Cervical Resorption Research Articles

A novel diode laser intervention in the management of external invasive cervical resorption

Abstract “Invasive cervical resorption (ICR)” is a rare category of “external root resorption.” It is a progressive and destructive condition with an unclear cause. Managing external “ICR” presents a significant challenge, even to the most seasoned dental professionals. The removal of excessively vascularized granulation tissue is viewed as a pivotal step. This case report highlights the use of a diode laser to excise granulation tissue, by achieving optimal tissue ablation, promoting better healing, and subsequently restoring the severely damaged crown of the external ICR tooth with an intracanal fiber post.

Treatment of Upper Incisor with Invasive Cervical Resorption

Treatment of Upper Incisor with Invasive Cervical Resorption

The role of infection in signalling root resorption: Anarrative review.

Root resorption consists of complex, multistep processes that involve cell signalling caused by inflammation and stromal cells, which promotes the secretion of receptor activator of nuclear factor κB ligand/ macrophage-colony stimulating factor (RANKL/M-CSF) resulting in a resorptive process. The aim of this narrative review was to analyse the literature related to root resorption resulting from microbial infection and to comparing it with non-microbial infection. An electronic literature search was performed using the PubMed database and applying keywords of articles published in English. Eligible papers were reviewed to reveal the descriptions of bone and root resorption processes. The abstracts were searched manually to identify articles about infection-stimulating bone and root resorption. Three main types of root resorption were identified, two associated with primary bacterial infection and one secondary to bacterial infection. These include external inflammatory resorption, internal inflammatory resorption and external cervical (invasive) resorption. The magnitude of cytokine involvement that promotes resorption and M-CSF/RANKL production depends on multiple factors, including pathogen virulence, site of infection and host genetic factors that activate the inflammation at the infection site. Two mechanisms activate the resorption mechanisms-the canonical and non-canonical pathways that can activate clastic cells independently of the RANKL/RANK canonical pathways. Two pathways of root resorption co-exist in the body. When resorption is caused by infection, chronic inflammation due to bacterial infection prolongs the secretions of pro-inflammatory cytokines that intensify root and bone resorption. The second pathway is bacterial independent of the non-infection root resorption that is part of the wound healing process, which is limited in time due to its innate ability.

Evaluation of peroxide release during nonvital bleaching using three different coronal barriers: An in vitro study.

Peroxide from bleaching agents can cause external cervical resorption. An intracoronal barrier is used to prevent leakage of bleaching agents into the periradicular space. This study aims to determine and compare the amount of peroxide released, during non vital bleaching at the end of 1st and 3rd day using Glass ionomer cement (GIC), Mineral Trioxide aggregate (ProRoot MTA) and Biodentine as intracoronal barriers. Forty-five single-rooted teeth were selected for the study and root canal therapy was performed. Three millimeters of the coronal gutta-percha were removed and according to the coronal barrier placed, samples were divided into Group A: GIC, Group B: ProRoot MTA, and Group C: Biodentine. Nonvital bleaching was done using sodium perborate and 30% H2O2. Peroxide released at the end of the 1st and 3rd day was analyzed using potassium iodide and ultraviolet spectrophotometer. This was done using the Wilcoxon matched pair test and the Kruskal-Wallis test. No significant difference in intergroup comparison at the end of 1st and 3rd day, respectively (P > 0.05), a significant difference was found in the MTA group at follow-up dates (P < 0.05). All the three tested materials (GIC, MTA, and Biodentine) may be preferred as intracoronal barrier for nonvital bleaching.

Treatment options for impacted maxillary canines and occurrence of ankylotic and resorptive processes: a 20-year retrospective study

