External Root Resorption Research Articles

Application of High-Frequency Conduction for Persistent Apical Periodontitis: A Case Report

We report the case of a 39-year-old male with Persistent Apical Periodontitis (PAP) caused by infection in an uninstrumented area, wherein conventional chemical root canal treatment is not possible, which was sterilized via highfrequency conduction. He underwent root canal filling after multiple endodontic treatments for tooth #4. As symptoms recurred, he was referred to our department with the chief complaint of dull pain during mastication. Present symptoms were percussion pain of the tooth, buccal mucosa swelling at the apical portion, and grade 1 mobility. Radiography revealed inadequate root canal filling. A radiolucent image 5×6 mm in diameter and with an unclear boundary was observed around the apex. External root resorption was mainly observed in the apical foramen, with a crown root ratio of approximately 1:1. Using 6% sodium hypochlorite under dental microscopy, chemomechanical root canal preparation was performed. Passive ultrasonic irrigation and calcium hydroxide application were conducted three times; however, periapical tissue inflammation did not subside. Therefore, the patient was diagnosed with PAP, and the uninstrumented area was sterilized via high-frequency conduction. High-frequency currents were applied to the apex, root surface, and periapical lesion at 500 kHz and 90 V; periapical tissue inflammation resolved after 2 weeks. Subsequently, the root canal was filled. Follow-up radiography revealed a bone regeneration-like image at 2 months. Bone defects healed at 11 months. Although surgical endodontic therapy is conventionally performed in PAP patients, high-frequency conduction could be a minimally invasive nonsurgical endodontic treatment option for uninstrumented areas in PAP patients.

Frequency and risk factors of root resorption in endodontic practice

The frequency of root resorption and correlated factors in patients were seen at the Endodontics Clinic of the Universidade Federal da Bahia. Objective: To evaluate the clinical and radiographic features of endodontic root resorption, considering that it is important to further our knowledge about root resorption frequency and pathogenesis. Material and methods: A cross[1]sectional study was conducted with a representative sample of 120 teeth indicated for endodontic treatment. Clinical and radiographic evaluation was accomplished to detect the presence and type of root resorption, etiology, presence of caries, dental trauma, and periapical lesion. Gender and affected teeth were also collected. The data were analyzed by the χ2 test, Fisher’s exact test, and multiple logistic regression (p < 0.05). Results: A total of 53 teeth presented with root resorption. Female and the maxillary incisors were the most affected. Inflammatory root resorption was the most prevalent resorption type (p = 0.0013), and the apical third was the most affected portion (p = 0.001). Conclusion: There was a significant occurrence of external inflammatory root resorption in the apical third of the root. A large follow-up of these patients is necessary for preventing undesirable tooth loss.

Expression of matrix metalloproteinases 2 and 9 in replanted teeth with external root resorption: A cross-sectional study

ObjectiveTo evaluate matrix metalloproteinase (MMP) expression in replanted permanent teeth with external root resorption (ERR). DesignThe present cross-sectional study included 42 patients with replanted permanent teeth, presenting with progressive forms of ERR, and referred for extraction according to the rehabilitation treatment plan or due to root fractures. The control group consisted of 12 healthy premolars, from 5 patients with good periodontal health and no radiographic evidence of root resorption, referred for extraction for orthodontic reasons. Root fragments were processed soon after extraction, and the supernatant was collected to measure matrix metalloproteinase 2/tissue inhibitor of metalloproteinase 2 (MMP-2/TIMP-2) and matrix metalloproteinase 9/tissue inhibitor of metalloproteinases 2 (MMP-9/TIMP-2) complexes through a double-ligand enzyme-linked immunosorbent assay (ELISA). ResultsCase groups with external inflammatory root resorption (EIRR) or external replacement root resorption (ERRR) showed significantly higher levels of MMP-2/TIMP-2 and MMP-9/TIMP-2 complexes than the control group. Additionally, comparisons between the case groups demonstrated that the MMP-2/TIMP-2 complex also had significantly higher levels in the ERRR group (p < 0.001). ConclusionsOur results suggest that MMP-2 and MMP-9 participate in the pathobiology of both types of ERR. In addition, the higher levels of MMP-2/TIMP-2 complex in the ERRR group support common modulation mechanisms with physiological bone turnover.

