Hypoxic dental pulp stem cells-released succinate promotes osteoclastogenesis and root resorption.

Introduction: Clinical studies have shown that endodontically-treated nonvital teeth exhibit less root resorption during orthodontic tooth movement. The purpose of this study was to explore whether hypoxic dental pulp stem cells (DPSCs) can promote osteoclastogenesis in orthodontically induced inflammatory root resorption (OIIRR). Methods: Succinate in the supernatant of DPSCs under normal and hypoxic conditions was measured by a succinic acid assay kit. The culture supernatant of hypoxia-treated DPSCs was used as conditioned medium (Hypo-CM). Bone marrow-derived macrophages (BMDMs) from succinate receptor 1 (SUCNR1)-knockout or wild-type mice were cultured with conditioned medium (CM), exogenous succinate or a specific inhibitor of SUCNR1 (4c). Tartrate-resistant acid phosphatase (TRAP) staining, Transwell assays, qPCR, Western blotting, and resorption assays were used to evaluate osteoclastogenesis-related changes. Results: The concentration of succinate reached a maximal concentration at 6 h in the supernatant of hypoxia-treated DPSCs. Hypo-CM-treated macrophages were polarized to M1 proinflammatory macrophages. Hypo-CM treatment significantly increased the formation and differentiation of osteoclasts and increased the expression of osteoclastogenesis-related genes, and this effect was inhibited by the specific succinate inhibitor 4c. Succinate promoted chemotaxis and polarization of M1-type macrophages with increased expression of osteoclast generation-related genes. SUCNR1 knockout decreased macrophage migration, M1 macrophage polarization, differentiation and maturation of osteoclasts, as shown by TRAP and NFATc1 expression and cementum resorption. Conclusions: Hypoxic DPSC-derived succinate may promote osteoclast differentiation and root resorption. The regulation of the succinate-SUCNR1 axis may contribute to the reduction in the OIIRR.

A 3-year follow-up of implant placement in proximity to canalis sinuosus: Case study.

BACKGROUND: While the nasal fossa and nasopalatine canal are recognized limitations for immediate implants in esthetic areas, the canalis sinuosus (CS) and its branches have been largely overlooked. Neglecting this anatomy can lead to sensory issues, pain, and implant failure underscores the necessity of meticulous pre-surgical assessment and planning to mitigate risks and ensure implant success. This case highlights the need for comprehensive pre-surgical evaluation and precise planning to minimize these complications and ensure successful implant outcomes in this scenario. METHODS AND RESULTS: A 41-year-old woman with a history of root perforation and external root resorption was referred for dental implant placement. Following clinical evaluation and computed tomography, the presence of an accessory canal of the CS was identified. After meticulous planning to avoid implant contact with this structure, ridge preservation was performed. After 6 months, the implant was successfully placed following guided osteotomy. The case demonstrates clinical and radiographic stability after 36 months of follow-up. CONCLUSION: The correct diagnosis and planning, within a multidisciplinary team, can lead to successful implant placement in a challenging site with an anatomical variation. This study, to our knowledge, represents the first to propose an alternative treatment approach in the presence of CS in an esthetic region. KEY POINTS: Why is this case new information? This case emphasizes the importance of thorough pre-surgical evaluation to mitigate potential complications related to the CS. It is the first, to our knowledge, to propose an alternative treatment approach in the presence of this anatomical variation in an esthetic region. What are the keys to successful management in this case? Comprehensive pre-surgical evaluation, precise planning with detailed CBCT assessment to identify the CS, careful consideration of its anatomy during surgical intervention, knowledge of the limitations of tissue reconstructions, and precise clinical strategies to minimize associated complications. What are the primary limitations to success in this case? The need to position the implant with a safety margin from the CS led to implant positioning resulting in fenestration of the buccal bone plate, preventing its reconstruction due to the bone envelope's design, resulting in a discrepant gingival margin compared to the contralateral tooth, which did not allow for further crown lengthening due to a rather short root.

Root Regeneration with Photobiomodulation of an Upper Lateral Incisor Associated with Root Resorption Due to an Impacted Maxillary Canine: A Case Report.

