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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

Comparative Evaluation of Duration of Extraction Space Closure and Degree of Root Resorption with Conventional and Self-Ligation Brackets

Introduction: Determination of difference between conventional and passive self?ligating brackets (SLBs) in respect of extraction space closure, patient perception and root resorption. Material and Methods: Eighty patients were divided into four groups of 20 each with age?sex?matched control using a simple randomisation technique and allocation concealment with a closed opaque envelope method. Group 1 consisted of conventional brackets with Connecticut New Archwire (CNA) wire mushroom loop, group 2 consisted of conventional brackets with TAD (AbsoAnchor, Korea) supported retraction, group 3 consisted of passive SLB with CNA archwires (Libral Traders, India) mushroom loop and group 4 consisted of passive SLB brackets with TAD (AbsoAnchor, Korea) supported retraction. The rate of retraction, root resorption and patient satisfaction were assessed. All conventional brackets (Orthox, USA) and passive SLBs (CaptainOrtho, India) had 0.018 Roth prescriptions with a slot size of 0.018 × 0.025. Results: Retraction was the fastest in group 2 with a mean of 1.266 ± 0.14 mm/4 week and a duration of 23.40 weeks. Similarly, group 4 showed the most sluggish movement with a mean of 1.182 ± 0.80 mm/4 weeks with a total duration of 25 weeks; howeverdifferencesce among groups were not statistically significant (P = 0.470). Conclusion: SLBs have advantage of better patient comfort, less pain and reduced chairside time. Though the present study found increased treatment duration with SLB along with friction mechanics, refuting the previous claims of reduced friction with SLBs, however, the difference was not statistically significant and results have to be extrapolated with caution and experience considering other advantages of SLBs.

An unusual repair of perforating internal inflammatory root resorption; a case report of endodontic treatment

Internal inflammatory root resorption (IIRR) can occur as a serious complication of dental trauma which leads to progressive loss of the root structure. An early diagnosis could influence the therapeutic approach, but endodontic treatment becomes a challenge with a doubtful prognosis. The present report described an unusual clinical presentation of an IIRR with perforation resulting from a trauma four years previous. A 15-year-old female patient was presented to our service with pain in the maxillary incisor region. Intraoral radiography revealed a large radioloucent area compatible with IIRR, communicating with the periodontium in the middle third on the distal root face of the right central incisor. The root canal of the right central incisor was chemo-mechanically prepared. The calcium hydroxide (CH) intracanal medication was used and renewed periodically four times. The root canal was filled only in the cervical region to the level of resorption by the inverted gutta-percha cone technique. Clinically and radiographically, all follow-up examinations revealed an asymptomatic tooth, evidencing periapical tissue repair and new bone formation. The tooth remained asymptomatic 3 years afterwards. The present case report supports the idea of executing satisfactory intracanal decontamination by chemo-mechanical preparation, thus creating a favourable environment for tissue repair.

Influence of clinical factors, IL4 and IL6 genes polymorphisms in functional healing in late replantation

Abstract To investigate the genetic association in a sample of replanted teeth, it is necessary to observe the extreme phenotypes, such as, teeth that underwent functional healing and those extracted due to severe external root resorption. Thus, this study aimed to investigate the association of age of the patients, root development, storage media, and polymorphisms in the interleukin 4 (IL4) and interleukin 6 (IL6) genes with teeth that presented extreme outcomes, as functional healing or extraction, in a group whose replantation techniques did not follow the International Association of Dental Traumatology (IADT) 2012 guidelines. Forty-three avulsed and replanted teeth that did not follow IADT 2012 guidelines and underwent functional healing or were extracted were included. Periapical radiographs employed for this study were taken soon after tooth replantation and after 1 year. For genotypic IL4 and IL6 genes analysis, DNA of oral mucosa cells was extracted. Real-time- PCR performed for genotyping polymorphisms in IL4 and IL6 genes. Clinical and genetic variables were analyzed by the Chi-square test and the "Z" test. P values < .05 were considered significant. The results showed that functional healing and extraction were associated with storage media and with the rs2243268 of IL- 4 gene polymorphisms. As conclusion, the C rs2243268 allele of IL4 gene may have a positive relationship with functional healing teeth that were replanted not following the 2012 IADT guidelines. Keeping the tooth dry is associated to a fast loss of avulsed and replanted teeth after 1-year follow-up.