The Radiological Assessment of Root Features and Periodontal Structures in Endodontically Treated Teeth Subjected to Forces Generated by Fixed Orthodontic Appliances. A Prospective, Clinical Cohort Study.

The various side effects of orthodontic treatment with fixed orthodontic appliances (FOAs) and their impact on apical and periodontal structures have been widely reported. However, the existing data is not yet conclusive. Aims and objectives: To investigate the status of roots and periodontium in endodontically treated teeth that have undergone orthodontic treatment with the use of FOAs and to evaluate their impact on apical/periodontal structures. Material and methods: The prospective clinical cohort study initially involved 69 participants aged 16–40, without underlying systemic conditions, who received orthodontic treatment with ligatureless FOA systems due to different types of mild and moderate malocclusions. To meet the required criteria, 88 teeth in 34 patients were assessed clinically and radiologically. Participants had at least one tooth treated endodontically while the corresponding tooth from the same anatomical group on the opposite side was vital and intact (a ‘split-mouth’ approach). Four cohorts were allocated: Group IA consisted of 15 teeth, treated utilising the principles of modern endodontics, that were subjected to orthodontic forces no less than six months after completing the root canal obturation. Group I consisted of 13 similarly endodontically treated teeth, which commenced orthodontic treatment at least six months after the completed endodontic therapy. Group II contained 16 teeth treated by conventional endodontic methods and the control group, Group III, contained 44 clinically and radiologically intact teeth (incisors and premolars) with vital and sound dental pulp. The response of apical and periodontal structures to FOAs was determined by data collected from intraoral periapical radiographs taken within the course of five consecutive appointments during the orthodontic treatment. Results: No statistically significant differences were observed in susceptibility to FOA-induced external apical root resorption (EARR) between combined Groups IA + IB and II. An association was, however, demonstrated, between the occurrence of EARR and the degree of expansion of the periodontal ligament (PDL) space, regardless the method of root canal treatment. Cumulative data revealed a positive correlation between the width of the PDL space and the stage of FOA treatment (the third and the fourth appointment). The subtle changes in radiological length of roots have been observed (min 0 mm/max 0.38 mm), particularly between the second and third appointment in Group II (p < 0.05). Conclusions: The standard orthodontic therapy with FOAs is a safe option with predictable outcome for persons who have recently received endodontic therapy. The anterior teeth, predominantly incisors, were more susceptible to minimal EARR than premolars, which suggests that the rate of EARR occurrence may depend upon the original morphology of the apical portion of the root. The use of additional orthodontic forces increases the risk of EARR and is associated with a higher incidence of radiologically detected PDL space widening.

Prognostic markers of post-traumatic dental external root resorption in children-a pilot study.

External inflammatory root resorption (EIRR) is a frequent complication of traumatic dental injuries (TDI). The aim of this cohort study was to identify novel non-invasive markers of post-traumatic EIRR by assessing the changes in the pulp's blood flow and the composition of gingival sulcus fluid (GCF) in children after dental trauma. Thirty-two children were enrolled and assessed within 48h of a TDI to their permanent incisors and during an additional three visits over a 6-months follow up period. During each visit, a radiograph and laser Doppler flow (LDF) measurements of the pulp blood flow were performed on the injured tooth, and the GCF was sampled. The permanent first molar tooth of the same subject served as a control for the LDF measurements and the GCF sampling. Concentrations of IL-1α in the GCF were measured using enzyme-linked immunosorbent assays. Radiographs were used to confirm EIRR. EIRR occurred in fourteen (43.8%) teeth in 32 patients. The teeth with EIRR showed diminished LDF readings when compared with controls at all visits. The LDF readings of the injured teeth continued to decrease at follow up visits. In the EIRR group, levels of IL-1α in the GCF of teeth with EIRR were increased and significantly higher than those of the control teeth at the visit when EIRR was diagnosed. The IL-1α levels were significantly higher in the EIRR group when compared to the injured teeth of patients without EIRR at the last follow-up visit. The occurrence of EIRR after mechanical trauma of permanent teeth with complete root development is accompanied by a significant reduction in the blood flow of the tooth's pulp. It is accompanied by an increase in concentrations of IL-1α in the GCF of EIRR affected teeth. The results of this pilot study identified the use of IL-1α in GCF and LDF as non-invasive markers of EIRR.

