Laser-Aided Circumferential Supracrestal Fiberotomy and Low-Level Laser Therapy Effects on Relapse of Rotated Teeth in Beagles

Objective:To investigate the effectiveness and periodontal side effects of laser circumferential supracrestal fiberotomy (CSF) and low-level laser therapy (LLLT) on orthodontically rotated teeth in beagles.Materials and Methods:Eighteen mandibular incisors from nine dogs were divided into three groups by treatment (n  =  6/group): A, orthodontic couple force application only (control); B, laser CSF following orthodontic couple force application; and C, LLLT following orthodontic couple force application. Both mandibular lateral incisors were rotated for 4 weeks, and the relapse tendency was observed for 4 weeks more without any retainers. The amount of relapse, sulcus depth, and gingival recession were measured at weeks 4 and 8. One-way analysis of variance (ANOVA) and Scheffé''s post hoc test were used for data analysis. Tissue specimens were examined at week 8 under light microscopy after hematoxylin-eosin (H&E) and Masson''s trichrome staining.Results:The mean percentage of relapse was 41.29% in group A, 14.52% in group B, and 56.80% in group C (P < .001). Four weeks after laser CSF, the sulcus depth increased by 0.67 mm, but no gingival recession was observed. There was no significant difference between groups A and C in terms of sulcus depth and gingival recession.Conclusions:Laser CSF is an effective procedure to decrease relapse after tooth rotation, causing no apparent damage to the supporting periodontal structures, whereas LLLT on orthodontically rotated teeth without retainers appears to increase the relapse tendency.     

Variations in root canal morphology of permanent incisors and canines among Asian population: A systematic review and meta-analysis

ObjectivesThis systematic review was designed to measure the pooled prevalence of morphological variations in the root canal of permanent incisors and canines among Asian adults.MethodsAn electronic search was conducted in the PubMed, Scopus, and EBSCO databases, and relevant studies were included. Studies reporting on the Vertucci canal configuration (types I to VIII) were included. A weighted proportion (pooled prevalence) with 95% confidence interval was calculated for each canal type, and the outcome was stratified based on country, technique of assessment, gender, and age.ResultsSixty articles were included in the final review. In all types of maxillary anterior teeth, the pooled prevalence of type I canal configuration was greater than 97%, whereas mandibular central incisor, lateral incisor, and canines had a prevalence of 78.4%, 69.2%, and 91.1%, respectively. Studies considering mandibular anterior teeth as a single entity had a lower prevalence of type I configuration (70.1%). Variations in root canal configurations were also observed between countries. Among gender, males had a significantly lower prevalence of type I and a higher prevalence of type II and III canal configurations in the mandibular anterior teeth. A variation in canal types was also noted with advancing age, with younger age groups showing more variations.ConclusionThe majority of maxillary and mandibular anterior teeth have type I Vertucci canal configuration, but variations in mandibular anterior teeth, especially lateral incisors, are also common. Variations were also observed among population, gender, age, and prevalence based on the diagnostic techniques used.     

Comparisons of different treatment methods and their outcomes for impacted maxillary and mandibular canines: A retrospective study

BackgroundImpacted canines may pose a functional and an esthetic problem for patients and can affect neighboring incisors. The aim of the study was to compare different treatment methods and their outcomes for impacted maxillary and mandibular canines.MethodsThe authors included 102 patients with 118 impacted canines (82 maxillary and 36 mandibular canines). Impacted canine were confirmed during clinical and radiologic examinations. Eighty-five patients (83%) with 97 impacted canines started the treatment. The authors analyzed treatment types and outcomes. Two maxillary and 4 mandibular canines were scheduled for extraction.ResultsOrthodontic extrusion was used most frequently to treat impacted maxillary canines (89%), whereas orthodontic extrusion and transalveolar transplantation were performed most frequently in impacted mandibular canines (33% and 37.5%, respectively). The treatment was successful in 96% of the maxillary and 95% of the impacted mandibular canines.ConclusionsDifferent methods were used for impacted maxillary and mandibular canines, but their overall success rate was high.Practical ImplicationsSuccessful outcome is determined via a well-planned and carefully executed orthodontic and surgical treatment. Early diagnosis is pivotal in facilitating spontaneous canine eruption and implementing transalveolar transplantation in a timely way.     

