st, 4th, 8th, and 12th day of modeling, while the rats in the control group were injected with 25 μL of PBS. The rat maxillary models were obtained before and after 7 and 14 days of force application, and 10 rats in each group were killed and sampled after 7 and 14 days of force application. The OTM distance was measured by stereomicroscope, the root morphology of the pressure side was observed by scanning electron microscope and the root resorption area ratio was measured. The root resorption and periodontal tissue remodeling of the pressure side were observed by HE staining and the root resorption index was calculated. The number of cementoclast and osteoclast in the periodontal tissue on the pressure side was counted by tartrate resistant acid phosphatase staining.@*RESULTS@#The TOM distance of both groups increased with the extension of the force application time, and there was no significant difference ( P<0.05). There was no significant difference in OTM distance between the experimental group and the control group after 7 and 14 days of force application ( P>0.05). Scanning electron microscope observation showed that small and shallow scattered resorption lacunae were observed on the root surface of the experimental group and the control group after 7 days of force application, and there was no significant difference in the root resorption area ratio between the two groups ( P>0.05); after 14 days of application, the root resorption lacunae deepened and became larger in both groups, and the root resorption area ratio in the experimental group was significantly lower than that in the control group ( P<0.05). The range and depth of root absorption in the experimental group were smaller and shallower than those in the control group, and the root absorption index in the experimental group was significantly lower than that in the control group after 14 days of force application ( P<0.05). The number of cementoclast in the experimental group was significantly lower than that in the control group after 7 and 14 days of force application ( P<0.05); the number of osteoclasts in the experimental group was significantly lower than that in the control group after 14 days of force application ( P<0.05).@*CONCLUSION@#Local transplantation of hADSCs may reduce the area and depth of root resorption by reducing the number of cementoclasts and osteoclasts during OTM in rats, thereby inhibiting orthodontic-derived root resorption.

3D reconstruction of lower anterior teeth from CBCT images: automatic segmentation with manual refinements

ABSTRACT Objective: To develop a well-detailed and reproducible tooth segmentation method, when quantifying tooth volumetric measurements is needed. Material and Methods: This was an in vitro study in which lower incisors and canines of five patients were 3D reconstructed by means of an automatic segmentation with manual refinements process. All the images were obtained using a 0.3-mm voxel size CBCT imaging. The software utilized was the ITK-SNAP®. The primary outcomes were the intra-rater and inter-rater reliabilities and the respective measurement errors. Results: The intra-rater reliability was excellent, with a mean measurement error of 4.16%. The inter-rater reliability was good, with a mean measurement error of 7.11%. Accuracy assessment was not possible, as the assessed teeth were not extracted. Conclusions: Although the described method is reliable, tooth volumetric error measurements may become significant, depending on the assessed situation.

RESUMO Objetivo: Desenvolver um método de segmentação dentária bem detalhado e reprodutível, para quando for necessário quantificar as medidas volumétricas dos dentes. Material e Métodos: Esse foi um estudo in vitro no qual incisivos inferiores e caninos de cinco pacientes foram reconstruídos em 3D por meio de um processo de segmentação automática com refinamentos manuais. Todas as imagens de TCFC foram obtidas usando tamanho de voxel de 0,3 mm. O software utilizado foi o ITK-SNAP®. Os resultados primários foram as confiabilidades intra-avaliadores e interavaliadores e os respectivos erros de medição. Resultados: A confiabilidade intra-avaliador foi excelente, com erro médio de medição de 4,16%. A confiabilidade interavaliadores foi boa, com erro médio de medição de 7,11%. A avaliação da precisão não foi possível, pois os dentes avaliados não foram extraídos. Conclusões: Embora o método descrito seja confiável, os erros nas medições volumétricas dos dentes podem se tornar significativos, dependendo da situação avaliada.

