Effect of apical root resection, orthodontic extrusion, and surgical crown lengthening on load capability.

OBJECTIVES: This study aims to investigate the load-to-fracture of procedures changing crown-to-root ratio (RCRR) aimed to restore severely damaged upper central incisors to avoid tooth extraction compared to implant placement. There is no evidence on load capability after apical root resection (AR), orthodontic extrusion (OE), and surgical crown lengthening (SCL) in respect to RCRR, respectively. MATERIAL AND METHODS: Human maxillary central incisors were endodontically treated, decoronated, and divided into 4 groups (n = 48). The following specimen preparation was performed: (I) adhesive core-and-post build-up (control), (II) as (I) and 2 mm apical root resection (AR), (III) before adhesive core-and-post build-up teeth were shortened 2 mm coronally (OE) (IV) as (I), but specimens were embedded 4 mm instead of 2 mm below the CEJ (SCL), group (V) implant-borne restoration with individual all-ceramic abutments (n = 12; ∅4.1/l = 12 mm) (IBR). All specimens received all-ceramic crowns, thermo-mechanical (TML), and subsequent linear loading (LL) until failure. RCRR were calculated and log-rank, Kruskal-Wallis, Mann-Whitney U, ANOVA, and chi-square tests applied (p = 0.05). RESULTS: Fracture loads after subsequent LL differed significantly (p = 0.001) between groups, while implants showed the highest values. Fmax median (min/max) were as follows: (I) 252 (204/542), (II) 293 (243/443), (III) 253 (183/371), (IV) 195 (140/274), and (V) 446 (370/539). Pair-wise comparison showed significant differences (p = 0.001) between group I/IV and group V, I, and IV (p = 0.045), II and IV (p = 0.001), and III compared to IV (p = 0.033), respectively. RCRR below 1 significantly increased load capability compared to RCRR = 1. CONCLUSIONS: OE appears to preferably ensure biomechanical stability of teeth that are endodontically treated and receive core-and-post and crown placement compared to SCL. AR has no adverse biomechanical impact. RCRR < 1 is biomechanically beneficial. CLINICAL RELEVANCE: For endodontically treated and restored teeth, orthodontic extrusion should be preferred compared to surgical crown lengthening prior single-crown restoration. As orthodontic extrusion, apical root resection has no adverse effect on load capability. Single-crown implant-borne restorations are most load capable.

A Novel Approach for Orthodontic Extrusion Prior to Intentional Replantation: A Case Report.

AIM: This case report aimed to present a novel surgical technique involving orthodontics luxation of the offended tooth using miniscrew prior to performing intentional replantation (IR) to remove an extruded separated instrument that injured the inferior alveolar nerve (IAN). BACKGROUND: Intentional replantation is a dental procedure that involves extracting a tooth, managing the root canal, and then reinserting the tooth back into its socket. This procedure is typically used as a last resort when other treatment options have failed or are not possible. Intentional replantation can be successful in preserving the tooth and preventing tooth loss, but it is important to note that there are risks involved. Maintaining the viability of the periodontal ligament (PDL) is a pivotal step to achieve a favorable outcome. CASE DESCRIPTION: A 15-year-old female patient came to the clinic complaining of electric-like pain in the left mandibular posterior area that radiated to the left ear and sometimes caused a headache. Upon clinical and radiographic evaluation, extruded endodontic file from the mesial root of the left first molar that penetrated the IAN canal was noticed. Nonsurgical root canal retreatment was performed, which failed to retrieve the separated file. Orthodontics luxation of the offended tooth was done 2 weeks before the surgical intervention using a miniscrew to induce PDL inflammation, which increased the tooth mobility and PDL volume, facilitating the atraumatic extraction and reduced the risk of complications, such as root resorption and ankylosis. Then, IR was performed, and the extruded file was successfully retrieved. Three months follow-up showed complete recovery of the endodontics-related IAN injury symptoms. Preapical radiographic evaluation and cone-beam computed tomography scan showed complete healing of the periapical radiolucency/area of low density and complete formation of the PDL space and lamina dura around the resected roots. CONCLUSION: This novel approach using a miniscrew suggests a noninvasive technique that minimizes the damage to the offended tooth surrounding tissues as well as minimizing the morbidity of the adjacent teeth and the vital anatomical structures. CLINICAL SIGNIFICANCE: Multidisciplinary comprehensive preplanning of complicated cases is essential to maximize treatment efficiency. The orthodontic extrusion facilitates the extraction process that helps in preserving the PDL, and ultimately increases the survivability of the teeth. How to cite this article: Alharbi MA, Alghamdi BA, Alswajy WA, et al. A Novel Approach for Orthodontic Extrusion Prior to Intentional Replantation: A Case Report. J Contemp Dent Pract 2023;24(11):895-901.