Comparison of orthodontic root resorption of root-filled and vital teeth: A meta-analysis

BackgroundIn this systematic review, the authors aimed to answer the following question: Do vital teeth differ in the level of external root resorption induced by means of orthodontic treatment compared with root-filled teeth?Types of Studies ReviewedThe search strategy was performed in 6 electronic databases and in gray literature for articles published until July 29, 2021. Two reviewers independently assessed potentially eligible studies according to the following criteria: studies that evaluated patients undergoing fixed orthodontic therapy and compared the mean difference in millimeters of orthodontically induced external root resorption in endodontically treated teeth with the vital contralateral tooth. Only randomized, quasi-randomized, nonrandomized, cohort, case–control, or cross-sectional studies were considered eligible. There were no restrictions on language or publication time. Two reviewers also independently extracted data on the characteristics of the included studies, methods, and results, and performed risk-of-bias analysis using the Meta-Analysis of Statistics Assessment and Review instrument. Estimates of interest were calculated using random-effects meta-analyses. The certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation tool.ResultsEleven studies were included in the quantitative synthesis. Endodontically treated teeth had a lower level of root resorption (mean difference, 0.45 mm; 95% CI, –0.69 to –0.21 mm). However, the level of certainty of the evidence was considered very low owing to confounding factors.Conclusions and Practical ImplicationsEndodontically treated teeth may have a lower level of orthodontically induced root resorption than vital teeth, but the evidence is still uncertain about this outcome. Furthermore, owing to the small effect size, this difference might not be clinically significant (up to 1 mm).     

Stability of maxillary interincisor diastema closure after extraction orthodontic treatment

ObjectivesTo evaluate the stability of maxillary interincisor diastema closure and the relationship between space relapse and interincisor diastema width, overjet, overbite, angulations between adjacent maxillary anterior teeth and presence of intermaxillary osseous cleft after orthodontic treatment with extractions.Materials and MethodsTwenty-four individuals with a maxillary interincisor diastema pretreatment, treated with maxillary first premolar extractions were evaluated. Dental casts and panoramic radiographs taken at pretreatment (T1), posttreatment (T2), and posttreatment follow-up (T3) were assessed. Periapical radiographs at T1 and T2 were also evaluated. Diastema relapse was assumed when T3-T2 interincisor space change was greater than zero. Diastema relapse was considered clinically significant when it was at least 0.50 mm. Data were analyzed using repeated-measures analysis of variance followed by post hoc Tukey tests or Friedman followed by Wilcoxon tests. T-test or Mann-Whitney U-test, Pearson correlation coefficient, and multiple linear regression analyses were also performed.ResultsNo statistically significant relapse of maxillary interincisor diastemas was found. The percentage of clinically significant relapse of the maxillary interincisor diastemas was 27.78%. Specifically, for the interincisor midline diastema, it was 8.33%.ConclusionsMaxillary interincisor diastema closure showed no statistically significant relapse after orthodontic treatment with premolar extractions. Clinically significant stability for maxillary interincisor diastema closure was 72.22% and, specifically, for interincisor midline diastema closure, it was 91.67%.     

