Orthodontically Induced External Root Resorption: A Finite Element Analysis.

BackgroundThis study assesses and compares the knowledge level of endodontists (ENDs) and general dental practitioners (GPs) from Brazil and United States of America (USA) in the diagnosis and treatment of internal and external inflammatory root resorptions through periapical radiographic (PA) and cone beam computed tomography (CBCT) examinations. Material and MethodsA cross-sectional online questionnaire-based survey was presented to the volunteers containing questions regarding personal and professional profile, as well as three clinical cases of internal and external inflammatory root resorption. A series of multiple-choice questions about the diagnosis and treatment options were surveyed. The data collected was analysed by the Chi-square test with Yates correction with a significance level of 5 %. ResultsMost answers were considered adequate when all three questions about the diagnosis and all two questions relating to the treatment were answered accurately. A total of 374 dentists answered the survey (n: 229 from Brazil vs. 145 from USA) being 41% END and 59% GP. END presented higher level of knowledge than GP regarding to diagnosis and treatment of inflammatory root resorptions both in Brazil and USA (p<0.05); USA presented higher level of adequate responses than Brazil (p<0.05). ConclusionsEND achieved a level of knowledge of the diagnosis and treatment of root resorption superior to the GP. Comparing the results obtained in both countries, it was observed that the USA had a higher correct response rate than Brazil. Key words:Internal root resorption, external root resorption, management, diagnosis, treatment.

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

External root resorption in permanent teeth can occur as a result of a multitude of local and systemic factors. Root resorption that is idiopathic or occurring without any identifiable underlying cause is an unusual phenomenon, especially in children. This article describes a rare case of extensive external apical root resorption affecting multiple teeth and occurring concomitantly with localized periodontitis in a 13 year-old child. No significant systemic, local or familial findings could be identified as a plausible cause for the root resorption.

Overall stress in periodontal ligament under orthodontic movement during a periodontal breakdown

Introduction: Rhinoplasty, frequently ranked among the most performed cosmetic surgeries around the world, is usually done to adjust the nose’s shape for appearance (aesthetic) or breathing (functional) purposes, or both. Because the procedure deals directly with nasal and facial anatomy, it doesn’t just stop there. It can, and often does, affect nearby structures. The dental region, in particular, tends to be more vulnerable than often anticipated. Risks extend beyond what’s immediately visible. One complication that might arise is root resorption. This involves a slow breakdown of dentin and cementum, set off by odontoclast cells, and can lead, over time, to tooth movement or even loss. Aim of the study: To investigate whether root resorption could emerge as a post-op complication in the maxillary anterior teeth after rhinoplasty. Materials and methods: A total of 195 individuals, aged 18 to 45, underwent either open or closed rhinoplasty procedures, without gender preference, addressing both aesthetic and functional concerns. CBCT scans were obtained at intervals of 3, 6, 9, and 12 months following surgery to check for root resorption evidence. Results: The statistical analysis found no significant relationship between rhinoplasty and root resorption development in maxillary anterior teeth. It found that root resorption occurrence was likely independent of the type of rhinoplasty (chi-square was 3.16, p-value was 0.07, not significant at p&gt;0.05). Conclusion: The study found a non-significant shift toward increased root resorption in the maxillary anterior teeth with rhinoplasty, and it did not suggest decisive evidence of a higher risk. The study also found that external root resorption was more common than internal resorption, and among the teeth observed, it found that the maxillary central incisors ended up being the ones most frequently involved.