Objective: To present a case report of maxillary lateral incisor root regeneration after severe root resorption, treated with photobiomodulation (PBM). Background: Impacted maxillary canines often come with the risk of maxillary lateral incisor root resorption, which is widely recognized as the predominant adverse effect in these situations. This progressive process of root resorption is currently irreversible, with no known way to reverse it. Materials and methods: A male patient was 14 years old. Radiographically it was observed that canine 23 is impacting against the root of 22 producing signs of root resorption and having a less than 1:1 crown-to-root ratio with mobility grade 1. From the beginning of the treatment, PBM-assisted orthodontics was proposed. To address the patient's dental concerns, the treatment plan outlined the extraction of the deciduous upper left canine tooth leaving the lateral as long as possible in the mouth. During each appointment, PBM was applied with a diode laser. The wavelength was 810 nm, Ap = 0.2 W, 4.4 J, 22 sec every 21 days, 13 applications in total (57.2J), with a 400 µm inactive surgical tip, in a scanning movement, 1 mm from the mucosa while moving following the vestibular surface of the upper left lateral and canine roots. Results: After 12 months, the 22 had root neoformation and complete closure of the apex with vitality. Conclusions: PBM with an 810 nm diode laser in this clinical case promoted root regeneration of an upper lateral incisor, with severe root resorption, owing to an impacted maxillary canine while still vital.

[Pulp revascularization procedure for external inflammatory dental root resorption treatment]. / Primenenie metodiki regeneratsii pul'popodobnoi tkani dlya ostanovki naruzhnoi vospalitel'noi rezorbtsii kornya zuba.

THE AIM OF THE STUDY: To assess the effectiveness of pulp revascularization procedure in children with external inflammatory root resorption (EIRR) after constant teeth injury. MATERIALS AND METHOS: The study comprised 17 children aged 6-10 years diagnosed with EIRR as a long-term complication of dental trauma in 19 teeth. EIRR was diagnosed with periapical radiographs and CBCT was performed to further assess the pathology extension. Pulp revascularization was carried out in all 19 teeth. RESULTS: There was no resorption progression in all cases. EIRR areas were substituted by bone. In 10 from 19 teeth with early stages of root development bone or cement-like tissue ingrowth into the root canal was observed radiologically. In cases of severe EIRR this ingrowth may partially compensate for lost tissues which is confirmed by a high percentage (94.7%) of functional teeth during mean follow up time of 38±10 months. CONCLUSION: Pulp revascularization is an effective method for retaining teeth with EIRR for a relatively long period of time and allows maintaining alveolar bone volume both due to functional tooth preservation and healing of bone lesions in periapical and resorption areas.

Root resorption in clear aligner treatment detected by CBCT: a Systematic review and Meta-analysis.

OBJECTIVE: The aim of this study was to evaluate the amount of external apical root resorption in patients who had undergone orthodontic treatment with clear aligners evaluated using cone beam computed tomography. METHODS: Studies that evaluated external apical root resorption before and after comprehensive orthodontic treatment with clear aligners were assessed by performing an electronic search from 5 databases comprising PubMed, SCOPUS, EBSCO, Cochrane Library, and LILACS and manual searches in the relevant journals and the reference lists of the included studies. Database search, elimination of duplicate studies, and data extraction were performed independently by 2 authors. The quality of the included studies was assessed using the Risk of Bias in Non-randomised Studies-of Interventions and the Cochrane Collaboration's Risk of Bias Tool. Studies that reported the tooth length or volume were used for quantitative analyses. RESULTS: Nine studies were included in the meta-analysis. The overall root length after clear aligner treatment was significantly decreased compared with the pre-treatment length using cone beam computed tomography (mean differences = -0.56 mm, 95% confidence interval [-0.73, -0.38], P < .00001). However, only the maxillary central incisors, maxillary lateral incisors, and mandibular central incisors had significant reduction in root length. The meta-analysis from 3 studies also indicated that the root volume of the upper incisors also significantly decreased (mean differences = -13.34 mm3, 95% confidence interval [-16.57, -10.10], P < .00001). CONCLUSIONS: Current evidence suggests that clear aligners can cause minimal root resorption. The highest amount of root resorption was observed in the maxillary central incisors.

