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.

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.

Cone beam computed tomography for the diagnosis of external root resorption associated with orthodontic treatment: A review / Tomografía computarizada de haz cónico para el diagnóstico de la reabsorción radicular externa asociada al tratamiento de ortodoncia. Una revisión

External root resorption (ERR) is a highly prevalent, multifactorial problem frequently associated with orthodontic treatment. Treatment is complex due to the lack of solid knowledge regarding predisposing factors, systematic management for diagnosis and follow-up protocols or the fundamental theoretical bases of adequate imaging tools for each situation.This review describes the indications of the use of cone beam computed tomography (CBCT) and the factors related to its development and the characteristics of the techniques used in the diagnosis and monitoring of ERR in orthodontics. We compared the advantages and disadvantages of CBCT based on the risk/benefits. Methods: We have reviewed and summarized the information and the risk factors available on ERR in orthodontics and the use of CBCT in the diagnosis and follow-up of ERR with the aim of developing a management protocol. Likewise, CBCT is compared with other imaging techniques frequently used in ERR. The articles reviewed in this study coincide in terms of the advantages of precision of CBCT in the detection and linear and volumetric measurement of ERR associated with orthodontics over two-dimensional techniques. However, CBCT cannot completely replace other imaging techniques since its effectiveness is not significantly greater in cases with moderate ERR compromise. The use of CBCT should be optimized following specific criteria for its application. (AU)

La reabsorción radicular externa (RRE) es un problema frecuentemente asociado con el tratamiento de ortodoncia, de alta prevalencia, multifactorial y de considerable complejidad cuando se carece de conocimiento sólido respecto de los factores predisponentes, el manejo sistemático para el diagnóstico y el protocolo de seguimiento, además de bases teóricas fundamentales en cuanto a herramientas imagenológicas adecuadas para cada situación.El presente estudio tiene como objetivo describir las indicaciones para el uso de la tomografía computarizada de haz cónico (TCHC) para el diagnóstico y el seguimiento de la RRE asociada a ortodoncia, considerando factores informados en la literatura que intervienen en su desarrollo y en las características de las técnicas imagenológicas utilizadas, comparando sus ventajas y desventajas fundamentadas en el valor de riesgo/beneficio. La información descrita sobre RRE asociada a ortodoncia, factores de riesgo y uso de TCHC para el diagnóstico y seguimiento sugerido en la literatura se revisó y resumió para ser orientada hacia un protocolo de manejo. Asimismo, se realizaron comparaciones con otras técnicas imagenológicas frecuentemente utilizadas con el mismo propósito. Los artículos revisados en este estudio concuerdan en cuanto a las ventajas de precisión en la detección y en la medición lineal y volumétrica de la RRE asociada a ortodoncia, respecto de las técnicas bidimensionales; sin embargo, ya que las diferencias en términos de modificación del plan de tratamiento como consecuencia del hallazgo resultan ser poco significativas en situaciones de compromiso moderado. El uso de la TCHC debe optimizarse siguiendo criterios específicos para su aplicación. (AU)

Lateral and apical root resorption in teeth orthodontically moved into edentulous ridge areas

ABSTRACT Objective: The present study aimed at comparing the external lateral root resorption (ELRR) and external apical root resorption (EARR) between teeth moved through the atrophic edentulous ridge and those undergoing the usual orthodontic movement. Methods: Fifty-four premolars were evaluated, where 27 of them had been moved toward the edentulous ridge (Group 1) and 27 from the same patient, had not been translated, which comprised the control group (Group 2). ELRR was evaluated by 0-3 scores and EARR was evaluated by 0-4 scores, before and after movement. Measurements were compared by Kruskal-Wallis and Student-Newman-Keuls tests. Results: ELRR increased statistically only in the Group 1 (p< 0.05). After orthodontic treatment, it was observed that almost 56% (n = 15) of teeth in Group 1 presented scores 2 and 3, while Group 2 presented scores 2 and 3 in about 11% (n= 3) of the teeth. EARR increased in both groups after orthodontic movement, however, statistically analyses showed no significant differences between groups (p> 0.05). Conclusions: Orthodontic movement into the atrophic edentulous ridge is subject to a greater lateral external root resorption.