BackgroundThis 20-year retrospective study aimed to evaluate the treatment methods used in patients with impacted maxillary permanent canines and to determine the occurrence of ankylotic and resorptive processes and their association with potential risk factors.MethodsThe cohort consisted of 351 consecutive Caucasian patients (120 males and 231 females, mean age 18.4 and 19.9 years, respectively) with 420 impacted maxillary permanent canines. CT and CBCT findings were subsequently confirmed during surgery. Statistical analyses were performed by the generalized linear models, Pearson x2 and Fisher exact tests using the statistical programs R and Statistica v. 14.ResultsA total of 273 (65.0%) impacted canines were aligned in the dental arch by orthodontic traction after surgical exposure, this treatment was predominant in patients under 20 years of age. Surgical extraction was performed in 115 (27.2%) impacted canines and was more common in older patients. Ankylotic changes were recorded in 61 (14.5%) impacted canines. The probability of ankylosis increased with age, particularly after the patient’s 20th year of life (p < 0.001). Patients were 1.2% likely to develop ankylosis at age 15 years, 4.3% at age 20 years, 14.1% at age 25 years, and 96.8% at age 45 years. Invasive cervical root resorption (ICRR) was found in 8 (1.9%) canines. In 4 canines (1.0%), root ankylosis in addition to ICRR was observed. In contrast to ankylosis, whose frequency of occurrence increased with age, the occurrence of ICRR resulting from PDL damage during surgery was more typical in younger patients. Canines in a high position above the root apices of the adjacent teeth, with a horizontal inclination of the longitudinal axis, with the crown located deep in the center of the alveolar bone and with labiopalatal position, should be considered critically impacted canines with a high risk to failure of orthodontic traction.ConclusionIn conclusion, the treatment of impacted canines depends mainly on the age of the patient, and the position and inclination of the longitudinal axis of the impacted tooth. To select an adequate treatment method, we recommend CBCT examination, which allows a precise analysis of the position of impacted canines.

The sealing ability of different endodontic biomaterials as an intra-orifice barrier: evaluation with high-performance liquid chromatography.

This study evaluated the sealing ability of different biomaterials as intra-orifice barriers in the internal bleaching of discolored teeth with the walking bleaching technique. The release of hydroxyl ions from the bleaching materials can cause cervical root resorption, making it necessary to use intra-orifice barrier materials to prevent this issue. In the current study, the high-performance liquid chromatography (HPLC) method was used to measure the released hydroxyl ions. The study included 90 single-rooted and single-canal premolars, which were divided into four groups based on the intra-orifice barrier materials used (mineral trioxide aggregate [MTA], calcium-enriched mixture [CEM], Biodentine, and MTA+PG) and the type of bleaching material (sodium perborate + water or sodium perborate + hydrogen peroxide 30%). Two control groups were also considered in this study: a positive control group, where sodium perborate and hydrogen peroxide were placed inside the pulp chamber without any intra-orifice barriers; and a negative control group, where no bleaching agent or surgical obstruction was used, and the root surface was covered with wax up to the cemento-enamel junction (CEJ) level. The results showed that there was a significant difference in the concentration of hydroxyl ions released among the studied groups. The amount of hydroxyl ion released was highest in the positive control group and lowest in the CEM group. Among the intra-orifice barrier materials used, CEM cement was found to be the most appropriate material for use in the step-by-step internal bleaching method. The study highlights the importance of using appropriate intra-orifice barrier materials to prevent root cervical resorption in internal bleaching procedures.

Long-term prognosis for teeth with external cervical resorption based on periapical images and cone beam CT: A clinical study.

To evaluate whether supplemental information from CBCT changed long-term prognosis for teeth with external cervical resorption (ECR) compared to periapical (PA) images. Furthermore, to assess predictive findings in PA images and evaluate which findings in CBCT affected the long-term prognosis of teeth with ECR. One hundred and ninty-four patients, mean age 41.2, range 13-81, having 244 teeth with ECR were included. An initial long-term prognosis determined either good or poor was established based on intraoral images. Afterwards, the patients underwent CBCT, and final long-term prognosis was decided. From the PA images and CBCT, ECR using Heithersay's classification system, pulp involvement and extension of ECR was assessed. In CBCT, the number of surface lesion(s) was additionally assessed. Descriptive statistics evaluated changes in long-term prognosis after CBCT. Logistic regression analyses tested if findings in PA images and CBCT affected the long-term prognosis. Based on CBCT, out of 244 teeth the long-term prognosis was assessed to be poor for 173 (70.9%) teeth and good for 71 (29.1%) teeth. The long-term prognosis changed in 76 (31.1%) teeth after CBCT; 5 (2.0%) changed from poor to good, and 71 (29%) changed from good to poor long-term prognosis. In 81 (33.2%) teeth the H-class increased, and in 10 (4.1%) teeth the H-class decreased after assessing CBCT. In 70 (28.7%) teeth, there was a change from no pulp involvement to involvement of the pulp after CBCT; eight (3.3%) teeth changed in the opposite direction. H-class 2 and 4 in PA images significantly increased the probability for a change in long-term prognosis compared to an H-class 3 (p < .05). H-class 4, pulp involvement, ECR in the oral 1/3 of the root, and more than two surface lesions seen in CBCT significantly influenced a poor long-term prognosis (p < .05). Supplemental information from CBCT changed long-term prognosis in almost one third of teeth with ECR. In most cases, the long-term prognosis changed from good to poor. H-class 3 in PA images had a significant influence on change in long-term prognosis. Several findings in CBCT influenced a poor long-term prognosis.