BackgroundThe current study attempts to assess the impact of third molar impaction on external root resorption (ERR) of the adjacent second molars. We aimed to determine the prevalence, severity, and associated factors with ERR in a sample of panoramic radiographs.Material and MethodsA retrospective cross-sectional study was carried out at teaching hospital. We reviewed panoramic radiographs from September 2021 to September 2024, selecting images with second and third molars in patients over 16 years old and impacted third molars. ERR was analyzed with respect to patient age and sex. The presence of symptoms, site and severity of root resorption, relationship to angulation, and depth of impaction were also recorded.ResultsA total of 750 panoramic radiographs were examined, and ERR was observed in 32 cases (4.30%). ERR was slightly more common in males (62.5%) than in females (37.5%), but the difference was not statistically significant. The maximum number of ERR cases was found in the age group of 16-25 years (68.7%). Most classification of ERR was mild (71.8%). Mesioangular impacted third molars were associated with 65.6% of resorption cases and position C third molars were associated with 90.6% of resorption cases. The middle third of the root was the most common site of ERR (59.3%).ConclusionsERR of second molars was relatively more common among patients with impacted third molars. Associations were significant for angulation (mesioangular), depth of impaction, and ERR. Hence, a question arises in assessing the amount of risk associated with its impaction in panoramic radiographic imaging. Key words:Impacted, digital panoramic radiography, external root resorption, second molar, third molar.

To evaluate the influence of digital filters of intraoral radiographic systems on the diagnosis of simulated internal and external root resorptions and image quality. Internal root resorption (IRR) and external root resorption (ERR) were simulated in 34 teeth. For image acquisition, two radiographic systems were used: Digora Toto and VistaScan. All filters available in these systems were applied. Three observers scored the detection of root resorptions in a 5-point scale. The noise and the contrast-to-noise ratio (CNR) were calculated. The area under ROC curve, sensitivity, specificity, and accuracy were obtained. One-way ANOVA with Tukey's post hoc tests compared the diagnostic values, noise, and CNR between the filters (α = 0.05). For ERR, there were no significant differences in diagnostic values between the filters tested for both systems. For IRR, Original and Noise Reduction filters presented higher sensitivity than the Sharpen2 filter for images from Digora Toto, with no differences between the other groups. For VistaScan, there were no significant differences of diagnostic values between the groups studied. Noise values differed among the filters of both systems. The CNR of the filters differed only for the bone region for Digora Toto, while for VistaScan, both tooth and bone regions differed. Despite promoting changes in pixel intensities and affecting the noise level of the radiographic images, the digital filters of Digora Toto and VistaScan systems do not affect the diagnosis of internal or external root resorptions. Digital filters are common tools in digital radiographic systems and may be used by the professional without impairment in root resorptions diagnosis.

Objective This research investigate the presence of external root resorption (ERR) in second molars caused by impacted third molars in panoramic radiographs, relating to the position of third molars according to classification of Winter, Pell and Gregory. Material and method A cross-sectional, retrospective study using panoramic radiographs obtained from January 2014 to December 2015. The inclusion criterion was the presence of a second molar adjacent to an impacted third molar. Data were analyzed using descriptive and inferential statistics. Pearson's Chi-Square Test and Fisher's Exact Test (p≤0.05) were performed. Result The sample consisted of 584 panoramic radiographs, 356 (60.95%) of women, and 228 (39.05%) of men, the mean age was 25.31 years. The prevalence of ERR was 12.5%, and the group of 14-24 year olds was the most affected (p = 0.46). The presence of ERR was statistically higher in the mandible (42.1%) with p=0.01. The ERR located in the cervical (57.1%) and medium (58.8%) thirds was proportionally higher in the teeth with B2 (p=0.02) and mesio-angular positions (p=0.26). Conclusion The prevalence of ERR in second molars, caused by impacted third molars, was shown to be similar to results found in the literature, with no gender preference, this affects young patients, occurring frequently in mandible teeth, and presents greater severity in the cervical and middle thirds. The B2 and mesio-angular positions were more prone to ERR.

External apical root resorption diagnosis by using FII human dentine fraction and salivary IGg

In-vitro comparison of 2 cone-beam computed tomography systems and panoramic imaging for detecting simulated canine impaction-induced external root resorption in maxillary lateral incisors