Resorptions and orthodontics / Résorptions et orthodontie

Introduction: It's generally accepted that one of the risks associated with orthodontic treatment is apical root resorption, even though this may occur outside orthodontic treatment. In any case, it causes root shortening. Orthodontists are probably the only dental surgeons who use the inflammatory process as a therapeutic tool. They need to be aware of the risk factors for root inflammation. Along with recurrence, leukemia and periodontal problems, resorption is one of the "inconveniences" of orthodontics, which, if not inevitable, must at least be minimized. Material and Method: At present, the orthodontic literature on root resorption provides some clues as to the factors associated with the onset, severity and management of root resorption, although the complexity of this phenomenon does not allow us to arrive at a clear and unequivocal consensus. For this reason, it is important to identify potential risk factors for resorption, to take them into account before/during and after treatment, and to know what attitude to adopt in the event of resorption appearing, all in order to minimize this phenomenon, as everyone agrees that it can be a source of harm and stress for both patient and practitioner. Conclusion: There are still many grey areas in our understanding of the phenomenon, including how the elements of orthodontic treatment influence orthodontic resorption. Irreversible in nature, resorption can be sufficiently extensive to cast doubt on the benefit of successful orthodontic treatment.

Introduction: Il est généralement admis que l'un des risques associés au traitement orthodontique est la résorption radiculaire apicale même si elle peut se produire en dehors de tout traitement orthodontique. Quoi qu'il en soit, elle provoque le raccourcissement radiculaire. Les orthodontistes sont sans doute les seuls spécialistes de la chirurgie dentaire qui utilisent le processus inflammatoire en tant que moyen thérapeutique. Ils doivent connaître les facteurs de risque de cette inflammation sur la racine. La résorption fait partie, au même titre que la récidive, les leucomes et les problèmes parodontaux, des « inconvénients ¼ de l'orthodontie qui, à défaut d'être inévitables, doivent au moins être minimisés. Matériels et méthode: Actuellement, la littérature orthodontique sur la résorption radiculaire fournit quelques pistes sur les facteurs associés à l'apparition, la gravité et la gestion de la résorption radiculaire, même si la complexité de ce phénomène ne nous permet pas d'en dégager un consensus clair et équivoque. Pour cette raison, il est important d'identifier les facteurs de risque de résorption potentiels pour en tenir compte avant/pendant et après le traitement et connaître l'attitude à adopter en cas d'apparition de résorptions, tout ceci afin de minimiser ce phénomène, car tout le monde s'accorde sur le fait qu'elle peut être source de préjudice et de stress pour le patient et le praticien. Conclusion: De nombreuses zones d'ombres subsistent dans la compréhension du phénomène, notamment sur comment les éléments du traitement orthodontique influencent la résorption orthodontique. De nature irréversible, la résorption peut être suffisamment étendue pour jeter un doute sur le bénéfice apporté au succès du traitement orthodontique.

Full life cycle changes of low impacted mandibular third molar associated cystic lesions and adjacent tooth root resorption: a retrospective study.

OBJECTIVE: Low impacted third molars are usually asymptomatic and are often found by X-ray examination. The removal of asymptomatic low impacted third molars is one of the most controversial clinical issues in oral and maxillofacial surgery. METHODS: In this study, 806 patients with low impacted mandibular third molars (LIMTMs) (full bony impaction) were analyzed to determine the prevalence and risk factors for cystic lesions and adjacent tooth root resorption throughout the patients' entire life cycle. RESULTS: The results showed that the prevalence of adjacent tooth root resorption and cystic lesions was age-related, exhibiting a trend of first increasing and then decreasing; prevalence peaked at the age of 41 to 45 years old, the prevalence rates were 12.50% and 11.11% respectively. And the lowest prevalence rate was 2.86% and 2.44% in ≥ 61 group and 56- to 60-year age group respectively. Age was an independent risk factor for adjacent tooth root resorption of LIMTMs, whereas age and impaction type (especially inverted impaction) were independent risk factors for cystic lesions. CONCLUSIONS: The full life cycle management strategy for LIMTMs may need to be individualized. Surgical removal is recommended for LIMTMs in patients younger than 41 to 45 years, especially for inverted, mesioangular, and horizontally impacted LIMTMs. LIMTMs in patients older than 41 to 45 years may be treated conservatively with regular follow-up, but surgical removal of inverted impacted LIMTMs is still recommended to avoid cyst formation.