Comparative Evaluation of Activated and Nonactivated Microbubbles on the Efficacy of Bleaching Agents.

Intracoronal bleaching serves as a conservative option for nonvital teeth that exhibit discoloration.Hydrogen peroxide (H2O2) is frequently utilized in bleaching processes owing to its capability to produce free radicals.The main drawbacks of the currently available bleaching agents are the occurrence of cervical resorption and the multiple dental visits to achieve the desired result. Therefore, in our study, to address the limitations associated with cervical resorption and extended treatment duration for badly stained teeth, an attempt was made to incorporate a whitening agent (35% H2O2) with microbubbles. This study aimed tocompareandevaluatetheeffect ofactivated and nonactivated microbubbles on the efficacy of bleaching agents. Forty-five human central incisors were collected and divided into three groups:Group I (HP), H2O2 plain(n= 15) (Control); Group II (HPM), H2O2-infused microbubbles without ultrasonic activation (n= 15) (experimental group); and Group III (HPMU), H2O2-infused microbubbles with ultrasonic activation (n= 15) (experimental group).The crowns were artificially stained. Microbubbles containing 35% H2O2were generated using the probe sonication method.The bleaching agent H2O2 plain (0.04 mL) was syringed into the pulp chamber in group I, while H2O2-infused microbubbles (0.04 mL) were syringed into group II and group III. Group III was further activated ultrasonically. The evaluation of color shade differences was conducted using the Vita Lumin shade guide at three time points: baseline, day 7, and day 14. Data regarding color change using Vita shade were investigated for normality using theKolmogorov Smirnov test and assessed a non-normal distribution.Intergroup comparisons at each particular time interval (baseline, day 7, and day 14) were analyzed using the Kruskal-Wallis H test followed by multiple pairwise comparisons using the Adjusted Bonferroni post hoc test. Intragroup comparisons between different time intervals were analyzed using related samples from Friedman's test followed by multiple pairwise comparisons using the post hoc Dunn test. The level of statistical significance was determined at P< 0.05. There was no statistical difference in the baseline values of all three groups. Group I (HP) exhibited an average increase of three Vita Lumin shade tabs on day 7 and day 14, respectively, whereasGroup II (HPM)exhibited an average increase of six and four Vita Lumin shade tabs on day 7 and day 14, respectively, and Group III (HPMU)exhibited an average increase of 10 and 3 Vita Lumin shade tabs on day 7 and day 14, respectively. Microbubbles containing H2O2 were more efficient and faster than plain H2O2 for bleaching, and the efficacy of bleaching was enhanced when activated using ultrasonic technology.

Tooth Autotransplantation, Autogenous Dentin Graft, and Growth Factors Application: A Method for Preserving the Alveolar Ridge in Cases of Severe Infraocclusion-A Case Report and Literature Review.

Background: Tooth infraocclusion is a process in which a completely or partially erupted tooth gradually moves away from the occlusal plane. Submerged teeth can lead to serious complications. Treating teeth with infraocclusion is very challenging. One of the procedures allowing for the replacement of a missing tooth is autotransplantation. The aim of this paper is to review the literature on teeth autotransplantation, supported by a case report involving the autotransplantation of a third mandibular molar into the site of an extracted infraoccluded first mandibular molar, as well as the utilization of advanced platelet-rich fibrin (A-PRF) alongside autogenous dentin grafts for bone tissue regeneration. Methods: A severely infraoccluded first permanent right mandibular molar was extracted and then ground to obtain the dentin graft. A-PRF clots (collected from the patient's peripheral blood) were added to the autogenous dentin graft, to create the A-PRF membrane. An atraumatic extraction of the lower left third molar was performed and then it was transplanted into the socket of tooth no. 46. Immediately after transplantation, tooth no. 38 was stabilized with orthodontic bracket splints for 3 months. The patient attended regular follow-up visits within 12 months. Results: After one year, the patient did not report any pain. In the clinical examination, the tooth and surrounding tissues did not show any signs of infection. However, radiographically, cervical inflammatory resorption, unchanged pulp canal dimensions, absent root growth, periapical radiolucency, and lack of apical and marginal healing were observed. Reconstruction of the bone defect was obtained and the alveolar ridge of the mandible was preserved. Due to poor stability of the tooth and severe resorption, the tooth needed to be extracted. Conclusions: This study is designed to critically evaluate the efficacy of autotransplantation, the application of growth factors, and the integration of autogenous dentin grafts in remedying dental deficiencies resulting from reinclusion. We aim to point out the possible causes of treatment failure.

