Clinical Pathological Study On Multiple Idiopathic Cervical Root Resorption

Multiple idiopathic cervical root resorption(MICRR)is a clinical term used to describe a relatively uncommon,insidious and often aggressive form of cervical external tooth resorption.There are only 23 cases that have been reported abroad up to 2007,while Liu Rongsen published a clinical report in 2003.As previous studies were all case reports,the essence of MICRR is still lack of real understanding.This study was on the basis of two MICRRs.And we analyzed them from four aspects systematically,including clinical presentation, histopathologic features,molecular biological mechanism and clinical management.We hoped that the study can provide some useful information for clinical diagnosis and treatment of MICRR.Part 1 The clinical presentation of multiple idiopathic cervical root resorptionObjective:To report the clinical presentation of two MICRRs.Methods: Reported and analyzed the oral manifestation,general condition and radiographic image.Results:There were no significant systematic risk factors of the patients. And they had 14 and 11 involved teeth respectively which were in three different quadrants.MICRR could induce a clinically pink discoloration of the crown or even pathological root fracture.The extent of the lesion was from the coronal third of the root to the radical third of the crown,and the apical third of the root was normal.Conclusions:MICRR was a special disease which was different from other types of tooth resorption.Part 2 The histopathologic features of multiple idiopathic cervical root resorptionObjective:To clear the histopathologic features of MICRR.Methods:The removal teeth,the fibrous tissue filling in the cavity and the pulp were all studied by the pathological methods.Results:The performance of Hematoxylin-eosin stain revealed that this type of tooth resorption went straight through the cement or enamel and dept into the dentin.The resorption cavity was filled with a mass of fibrovascular tissue with active mononucleated and multinucleated classic cells. Masses of ectopic calcific tissue were evident in the fibrovascular tissue occupying the resorption cavity.And the bone-like tissue lay on the surface of the involved dentin.Ectopic calcific tissue could also be seen in the pulp.We did not observe any inflammatory cell.The performance of immunohistochemistry reveals that there were a lot of monocytes and macrophages in the fibrovascular tissue.The observation by TEM confirmed that point of view.Conclusions:The histopathologic features of MICRR was that the resorption cavity was filled with a mass of flbrovascular tissue which had a lot of monocytes and macrophages. MICRR was a process that resorption and repair were coexistence.Part 3 Molecular biological study on multiple idiopathic cervical root resorptionObjective:To investigate the relationship between MICRR and the exon 1 of TNFRSF11A gene.Methods:Genomic DNA was isolated from peripheral blood of two patients above and six health adults for polymerase chain reaction(PCR) amplification.We compared the sequence of the product with the sequence published by GenBank.Results:There was no mutation in the target gene locus of eight subjects above.Conclusions:There was no relationship between MICRR and the exon 1 ofTNFRSF11A gene.Part 4 The clinical management of multiple idiopathic cervical root resorptionObjective:To explore the clinical management of MICRR and evaluate its efficacy.Methods:The involved teeth of one patient above were treated by surgical and non-surgical management.Results:Among the ten teeth that had been treated,one was removed because of periodontal abscess and others remained.Conclusions:The exploration of the clinical management of MICRR revealed that proper intervention treatment could stop the resorption.