Evaluation of posttreatment stability after orthodontic treatment in the mixed and permanent dentitions

Objective:To investigate posttreatment changes in the maxillary and mandibular arches in patients who underwent orthodontic treatment during the mixed and permanent dentitions.Materials and Methods:The sample was collected retrospectively from three private practices and consisted of 42 patients who were at least 10 years out of orthodontic treatment. The longitudinal records of study casts and cephalometric radiographs were analyzed to quantify posttreatment changes.Results:Minimal changes in maxillary and mandibular irregularity occurred after an average of 16.98 years from completion of treatment. More than 10 years posttreatment, approximately 81% of the maxillary anterior teeth and 88% of the mandibular anterior teeth showed clinically acceptable incisor alignment (<3.5 mm). Mandibular fixed retainers greatly aided in maintaining the stability of the mandibular incisor alignment. However, posttreatment changes in maxillary incisor irregularity did not appear to be influenced by the presence of a mandibular fixed retainer. When compared with longitudinal changes observed in untreated subjects, the increase in incisor irregularity resembled a pattern similar to the regression line of untreated subjects and seems to be entirely age related. Arch width and arch depth was consistently decreased after treatment, but the magnitude of change was minimal at about 1 mm. No associations were found between any of the cephalometric measurements and changes in incisor irregularities.Conclusions:Orthodontic treatment stability can be achieved and mandibular fixed retention appears to be a valuable contributor, especially in patients with further growth expected.     

The influence of age and orthodontic debonding on the prevalence and severity of enamel craze lines

BackgroundCraze lines may cause esthetic concerns, especially when noted on the incisors. Various light sources with additional recording apparatus have been proposed to visualize craze lines, but a standardized clinical protocol is yet to be determined. This study aimed to validate the application of near-infrared imaging (NIRI) from intraoral scans to evaluate craze lines and to determine the influence of age and orthodontic debonding on their prevalence and severity.MethodsThe NIRI of maxillary central incisors from a full-mouth intraoral scan and photographs from an orthodontic clinic (N = 284) were collected. The prevalence of craze lines and influence of age and orthodontic debonding history on severity were evaluated.ResultsCraze lines were detected reliably as white lines distinguishable from dark enamel using the NIRI from intraoral scans. The craze line prevalence was 50.7%, which was significantly higher in patients 20 years or older than in patients younger than 20 years (P < .001), with more frequent severe craze lines for those 40 years or older than in patients younger than 30 years (P < .05). Prevalence or severity was similar between patients with and without an orthodontic debonding history regardless of the type of appliance.ConclusionThe prevalence of craze lines in the maxillary central incisor was 50.7%, with a higher prevalence in adults than in adolescents. Orthodontic debonding did not affect the severity of craze lines.Practical ImplicationsCraze lines were reliably detected and documented by means of applying NIRI from intraoral scans. Intraoral scanning can provide new clinical information on enamel surface characteristics.     

Permanent maxillary central incisor and first molar rotations in the mixed dentition in repaired complete unilateral cleft lip and palate and their relationship with absence of teeth in their vicinity

Objectives:To describe qualitatively and quantitatively the directions and magnitudes of rotations of permanent maxillary central incisors and first molars in the mixed dentition in repaired complete unilateral cleft lip and palate (UCLP) and study their associations with absence of teeth in their vicinity.Materials and Methods:Dental casts and orthodontic records taken prior to orthodontic preparation for alveolar bone grafting of 74 children with repaired UCLP (53 male, 21 female; aged 8.9 ± 1.0 years) were studied. Directions and magnitudes of permanent maxillary central incisor and first molar rotations were recorded. Tooth absence was confirmed from longitudinal radiographic records. Incisor and molar rotations were analyzed in relation to the absence of teeth in their vicinity.Results:Distolabial rotation of the permanent maxillary central incisor was noted in 77.14% on the cleft side, while distopalatal rotation was noted in 82.19% on the noncleft side. Incisor rotation was greater when a permanent tooth was present distal to the cleft side central incisor, in the greater segment. The permanent maxillary first molar showed mesiopalatal rotation, which was greater on the cleft side and when there was absence of one or more teeth in the buccal segment.Conclusions:Presence and absence of teeth were associated with the severity of incisor and molar rotations in UCLP. Crowding of anterior teeth in the greater segment was associated with a greater magnitude of rotation of the cleft side permanent central incisor. Absence of one or more buccal segment teeth was associated with greater magnitude of rotation of the molar.     