RESUMO Objetivo: O presente estudo teve como objetivo comparar a reabsorção radicular lateral externa (RRLE) e a reabsorção radicular apical externa (RRAE) em dentes movimentados sobre o rebordo edêntulo atrófico e naqueles submetidos à movimentação ortodôntica usual. Métodos: Foram avaliados 54 pré-molares, sendo 27 deles movimentados em direção ao rebordo edêntulo (Grupo 1) e 27 (dos mesmos pacientes) não transladados, que compuseram o grupo controle (Grupo 2). A RRLE foi avaliada por meio de escores de 0 a 3, e a RRAE foi avaliada por meio de escores de 0 a 4, antes e depois do tratamento. As medidas foram comparadas por meio dos testes de Kruskal-Wallis e de Student-Newman-Keuls. Resultados: O escore da RRLE aumentou estatisticamente apenas no Grupo 1 (p< 0,05). Após o tratamento ortodôntico, observou-se que quase 56% (n = 15) dos dentes do Grupo 1 apresentaram escores 2 e 3, enquanto o Grupo 2 apresentou escores 2 e 3 em cerca de 11% (n = 3) dos dentes. O escore da RRAE aumentou em ambos os grupos após a movimentação ortodôntica; entretanto, as análises estatísticas não mostraram diferenças significativas entre os grupos (p> 0,05). Conclusões: Dentes submetidos à movimentação ortodôntica sobre rebordo edêntulo atrófico estão sujeitos a uma maior reabsorção radicular externa lateral.

Reabsorções radiculares externas inflamatórias em dentes permanentes reimplantados: determinantes clínicos e epigenéticos / Reabsorções radiculares externas inflamatórias em dentes permanentes reimplantados: determinantes demográficos, clínicos e genético / Evaluation of Clinical Determinants and DNA Methylation profile in Inflammatory External Root Resorption in Replanted Permanent Teeth

A reabsorção radicular externa inflamatória (RREI) é um processo patológico definido como a perda progressiva de tecido mineralizado radicular, dentina e cemento, resultante da combinação entre a lesão às camadas protetoras da superfície externa da raiz e a presença de microrganismos no interior do sistema de canais radiculares. Estudos clínicos demonstraram o papel da idade e de fatores relacionados ao manejo e tratamento do dente avulsionado na etiopatogenia e evolução das RREI após reimplantes. Entretanto, não existem informações sobre a interação destes fatores, bem como poucos estudos avaliaram a influência do perfil genético e imunológico do paciente no padrão de cicatrização após reimplantes dentários. O presente estudo objetivou (1) avaliar a interação de fatores prognósticos para o desenvolvimento da RREI após o reimplante de dentes permanentes, bem como (2) investigar o papel da epigenética nos processos imunomediados das RREI pós-traumáticas. Para estudo dos determinantes clínicos e suas interações, o universo da pesquisa envolveu 427 pacientes (idade média de 12,6 anos) portadores de 581 dentes permanentes reimplantados, com rizogênese completa no momento do trauma, tratados na Clínica de Traumatismos dentários da Faculdade de Odontologia da Universidade Federal de Minas Gerais entre 1994 e 2018. Dados relativos à idade do paciente no momento do trauma, grau de rizogênese, condições de armazenamento e período extra alveolar do dente avulsionado, uso de antibioticoterapia sistêmica, tempo decorrido entre o reimplante e o início da terapia endodôntica radical (TER) e a duração do período de imobilização foram coletados dos prontuários dos pacientes. Tomadas radiográficas realizadas na consulta de início do TER foram utilizadas para diagnóstico da atividade de reabsorção. Sinais radiográficos de RREI foram encontrados em 80,7% da amostra (469 dentes). Os resultados demonstraram que a idade do paciente no momento do trauma e o tempo decorrido até o início do TER representaram importantes fatores prognósticos para a ocorrência de RREI. Além disso foi observada uma interação quantitativa entre estas duas variáveis uma vez que o aumento na idade do paciente atenuou significativamente o efeito do tempo até o início da terapia endodôntica. Este resultado inédito evidencia a maior vulnerabilidade do paciente mais jovem e enfatiza a importância de se considerar estas duas covariáveis conjuntamente durante a tomada de decisão clínica. Para o estudo epigenético, o perfil de metilação do DNA de 22 genes envolvidos na resposta imune foi avaliado em um pool de 08 amostras de fragmentos radiculares de dentes reimplantados portadores de RREI, indicados para exodontia. O grupo controle consistiu em um pool de 06 amostras de tecido ósseo saudável coletado durante a extração cirúrgica de dentes impactados. Os padrões de metilação do DNA dos 22 genes foram quantificados utilizando EpiTect Methyl II Signature Human Cytokine Production PCR Array. Os resultados do estudo da epigenética revelou que o pool de amostras com RREI apresentou nível mais alto de metilação do DNA na região promotora da FOXP3, em comparação com o pool de osso normal (65,95% e 23,43%, respectivamente). Esta é a primeira evidência de uma possível participação de eventos epigenéticos na modulação da RREI e especula-se se o padrão hipermetilado da FOXP3 poderia estar relacionado à presença da infecção endodôntica.