The influence of fluoxetine on orthodontic tooth movement in rats

Abstract This study aimed to evaluate the effects of chronic use of fluoxetine on the amount of orthodontic tooth movement and tissue changes in rats. A total of 192 Wistar rats were divided into 4 groups: S, 0.9% saline solution; F, 20 mg/kg of fluoxetine; SM, 0.9% saline solution with orthodontic movement; and FM, 20 mg/kg of fluoxetine with orthodontic movement. After 30 days of daily saline or fluoxetine administration, an orthodontic device (25cN) was used to mesially displace the first molar in animals of the groups SM and FM. The animals were euthanized 2, 7, 14, and 28 days after placement of the orthodontic appliances and animals of groups S and F were euthanized at the same time. The assessment of tooth movement was made in gypsum castings, the collagen neoformation was assessed by polarization microscopy, the number of osteoclasts and root resorption were evaluated using tartrate-resistant acid phosphatase, and presence of hyalinized areas was assessed by hematoxylin-eosin staining. Fluoxetine did not affect the amount of tooth displacement, percentage of collagen, number of osteoclasts, and presence of hyalinized areas (P>0.05). There was a higher frequency of root resorption areas in the FM group than in the SM group only on the second day (P<0.05). The findings of this study show that chronic use of 20 mg/kg fluoxetine does not affect the amount of tooth movement, collagen neoformation, number of osteoclasts, or hyalinized areas and does not affect root resorption until the last day of orthodontic movement.

Impact of low intensity pulsed ultrasound on volumetric root resorption of maxillary incisors in patients treated with clear aligner therapy: A retrospective study

ABSTRACT Objective: The aim of this study was to evaluate the volumetric root resorption in maxillary incisors following clear aligner therapy (CAT) with low-intensity pulsed ultrasound (LIPUS), and compare the results to CAT alone. Material and Methods: This retrospective study evaluated pretreatment (T0) and post-treatment (T1) cone-beam computed tomography imaging of 42 adult patients. Twenty-one patients (14 females, 7 males, mean age= 38.1±12.96 years) were treated using CAT with LIPUS device, whereas the other twenty-one matching controls patients (15 females, 6 males, mean age= 35.6±11.7 years) were treated using CAT alone. Images were analyzed and a segmentation protocol was applied on the maxillary incisors. Each segmented tooth volume was exported as a surface mesh in the Visualization Toolkit (VTK) file format. The VTK files for all maxillary incisors were coded and corresponding teeth volumes from T0 and T1 were superimposed. Clipping the crown of each tooth was done, then measurements of root volumes and differences between groups were performed. Changes in root volumes were assessed (p<0.05). Results: Root loss was evident in all teeth in both groups, but was significantly increased in all maxillary incisors of the control group (p<0.001) and in upper left central incisor of LIPUS group (p=0.009). When both groups were compared, there was statistically significant minimal volumetric root loss in LIPUS group (3.50-7.32 mm3), when compared to control group (11.48-12.95 mm3) (p<0.05). Conclusion: LIPUS group showed less volumetric root resorption compared to control group during the studied treatment time using clear aligners.

RESUMO Objetivo: O objetivo deste estudo foi avaliar volumetricamente a reabsorção radicular em incisivos superiores após tratamento com alinhadores transparentes (CAT) com e sem uso adjuvante de ultrassom de baixa intensidade (LIPUS). Material e Métodos: Esse estudo retrospectivo avaliou imagens de tomografia computadorizada de feixe cônico pré-tratamento (T0) e pós-tratamento (T1) de 42 pacientes adultos: 21 pacientes (14 mulheres, 7 homens, idade média= 38,1±12,96 anos) foram tratados com CAT e LIPUS, enquanto os outros 21 pacientes controles correspondentes (15 mulheres, 6 homens, idade média= 35,6±11,7 anos) foram tratados apenas com CAT. As imagens foram analisadas e foi aplicado um protocolo de segmentação dos incisivos superiores. Os volumes de cada dente segmentado foram exportados como malhas de superfície, em arquivos no formato Visualization Toolkit (VTK). Os arquivos VTK de todos os incisivos superiores foram codificados e foram sobrepostos os volumes dos dentes correspondentes a T0 e T1. Foi realizada a clipagem da coroa de cada dente e, em seguida, foram realizadas medições dos volumes radiculares e comparadas as diferenças entre os grupos, avaliando-se as alterações nos volumes de raízes (p<0,05). Resultados: A perda radicular foi evidente em todos os dentes em ambos os grupos, mas foi significativamente maior em todos os incisivos superiores do grupo controle (p<0,001) e no incisivo central superior esquerdo do grupo LIPUS (p=0,009). Quando ambos os grupos foram comparados, houve perda volumétrica mínima estatisticamente significativa no grupo LIPUS (3,50-7,32 mm3), em comparação ao grupo controle (11,48-12,95 mm3) (p<0,05). Conclusão: O grupo LIPUS apresentou menor volume de reabsorção radicular, em comparação ao grupo controle, durante o tempo de tratamento estudado usando alinhadores transparentes.

