Evaluation of the aesthetics and clinical findings in patients with missing maxillary lateral incisors treated with a 10-year interval.

INTRODUCTION: The most common treatment approaches for patients missing maxillary lateral incisors are implant replacement (IT) and orthodontic space closure (SC). Treatment techniques change and improve over time, and it is of interest to know if improvements differ between the methods. AIM: To compare the aesthetic outcome and other clinical findings in patients with one or two missing maxillary lateral incisors who were treated with a 10-year difference in time, with either orthodontic space closure or implant replacement. MATERIAL AND METHODS: A total of 88 patients were included in the study. Forty-four patients treated between 2011 and 2018 were included as the latter cohort (LC). The LC was compared to the early cohort (EC; n = 44), treated between 2001 and 2008. A total of 132 teeth was analysed: 62 teeth in the EC (28 teeth in IT cases and 34 teeth in SC cases) and 70 teeth in the LC (34 teeth in IT cases and 36 teeth in SC cases). Long-term clinical and aesthetic outcomes were evaluated. RESULTS: An improvement over time was found in crown length, BoP, papilla, the inclination of incisors, and overall appearance in IT cases and in crown colour and overbite in SC cases. A deterioration over time was found in crown length and BoP among the SC cases. CONCLUSION: Among the IT cases, an improvement in outcomes was noted over time. When comparing SC cases the colour of the crown and overbite had improved, while crown length and BoP had deteriorated over time.

A cost analysis of orthodontic space closure and implant treatment in patients missing maxillary lateral incisors with a long-term perspective.

OBJECTIVE: Few studies within orthodontics present both economic and clinical findings. Missing maxillary lateral incisors is a frequently occurring anomaly. The treatment alternatives most used are orthodontic space closure and prosthetic replacement of the missing tooth. Our aim is to compare the total societal costs of orthodontic space closure (SC) and implant therapy (IT) in patients missing maxillary lateral incisors. METHODS: Records of 32 patients treated with SC (n = 18) or IT (n = 14) due to missing maxillary lateral incisors were retrieved from the archives. Direct costs and indirect costs in the short- and long-term were analysed using a cost analysis with a societal perspective up of to 12 years post-treatment. RESULTS: Comparing cases treated with SC and IT, the difference in direct short-term costs for treatment is €735.54, whereas SC is the least costly. There is no difference between SC and IT in short-term parent loss of productivity, long-term loss of productivity, costs for transportation, or direct long-term costs. A difference was found between SC and IT-in favour of SC-when comparing patients' loss of productivity (P = 0.007), short-term societal costs (P < 0.001), long-term societal costs (P = 0.037), and total societal costs (P < 0.001). LIMITATIONS: There is a limited number of patient records. Local factors such as subsidies, urban versus rural areas, taxes, etc. can influence monetary variables, so the transferability to other settings may be limited. CONCLUSION: Patients treated with SC have a lower total societal cost compared to patients treated with IT. There was a difference in productivity loss for patients between SC and IT; however, concerning other indirect parameters and direct long-term costs, there was no difference between the two treatments.

Malocclusions, pathologic tooth migration, and the need for orthodontic treatment in subjects with stage III-IV periodontitis. A cross-sectional study.

BACKGROUND: Literature is scarce on malocclusion prevalence and orthodontic treatment need (OTN) in subjects with stage III-IV periodontitis. Study aims were to assess prevalence of primary and secondary malocclusions in subjects with stage III-IV periodontitis and OTN based on pathologic tooth migration (PTM) and occlusal trauma of anterior teeth (AT). SUBJECTS AND METHODS: One hundred and twenty-one subjects with stage III-IV periodontitis were examined. A comprehensive periodontal-orthodontic examination was performed. Exclusion criteria: age <30 years, removable prosthetics, uncontrolled diabetes, pregnancy/lactation, and oncologic disease. RESULTS: Class II malocclusion was found in 49.6% (Class II div 1-20.7%, Class II div 2-9.9%, subdivision Class II-19.0%), Class I-31.4%, Class III-10.7%, no malocclusion-8.3% of subjects. PTM was observed in 74.4% of maxillary and 60.3% of mandibular AT. Spacing and extrusion were the main types of PTM of AT. Odds ratio for PTM of maxillary AT was 9.3 in cases with >30% of sites with clinical attachment loss ≥5 mm (P = 0.001). Spacing of maxillary AT was influenced by periodontitis, Class III malocclusion, and lost teeth. Tongue habit had impact on spacing of mandibular AT. Dental Health Component of Index of Orthodontic Treatment Need yielded that OTN was found in >50% and OTN due PTM, occlusal trauma and impaired function in 66.1% of subjects. CONCLUSIONS: The most prevalent malocclusion was Class II. Spacing and extrusion were prevalent types of PTM of AT. OTN was found in more than half of the subjects. The study highlights the need for preventive measures for PTM in subjects with stage III-IV periodontitis.