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.

Risk of pulp necrosis and related complications in the permanent anterior teeth with lateral luxation: A systematic review and meta-analysis.

This systematic review aimed to evaluate the evidence related to the occurrence of pulp necrosis and related complications in permanent anterior teeth with lateral luxation. It was envisaged to address the ambiguity related to the recommendation for pulp extirpation in teeth with mature root apex. An a priori protocol was formulated as per the best practices of evidence-based medicine and registered in PROSPERO. A comprehensive search was performed electronically in PubMed, LILACS, Web of Science, EMBASE, Scopus, and Cochrane on July 10,2023 without any restriction of language or year of publication. The screening of titles and abstracts and later the full-text articles were performed. Later, the data extraction was performed by using a self-designed sheet, risk of bias (ROB) assessment was done, meta-analysis was performed, and the GRADE approach was used to assess the quality of evidence. The qualitative synthesis was performed on 13 studies done from 1985 to 2020 in hospital settings. There was variability in the minimum and total observation periods, sample sizes, and characteristics of the sample population. The overall pooled prevalence of pulp necrosis was found to be 57% (95% CI: 42, 72%). It was 12% (95% CI: 8%, 18%, I2 = 0%) in immature teeth, and 58% (95% CI: 42, 73%, I2 = 86%) in mature teeth. The pooled prevalence of EIRR was found to be 11% (95% CI: 4, 27%, I2 = 95%) with greater risk in teeth with mature root apex (RR: 1.26, 95% CI: 1.12, 1.42, I2 = 0%). The ROB was moderate or high in nine studies and the GRADE of evidence was very low in 14 of 15 outcomes. There are greater chances of pulp necrosis in teeth with lateral luxation, especially with mature apex. However, it can still be less than 60% in most cases with the prevalence of EIRR less than 20%. Hence, an absolute recommendation for endodontic intervention in mature teeth with lateral luxation must be interpreted with slight caution.

Clinical and radiographic characterization of external root resorption. / Características clínicas y radiográficas de reabsorciones radiculares externas.

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.

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.

Diagnostic Accuracy of Cone Beam Computed Tomography and Periapical Radiography for Detecting Apical Root Resorption in Retention Phase of Orthodontic Patients: A Cross-Sectional Study.

Objectives: This clinical study aimed to evaluate and compare the diagnostic accuracy of intraoral periapical radiography (PR) and cone beam computed tomography (CBCT) in detecting external apical root resorption (EARR) in orthodontic patients during the retention phase. Methods: The research involved 41 Caucasian patients who had undergone comprehensive orthodontic treatment, with a total of 328 teeth analyzed. The Kappa values for inter- and intra-examiner agreement were high for both PR and CBCT, indicating a robust level of agreement among examiners. The study used a four-point scale for classifying EARR. Results: This study showed comparable accuracy, sensitivity, and specificity between PR and CBCT when using the most stringent criterion of "Definitely present". The data suggested that CBCT outperformed PR when using a less stringent criterion ("Definitely present" or "Probably present"), particularly for maxillary incisors. However, overall diagnostic performance, as measured by the area under the ROC curve, showed only a slight advantage for CBCT over PR. Areas under the ROC curve range between 0.85 and 0.90 for PR and between 0.89 and 0.92 for CBCT. According to DeLong's test, there is no evidence to conclude that the area under the ROC curve is different for PR and CBCT. Conclusions: Both PR and CBCT are accurate diagnostic tools for identifying EARR, with PR being deemed more suitable for routine clinical use due to its cost-effectiveness and lower radiation exposure. The findings emphasize the importance of considering the risk-benefit ratio when deciding on imaging modalities for monitoring EARR in orthodontic patients.

Effects of Orthodontic Mechanics on Root Resorption: A Comparative Study.