Resumo Para investigar a influência genética em uma amostra de dentes reimplantados, é necessário observar os fenótipos extremos, como os dentes que sofreram cura funcional e os extraídos devido à reabsorção radicular externa severa. Assim, este estudo teve como objetivo investigar a associação da idade dos pacientes, desenvolvimento radicular dos dentes, assim como o meio de transporte até o reimplante e polimorfismos nos genes da interleucina 4 (IL4) e da interleucina 6 (IL6) com dentes que apresentaram cura funcional ou extração, em um grupo cujas técnicas de reimplante não seguiu a International Association of Dental Traumatology (IADT) 2012. Foram incluídos 43 dentes avulsionados e reimplantados que não seguiram as diretrizes do IADT, e tiveram cura funcional ou foram extraídos. As radiografias periapicais utilizadas para este estudo foram feitas logo após o reimplante dentário e após 1 ano. Para a análise genotípica dos genes IL4 e IL6, foi extraído DNA de células da mucosa oral. PCR em tempo real realizou a análise dos polimorfismos dos genes. As variáveis ​​clínicas e genéticas foram analisadas pelos testes Qui-quadrado e "Z". Valores de p <0,05 foram considerados significativos. Os resultados mostraram que a cura ou perda dos dentes está associada ao meio de armazenamento e polimorfismos no gene rs2243268 da IL-4. Como conclusão, o alelo C rs2243268 do gene IL4 pode ter uma relação positiva com a cura functional do dente reimplantado. Manter o dente seco está associado a uma perda rápida de dentes avulsionados e reimplantados que não seguiram o IADT 2012.

Quantitative Assessment of Dentine Sialophosphoprotein, Aspartate Aminotransferase and Lactate Dehydrogenase in Gingival Crevicular Fluid of Teeth with Root Resorption

ABSTRACT@#Root resorption is a shortening of root dentine which occurs physiologically in deciduous teeth. The present study aimed to quantify dentine sialophosphoprotein (DSPP), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) in gingival crevicular fluid (GCF) during the physiological process of root resorption of deciduous teeth. A cross-sectional study was conducted with 25 children aged between 4 and 10 years old. GCF was collected from the gingival sulcus using periopaper strips from the upper first deciduous molar (n = 45). The samples were divided equally into three groups, no resorption (R0), moderate resorption (RM) and severe resorption (RS), based on the existing radiographs taken. The GCF samples were then analysed using an enzyme-linked immunosorbent assay (ELISA) kit to determine the DSPP concentration levels and BioAssays System kit for AST and LDH. One-way ANOVA was used to determine the statistical differences between the means of the DSPP, AST and LDH concentration level in the three groups. A difference was considered significant when p < 0.05. High concentration levels of DSPP were significantly noted in RS (p < 0.05), compared to RM and R0. AST also portrayed significant high activity level (p < 0.05) similar to DSPP but LDH showed no significant changes between groups (p > 0.05). The high quantification of DSPP and AST levels in the severe and moderately resorbed roots indicated the potential use of this protein as a biomarker for detecting moderate-severe stages of root resorption.

External apical root resorption after orthodontic treatment: analysis in different chronological periods

ABSTRACT Introduction: External apical root resorption (EARR) is characterized by the definitive loss of tooth root structure, with a higher incidence in lateral and central maxillary incisors. Objective: To identify, in different chronological periods, the incidence of EARR in the maxillary incisors (MI) of patients orthodontically treated with or without premolars extraction. Methods: Periapical radiographs before and after orthodontic treatment of 1,304 MIs from 326 patients (205 women and 121 men) were evaluated for EARR, divided into five groups, according to the chronological period in which treatments were started: G90) from 1990 to 1994, G95) from 1995 to 1999, G00) from 2000 to 2004, G05) from 2005 to 2009, G10) from 2010 to 2015. The evaluation was performed in each group, in patients who underwent maxillary first premolars extraction and those who did not. For statistical analysis, Fisher's exact test was used, with a significance level of p < 0.05. The EARR was measured using the adapted Levander and Malmgren classification. Results: Incidence of EARR was higher in MIs of patients treated with maxillary premolar extraction (p < 0.05) in two chronological periods (G00 and G10), also being influenced by orthodontic treatments with longer duration, and due to possible individual genetic factors. Conclusion: Even with the limitations of a retrospective study, the lack of a defined EARR pattern in the MIs at different chronological periods was larger in the experimental group, due to the sum of factors such as premolars extraction, prolonged orthodontic treatment, possible genetic characteristics, and root shape, without the influence of the sex and age.