Pain and discomfort during the first week of maxillary expansion using two different expanders: patient-reported outcomes in a randomized controlled trial.

BACKGROUND: Quad Helix (QH) is the appliance most preferred by orthodontists to correct unilateral posterior crossbite in the early mixed dentition while other orthodontists suggest rapid maxillary expansion (RME) on deciduous teeth in these patients. OBJECTIVES: To evaluate and compare perceived pain intensity, discomfort, functional jaw impairment, and analgesic consumption during the first week of treatment with either RME or QH appliances. TRIAL DESIGN: Two-arm parallel group, two-centre, randomized controlled trial. MATERIAL AND METHODS: Seventy-two patients, mean age 9.5 (SD ±0.8) years, with unilateral posterior crossbite requiring maxillary expansion were randomly allocated to either the RME (22 boys, 14 girls) or QH (22 boys, 14 girls) group. Validated questionnaires were used to assess pain intensity, discomfort, jaw function impairment, and analgesic consumption, on the first, fourth, and seventh days after appliance insertion and activation. BLINDING: Due to clinical limitations, only the outcome assessors were blinded to the groups to which the patients were allocated. RESULTS: Seventy patients completed the questionnaires. Pain from the tongue and chafe from the appliance were significantly higher in the QH group on the first day of treatment (P = 0.003 and P = 0.000, respectively). On the fourth day, the chafe from the appliance was still significantly higher in the QH group (P = 0.007). Speech was affected in both groups on day 1; this impairment continued and was significantly higher in the RME group days 4 and 7. No significant difference in analgesic consumption was found between the groups at any time. The analgesic consumption was highest at day 1 of treatment. HARMS: No harm was observed in any patient. LIMITATIONS: Double blinding was not possible due to the clinical limitations. CONCLUSION: During the initial 4 days of treatment, pain from the tongue and chafe from the appliance caused the most reported inconvenience in the patients in the QH group. A majority of reported visual analogue scale values were in the lower mid-range, suggesting low to moderate pain and discomfort in both groups. CLINICAL TRIAL REGISTRATION: NCT04458506.

Laypeople and dental professionals' perception of the aesthetic outcome of two treatments for missing lateral incisors.

OBJECTIVE: To investigate laypeople and dental professionals' opinions of the aesthetic outcome from implant therapy (IT) and orthodontic space closure (SC) for missing maxillary lateral incisors. MATERIAL AND METHODS: Evaluation was performed by three groups: laypeople 20-30 years of age (n = 26), laypeople 50-70 years of age (n = 26) and orthodontists (n = 25). The assessors viewed photographs of 44 different cases treated with IT or SC, and made an evaluation of the aesthetics. RESULTS: The gingival color adjacent to the replaced tooth was rated as having better aesthetics in the SC cases (p = 0.000). The orthodontists preferred the aesthetics of the dentition in the SC cases (p = 0.042). The young laypeople, compared to the older laypeople and orthodontists, were more dissatisfied with the color of the tooth replacing the missing lateral incisor in SC cases (p = 0.043). CONCLUSION: The color of the gingiva adjacent to the implant-supported crowns had a lower aesthetic rating than the SC group. Laypeople rated both treatments as equally good. The orthodontists had a slight preference for the aesthetics in the SC cases.

Open and closed surgical exposure of palatally displaced canines: a cost-minimization analysis of a multicentre, randomized controlled trial.