The aim of this study was to correlate the root apex anatomies with external root resorption in patients orthodontically treated through panoramic radiography and cone beam computed tomography (CBCT) methods. Two hundred and forty dental roots were evaluated by tomographic and radiograph images from thirty patients submitted to orthodontic treatment. Orthodontic treatment with fixed appliances was developed based on the technique of straight arc (Straightwire) with Roth prescription. Dental roots anatomy were classified based on shape as: Score 0 – normal root; Score 2 – short root; Score 2 – blunt; Score 3 – bent; and Score 4 – pipette shape. Measurements of external root resorption (ERR) were performed before and after orthodontic treatment by means of CBCT and panoramic radiograph. All patients and 72% of the 173 roots presented with ERR. The frequency of root type, the normal root (score 0) was 88.75% in panoramic radiography and only 18.75% for CBCT. The frequency of ERR was high in maxillary central incisors (73%), maxillary lateral incisors (73%), mandibular central incisors (72%), mandibular lateral incisors (70%). Statistical analysis showed no correlation between the methods, type root and tooth type (p &lt; 0.05). The CBCT had better results for identifying apical roots resorption than panoramic radiograph, but the correlation between the type of root and ERR was not confirmed. How to cite this article Gilbert TJ, Silva MB, Pinto SCS, Bhandi SH, de Musis CR, Castro I, Estrela C, Borges AH, Tonetto MR, Bandeca MC. Is there Correlation between the Root Apex Anatomy with External Root Resorption? World J Dent 2014;5(3):162-165.

To evaluate the influence of enhancement filters on panoramic radiographs for the detection of external root resorption (ERR) in lower second molars caused by impacted third molars. One hundred and twenty-four panoramic radiographs with 182 lower third molars were selected. The corresponding cone-beam computed tomography scans were assessed to create the reference standard. The panoramic radiographs were then exported with and without four enhancement filters (Sharpness, Invert, Invert + Sharpness, and Equalized + Magnification) and independently evaluated by five examiners using a five-point scale for ERR presence. The area under the ROC curve (AUC), sensitivity, and specificity were calculated, and differences between filters were analyzed using ANOVA and Tukey's test. Intra- and inter-examiner agreements were assessed using weighted Kappa index. Diagnostic values were similar across filters for AUC (0.56 to 0.61; p = 0.359), but sensitivity was lower (0.25 to 0.50; p = 0.004) and specificity higher (p = 0.002) for the Invert and Invert + Sharpness filters than for the other situations. Intra-examiner agreement was moderate, while inter-examiner agreement was fair. The diagnostic accuracy of ERR in mandibular second molars on panoramic radiographs is unaffected by filters, but sensitivity decreases with Invert and Invert + Sharpness filters.

The prognosis of replanted teeth depends on several factors, the most important being the length of extra-oral dry time. Studies show that after 60 min dry time, root resorption is predicted. Immediate intracanal placement of Ledermix, a paste containing triamcinolone (corticosteroid) and demeclocycline (tetracycline) has been shown to inhibit root resorption after extended dry time. However, discoloration is possible from the tetracycline in Ledermix. To evaluate the individual influence of corticosteroid and tetracycline on external root resorption after extended extra-oral dry time. Sixty-nine premolar roots of four beagle dogs were extracted and instrumented with NiTi files. Group 1 (negative control) was immediately replanted after root filling with GP and sealer; Group 2 (positive control) was root filled with GP and sealer and replanted after 60 min dry time; In groups 3-5, the canals were filled with Ledermix, Triamcinolone, and Demeclocycline, respectively, and replanted after 60 min dry time. After 4 months, the dogs were sacrificed and the roots were examined histologically for type of healing (favorable or unfavorable) and remaining root diameter. The groups treated with Ledermix, Triamcinolone and Demeclocycline had statistically significantly more favorable healing (75.8%; 69.8%; 52.4%) and more remaining root structure (5.59; 5.48; 5.09) than the group filled with GP and sealer (positive control) (0; 1.15). Corticosteroids were as effective as Ledermix at inhibiting external root resorption.

An elastic finite element analysis was conducted to evaluate the stress distribution in the initiation zone of the adhesive rupture during the 3-point bending test. This test is used to measure the adherence between a polyepoxy adhesive and aluminum alloy with different surface treatments. The purpose is to compare, in the high stress concentration areas, the stress fields calculated using finite element method with the experimental data obtained in different configurations. Focusing on the load level at crack initiation, on the localization and the size of adhesive failure initiation, a local criterion for adhesive fracture is proposed based on the value of the stress normal to the interface.

Residents' journal review