Management of rarely seen internal tunnelling root resorption associated with a maxillary permanent incisor

This case presents clinical techniques and materials that may be applied in the management of internal tunnelling root resorption, a rare condition which has little published literature.A 25-year-old woman was referred to a specialist centre by her general dental practitioner following an incidental finding of a radiographic radiolucency, suggestive of root resorption associated with tooth 21. A provisional diagnosis of external cervical resorption was made, and following cone beam computed tomography (CBCT), a definitive diagnosis of internal tunnelling root resorption given. Non-surgical endodontic treatment was completed using continuous wave compaction with a calcium-silicate based sealer. No further intervention has been required.A summary of the histology, aetiology, prevalence, diagnosis, management and prognosis of internal tunnelling root resorption is provided. The benefits of CBCT for diagnosing and managing internal tunnelling resorption defects and using continuous wave compaction with a calcium-silicate based sealer, compared to cold obturation techniques, are discussed.

Influence of tube current and metal artifact reduction on the diagnosis of external cervical resorption in teeth adjacent to a dental implant in CBCT: an ex-vivo study.

This ex-vivo study aimed to assess the influence of tube current (mA) and metal artifact reduction (MAR) on the diagnosis of early external cervical resorption (EECR) in cone-beam computed tomography (CBCT) in the presence of an adjacent dental implant. Twenty-three single-rooted teeth were sectioned longitudinally and EECR was induced using a spherical drill and 5% nitric acid in 10 teeth. Each tooth was positioned in the socket of the lower right canine of a dry human mandible and CBCT scans were acquired using 90 kVp, voxel of 0.085 mm, field of view of 5 x 5 cm, and varying tube current (4, 8 or 12 mA), MAR (enabled or disabled) and implant conditions (with a zirconia implant in the socket of the lower right first premolar or without). Five oral radiologists evaluated the presence of EECR in a 5-point scale and the diagnostic values (area under the receiver operating characteristic curve - AUC, sensitivity, and specificity) were compared using multi-way Analysis of Variance (α = 0.05). Kappa test assessed intra-/inter-evaluator agreement. The tube current only influenced the AUC values in the presence of the implant and when MAR disabled; in this case, 8 mA showed lower values (p<0.007). MAR did not influence the diagnostic values (p>0.05). In general, the presence of an implant reduced the AUC values (p<0.0001); sensitivity values with 8 mA and MAR disabled, and specificity values with 4 mA and MAR enabled and 8 mA regardless MAR were also decreased (p<0.0001). Variations in tube current and MAR were unable to improve EECR detection, which was impaired by the presence of an adjacent implant. Increasing tube current or activating MAR tool does not improve EECR diagnosis, which is hampered by the artifacts generated by dental implants.

Challenges in differential diagnosis and treatment of cervical root resorption vs. root caries.

External cervical root resorption may be occasionally mistaken for root caries and vice versa. Radiographical and clinical differential diagnoses of cervical root resorption and root caries are essential for correct treatment planning and a successful treatment outcome. This article reviews the contemporary literature and summarises the prevailing professional consensus pertaining to external cervical root resorption. Clinical diagnostics which help distinguish cervical root resorption from root caries are outlined and treatment approaches of external cervical root resorption are discussed.

The Outcome of Decoronation in Severe Cases of External Cervical Root Resorption in Young Patients.

This study examines decoronation as a treatment option for teeth with progressive external cervical root resorption (ECR). Six young patients aged 9.5-13, with a total of nine incisor teeth affected by ECR due to previous dental trauma, were treated by decoronation. Six teeth were classified as class 4 and two as class 3, according to Heithersay's classification. Another tooth with class 2 resorption also had a perforation. After decoronation, all cases showed favorable outcomes during a follow-up period of 2.5-8 years. The procedure halted the progression of ECR and promoted vertical and horizontal ridge development above the submerged root. Decoronation can be considered for the successful treatment of advanced cases of ECR in young patients.