An in vitro study evaluating the effect of ferrule design on the fracture resistance of endodontically treated mandibular premolars after simulated crown lengthening or forced eruption methods.

BACKGROUND: The purpose of this study was to evaluate the effect of ferrule design on the fracture resistance of endodontically treated mandibular first premolars after simulated crown lengthening and orthodontic forced eruption methods restored with a fiber post-and-core system. METHODS: Forty extracted and endodontically treated mandibular first premolars were decoronated to create lingual-to-buccal oblique residual root models, with a 2.0 mm height of the lingual dentine wall coronal to the cemento-enamel junction, and the height of buccal surface at the cemento-enamel junction. The roots were divided randomly into five equal groups. The control group had undergone incomplete ferrule preparation in the cervical root, with 0.0 mm buccal and 2.0 mm lingual ferrule lengths (Group F0). Simulated surgical crown lengthening method provided ferrule preparation of 1.0 mm (Group CL/F1) and 2.0 mm (Group CL/F2) on the buccal surface, with ferrule lengths of 3.0 mm and 4.0 mm on the lingual surface, respectively. Simulated orthodontic forced eruption method provided ferrule preparation of 1.0 mm (Group OE/F1) and 2.0 mm (Group OE/F2) on the buccal surface and ferrule lengths of 3.0 mm and 4.0 mm on the lingual surface, respectively. After restoration with a glass fiber post-and-core system and a cast Co-Cr alloy crown, each specimen was embedded in an acrylic resin block to a height on the root 2.0 mm from the apical surface of the crown margin and loaded to fracture at a 135° angle to its long axis in a universal testing machine. Data were analyzed statistically using two-way ANOVA with Tukey HSD tests and Fisher's test, with α = 0.05. RESULTS: Mean fracture loads (kN) for groups F0, CL/F1, CL/F2, OE/F1 and OE/F2 were as follows: 1.01 (S.D. = 0.26), 0.91 (0.29), 0.73 (0.19), 0.96 (0.25) and 0.76 (0.20), respectively. Two-way ANOVA revealed significant differences for the effect of ferrule lengths (P = 0.012) but no differences for the effect of cervical treatment methods (P = 0.699). The teeth with no buccal ferrule preparation in control group F0 had the highest fracture resistance. In contrast, the mean fracture loads for group CL/F2 with a 2.0-mm buccal and 4.0-mm lingual ferrule created by simulated crown lengthening method were lowest (P = 0.036). CONCLUSIONS: Increased apically complete ferrule preparation resulted in decreased fracture resistance of endodontically treated mandibular first premolars, regardless of whether surgical crown lengthening or orthodontic forced eruption methods been used.

Root length and alveolar bone level of impacted canines and adjacent teeth after orthodontic traction: a long-term evaluation.

OBJECTIVE: The aim of this retrospective study was to evaluate the long-term effects of orthodontic traction on root length and alveolar bone level in impacted canines and adjacent teeth. MATERIAL AND METHODS: Sample consisted of 16 patients (nine males and seven females), mean initial age 11 years and 8 months presenting with unilaterally maxillary impacted canines, palatally displaced, treated with the same surgical and orthodontic approach. Teeth from the impacted-canine side were assigned as Group I (GI), and contralateral teeth as control, Group II (GII). The mean age of patients at the end of orthodontic treatment was 14 years and 2 months and the mean post-treatment time was 5 years and 11 months. Both contralateral erupted maxillary canines and adjacent teeth served as control. Root length and alveolar bone level (buccal and palatal) were evaluated on cone-beam computed tomography (CBCT) images. The comparison of root length and alveolar bone level changes between groups were assessed by applying paired t-test, at a significance level of 5% (p<0.05). RESULTS: There were no statistically significant differences in root length and buccal and palatal bone levels of canines and adjacent teeth among groups. CONCLUSIONS: Impacted canine treatment by closed-eruption technique associated with canine crown perforation, has a minimal effect on root length and buccal and palatal alveolar bone level in both canine and adjacent teeth, demonstrating that this treatment protocol has a good long-term prognosis.