Inflammatory external root resorption (IERR) is a pathological process defined as the progressive loss of root mineralized tissue, dentin and cement, resulting from both: damage to the protective layers in the root external surface and the presence of endodontic infection inside the root canal. Clinical studies have demonstrated the role of age and factors related to the management and treatment of avulsed teeth in the etiopathogenesis and progression of RREI. However, there is no information on the interaction of these factors and few studies have evaluated the influence of the patient's genetic and immunological profile on the healing pattern after dental replantation. The present study aimed to (1) evaluate the interaction of prognostic factors for the development of RREI after replantation of permanent teeth, as well as (2) to investigate the role of epigenetics in the immunomediated processes of posttraumatic RREI. To study the clinical determinants and their interactions, the sample comprised 427 patients (mean age 12.6 years) with 581 replanted mature permanent teeth treated at the Dental Trauma Clinic of the Faculty of Dentistry from the Federal University of Minas Gerais between 1994 and 2018. Patients' records were evaluated to collect data such as patient's age at the time of the trauma, storage conditions and extra alveolar period of the avulsed tooth, systemic antibiotic therapy prescription, time elapsed between reimplantation and onset of endodontic therapy (TER) and splinting timing. The presence and index of IERR was assessed radiographically at the visit of pulpectomy. Radiographic signs of IEER were found in 80.7% of the sample (469 teeth) and were absent in 19.7% of cases (112 teeth). The results showed that the patient's age at the time of the trauma and the time that elapsed until the beginning of TER represented important prognostic factors for the occurrence of RREI. In addition, a quantitative interaction was observed between these two variables since the increase in the patient's age significantly attenuated the effect of time until the beginning of endodontic therapy. This is an original result that highlights the greater vulnerability of the younger patients and emphasizes the importance of considering these two covariates together during clinical decision-making. For the epigenetic study, the DNA methylation profile of 22 genes involved in the immune response was evaluated in a pool of 08 samples of root fragments of replanted teeth with RREI, referred to extraction. The control group consisted of a pool of 06 samples of healthy bone tissue collected during surgical extraction of impacted teeth. The DNA methylation pattern was quantified using EpiTect Methyl II Signature Human Cytokine Production PCR Array. The results of the epigenetics study revealed that the sample pool with RREI showed a higher level of DNA methylation in the FOXP3 promoter region, compared to the normal bone pool (65.95% and 23.43%, respectively). This is the first evidence of a possible participation of epigenetic events in the modulation of RREI and it is speculated whether the hypermethylated pattern of FOXP3 could be related to the presence of endodontic infection.