Orthodontic aligners: between passion and science

ABSTRACT Introduction: The benefits and safety of using orthodontic aligners have been reported more by clinical experience and expert opinion than by scientific evidence. Another important aspect is that aligners are constantly evolving. It is important to obtain evidence that allows for new updates in manufacturing technology, in the development of new movement planning protocols, in the incorporation and design of attachments, and in the aid of skeletal anchorage. Methods: Evidence retrieved from six electronic databases (CINAHL, MEDLINE, EMBASE, Psych Info, the Cochrane Library and the Joanna Briggs Library) is presented by means of questions and answers. Conclusions: There is evidence that the aligners presented different levels of difficulty in performing each type of movement, with rotational and vertical movements being the most difficult to perform. Regarding perception of pain due to tooth movement, it seems to have less impact at the beginning of treatment; but dealing with more phonoarticulatory changes seems to require more treatment time in more complex cases. Aligners do not prevent the occurrence of root resorption, although the incidence and severity of resorption may be reduced, making oral hygiene easier and accepting the risk of white spots, caries and periodontal disease. Given the conflicting evidence, the release of bisphenol-A from the aligner cannot be denied. Solutions must be found to reduce the environmental impact of aligners disposal. There is an urgent need for well-designed randomized controlled trials.

RESUMO Introdução: As vantagens e desvantagens do uso de alinhadores ortodônticos têm sido reportadas com base mais na experiência clínica e opinião de experts do que em evidências científicas. Outro aspecto importante é que os alinhadores estão em processo de evolução constante. Assim, torna-se importante obter evidências recentes, que abranjam as novas atualizações na tecnologia de confecção, no desenvolvimento de novos protocolos de planejamento para as movimentações, a incorporação e desenho dos attachments e o auxílio da ancoragem esquelética. Métodos: As evidências encontradas em seis bases de dados eletrônicas (CINAHL, MEDLINE, EMBASE, Psych Info, Biblioteca Cochrane e Biblioteca Joanna Briggs) serão apresentadas por meio de perguntas e respostas. Conclusões: Há evidências de que os alinhadores apresentam diferentes níveis de dificuldade para realizar cada tipo de movimento, sendo os movimentos rotacionais e verticais os mais difíceis de serem executados. Quanto à percepção da dor causada pela movimentação dentária, parece haver menos impacto no início do tratamento, mas os alinhadores produzem mais alterações fonoarticulatórias e parecem exigir mais tempo de tratamento em casos mais complexos. Não há evidência de diferença na estabilidade pós-tratamento, e os alinhadores não impedem a ocorrência de reabsorção radicular, apesar da incidência e a gravidade da reabsorção poderem ser menores, facilitam a higiene bucal, reduzindo o risco de manchas brancas, cáries e doenças periodontais. Dada a evidência conflitante, a liberação de bisfenol-A pelo alinhador não pode ser negada. É preciso encontrar soluções que reduzam o impacto ambiental do descarte dos alinhadores. Há uma necessidade urgente de ensaios clínicos randomizados bem desenhados.