External root resorption in common odontogenic cysts and ameloblastomas of the jaw: A retrospective radiographic study in an Asian population

AbstractAimTo evaluate the frequency of external root resorption on adjacent teeth of common cysts and ameloblastomas of the jaw in an Asian population and to investigate the association of size or location of the lesions on such root resorption potential.Material and methodsA retrospective radiographic study using cone beam computed tomography (CBCT) scans to examine the frequency of external root resorption (ERR) of teeth in proximity of 160 lesions comprising periapical radicular cysts, dentigerous cysts, odontogenic keratocysts and ameloblastomas was carried out. Fisher's exact test, Pearson's chi square test and logistic regression analysis were used to investigate differences in the frequency of ERR of teeth adjacent to these lesions and to assess the association of the size or location of the lesions on such root resorption potential.Results and conclusionsThere were 40% of lesions located in the maxilla and 60% in the mandible. Adjacent teeth ERR was noted in 61 (38.1%) lesions. Compared with odontogenic keratocysts, ameloblastomas were eight times more likely (p = 0.005) and dentigerous cysts were three times more likely (p = 0.028) to be associated with ERR after adjusting for the size and location of the lesion. Location and size of a lesion did not influence the prevalence of adjacent teeth ERR. The four types of lesions studied exhibit different frequencies of ERR in adjacent teeth. Based on this study, the presence of ERR in adjacent teeth is a useful supportive measure in the diagnosis of these lesions.

External apical root resorption after orthodontic treatment: Incidence, severity and risk factors.

Background. This study aimed to evaluate the incidence and severity of orthodontically induced inflammatory external apical root resorption (OIIEARR) and the relationship between OIIEARR and possible risk factors such as orthodontic treatment type, treatment duration, gender, and age of the patients. A further aim was to determine the prevalence of OIIEARR in different tooth groups. Methods. The study sample consisted of 1356 orthodontically treated patients (857 females and 498 males; mean age: 14.4±2.8 years). OIIEARR was evaluated using pre- and post-treatment panoramic radiographs for all the tooth groups. Teeth with severe resorption were also assessed. Patient- and treatment-related risk factors for OIIEARR were assessed statistically using Pearson’s chi-squared test, independent-samples t test, and one-way ANOVA. Results. The incidence of severe root resorption following orthodontic treatment was 14.8%. Males exhibited a higher incidence of root resorption compared to females. Orthodontic treatment duration and treatment with extractions were positively correlated with OIIEARR (P < 0.05). OIIEARR was observed most frequently in maxillary incisors, followed by mandibular incisors. Conclusion. Orthodontic treatment with extraction, prolonged treatment duration, and large movements of the incisors should especially be taken into consideration for OIIEARR risk. Routine radiographic follow-up during orthodontic treatment is recommended.

Diagnosis of cracked teeth using cone-beam computed tomography: literature review and clinical experience

Cone-beam computed tomography (CBCT) has been widely used in diagnosis of vertical root fractures (VRFs) in recent years. According to the American Association of Endodontists (AAE) classification, there are five types of cracked teeth and VRF is one of them. Due to the variability and overlapping of the cracks and fractures, some narrow fractures on the roots of VRFs could not be detected by CBCT, and some wide cracks on the crown of cracked teeth could be detected by CBCT. In this review, we firstly discussed the value of CBCT in the diagnosis of the AAE five types of cracked teeth and presented CBCT manifestations of some typical cases. Secondly, we summarized the factors influencing the diagnosis of cracks/fractures using CBCT, namely, CBCT device-related factors, patient-related factors, and evaluator-related factors. The possible strategies to improve the diagnostic accuracy in the clinic practice are also discussed in this part. Finally, we compared the differences of root fractures with lateral canals and external root resorption on CBCT images.