Effectiveness of computer-assisted orthodontic treatment technology to achieve predicted outcomes

Objective:To evaluate the effectiveness of computer-assisted orthodontic treatment technology to produce the tooth position prescribed by the virtual treatment plan.Materials and Methods:Posttreatment models of 23 patients treated with SureSmile were digitally superimposed on their corresponding virtual treatment plan models utilizing best-fit surface-based registration. Individual tooth-position discrepancies between virtual treatment plan and actual outcome were computed. Discrepancies less than 0.5 mm in mesial-distal, facial-lingual, and vertical dimensions, and less than 2° for crown torque, tip, and rotation were considered clinically ideal. One-sided test of equivalence was performed on each discrepancy measurement, with P < .05 considered statistically significant.Results:Mesial-distal tooth position was clinically ideal for all teeth with the exception of maxillary lateral incisors and second molars. Facial-lingual tooth position was clinically ideal for all teeth except maxillary central incisors, premolars, and molars, and mandibular incisors and second molars. Vertical tooth position was clinically ideal for all teeth except mandibular second molars. For crown torque, tip, and rotation, discrepancy exceeded the limits considered clinically ideal for all teeth except for crown torque on mandibular second premolars and crown tip on mandibular second premolars and first molars.Conclusions:The effectiveness of computer-assisted orthodontic treatment technology to achieve predicted tooth position varies with tooth type and dimension of movement.     

Changes in the gingival thickness and keratinized gingival width of maxillary and mandibular anterior teeth after orthodontic treatment

ObjectivesTo evaluate changes in the gingival thickness (GT) and keratinized gingival width (KGW) of the maxillary and mandibular central and lateral incisors and canines after fixed orthodontic treatment and their association with sagittal tooth movement (STM).Materials and MethodsIn this study of both arches, 60 periodontally healthy subjects who had completed fixed orthodontic treatment were included. Using pretreatment and posttreatment lateral cephalograms, STM of the maxillary (1-NA angle and distance, and 1-SN angle) and mandibular (1-NB angle and distance, and IMPA angle) incisors were evaluated to divide the subjects into protrusion and retrusion groups. Pretreatment and posttreatment GT was identified via transgingival probing, and KGW was calculated from the free gingival margin to the mucogingival junction.ResultsThe intragroup pretreatment and posttreatment comparison results showed a significant decrease in the GT of the maxillary and mandibular anterior teeth in the protrusion and retrusion groups and a decrease in the KGW of the maxillary lateral incisors in the protrusion group. Pearson correlation coefficient analyses for maxillary and mandibular anterior teeth revealed that the GT changes were not significantly associated with STM. However, a positive correlation existed between the KGW of tooth numbers 13 and 41 and STM.ConclusionsSTM was not significantly associated with decreased GT of the maxillary and mandibular anterior teeth, but it was positively correlated with the KGW of tooth numbers 13 and 41.     

Mandibular irregularity index stability following alveolar corticotomy and grafting: A 10-year preliminary study

Objective:To evaluate mandibular irregularity index stability following orthodontic treatment facilitated by alveolar corticotomy and augmentation bone grafting (Cort+).Materials and Methods:The irregularity index of 121 orthodontically treated and 15 untreated patient study casts was analyzed at 5 years and 10 years.Results:Cort+ resulted in significantly lower mandibular irregularity index scores at both 5 years (1.5 mm vs 4.2 mm, P < .000) and 10 years (2.1 mm vs 4.1 mm, P < .000) compared with conventionally treated patients.Conclusions:Unmatched samples advise caution with conclusions, but orthodontic therapy combined with Cort+ enhanced the stability of the postorthodontic mandibular irregularity index for at least 10 years in this preliminary study.     