Alignment efficiency and three-dimensional assessment of root resorption after alignment with conventional and copper-nickel-titanium archwires: A randomized controlled trial

ABSTRACT Objective: To compare alignment efficiency and root resorption between nickel-titanium (NiTi) and copper-nickel-titanium (CuNiTi) archwires after complete alignment in mandibular anterior region. Methods: In this two-arm parallel single-blind randomized controlled trial, forty-four patients with Class I malocclusion with mandibular anterior crowding were recruited form orthodontic clinic of All India Institute of Medical Sciences (Jodhpur, India). Patients were randomly allocated into NiTi and CuNiTi groups, with a 1:1 allocation. Alignment was performed using 0.014-in, 0.016-in, 0.018-in, 0.019x0.025-in archwire sequence in the respective groups, which terminated in 0.019 x 0.025-in stainless-steel working archwire. The primary outcome was alignment efficiency, measured on study models from baseline (T0) to the first, second, third, fourth and fifth-month (T5). Secondary outcome was root resorption, measured from CBCT scans taken at T0 and T5. Mixed-factorial ANOVA was used to compare Little's Irregularity Index (LII). For assessing the proportion of patients with complete alignment at the end of each month, Kaplan-Meier survival curve was built and time to treatment completion was compared between groups using log rank test. Paired t-test was used to assess external apical root resorption (EARR) within groups, whereas independent t-test was used to evaluate LII and EARR between the groups. Results: Twenty-two patients were recruited in each group. One patient was lost to follow-up in the CuNiTi group. No statistically significant differences were observed in alignment efficiency between the groups (p>0.05). Intergroup comparison revealed that the changes in root measurement in three-dimensions were not statistically significant (p>0.05), except for mandibular right central incisor, which showed increased resorption at root apex in NiTi group (p<0.01). Conclusion: The two alignment archwires showed similar rate of alignment at all time points. Root resorption measurement did not differ between the NiTi and CuNiTi groups, except for the mandibular right central incisor, which showed more resorption in NiTi group.

RESUMO Objetivo: Comparar os fios de níquel-titânio (NiTi) e de cobre-níquel-titânio (CuNiTi) quanto à eficiência do alinhamento e quantidade de reabsorção radicular, após alinhamento completo dos dentes da região anterior inferior. Métodos: Neste estudo clínico randomizado, cego, paralelo, de dois braços, quarenta e quatro pacientes com má oclusão Classe I e apinhamento anterior inferior foram recrutados na clínica ortodôntica do All India Institute of Medical Sciences (Jodhpur, India). Os pacientes foram alocados aleatoriamente nos grupos NiTi e CuNiTi, na proporção de 1:1. O alinhamento foi realizado usando a sequência de fios 0,014", 0,016", 0,018" e 0,019" x 0,025" nos respectivos grupos, finalizando com o arco de trabalho 0,019" x 0,025" de aço inoxidável. O desfecho primário foi a eficiência do alinhamento, medida nos modelos de estudo nos tempos inicial (T0) e após um, dois, três, quatro e cinco meses (T5). O desfecho secundário foi a reabsorção radicular, medida a partir de tomografias computadorizadas realizadas em T0 e T5. ANOVA fatorial mista foi utilizada para comparar o Índice de Irregularidade de Little (IIL). Para avaliar a proporção de pacientes com alinhamento completo ao fim de cada mês, foi construída uma curva de sobrevida pelo método de Kaplan-Meier, e o tempo até o fim do tratamento foi comparado entre os grupos por meio do teste log-rank. Um teste t pareado foi utilizado para avaliar a reabsorção radicular apical externa (RRAE) dentro dos grupos, enquanto um teste t independente foi utilizado para avaliar o IIL e a RRAE entre os grupos. Resultados: Vinte e dois pacientes foram recrutados em cada grupo. Um paciente perdeu o acompanhamento no grupo CuNiTi. Não foram observadas diferenças estatisticamente significativas entre os grupos quanto à eficiência do alinhamento (p>0,05). A comparação intergrupos revelou que as alterações na RRAE medida em três dimensões não foram estatisticamente significativas (p>0,05), exceto para o incisivo central inferior direito, que apresentou aumento da RRAE no grupo NiTi (p<0,01). Conclusão: Os dois tipos de fios de alinhamento apresentaram taxa de alinhamento semelhante em todos os momentos. A medida da reabsorção radicular não diferiu entre o grupo NiTi e CuNiTi, exceto para o incisivo central inferior direito, que apresentou maior reabsorção no grupo NiTi.