External Root Resorption of the Mandibular Second Molar Associated with Completely Impacted Third Molar: A Case Report and Review of the Literature

External root resorption (ERR) of permanent teeth is believed to result from mechanical or inflammatory factors, such as the force pressure of orthodontic appliances, dental trauma, cysts or tumours, chronic apical periodontitis, and poor regeneration of the periodontium in reimplanted or transplanted teeth. Another factor frequently associated with ERR of second molars is an unerupted third molar close to the root of the second molar. This type of root resorption has been observed at the site of contact with the impacted tooth, indicating that the impacted tooth's pressure participates in the resorption process. Though this resorption mechanism is not yet apparent, some investigators deem it similar to the mechanism involved in the resorption of primary teeth. This case report aims to describe a second molar resorption case triggered by an impacted third molar and perform a literature review. Key Words External Root Resorption, Mandibular third molar, Pressure resorption,

Evaluation of External Root Resorption of Endodontically Treated and Vital Teeth during Orthodontic Treatment: A Systematic Review

Evaluation of External Root Resorption of Endodontically Treated and Vital Teeth during Orthodontic Treatment: A Systematic Review

CLINICAL AND RADIOGRAPHIC EVALUATION OF INTENTIONAL REPLANTATION OF TEETH UTILIZING ATRAUMATIC EXTRACTION TECHNIQUE AND BIODENTIN AS ROOT END RESTORATIVE MATERIAL. AN IN VIVO STUDY

Aims: Aim is to evaluate the clinical and radiographic outcome of Intentional Replantation of teeth utilizing Atraumatic extraction technique and Biodentin as root end restorative material&#x0D; Materials and Methods: Any patients irrespective of age &amp; sex who reported to the Department of Conservative Dentistry &amp; Endodontics, D. J. College of Dental Sciences &amp; Research with the post endodontic treatment periapical pathology where orthograde retreatment and apical surgery was unfeasible or declined by patients and where extraction be the last resort was selected for the procedure. Informed consent was taken. Retention and healed status without complications (periapical radiolucency, external root resorption, ankylosis, signs/symptoms, probing &lt;6 mm) was recorded and analyzed with Kaplan-Meier survival analysis and Cox proportional hazard regression model (P &lt; .05). Bivariate associations of the investigated variables with the main complications (ankylosis, periapical radiolucency, external root resorption) evaluated. &#x0D; Results: Cumulative healed rates from 60% at 6 months to 92% at 12months seen. Complications leading to extraction observed in 1 of 15 attending teeth. The Kaplan-Meier survival function suggested an expected 1-year cumulative retention rate of 92%. Among the 15 teeth, 1 tooth with complication was due to persistent periapical radiolucency and mobility.&#x0D; Null hypothesis was that IR is to preserve the natural dentition, there by upholding the main goal of Conservative treatment.&#x0D; Conclusions: Within the limitations of this study, after analyzing the results and obtaining a complete follow up of 12 months radiographically and clinically, it can be concluded that Intentional replantation is an alternative treatment and should be included in the savior procedures as it has shown a success rate of 92%.&#x0D; Keywords: endodontic complications, intentional replantation, physics forceps, Biodentin

The Effect of Amitriptyline and Sertraline on the Tooth Movement, Root Resorption and Alveolar Bone Remodeling After Load Application in Dogs