Root length and alveolar bone level of impacted canines and adjacent teeth after orthodontic traction: a long-term evaluation

Abstract Objective The aim of this retrospective study was to evaluate the long-term effects of orthodontic traction on root length and alveolar bone level in impacted canines and adjacent teeth. Material and Methods Sample consisted of 16 patients (nine males and seven females), mean initial age 11 years and 8 months presenting with unilaterally maxillary impacted canines, palatally displaced, treated with the same surgical and orthodontic approach. Teeth from the impacted-canine side were assigned as Group I (GI), and contralateral teeth as control, Group II (GII). The mean age of patients at the end of orthodontic treatment was 14 years and 2 months and the mean post-treatment time was 5 years and 11 months. Both contralateral erupted maxillary canines and adjacent teeth served as control. Root length and alveolar bone level (buccal and palatal) were evaluated on cone-beam computed tomography (CBCT) images. The comparison of root length and alveolar bone level changes between groups were assessed by applying paired t-test, at a significance level of 5% (p<0.05). Results There were no statistically significant differences in root length and buccal and palatal bone levels of canines and adjacent teeth among groups. Conclusions Impacted canine treatment by closed-eruption technique associated with canine crown perforation, has a minimal effect on root length and buccal and palatal alveolar bone level in both canine and adjacent teeth, demonstrating that this treatment protocol has a good long-term prognosis.

The Prognosis of Altered Sensation after Extrusion of Root Canal Filling Materials: A Systematic Review of the Literature.

INTRODUCTION: The aim of this study was to systematically review and evaluate the literature regarding the prognosis of altered sensation after extrusion of root canal filling materials and the possible factors influencing it. METHODS: A systematic search of the literature was performed to identify studies that reported on altered sensation after extrusion of root canal filling materials during endodontic treatments. The articles were evaluated for their relevance based on strict inclusion criteria, and the identified suitable articles were subject to data extraction and analysis. RESULTS: Initially, 109 possibly relevant articles were identified. After screening and full-text evaluations, 28 articles that met the inclusion criteria were analyzed, reporting on a total of 84 patients with altered sensation after extrusion of root canal filling materials. All the included studies, except 1 case series, were case reports. Under the limited available data, the extracted data showed that 91% of the patients had fully or partially recovered over time. Most of the cases in the lower molars as well as most of the cases in which the obturation was performed using paraformaldehyde-containing sealer or cases in which an immediate treatment was not performed did not fully recover. CONCLUSIONS: The current scientific knowledge regarding the prognosis of nerve injuries caused by overextruded endodontic materials relies primarily on case reports. Within the limitations of the published data, it seems that the tooth locations, types of extruded materials and the obturation technique, and treatment after the injury may affect the nerve injury prognosis.

A comparison of apical root resorption after orthodontic treatment with surgical exposure and traction of maxillary impacted canines versus that without impactions.

SUMMARY BACKGROUND/OBJECTIVES: Orthodontic management of maxillary canine impaction (MCI), including forced eruption, may result in significant root resorption; however, the association between MCI and orthodontically induced root resorption (OIRR) is not yet sufficiently established. The purpose of this retrospective cohort study was to comparatively evaluate the severity of OIRR of maxillary incisors in orthodontically treated patients with MCI. Additionally, impaction characteristics were associated with OIRR severity. SUBJECTS AND METHODS: The sample comprised 48 patients undergoing fixed-appliance treatment-24 with unilateral/bilateral MCI and 24 matched controls without impaction. OIRR was calculated using pre- and post-operative panoramic tomograms. The orientation of eruption path, height, sector location, and follicle/tooth ratio of the impacted canine were also recorded. Mann-Whitney U-test and univariate and multivariate linear mixed models were used to test for the associations of interest. RESULTS: Maxillary central left incisor underwent more OIRR in the impaction group (mean difference = 0.58mm, P = 0.04). Overall, the impaction group had 0.38mm more OIRR compared to the control (95% confidence interval, CI: 0.03, 0.74; P = 0.04). However, multivariate analysis demonstrated no difference in the amount of OIRR between impaction and non-impaction groups overall. A positive association between OIRR and initial root length was observed (95% CI: 0.08, 0.27; P < 0.001). The severity of canine impaction was not found to be a significant predictor of OIRR. LIMITATIONS: This study was a retrospective study and used panoramic tomograms for OIRR measurements. CONCLUSIONS: This study indicates that MCI is a weak OIRR predictor. Interpretation of the results needs caution due to the observational nature of the present study.