A long-term prospective evaluation of the circumferential supracrestal fiberotomy in alleviating orthodontic relapse

This prospective study conducted during a period of nearly 15 years initially involved 320 consecutively selected cases. The primary purpose of the investigation was to statistically evaluate the efficacy of the circumferential supracrestal fiberotomy (CSF) procedure in alleviating dental relapse following orthodontic treatment. The "Irregularity Index" method of Little for measuring the malposition of teeth was used to quantitatively record the relapse of the control and CSF cases at approximately 4 to 6 years after active treatment and again at 12 to 14 years after active treatment. The differences between the mean relapses of the control and the CSF cases were highly significant at both time intervals. The surgical procedure appeared to be somewhat more effective in alleviating pure rotational relapse than in labiolingual relapse. On a long-term basis, the CSF procedure was shown to be more successful in reducing relapse in the maxillary anterior segment than in the mandibular anterior segment. Nevertheless, a significant and unpredictable variation in individual tooth movement following orthodontic treatment was observed in both the control and CSF groups. No clinically significant increase in the periodontal sulcus depth nor decrease in the labially attached gingiva of the CSF teeth was observed at 1 and 6 months following the surgical procedure.     

Three-dimensional evaluation of long-term skeletal relapse following Le Fort I maxillary advancement surgery: a 2-year follow-up study

The aim of this study was to assess relapse following Le Fort I (LFI) maxillary advancement with superior or inferior repositioning at 2 years of follow-up. A total of 50 patients (26 female, 24 male; age range 15–56 years) with skeletal class II or III, who underwent bimaxillary surgery with LFI maxillary advancement in combination with either superior or inferior repositioning and also mandibular advancement/setback, were recruited. Preoperative (T0), immediate postoperative (T1), and 2-year postoperative (T2) cone beam computed tomography scans were acquired. Data were imported into a validated module to assess the skeletal movement (T0–T1) and relapse (T1–T2). Overall, the majority of the translational and rotational movements showed a relapse of <1 mm and <1°. Patients undergoing maxillary advancement with inferior repositioning in combination with mandibular advancement showed the highest amount of translational relapse in a superior (0.86 ± 0.85 mm, P < 0.0001) and posterior direction (?0.65 ± 1.11 mm, P < 0.0001). In relation to patients who received a bone graft, inferior repositioning with mandibular setback showed the highest maxillary relapse in a superior direction (1.20 ± 1.56 mm, P = 0.0719) with counterclockwise pitch rotation (2.15 ± 0.64°, P = 0.3759). Amongst the non-grafted procedures, superior repositioning with mandibular setback exhibited the highest relapse in a medial direction (1.38 ± 2.78 mm, P = 0.3981). Maxillary advancement was found to be a highly stable procedure with a lack of superoinferior stability in patients undergoing inferior repositioning.     

扭转前牙牙龈环切术的临床应用

扭转牙的复发是正畸临床治疗后牙稳定性的难题之一。本文介绍一种简单的手术方法用来防止扭转牙矫正后的复发,即牙龈环切术的原理和临床应用。通过对3例前牙扭转外翻的患者进行正畸治疗,然后采用牙龈环切术,观察术后扭转牙的稳定性。通过3个月的随访观察,扭转牙齿保持良好。牙龈环切术方法简单、操作简便,防止扭转牙复发有效,值得在临床推广应用。     

Short-term effects of fiberotomy on relapse of anterior crowding

The effects of fiberotomy were evaluated in alleviating dental relapse of incisors after orthodontic treatment. The study sample consisted of 23 patients with crowded maxillary and mandibular incisors before orthodontic treatment. The amount of initial crowding was determined according to Little's irregularity index. Fiberotomy procedures were performed on 11 of the patients 1 week before debonding. The other 12 subjects served as the control group. All patients wore Hawley retainers. Lateral cephalometric headfilms and dental casts of the patients were taken at the beginning (T1) and at the end (T2) of treatment, 6 months into the retention phase (T3), and 1 year after orthodontic treatment (T4). Significant increase of irregularity index was noted in the control group at T3 and T4 for both maxillary and mandibular anterior segments (P <.05, P <.01). Meanwhile, in the group where circumferential supracrestal fiberotomy was performed, no significant increase of the irregularity index was noted.