Introduction: Antidepressant drugs are the most commonly prescribed classes of pharmacologic agents in the public. The drugs have been shown to have a role in the regulation of bone cell function and as a result affecting the orthodontic tooth movements. The aim of this study was to determine the effect of Amitriptyline and Sertraline on the tooth movement, root resorption and alveolar bone remodeling after load application in dogs. Materials and Methods: In this experimental study, 9 male dogs were randomly divided into three groups, first group sertraline, second group Amitriptyline and the control group (normal saline). A nickel titanium spring (200 gr) was used between second premolar and canine after 1st premolar extraction. After 2 months, the reduction of distance between 2nd premolar and canine was measured. The percentages of root resorption and bone formation were determined. The data were analyzed using repeated measures analysis at significance level of 0.05. Results: In the three groups of amitriptyline, sertraline and control, the mean of teeth movement (p value = 0.483), external root resorption (p value = 0.608), total bone mineral density (p value = 0.078), bone formation percentage (p value = 0.616) and immature and lamellar bone formation (p value = 0.083), there was no statistical difference in any group and in premolar teeth Conclusions: The rate of tooth movement and the percentages of bone formation and root resorption in dogs decreased with systemic administration of amitriptyline and sertraline; although this reduction was not statistically significant in comparison with control group.

Volumetric cone-beam computed tomography evaluation and risk factor analysis of external apical root resorption with clear aligner therapy.

To investigate the prevalence and severity of external apical root resorption (EARR) volumetrically with clear aligner therapy using cone-beam computed tomography (CBCT) as well as determine the possible risk factors and develop a prediction model for EARR. In this retrospective study, 320 incisors from 40 Class II patients treated with aligners (Invisalign) were included in this study. CBCT images were obtained at pretreatment (T0) and posttreatment (T1). Root volume was calculated by three-dimensional reconstruction of CBCT images, and apical tooth movement was measured from superimposed CBCT images. Changes in root volume were compared using paired t-tests, and the relationship between root volume loss and potential risk factors was analyzed by multiple linear regression. All of the measured incisors showed root volume loss, with an average of 11.48 ± 6.70 mm3, and the prevalence of severe resorption was 0.625%. The prediction model for EARR included variables of posttreatment sagittal root position (SRP), extraction, tooth type, and apical intrusion and extrusion displacements, with an R2 of 0.51. Age, sex, duration, pretreatment SRP, attachment, advancement, and retraction movements were excluded from the model. Most incisors showed mild to moderate resorption during aligner treatment; only a minimal percentage showed severe resorption. Posttreatment SRP (which showed the highest association with EARR), extraction, tooth type, and apical intrusion and extrusion displacements were risk factors for EARR.

Tissue-specific biomarkers in gingival crevicular fluid are correlated with external root resorption caused by constant mechanical load: an in vivo study.

This study investigated the association of changes in cementum protein-1 (CEMP-1), dentine phosphoprotein (DPP), and c-terminal cross-linked telopeptide of type I collagen (CTX-I) levels in human gingival crevicular fluid (GCF) under constant load with external root resorption volume and amount of tooth movement. In total, 11 healthy adult patients (mean age, 23.5 years [range, 18.3-37.7]; four men and seven women) were enrolled. GCF samples were obtained from premolars at T0, T1 (1 day), T2 (1 week), T3 (2 weeks), T4 (4 weeks), and T5 (8 weeks) under constant 100-gm buccal tipping force. Opposite premolars were used as controls. Teeth were extracted at T5, followed by quantification of external root resorption volume and histological analysis. In the test group, T5/T0 ratios of CEMP-1 and DPP levels, differential CEMP-1 levels between T5 and T0, and differential DPP levels between T2 and T0 correlated positively with root resorption volume (r = 0.734, 0.730, 0.627, and 0.612, respectively, all p < 0.05). CEMP-1 levels at T0 and T3 correlated negatively with root resorption volume (r = -0.603 and -0.706; all p < 0.05). CTX-I levels at T5 correlated positively with the amount of tooth movement (r = 0.848, p < 0.01). Alterations in CEMP-1 and DPP levels in human GCF at specific timepoints during orthodontic treatment may be associated with different degrees of external root resorption. This study demonstrates that changes in the levels of tissue-specific biomarkers in GCF may facilitate early detection of external root resorption during orthodontic tooth movement.