Adverse events of surgical extrusion in treatment for crown-root and cervical root fractures: a systematic review of case series/reports.

BACKGROUND: Crown-root and cervical root fractures constitute a restorative challenge due to sub-gingival position of the fracture margin. Surgical tooth extrusion is one of the treatment options. There is uncertainty regarding the prognosis of such treatment modality. OBJECTIVE: To assess adverse events of surgical tooth extrusion in the treatment for crown-root and cervical root fractures in permanent teeth. METHODS: PubMed, Embase, and Google Scholar were searched through 15th of June 2012. Search was limited to English and Arabic languages. Reference list of relevant studies were hand-searched. Grey literature was searched using Open Grey. Two review authors independently extracted data, while only one assessed trial quality using 8-point methodological index for non-randomized studies (MINORS) scale. A sensitivity analysis was performed to exclude studies with suspected patients' duplicates. RESULTS: Eleven case reports and eight case series involving 226 patients with 243 teeth were identified. No randomized controlled trials were found. The mean quality score for all case series was 9 suggesting a fair quality, while that of all case reports was 5 suggesting poor quality. Non-progressive root resorption is the most common finding following surgical extrusion with an event rate of 30% (95% CI 24.6-36.7%). This is followed by low event rates of tooth loss (5%), slight mobility (4.6%), marginal bone loss (3.7%), and progressive root resorption (3.3%). No ankylosis occurred to any extruded tooth, while severe tooth mobility showed negligible overall event rate of 0.4%. CONCLUSION: The available evidence suggests that surgical tooth extrusion is a valid technique in management of crown-root and cervical root fracture of permanent teeth. Minimal adverse events and good prognosis are expected. Further, surgical extrusion can be considered as a treatment option in teeth suffering sub-gingival decay.

Controlled tooth movement to correct an iatrogenic problem.

This case report describes the treatment of a 9-year old boy, who had his maxillary central incisors extruded by noncontrolled elastic mechanics to close a diastema. The article describes the consequences of this movement and how the problem was solved with controlled intrusion.

Analysis of failure in the treatment of impacted maxillary canines.

INTRODUCTION: In this study, we aimed to evaluate the reasons for failure of orthodontic treatment for impacted maxillary canines and to recommend measures to overcome them. METHODS: Twenty-eight patients (ages, 17.4 +/- 4.3 years) with 37 maxillary impacted canines were referred after a failed attempt to resolve the impaction. Reasons for failure were analyzed, and corrective measures undertaken. The success rate of the revised treatments and the durations of both treatments were recorded. RESULTS: The mean duration of the failed treatments was 26.2 +/- 17.2 months. The failed treatments were mostly based on plane radiographs, intra-arch dental anchorage, and elastic traction directly to the labial archwire. The major reasons for failure were inadequate anchorage (48.6%), mistaken location and directional traction (40.5%), and ankylosis (32.4%). In several patients, there was more than 1 possible reason for failure. The success rate of the revised treatments was 71.4%, and the mean duration was 14.4 +/- 7.2 months. Repeat surgery was needed for 62.9% of the canines in which corrective treatment was started, mostly to redirect the ligature wires. The corrective measures included the use of 3-dimensional imaging and a change in the direction of traction. Anchorage was reinforced by dental and skeletal means. CONCLUSIONS: Inaccurate 3-dimensional diagnosis of location and orientation of impacted teeth and failure to appreciate anchorage demands were the major reasons for failure in the treatment of impacted canines.

Influence of orthodontic extrusion on pulpal vitality of traumatized maxillary incisors.