Stress distribution in endodontically treated external cervical resorption lesions restored with MTA and biodentine – A finite element analysis

IntroductionRoot resorption poses a significant challenge in dental practice, with external cervical resorption (ECR) being a common manifestation. ECR is often asymptomatic until advanced stages, complicating its diagnosis and management. Various factors contribute to its etiology, ranging from trauma to orthodontic treatment. The classification system proposed by Patel et al. (2018) offers a comprehensive framework for characterizing ECR lesions based on location and extent. Treatment strategies for ECR involve a combination of endodontic intervention and restorative techniques, with bioactive materials like mineral trioxide aggregate (MTA) and Biodentine emerging as promising options. However, the biomechanical behavior of teeth restored with these materials in the context of ECR remains underexplored. Materials and methodsThis study utilized finite element analysis (FEA) to assess stress distribution in teeth with simulated ECR lesions of varying sizes and locations, restored with MTA or Biodentine. Three-dimensional models of maxillary central incisors were generated based on CBCT scans, incorporating periodontal ligament and surrounding bone structures. Eight experimental models representing different ECR configurations were created and subjected to FEA using Optistruct software based on dimensional classification given by Patel et al., in 2018, A70 M & A70B: 1Ap, A130 M & A130B: 1Bp, B70 M & B70B: 2Ap, B130 M & B130B: 2Bp. All the models were tested for stress distribution by restoring the lesions with either M: MTA or B: Biodentine. Oblique load of 100 N was applied at 45°angle to the long axis 2 mm lingual to incisal edge. vonMises Stress distribution in enamel, dentine, restoration and at all the interfaces were observed. ResultsThe analysis revealed that both MTA and Biodentine restorations exhibited uniform stress distribution around ECR lesions, with no significant differences based on lesion location or size. Maximum stress concentrations were observed around the restorations, particularly in subcrestal lesions. However, overall stress levels were comparable between MTA and Biodentine restorations, indicating similar biomechanical performance. ConclusionFinite element analysis provides valuable insights into the biomechanical behavior of teeth with ECR lesions restored with MTA and Biodentine. Both materials exhibit similar stress distribution patterns and offer adequate reinforcement against mechanical forces. Clinicians can confidently utilize MTA or Biodentine in the management of ECR, considering their favorable biomechanical properties and clinical outcomes. Further research is necessary to validate these findings and optimize treatment protocols for ECR.

Predentin's influence on clastic cell behavior in human external cervical resorption: Evidence from a case study

External cervical resorption (ECR) is an aggressive disease characterized by resorption of the tooth root structure. While the pericanalar resorption-resistant sheet (PRRS) impedes ECR progression towards the pulp, the underlying mechanisms of its protective role in human teeth remain unclear. This study aimed to elucidate the pathology of ECR in a 31-year-old female patient by employing radiographic, histological, and immunohistochemical analyses of an extracted tooth. Histological examination revealed that the PRRS comprised dentin, predentin, and reparative bone-like tissue. Notably, clastic cells were observed on the surfaces of all three tissues within the same specimens. Immunohistochemical staining for cathepsin K demonstrated diminished resorptive activity of clastic cells on predentin compared to dentin and bone-like tissue. These findings suggest a potential role for predentin in attenuating clastic cell activity, potentially serving as the final barrier safeguarding the pulp tissue.

Cytotoxicity of Bleaching Products: A Systematic Review

The high demand for aesthetic treatments among the population has resulted in a wide array of bleaching products available on the market. It is imperative to investigate the potential adverse effects these products may have on dental health. The objective of this systematic review is to assess, based on available experimental in vitro studies in the scientific literature, whether bleaching products exhibit cytotoxic properties against pulp stem cells and fibroblasts. A comprehensive literature search was conducted across the Medline, Scopus, and Lilacs databases using the search formula ((Tooth whitening) OR (bleaching agent)) AND cytotoxicity AND ((stem cell*) OR fibroblast). Following the application of inclusion and exclusion criteria, 14 articles were deemed suitable for full analysis. The most utilized assay in the evaluated studies was the MTT cell viability assay. Fibroblasts emerged as the most scrutinized cell type due to the potential adverse effects of bleaching, such as invasive cervical resorption, which primarily affects the periodontal ligament where fibroblasts are located. It was observed that as the concentration of hydrogen peroxide increases, so does the cytotoxicity of the product. Additionally, other factors such as application time, activation methods, and the type of peroxide used also play a significant role. Bleaching products have been shown to exert cytotoxic effects on fibroblasts. Further exploration of the impact of bleaching agents on dental pulp stem cells is warranted to better understand their implications for these cells.