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.

Root Resorption On Adjacent Teeth Associated With Included Permanent Canines: A Study With Computerized Tomography

Introduction: The most common complication that an impacted canine can generate is root resorption in neighboring pieces. The objective of this study is to describe the prevalence and location of root resorption in teeth adjacent, diagnosed with computed tomography. The database of the diagnoses of all the patients evaluated during theMethod: years 2020 and 2021 between 15 and 22 years of age was reviewed. All the pieces with the diagnosis of included canine were included in the study. Those pieces with incorrect diagnosis and those that did not have an image or its report were excluded. The variables: affected teeth, damaged root third and compromised root canal were analyzed. Of theResults: total of 62 patients, 14 presented root resorption associated with included canines. Of these 14 patients, all were female. The frequency of root resorption generated in neighboring teeth was 25.37%. The most affected pieces were lateral incisors (58.82%). Our results reported a similar frequency of root resorption compared to internationalConclusion: studies on the subject, following a similar pattern in terms of their affected surface in the root thirds.

Detection of oral biomarkers as a diagnostic tool for orthodontically induced inflammatory root resorption: a literature review / Detección de biomarcadores orales como herramienta de diagnóstico para la reabsorción radicular inflamatoria inducida ortodónticamente: una revisión de la literatura

ABSTRACT Orthodontically induced inflammatory root resorption (OIIRR) is one of the most common complications of orthodontic treatment. Historically, only radiographic methods were available, while offering ease of use and accessibility, many limitations exist. Problems of technique, standardization, limited points of view and radiation exposure remain. Resorption can only be detected after a significant portion of the root has been lost (60% to 70% mineralized tissue). Moreover, these methods are static and cannot indicate if the process of root resorption has arrested or is ongoing. Recently, oral fluids have been used as a tool for the diagnosis and monitoring of oral and systemic diseases through the detection of biomarkers. The purpose of this review is to describe the scientific evidence related to the prevalence, etiology, the traditional diagnostic methods and the advances in the detection of oral biomarkers through molecular biology for this pathology.

RESUMEN La reabsorción radicular inflamatoria inducida ortodónticamente (RRIIO) es una de las complicaciones más comunes del tratamiento de Ortodoncia. Históricamente, solo estaban disponibles los medios radiográficos para detectarla, sin embargo, requieren de exposición a radiaciones ionizantes potencialmente dañinas, la técnica radiográfica es sensible, detecta la reabsorción después de que se ha perdido una porción significativa de la raíz (60% al 70% del tejido mineralizado) y no proporciona información sobre su actividad. Recientemente, los fluidos orales vienen siendo utilizados como herramienta para el diagnóstico y monitoreo de enfermedades orales y sistémicas mediante la detección de biomarcadores. El propósito de esta revisión es describir la evidencia científica relacionada con la prevalencia y etiología, los métodos diagnósticos tradicionales y los avances en la detección de biomarcadores orales mediante biología molecular.

Novel management of internal root resorption with vertical root fracture using mineral trioxide aggregate - A case report

Introduction: This case report presents the diagnosis and management of extensive internal root resorption (IRR) in a 17?year?old male patient, with a 9?year?old history of trauma. Method: The affected tooth 21 was associated with vertical root fracture (VRF) and incomplete apex closure with a substantial loss of tooth structure, including dentin and cementum. Encouraged by a healthy periodontal condition, the choice was made to use mineral trioxide aggregate (MTA) to reconstruct and reinforce the resorptive defect and the fractured segment. A composite veneer was placed to enhance the aesthetics. Result: A follow?up of the patient after 2 years revealed healing with a resolution of the lesion. Conclusion: This case report highlights the use of MTA as a lone?standing filling material for the treatment of IRR with VRF in a non?vital immature tooth