INTRODUCTION: The aim of this retrospective study was to examine the effect of orthodontic extrusion on the pulpal vitality of maxillary incisors with a history of trauma. METHODS: Pulpal condition was examined clinically (rating of crown color and sensitivity testing with a cryogenic spray) and radiologically (periapical and panoramic radiographs) after orthodontic extrusion of previously traumatized (Orthodontics/Trauma group, n = 77) and nontraumatized teeth (Orthodontics group, n = 400) and after previous dental trauma without subsequent orthodontic treatment (Trauma group, n = 193). Dental traumata were divided into hard tissue injuries (fracture of enamel and enamel chipping, fracture of enamel-dentin without pulpal involvement, fracture of enamel-dentin with pulpal involvement, root fracture, crown-root fracture) and periodontal injuries (concussion, subluxation, intrusion, extrusion, lateral luxation, and avulsion). RESULTS: Teeth in the Orthodontics/Trauma group showed a significantly higher frequency of pulp necrosis than teeth in the Orthodontics group (P < .001) or teeth in the Trauma group (P < .009). In addition, teeth in the Orthodontics/Trauma group with periodontal injuries showed a significantly higher rate of pulp necrosis than teeth in the Orthodontics group (P < .001) or the corresponding teeth in the Trauma group (P = .004). No significant differences were observed between teeth in the Orthodontics/Trauma group with previous hard tissue injuries and teeth in the Orthodontics group or the corresponding teeth in the Trauma group. In addition, no statistically significant differences were determined between central and lateral incisors. CONCLUSIONS: The results indicated that maxillary incisors with a history of severe periodontal injury have a higher susceptibility to pulp necrosis during orthodontic extrusion than nontraumatized teeth.

Fracture resistance after simulated crown lengthening and forced tooth eruption of endodontically-treated teeth restored with a fiber post-and-core system.

PURPOSE: To evaluate the effect of ferrule preparation length on the fracture resistance after simulated surgical crown lengthening and after forced tooth eruption of endodontically-treated teeth restored with a carbon fiber-reinforced post-and-core system. METHODS: 40 extracted endodontically-treated mandibular first premolars were decoronated 1.0 mm coronal to the buccal cemento-enamel junction. The teeth were divided randomly into five equal groups. The control group had no ferrule preparation (Group A). Simulated crown lengthening provided ferrule preparations of 1.0 mm (Group B) and 2.0 mm (Group C). Simulated forced tooth eruption provided ferrule preparations of 1.0 mm (Group D) and 2.0 mm (Group E). After restoration with a carbon fiber post-and-core system, each root was embedded in an acrylic resin block from 2.0 mm apical to the margins of a cast Ni-Cr alloy crown, and loaded at 150 degrees from the long axis in a universal testing machine at a crosshead speed of 1.0 mm/minute until fracture. Data were analyzed using ANOVA with Tukey HSD tests, and Fisher's exact test, with alpha = 0.05. RESULTS: Mean failure loads (kN) for Groups A, B, C, D and E were: 1.13 (SD = 0.15), 1.27 (0.18), 1.02 (0.11), 1.63 (0.14) and 1.92 (0.19), respectively. Significant differences were shown for the effects of treatment method and ferrule length, with significant interaction between these two sources of variation (P < 0.0001). Increased apical ferrule preparation lengths resulted in significantly increased fracture resistance for simulated forced tooth eruption (P < 0.0001), but not for simulated crown lengthening (P > or = 0.24).

Significant association between tooth extrusion and tooth resorption in domestic cats.

Abnormal extrusion of canine teeth is often noted in middle-aged and geriatric domestic cats. The same age group of cats also is commonly affected by tooth resorption (TR). This study explored the relationship between these two phenomena of unknown etiology. Using digital radiography, the distance between the alveolar margin (AM) and cementoenamel junction (CEJ), referred to as the AM-CEJ distance, was measured in clinically and radiographically healthy maxillary canine teeth of 24 TR-affected and 29 TR-free cats. The mean AM-CEJ distance of maxillary canine teeth of cats with and cats without TR was 2.68-mm and 2.22-mm, respectively. An analysis of covariance adjusting for age revealed a significant correlation (p = 0.02) between tooth extrusion and TR. Extrusion of the maxillary canine teeth became clinically apparent when an AM-CEJ distance of 2.5-mm or greater was evident in the absence of horizontal or vertical alveolar bone loss. Based on this criterion, 15 of 24 cats with TR (63.0 %) exhibited extrusion of maxillary canine teeth, compared to 9 of 29 cats without TR (31.0 %). Four extruded and five non-extruded maxillary canine teeth were evaluated histologically. Cementum of extruded teeth was significantly thicker compared to that of non-extruded teeth. Four of 4 canine teeth with extrusion (100 %) showed histological evidence of resorption, compared to 1 of 5 canine teeth without extrusion (20.0 %). These results suggest that tooth extrusion is linked to or may be caused by similar factors responsible for the development of TR.