INVASIVE CERVICAL RESORPTION OF UNCOMMON ORIGIN: A CASE REPORT WITH 14-YEAR FOLLOW-UP

Background: Invasive cervical resorption (ICR) is a complex, relatively uncommon, and insidious phenomenon. Its occurrence is associated mainly with local predisposing factors, but systemic risk factors may be involved as well. An ICR lesion that develops in the absence of an identifiable cause is termed 'idiopathic'. Case report: This study presents the surgical management and very long-term follow-up results of an "idiopathic" Class 3 ICR lesion in the maxillary central incisor. The case provides a unique insight into an uncommon ICR lesion that exhibited an unusual appearance and features. For the repair material, a sandwich technique was applied using mineral trioxide aggregate (MTA) covered with glass ionomer cement (GIC). At the 14-year follow-up, the tooth was symptom-free and functional; however, the disadvantages of both materials were clearly demonstrated. From that perspective, the study highlighted the discoloration potential of the white form of MTA-Angelus and the lack of regenerative properties of the GIC used. Remarkably, 12 years after the surgery, the patient was diagnosed with Familial Mediterranean fever, a rare systemic disease. However, the connection between this genetic disease and the initiation of ICR remains an open question for now. Conclusion: The clinician should be alert for the occurrence of ICR lesions, especially in patients with concomitant systemic disorders. The right choice of appropriate repair material is a key factor for the healing outcome of ICR lesions in the anterior zone.

An Evaluation of the Fracture Resistance of Teeth with Simulated External Cervical Resorption Cavities Categorized Using Three-Dimensional Classification.

(1) Background: External cervical resorption causes dental hard tissue destruction that may reduce the fracture resistance of affected teeth. By using a compressive strength test, this study aimed to evaluate the fracture resistance of teeth with simulated external cervical resorption cavities that have different three-dimensional classifications. (2) Methods: In total, 170 teeth with simulated external cervical resorptions were divided into 16 experimental groups (n = 10) and 1 control group (n = 10) based on the three-dimensional classification: 1Ap, 1Bp, 1Cp, 1Dp, 2Ap, 2Bp, 2Cp, 2Dp, 3Ap, 3Bp, 3Cp, 3Dp, 4Ap, 4Bp, 4Cp, 4Dp and a control group. Defects were restored with mineral trioxide aggregate. The fracture resistances of the samples were statistically analyzed using two-way repeated ANOVA and the Bonferroni correction for multiple comparisons at a significance level of p < 0.05. (3) Results: The lowest resistance to fracture was observed in samples with vertical height level "4" and circumferential spread of "D" (p < 0.001). In the groups with circumferential spreads "B", "C" and "D", there were significant differences between the samples with vertical height levels "1", "2", "3" and "4" regarding fracture resistance (p < 0.001). (4) Conclusions: The circumferential spread and vertical height of the external cervical resorption influenced the fracture resistance of the affected teeth.

Clinical and radiographic characterization of external root resorption.

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. 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. 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. 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.

Clinical and Genetic Analysis of Multiple Idiopathic Cervical Root Resorption.

To explore the genetic background and clinical phenotypes of multiple idiopathic cervical root resorption (MICRR) in a Chinese family. The proband and his three family members were clinically examined and had radiographs taken with a radiovisiography (RVG) system and CBCT to define the diagnosis of MICRR. Genomic DNA (gDNA) was extracted from peripheral blood samples of the patient, his father, mother and younger sister for whole exome sequencing (WES). The pathogenicity of rare variants with minor allele frequency (MAF) less than 0.005 were analysed following possible inheritance patterns, predicted results from 12 software programs, the American College of Medical Genetics (ACMG) 2015 criteria, and information from ClinVar, OMIM and HGMD databases as well as gene function. The proband presented the typical MICRR phenotypes such as thin cervical pulp wall and apple core-like lesions in radiographs. Following the recessive inheritance pattern, WES analysis identified SHROOM2, SYTL5, MAGED1 and FLNA with a higher chance of causing MICRR. Four genes with compound heterozygous variants and another 27 genes with de novo variants either in autosomal-dominant or autosomal-recessive pattern were also found to have the potential pathogenicity. A total of 35 novel potential pathogenic genes were found to be associated with MICRR from a Chinese family through WES. The new genetic background of MICRR may be helpful for clinical and molecular diagnosis.