RESUMO Introdução: A reabsorção radicular apical externa (RRAE) é caracterizada pela perda definitiva da estrutura dentária na região radicular, com maior incidência em incisivos centrais e laterais superiores. Objetivo: Identificar, em diferentes períodos cronológicos, a incidência de RRAE em incisivos superiores (IS) de pacientes tratados ortodonticamente com e sem extração de pré-molares. Métodos: Por meio de radiografias periapicais antes e após o tratamento ortodôntico, 1.304 IS de 326 pacientes (205 mulheres e 121 homens) foram avaliados quanto à RRAE, divididos em cinco grupos, de acordo com o período cronológico em que os tratamentos foram iniciados: G90) de 1990 a 1994; G95) de 1995 a 1999; G00) de 2000 a 2004; G05) de 2005 a 2009; e G10) de 2010 a 2015. Em cada grupo, foi realizada avaliação nos pacientes submetidos à extração dos primeiros pré-molares superiores e nos que não foram. Para análise estatística, foi utilizado o teste exato de Fisher, com p< 0,05; a RRAE foi mensurada por meio da classificação de Levander e Malmgren modificada. Resultados: A incidência da RRAE foi maior em IS de pacientes tratados com extrações de pré-molares (p< 0,05) em dois períodos cronológicos (G00 e G10), além de ter sido influenciada por tratamentos ortodônticos de maior duração e por possíveis fatores genéticos individuais. Conclusão: Mesmo com as limitações de um estudo retrospectivo, a ausência de um padrão definido de RRAE nos IS nos diferentes períodos cronológicos foi maior no grupo experimental, devido à soma de fatores, como extração de pré-molares, tratamento ortodôntico prolongado, possíveis características genéticas e morfologia radicular, sem influência do sexo e da idade.

Root resorption pattern in panoramic radiographs of pediatric patients with unilateral posterior crossbite: a cross-sectional and retrospective study / Patrón de reabsorción radicular en radiografías panorámicas de pacientes pediátricos con mordida cruzada posterior unilateral: estudio transversal y retrospectivo

SUMMARY: temporary mandibular molars in panoramic radiographs of pediatric patients with unilateral posterior crossbite (UPCB). This cross-sectional and retrospective study analyzed 114 orthopantomograms of patients between 6 - 9 years of age with unilateral posterior crossbite diagnosis. The first and second mandibular molars were analyzed. Their root resorption stage was typified, and the root lengths were measured; to later compare the data obtained depending on the malocclusion side. 86.4 % of molars showed a linear resorption pattern, and atypical resorption prevalence in patients with UPCB was 13.5 %. The total length average of the first molars on the side of the malocclusion was 8.20 mm, while the contralateral exhibited a mean of 9.29 mm. Lastly, the second molars had a mean length of 11.12 mm in crossbite side and 12.30 mm in the normal occlusion side. UPCB could affect physiological resorption by observing a resorption alteration in those mandibular molars located on the malocclusion side.

RESUMEN: El trabajo de este estudio se realizó en molares mandibulares temporales en radiografías panorámicas de pacientes pediátricos con mordida cruzada posterior unilateral (MCPU). Este estudio transversal y retrospectivo analizó 114 ortopantomografías de pacientes entre 6 - 9 años de edad con diagnóstico de mordida cruzada posterior unilateral. Se analizaron los primeros y segundos molares mandibulares. Se tipificó su estado de reabsorción radicular y se midió la longitud de las raíces; para luego comparar los datos obtenidos según el lado de la maloclusión. El 86,4 % de los molares mostró un patrón de reabsorción lineal y la prevalencia de reabsorción atípica en pacientes con MCPU fue del 13,5 %. El promedio de longitud total de los primeros molares del lado de la maloclusión fue de 8,20 mm, mientras que el contralateral exhibió una media de 9,29 mm. Por último, los segundos molares tenían una longitud media de 11,12 mm en el lado de mordida cruzada y de 12,30 mm en el lado de oclusión normal. La MCPU podría afectar la reabsorción fisiológica al observar una alteración de la reabsorción en aquellos molares mandibulares ubicados en el lado de la maloclusión.

Immunohistochemistry of resorption and inflammation factors in the periodontal ligament of human deciduous teeth

Abstract: The understanding of the biological mechanisms involved in root resorption in deciduous teeth is important to the future development of preventive measures and treatments of this condition. The aim of the present study was to compare the expression and immunostaining of iNOS, MMP-9, OPG and RANKL in the periodontal ligament (PDL) of deciduous teeth with physiologic root resorption (GI), inflammatory pathological root resorption (GII) and permanent teeth (GIII), the negative control. Teeth in GI (n = 10), GII (n = 10) and (GIII) (n = 10) were submitted to immunohistochemical analysis to determine the expression of iNOS, MMP-9, OPG, and RANKL. The immunostaining was analysed by optical density. Statistical analysis included one-way ANOVA, followed by Student-Newman-Keuls post hoc test (p < 0.05). The results showed that iNOS, MMP-9 and RANKL expression in the PDL was higher in GII compared to GI and GIII (p < 0.05). Moreover, RANKL expression was higher in GI compared to GIII (p < 0.001), while OPG immunolabelling was lower in GII compared to GI and GIII (p < 0.001). The PDL of deciduous teeth bearing inflammatory processed exhibited upregulation of resorption-associated factors as well as enzymes related to tissue degradation which, in turn explains the exacerbation and greater susceptibility of those teeth to root resorption process.