Adverse effects of orthodontics: a report of 2 cases.

Adverse effects are results beyond the expected good outcomes of treatment. Like any other field in dentistry and medicine, orthodontics is not immune to such effects. The probability of adverse results in orthodontics increases when important rules and facts are ignored. To illustrate this, treatment and its adverse effects in 2 patients are discussed. In 1 young adult female, a palatally impacted maxillary canine was being moved into its place in the arch when it became ankylosed. Despite the cessation of movement, the orthodontist continued to apply mechanical forces to the canine for an additional 16.5 years. The effect of this extremely prolonged treatment period on the rest of the dentition was devastating. In another case, a 12-year 10-month-old boy with a mild Class II, Division 1 malocclusion, developed alopecia areata 4 months after the onset of orthodontic treatment. Four months later, he had lost all of his hair (alopecia totalis). The etiology of this condition was determined to be psychological stress and anxiety evoked by the orthodontic treatment. In both cases, the orthodontists failed to recognize existing problems or chose to ignore them. It was concluded that these adverse effects of orthodontic treatment could have been avoided if the orthodontists would have paid closer attention to the tissue response to mechanotherapy, as well as to the patient's attitude toward treatment. The latter conclusion is particularly noticeable when treating children and teenagers, who can reject being forced by their parents to undergo orthodontic treatment.

Comparison of surgical and non-surgical methods of treating palatally impacted canines. I. Periodontal and pulpal outcomes.

BACKGROUND: Inferior periodontal and pulpal outcomes may follow surgical exposure of palatally impacted maxillary canines. OBJECTIVES: To compare the periodontal and pulpal health of palatally impacted maxillary canines following either surgical exposure and assisted eruption (SE) or unassisted eruption following extraction of the overlying deciduous canine and orthodontic creation of space in the arch (OT). METHODS: Twenty-eight subjects (OT group: N = 14; SE group: N = 14) with unilateral palatally impacted canines were examined at least six months after orthodontic treatment. The gingival index score, plaque index score, pocket depth, attachment loss, tenderness to percussion, pulpal responses to stimuli and radiographic assessment of changes in the pulpal cavities and peri-radicular areas were collected on the maxillary canines, lateral incisors and premolars. The contralateral teeth were used as controls. RESULTS: There were no significant differences in the plaque index scores, the gingival index scores or the periodontal outcomes between the impacted canines in the two groups (SE and OT). More impacted canines than control canines had lost some periodontal attachment in the SE group (p = 0.004). Although more lateral incisors, canines and premolars on the impacted side had partially obliterated pulps than the corresponding teeth on the control side, the teeth in both groups had similar pulpal responses (p = 0.064). CONCLUSIONS: Natural eruption and conservative surgical exposure with orthodontic alignment have minor effects on the periodontium. Impacted canines treated surgically and non-surgically had a higher prevalence of pulpal changes than the control canines. Ultimately, the choice of treatment may depend on the clinical indications, the patient's and the orthodontist's preferences.

Orthodontic and periodontal outcomes of treated impacted maxillary canines.

OBJECTIVE: To evaluate the influence of pretreatment radiographic features (alpha-angle, d-distance, and s-sector) on (1) the duration of active orthodontic traction and (2) the posttreatment periodontal status (pocket depth [PD] and keratinized tissue width [KT]) of impacted maxillary canines treated by a combined surgical (flap approach) and orthodontic (direct traction to the center of the ridge) treatment. MATERIAL AND METHODS: A study population of 168 patients (168 canines) was evaluated. Multiple regression analysis was used. RESULTS: Pretreatment radiographic variables were associated significantly with the duration of orthodontic traction. Age, sex, and site of impaction did not significantly affect the duration of traction. No significant differences in PD and KT were present at the end of surgical-orthodontic treatment with respect to any of the variables considered. The analysis of PD and KT variables after orthodontic treatment revealed a healthy periodontium. CONCLUSIONS: alpha-angle, d-distance, and s-sector are valid indicators for the duration of orthodontic traction. They are not prognostic indicators of final periodontal status of orthodontically-repositioned canines.