Interdisciplinary Management of Maxillary Anterior Teeth with External Root Resorption: A Case Report

Introduction: This is a case report showing interdisciplinary management of a tooth with external and cervical root resorptionusing mineral trioxide aggregate (MTA).Case Report: A 35-year-old female with a complaint of pain in upper jaw with a history road traffic accident 8 year back.Non-surgical root canal therapy was performed with the use of calcium hydroxide and triple antibiotic paste as intracanalmedicament. About 2% chlorhexidine solution was used as the final irrigant. MTA obturation was done in both central incisors;external cervical resorption in the left central incisor was repaired by reflecting the mucoperiosteal flap and sealing with MTA:The 3-month follow-up of the present case shows satisfactory results both clinically and radiographically.Conclusion: Resorption cases has to be ruled out radiographically and clinically for successful management of these cases.Non-surgical and surgical treatment has been done hand in hand for management of this case.

Research progress on the pathogenesis of inflammatory external root resorption / 华西口腔医学杂志

Inflammatory external root resorption (IERR) refers to the pathological process of dissolving the hard tissue on the outer surface of the tooth root by the body's own immune system under the stimulation of various physical and chemical factors such as infection, stress, trauma and orthodontic treatment. Severe IERR can lead to endodontic and periodontal diseases, and even the loss of teeth. Therefore, understanding the etiology and the pathogenic mechanism of IERR are of importance in its prevention and treatment. This article will review the etiology and the regulation mechanisms of IERR.

Prognosis of teeth with external root resorption caused by adjacent impacted teeth / 华西口腔医学杂志

OBJECTIVE@#This study aimed to investigate the prognosis of permanent teeth with external root resorption (ERR) caused by adjacent impacted teeth.@*METHODS@#A total of 75 ERR teeth (permanent teeth) caused by adjacent impacted teeth of 63 patients were included. The prognosis of ERR teeth was analyzed followed by minimally invasive extraction of the adjacent impacted teeth. The time of follow-up was six months. The relationship between prognosis of ERR teeth and patients' age, gender, root number, type of root resorption and degree of root resorption were analyzed.@*RESULTS@#In the 75 ERR teeth, 67 teeth (89.3%) did not show pulpitis symptoms. The clinical outcome was found to be related with age (r=0.330, P0.05). Pulpitis symptom was not found in ERR teeth of patients under 30 years old.@*CONCLUSIONS@#For ERR teeth caused by adjacent impacted teeth, keeping the pulp vital after surgical removal of impacted teeth is highly probable. Post-operative follow-up instead of preventive root canal therapy of ERR teeth is recommended.

Polimorfismo (+3954c>T) del gen IL-1B y su asociación con la resorción radicular apical externa post-tratamiento ortodóntico / IL-1B (+3954c>T) gene polymorphism and its association with external root resorption after orthodontic treatment

El objetivo fue determinar la presencia del polimorfismo rs1143634 (+3954C>T) del gen Interleuquina 1 Beta (IL-1B) y su asociación con la resorción radicular apical externa (RRE) post-tratamiento ortodóntico. Se realizó un estudio piloto de individuos tratados con aparatología ortodontica, 13 (casos) presentaron RRE posterior al tratamiento ortodóntico y 22 (controles) estaban clínicamente sanos. A partir de muestras de células epiteliales de mucosa bucal se extrajo ADN y se genotipificó el polimorfismo rs1143634 (+3954C>T) del gen IL-1B mediante la reacción en cadena de la polimerasa y digestión del producto con la enzima de restricción TaqI. Se estimaron las frecuencias alélicas y genotípicas del rs1143634; además, se evaluó la desviación del equilibrio de Hardy-Weinberg. Las frecuencias alélicas y genotípicas se compararon mediante la prueba de c2 con razón deverosimilitud (p <0,05). El promedio de edad de los participantes fue 28,1 (DE=11,5) años y el 68,6 % era mujeres. Al comparar la distribución de los genotipos del polimorfismo IL-1B (+3954C>T) entre grupos no se encontró una diferencia estadísticamente significativa (p=0,0926). Sin embargo, se observó una diferencia significativa en la distribución de alelos (p= 0,035), siendo el alelo T (alelo 2) más prevalente en el grupo control. El polimorfismo IL-1B (+3954C>T) se encontró presente en la población de estudio. Aunque no existieron diferencias en la distribución de los genotipos que apoyara una asociación entre este polimorfismo y la RRE, si hubo una diferencia en la distribución de los alelos, sugiriendo que el alelo T posiblemente actúa como factor protector contra el desarrollo de la RRE.