Delayed Replantation of Avulsed Teeth: A Case Report

Introduction: Dental avulsion is a severe injury in which the tooth is totally displaced out of its alveolar socket. Replantation of avulsed teeth is a standard procedure. The success of the treatment of traumatized teeth revolves around the status of periodontium since it is a vital structure. Furthermore, other factors, including extra-alveolar time period, choice of storage media, and contamination of the avulsed tooth, can determine the success of replantation. Delay in the replantation of avulsed incisors increases the risk of dentoalveolar ankylosis and replacement root resorption. Case Presentation: This case report presented a 9-year-old girl with tooth avulsion subjected to a 3-year follow-up after the replantation of avulsed maxillary central incisors kept in dry conditions for seven days. The avulsed mature permanent teeth were managed through the application of treatment guidelines with prolonged extra-oral time. The avulsed teeth were replanted and splinted for four weeks. The canals of both teeth were filled with calcium hydroxide and replaced by mineral trioxide aggregate after six months. Two months after replantation, there were signs of external root resorption in tooth 21. Conclusions: In the third year of follow-up, both teeth were infraoccluded, although they had an acceptable level of functionality and appearance. These ankylosed incisors can be managed successfully with the decoronation technique in the future.

Effect of micro-osteoperforations on external apical root resorption: A randomized controlled trial.

ObjectiveThis study aimed to investigate the effect of micro-osteoperforations (MOPs) on external apical root resorption (EARR) during the initial orthodontic alignment phase of maxillary anterior crowding.MethodsThirty patients (25 females, 5 males; mean age, 22.66 ± 3.27 years) who presented with moderate crowding of the upper labial segment and underwent extraction-based fixed appliance treatment were recruited. They were randomly allocated to receive adjunctive therapy with MOPs (n = 15) or treatment with fixed appliances only (control group; n = 15). EARR was measured from long-cone periapical radiographs taken at the start and the sixth month of treatment. A correction factor for the enlargement difference was used to calculate EARR. Data were analyzed with descriptive statistics and repeated-measures analysis of variance.ResultsThe mean root lengths of 168 teeth were measured and showed no statistically significant difference (p > 0.05) after six months of fixed appliance treatment in the MOP (mean difference [MD] = 0.13 mm; 95% confidence interval [CI] = −0.10–0.35) and control group (MD = 0.14 mm; 95% CI = −0.10–0.37). Most of the roots in the MOP and control groups (42.86% and 52.38%, respectively) showed only mild resorption. Less than 8% of the roots in both groups (7.14% in the MOP group and 4.76% in the control group) showed moderate resorption.ConclusionsAcceleration of orthodontic tooth movement with adjunctive MOPs therapy during the alignment phase does not exacerbate EARR in patients with moderate crowding of the upper labial segment in comparison with controls.

A Bioinformatics Systems Biology Analysis of the Current Oral Proteomic Biomarkers and Implications for Diagnosis and Treatment of External Root Resorption.

External root resorption (ERR) is a silent destructive phenomenon detrimental to dental health. ERR may have multiple etiologies such as infection, inflammation, traumatic injuries, pressure, mechanical stimulations, neoplastic conditions, systemic disorders, or idiopathic causes. Often, if undiagnosed and untreated, ERR can lead to the loss of the tooth or multiple teeth. Traditionally, clinicians have relied on radiographs and cone beam computed tomography (CBCT) images for the diagnosis of ERR; however, these techniques are not often precise or definitive and may require exposure of patients to more ionizing radiation than necessary. To overcome these shortcomings, there is an immense need to develop non-invasive approaches such as biomarker screening methods for rapid and precise diagnosis for ERR. In this review, we performed a literature survey for potential salivary or gingival crevicular fluid (GCF) proteomic biomarkers associated with ERR and analyzed the potential pathways leading to ERR. To the best of our knowledge, this is the first proteomics biomarker survey that connects ERR to body biofluids which represents a novel approach to diagnose and even monitor treatment progress for ERR.