Background: Orthodontic treatment is a common dental procedure aimed at correcting malocclusions and improving dental aesthetics. However, one of the potential side effects of orthodontic treatment is root resorption, which can lead to permanent damage to the tooth's root structure. Materials and Methods: In this comparative study, 60 orthodontic patients were divided into three groups, each receiving a different orthodontic treatment approach: Group A-conventional fixed orthodontic appliances, Group B-self-ligating orthodontic appliances, and Group C-clear aligners. Digital radiographs were taken before and after treatment to assess root resorption. The extent of root resorption was quantified using a standardized measurement scale. Results: The results indicated that Group A exhibited an average root resorption of 0.2 mm, Group B showed an average root resorption of 0.1 mm, and Group C had the lowest average root resorption of 0.05 mm. These findings suggest that clear aligners resulted in significantly less root resorption compared to conventional fixed orthodontic appliances and self-ligating orthodontic appliances (P < 0.05). Conclusion: This comparative study highlights the differential effects of various orthodontic mechanics on root resorption. Clear aligners demonstrated the least amount of root resorption when compared to conventional fixed orthodontic appliances and self-ligating orthodontic appliances.

Evaluation of rise in pH and oxygen release at the site of simulated external root resorption cavities using different oxygen-releasing biomaterials: An in vitro study.

Context: External inflammatory root resorption has rapid onset and progresses aggressively. It leads to cementum loss, which allows communication between the infected pulp and the periodontium through the denuded dentinal tubules. Primary management strategy includes adequate chemomechanical debridement and lesion arrest for which maintaining alkaline pH and aerobic conditions is essential for healing and repair of the resorption defect. Aims: The aim of this study is to evaluate rise in pH and oxygen release at the site of simulated external root resorption cavities using different oxygen-releasing biomaterials. Materials and Methods: In 40 extracted single-rooted teeth access opening and chemomechanical debridement were done. Cavities simulating resorption defect are prepared on the roots. The samples are divided into four groups (n = 10) based on the biomaterial used. After placing the biomaterial, the root apices were sealed. Half of the samples from each group were tested for oxygen release using dissolved oxygen meter and the other half for rise in pH using pH meter at 7, 14, 21, and 28 days. Statistical Analysis: The pH values were analyzed using Friedman 2-way analysis of variance (ANOVA) and Kruskal-Wallis test. Oxygen release was measured using the two-way and repeated-measures ANOVA. Results: Calcium peroxide group showed the highest mean pH and oxygen release than other groups at any given point of time. Conclusions: Incorporating oxygen-releasing biomaterials such as calcium peroxide and perfluorodecalin into intracanal medicaments, such as calcium hydroxide, creates an alkaline and oxygen-enriched milieu in the periapical tissues.

Efficacy of maxillary molar intrusion and quantification of related external apical root resorption - A comparison of two approaches.

OBJECTIVE: This retrospective single-centre study aimed to compare the efficacy of maxillary second molar intrusion with two different approaches, miniscrew-assisted molar intrusion and traditional segmental archwire intrusion, and to compare orthodontically induced external apical root resorption (OIERR) during intrusion between two groups via cone beam computed tomography (CBCT). MATERIALS AND METHODS: A total of 40 adult patients (33.6 ± 10.3 years old) with supraerupted maxillary second molars due to the loss of antagonistic teeth were recruited, with 20 patients in each group. A segmental archwire with adjacent teeth as an anchorage was used in the control group, and 60-100 g of intrusive force was applied by using miniscrews in the experimental group to intrude the overerupted molars. Full-volume CBCT was performed before and after intrusion, and the amount of intrusion and extent of OIERR of the overerupted molars were compared between the two groups. RESULTS: Supraerupted maxillary second molars could be successfully intruded in an average of 5 months. There was more intrusive movement of the buccal and palatal cusps in the mininscrew group than that in the segmental archwire group (P < .05). The intrusive amount of palatal cusp was 3.67 ± 1.13 mm in the miniscrew group and 2.38 ± 0.74 mm in the segmental archwire group. More palatal OIERR was observed in the miniscrew group (30.3 ± 11.6 mm3) than in the segmental archwire group (21.0 ± 8.66 mm3) (P = .0063). There was no significant difference in OIERR between the two groups for mesial and distal buccal roots (P > .05). CONCLUSION: Miniscrews help effectively with supraerupted maxillary second molar intrusion, especially for palatal cusps. There was more OIERR in the palatal root when using miniscrews compared to the segmental archwire approach.