The objective of this study was to determine the presence of Interleukin 1 beta (IL-1B) rs1143634 (+3954C>T) gene polymorphism and its association with external apical root resorption (ERR) after orthodontic treatment. We conducted a pilot study of individuals treated with orthodontic treatment, 13 (cases) had ERR after orthodontic treatment and 22 (controls) were clinically healthy. DNA was extracted from samples of epithelial cells from the oral cavity and IL-1B rs1143634 (+3954C>T) gene polymorphism was genotyped by polymerase chain reaction and digestion product through the TaqI restriction enzyme. Genotype and allele frequencies of rs1143634 were estimated; in addition, the deviation from Hardy-Weinberg equilibrium was assessed. Allele and genotype frequencies were compared using the c2 test with likelihood ratio (p <0.05). The mean age of participants was 28.6 (SD= 11.5) years and 68.6 % were females. No statistically significant association was found between the genotypes distribution of IL-1B (+3954C>T) polymorphism with ERR (p= 0.0926). However, a significant difference in the alleles distribution (p= 0.035) was observed, where the allele T (allele 2) was more prevalent in the control group. IL-1B (+3954C>T) polymorphism was present in the study population. Although there were no differences in the genotypes distribution to support an association between this polymorphism with ERR, there was a difference in the alleles distribution, suggesting that the allele T possibly acts as a protective factor against the development of ERR.

Reabsorción radicular externa cervical idiopática múltiple. Presentación de un caso / Externalmultipleidiopathic cervical root resorption. Report of a case

Fundamento: La reabsorción radicular externa cervical idiopática múltiple es una condición poco frecuente, se diagnostica cuando no puede atribuirse alguna causa específica que la origine. Objetivo: Divulgar un efecto no deseado y de poca frecuencia con afectación agresiva de múltiples dientes. Presentación de caso: Paciente de 48 años de edad, blanco, sexo masculino, antecedentes de hipertensión arterial, cólicos nefríticos a repetición, prostatitis, tratamiento ortodóncico fijo en el maxilar. En radiografía intraoral panorámica se observó en la mandíbula zonas radiolúcidas en mesial y distal en la región cervical de: 32, 33, 34, 35, 36, 37, que provocaron fractura a nivel coronario y confirmaron la reabsorción dentaria. Se realizó la exodoncia de los dientes afectados. Conclusiones: La reabsorción radicular externa cervical idiopática múltiple es poco frecuente, cursa asintomática, son numerosas las causas que pueden originarla, en el caso estudiado produjo afectación rápida y agresiva de múltiples dientes que provocó la exodoncia de los mismos. Realizar su correcto diagnóstico es esencial por lo que se requieren exámenes radiológicos y de laboratorio clínico para proponer protocolos de tratamiento de elección de acuerdo con el caso, en el momento oportuno y el seguimiento evolutivo.