Evaluation of apical root resorption occurrence in orthodontic patients treated with fixed braces depending on selected clinical parameters

Abstract An aim of the work was analysis of the possible connections between the selected clinical parameters and external apical root resorption (EARR) in patients after orthodontic treatment. The study comprised 101 persons, who underwent complex orthodontic treatment with the use of fixed braces (straight-arch technique). The teeth chosen for measurement of resorption level were central and lateral incisors of mandible and maxilla, as well as maxillary first molars, which are the most susceptible to root resorption. The roots were measured on the basis of the dental radiographs taken before and at the end of treatment. The measurements were made on digital radiographs with the use of diagnostic software (Planmeca Romexis® Viewer), which allows the image filters ensure the highest precision when localizing roots end points. Proportional measurements of the chosen teeth were made with the use of Linge’s method and Linge’s method modified by Brezniak et al. For further analysis, the persons taking part in the study were divided into two groups depending on the presence of postorthodontic EARR or its lack, resulting from radiographic measurements: a control group comprising 61 patients without EARR (with 0.90 ≤ rRCR ≤ 1.00) and a study group including 40 patients with EARR (rRCR &lt; 0.90). In statistical analysis there was used verification of statistical hypotheses based on the following tests: Pearson’s chi-squared test, Student’s t-test, Mann-Whitney U test. On the basis of the made analyses and achieved results, it was found out that age, sex, type of skeletal malocclusion, increased overjet and overbite do not constitute risk factors for EARR occurrence. Excessive proclination of central and lateral incisors of mandible and maxilla predisposes to shortening the roots of these teeth during orthodontic treatment with fixed braces (p &lt; 0.01).

Multiple Idiopathic Cervical Root Resorption: A Challenge for a Transdisciplinary Medical-Dental Team.

The goal of this perspective article is to use multiple idiopathic cervical root resorption (MICRR) as a model to demonstrate the need for transdisciplinary collaborations, from basic science to treatment planning, to improve the quality of health care for all. This is not a review of the literature on the current state of MICRR. Tooth root resorption is a normal physiological process required for resorption and exfoliation of primary teeth; however, root resorption of adult teeth is largely pathological. MICRR is an aggressive form of external root resorption, which occurs near the cemento-enamel junction (CEJ). The cause of MICRR remains elusive, however, it is mediated primarily by osteoclasts/odontoclasts. Accumulating case studies and experiments in animal models have provided insights into defining the etiologies and pathophysiological mechanisms for MICRR, which include: systemic conditions and syndromes, inherited genetic variants affecting osteoclast/odontoclast activity, altered periodontal structures, drug-induced root resorption and rebound effects after cessation of anti-resorptive treatment, chemotherapy, exposure to pets or viral infections, and other factors such as inflammatory conditions or trauma. To determine the causative factors for MICRR, as well as other oral-dental conditions, at minimum, a comprehensive health history should be collected for all patients by dental care providers, discussed with other health care providers and appropriate collaborations established. The examples highlighted in this perspective emphasize the need for transdisciplinary research collaborations coupled with integrated management strategies between medicine and dentistry in order to identify cause(s) early and improve clinical outcomes.

Comparative Evaluation of Root Resorption in Correction of Class II Malocclusion

INTRODUCTION: External apical root resorption is a common iatrogenic side effect of orthodontic treatment and has been reported particularly in anterior teeth. The etiology of resorption is multifactorial, complex and individual susceptibility to resorption depends on various factors.MATERIALS AND METHOD: The degree of root resorption during orthodontic treatment was evaluated on the post-treatment RVGs of the maxillary and mandibular central and lateral incisors of 28 skeletal Class II patients with mandible retrusion treated with non-extraction treatment protocol using elastics and PowerScope. RESULTS: There was no statistically significant difference in root resorption between the groups for the overall score and comparison of root resorption in individual teeth between two groups showed significantly more resorption in PowerScope group in mandibular lateral incisors.CONCLUSION: Both elastic and PowerScope groups showed mostly mild to moderate root resorption which is clinically acceptable and lower lateral incisors showed statistically more root resorption in PowerScope group.