Evaluation of Aligners and Root Resorption: An Overview of Systematic Reviews.

Background: To evaluate the current evidence on clear aligners and root resorption using 3D and/or combined 2D and 3D methods from available systematic reviews and meta-analyses and to determine the relationship between root resorption and clear aligners using the AMSTAR 2 tool. Methods: A comprehensive literature search of systematic reviews investigating aligners and root resorption, published up until 31 December 2022, was conducted. The following electronic databases were searched: MEDLINE via PubMed, EMBASE, Google Scholar, Science Direct, Web of Science, Scopus, LIVIVO, and LILACS. There were no language restrictions. The inclusion criteria were restricted to studies focusing on root resorption utilizing either 3D methods exclusively or a combination of 2D and 3D techniques. Data were screened and analyzed for quality using the "A Measurement Tool to Assess Systematic Reviews (AMSTAR 2)" tool. Data extraction was conducted independently by two authors. The gathered information was categorized and synthesized narratively based on the primary findings elucidated within the reviews. Results: Out of a total of 1221 potentially eligible studies initially identified, 4 systematic reviews met the inclusion criteria following the exclusion of irrelevant studies. Among these, two systematic reviews (50%) were classified as low-quality, while the remaining two (50%) were deemed to be of critically low quality. Conclusions: Based on the findings of four systematic reviews, the root resorption rate was lower with the use of clear aligners than with fixed aligners. It is advisable to approach the interpretation of this conclusion with caution, as the quality of the available evidence is assessed to be very low. Higher quality systematic reviews are needed to substantiate this conclusion.

The Hydrostatic Pressure Distribution in the Periodontal Ligament and the Risk of Root Resorption-A Finite Element Method (FEM) Study on the Nonlinear Innovative Model.

Excessive orthodontic force can induce inflammatory tooth root resorption due to sustained high stresses within the periodontal ligament (PDL). This study aimed to analyze the PDL pressures during upper incisor retraction using the en masse method with TISAD. The finite element method (FEM) ensured consistent conditions across cases. The models included bone geometry, adjacent teeth, PDL, and orthodontic hardware, analyzed with LS-Dyna. The pressure ranged from 0.37 to 2.5 kPa across the dental arch, with the central incisors bearing 55% of the load. The pressure distribution remained consistent regardless of the force or hook height. The critical pressure (4.7 kPa) was exceeded at 600-650 g force, with notable pressure (3.88 kPa) on the palatal root wall of the right central incisor. Utilizing 0.017 × 0.025 SS archwires in MBT 0.018 brackets provided good torque control and reduced the root resorption risk when forces of 180-200 g per side were applied, maintaining light to moderate stress. Triple forces may initiate resorption, highlighting the importance of nonlinear finite element analysis (FEA) for accurate oral cavity simulations.

Long-term follow-up after the treatment of impacted canines in the maxilla causing severe root resorption of the lateral incisors: two case reports.

BACKGROUND: Root resorption of adjacent teeth due to impacted canines is common, and orthodontic treatment often leads to secondary resorption or even loss of adjacent roots. Clinical reports of long-term stability after treatment are rare. CASE PRESENTATION: This study reports two cases of maxillary impacted canines resulting in severe root resorption of the adjacent lateral incisors. Surgical exposure, orthodontic retraction, and alignment of the impacted canines were successful in both cases, and the resorbed lateral incisors were stable with no significant loosening and normal pulp vitality after treatment and at the 5- and 10-year follow-up appointments. CONCLUSIONS: Light orthodontic force may be used to move adjacent teeth with root resorption due to tooth obstruction. The path and direction in which the teeth are moved must be specifically designed so that the adjacent roots are not resorbed and so long-term stability can be achieved.

Evaluation of the use of a clinical practice guideline for external apical root resorption among orthodontists.