Background: Multiple idiopathic cervical external root resorption is a rare condition, diagnosed when any specific cause can be claimed. Objective: To disseminate an unwantedandinfrequent effect with aggressive involvement of multiple teeth. Case presentation:a 48 year-old, white, male patient withhistory of hypertension, recurrent kidney stones, prostatitis and fixed orthodontic treatment in the maxillary. In intraoral panoramic radiography in the mandible was observed in mesial and distal radiolucent areas in the cervical region: 32, 33, 34, 35, 36, 37 which caused fracture at coronary level and confirmed the dental resorption. The extraction of the affected teeth was performed. Conclusions: External multiple idiopathic cervical root resorption is rare, asymptomatic, there are many causes that can lead toit; in the case studied caused rapid and aggressive involvement of multiple teeth and the extraction of them. Making the correct diagnosis is essential so that radiological and clinical laboratory tests are required to propose treatment protocols of choice according to the case, at the right time and the evolutionary follow-up.

Comparison between two tomographic sections in the diagnosis of external root resorption

OBJECTIVES: To assess the accuracy of coronal and sagittal CT sections to detect cavities simulating root resorption. MATERIAL AND METHODS: 60 mandibular incisors were embedded in plaster bases, and cavities with 0.6, 1.2 or 1.8 mm in diameter and 0.3, 0.6 or 0.9 mm in depth (small, medium and large cavities) were drilled on the buccal surfaces with high-speed round burs with diameters of 0.6, 1.2 and 1.8 mm to simulate external inflammatory root resorption. Simulations in the cervical, middle and apical thirds of each tooth root were made randomly. The Dental Scan software was used to obtain 1-mm-thick axial images from direct scanning, which were reconstructed in the coronal and sagittal planes using 3D software (Syngo FastView). Each series was loaded into the software. Fourteen images of each tooth were reconstructed in the coronal plane and 14 in the sagittal plane. A total of 1,652 images were obtained for analysis. Series information, tooth number and the plane reconstructed were stored. The images generated were saved on a CD-ROM together with the visualization software (Syngo FastView). Images were analyzed by a previously calibrated blinded, radiologist. Cochran's Q test was conducted separately for each region analyzed followed by pair-wise comparison by the McNemar test (p=0.05). RESULTS: No statistically significant difference (p>0.05) was observed in the diagnosis of simulated resorption between the apical, middle, and coronal thirds. When the axial plane was assessed separately, diagnoses were statistically different (p<0.05) among the three root thirds. The apical third differed significantly (p<0.05) from the cervical and middle thirds. Diagnostic errors were more often observed in the apical third compared to the cervical and middle thirds. Mid-sized cavities revealed no statistically significant differences (p>0.05) between planes, irrespective of the third in which the resorptions were located. CONCLUSION: When tomographic sections are requested for the diagnosis of buccal or lingual external root resorption, sagittal sections afford the best image characterization of the resorption process.

Reparo de reabsorção radicular externa associada com queratocisto odontogênico; relato de caso / Healing of external root resorption associated with odontogenic keratocyst: case report

Introduction and Objective: A case of external root resorption associated to an Odontogenic Keratocyst is presented. Case Report and Conclusion: A review of the literature revealed that this cyst is not considered a common etiological factor for external root resorption. A X-ray examination showed root resorption in the teeth involved in an odontogenic keratocyst. Root canal treatment with calcium hydroxide mixed with propylenglicol was performed. The paste was applied at definite intervals during a 10 month period. X-rays were taken at each interval. At final X-rays examination there were no signs of root resorption and the filling was completed.

Introdução e Objetivo: O presente trabalho apresenta um caso de reabsorção externa associada a um Queratocisto Odontogênico. Relato do caso e Conclusão: A revisão da literatura pertinente revelou que tal cisto não é comumente associado à reabsorção externa da raiz. Exames radiográficos apresentaram reabsorção externa da raiz nos dentes envolvidos com a lesão cística.O tratamento endodôntico instituído utilizou hidróxido de cálcio associado ao propilenoglicol aplicado como medicação intra-canal em intervalos definidos durante 10 meses. Ao final do referido período o exame radiográfico demonstrou o reparo da reabsorção.