BACKGROUND: External apical root resorption (EARR) is a frequently observed adverse event in patients undergoing fixed appliance therapy. Assessing the patients' risk during treatment is important, as certain factors are assumed to be associated with an increased likelihood of occurrence. However, their predictive value remains limited, making evidence-based clinical decision-making challenging for orthodontists. To address this issue, the Dutch Association of Orthodontists (NvVO) developed a clinical practice guideline (CPG) for EARR in accordance with the AGREE II instrument (Appraisal of Guidelines for Research and Evaluation II) in 2018. The aim of this study is to get insight into the actual utilization and the practical implementation of the guideline among orthodontists. The hypothesis to be tested was that after its introduction, clinical practice for EARR has changed towards the recommendations in the CPG. OBJECTIVE: To investigate the use of the 2018 clinical practice guidelines for EARR among orthodontists 3 years after its introduction. METHODS: A questionnaire using a 7-point Likert scale was developed concerning four domains of EARR described in the guideline. The questionnaire was piloted, finalised, and then distributed digitally among Dutch orthodontists. REDCap was used for data collection, starting with an invitation email in June 2021, followed by two reminders. Effect was tested by the Mann-Whitney U test, and the influence of demographic variables was analysed. RESULTS: Questionnaires were sent out to all 275 and completed by 133 (response rate 48%); N = 59 females and N = 73 males were included; 81% had their training in the Netherlands, 89% had ≥ 6 years of work experience, and 89% worked in private orthodontic practice. One hundred thirty orthodontists (98.5%) reported changes in clinical practice. The biggest positive change in clinical behaviour regarding EARR occurred if EARR was diagnosed during treatment. Sex, clinical experience, country of specialist training, and working environment of the respondents did not affect clinical practices regarding EARR. CONCLUSIONS: This questionnaire demonstrated that, 3 years after introduction of the guideline, orthodontists improved their self-reported clinical practices to a more standardised management of root resorption. None of the demographic predictors had a significant effect on the results.

Complete idiopathic resorption of distobuccal root of a maxillary first molar: A case report.

Key Clinical Message: This case report provides a rare case of idiopathic root resorption in maxillary first molar and suggests the importance of CBCT in the diagnosis and treatment outcome of complex endodontic diseases. Endodontic surgery is an effective method for treating teeth with persistent apical periodontitis. Abstract: Idiopathic root resorption is an unexplained root resorption when the patient experiences root resorption without any local or systemic factors. Early diagnosis and appropriate treatment are crucial for long-term outcomes.

Three-Dimensional Measurement of Obturation Quality of Bioceramic Materials in Filling Artificial Internal Root Resorption Cavities Using Different Obturation Techniques: An In Vitro Comparative Study.

INTRODUCTION: Pathologic conditions such as internal root resorption (IRR) may complicate root canal filling. This study aimed to evaluate and compare the obturation quality by measuring the percentage of obturation volume (POV) in root canals with artificial IRR obturated with different materials and techniques using cone beam computed tomography (CBCT). METHODS: Forty single canal extracted mandibular premolars were decoronated to standardize their length to 14 mm. Following instrumentation, the roots were cut horizontally, and artificial IRR cavities were made at the level of 7 mm from the apex. The root halves were joined using cyanoacrylate adhesive. The samples were randomly assigned to 4 groups (n = 10), and the canals were filled as follows: single-cone technique (SC), bulk-fill Bio-C Sealer (BF), and Bio-C Repair for the coronal and middle third (BCR) + cold lateral condensation technique (CLC) for the apical third and continuous wave compaction technique (CWC). The pre- and postobturation volumes and the POV were measured in the total canal and for the apical, middle, and coronal thirds separately using CBCT and Mimics Medical software. The results were analyzed statistically using one-way ANOVA and Tukey HSD test, and statistical significance was set at P < .05. RESULTS: BF group resulted in significantly lower total, coronal, middle and apical POV values compared to SC, BCR + CLC, and CWC groups (P < .05), respectively. Also, at the apical third, the BCR + CLC group showed significantly lower POV than the SC and CWC groups (P < .05), respectively. The intra-group comparison showed that BF and BCR + CLC groups had a significantly lower POV in the apical third compared to the middle third (P < .05). Conversely, the CWC group had a significantly higher apical POV than the middle third (P < .05). CONCLUSIONS: The maximum POV was obtained using the CWC technique, Bio-C Repair, and SC technique with Bio-C Sealer, making their application in IRR more preferable than the BF Bio-C Sealer.