OBJECTIVE: To evaluate the costs of open and closed surgical exposure and subsequent orthodontic treatment for the correction of palatally displaced canines (PDCs). TRIAL DESIGN: A multicentre, two-arm parallel group randomized controlled trial. METHODS: One hundred twenty adolescents between 9 and 16 years of age, from three orthodontic specialist centres, were randomized to one of the two surgical exposure interventions. The randomization was conducted according to a two-arm parallel group 1:1 allocation ratio, using computerized lists with block randomization. In both the surgical techniques, whole mucoperiosteal flaps were raised, and bone covering the PDCs was removed. In the open technique, glass ionomer was built up on the PDC crown - reaching above the mucosa through a hole punched in the flap - to allow the canine to erupt autonomously. After eruption, the canine was orthodontically moved above the mucosa. In the closed technique, an eyelet was bonded onto the PDC, the flap was repositioned and the canine was orthodontically moved beyond the mucosa. The trial ended when the PDC was successfully aligned in the dental arch.Cost analysis was performed including costs for surgery, orthodontic treatment, emergency visits, and material, as well as costs for transports and time spent in connection with every appointment. BLINDING: Patients and caregivers could not be blinded due to obvious limitations of the clinical setting, while outcome assessors and data analysts were blinded. RESULTS: A cost-minimization analysis was performed since both exposure groups succeeded equally well in terms of treatment effects. The two different surgical exposures and following orthodontic treatments did not differ significantly in terms of costs. GENERALIZABILITY AND LIMITATIONS: Costs are estimated in the Swedish setting, which needs to be considered if applying the results in other settings. Calculations of total cost do not include finishing, debonding, retention, and follow-up. CONCLUSION: There is no significant difference in costs between closed and open surgical exposure with following orthodontic treatments in PDCs. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT02186548.

Open vs closed surgical exposure of palatally displaced canines: a comparison of clinical and patient-reported outcomes-a multicentre, randomized controlled trial.

OBJECTIVES: To compare treatment time, patients' perceptions during orthodontic treatment, dental fear and side effects, between open and closed surgical exposures in patients with palatally displaced canines (PDCs). TRIAL DESIGN: Multicentre, randomized controlled trial, with random 1:1 allocation of two parallel groups. MATERIALS AND METHODS: One hundred and twenty patients from three different orthodontic centres were randomized into one of the two intervention arms, open or closed surgical exposure. Both techniques had mucoperiosteal flaps raised and bone removed above the PDCs. In open exposure, tissue was removed above the canine, and glass ionomer - reaching above soft tissue - was built on the crown. The canine was then left to erupt spontaneously, prior to orthodontic alignment. At closed exposure, a chain was bonded to the canine and orthodontic traction was applied under the mucosa until eruption. Orthodontic alignment of the canines was undertaken after eruption into the oral cavity, with fixed appliances in both groups. All participants were treated according to intention to treat (ITT). BLINDING: Due to the nature of this trial, only outcome assessors could be blinded to the intervention group. RESULTS: One hundred and seventeen patients completed the trial. All PDCs were successfully aligned. Total treatment time was equal in the two techniques, mean difference -0.1 months (95% CI -3.2 to 2.9, P = 0.93). The closed group experienced more pain and discomfort during the active orthodontic traction. Dental fear, root resorption and periodontal status did not show any clinically significant differences between the groups. GENERALIZABILITY: Results of this randomized controlled trial (RCT) can be generalized only to a similar population aged 9-16 years, if exclusion criteria are met. CONCLUSION: The closed exposure group experienced more pain and discomfort mostly during active orthodontic traction. All other studied outcomes were similar between the two exposure groups. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT02186548 and Researchweb.org, ID: 127201.

Outcome of periodontal-orthodontic treatment in subjects with periodontal disease. Part II: a CBCT study of alveolar bone level changes.

AIM: To examine alveolar bone level (ABL) changes before (T1) and after (T2) orthodontic treatment (OT) in subjects with periodontal disease. METHODS: The study included 50 subjects with periodontal disease. All patients received subgingival debridement following baseline examination. Control group patients received final periodontal treatment before the start of OT. For the test group patients final periodontal treatment was performed simultaneous to OT. OT was performed with a straight-wire appliance. Micro-implants or temporary crowns on implants were used for posterior anchorage when needed. ABL measurements of 3821 tooth surfaces were performed on cone beam computed tomography images. RESULTS: No difference was observed between mean ABL at T1 and T2. ABL remained unchanged on 69 per cent of surfaces. A mean of 15.6 (SD 7.4) per cent of surfaces experienced ABL gain, and a mean of 15.1 (SD 7.5) per cent was found with ABL loss. Small significant median ABL difference was observed on mesial and distal surfaces (P < 0.001). A significant difference was found between median ABL changes on mesial/distal in comparison to buccal/lingual surfaces (P < 0.01). Significantly more buccal (17.9 %) and lingual (18.5 %) surfaces experienced ABL loss when compared with mesial (11.3 %) and distal (12.0 %) surfaces (P < 0.001). Significant difference was found in the median ABL change of intruded (0.5 (IQR 0.94) mm) and non-intruded (-0.4 (IQR 1.07) mm) maxillary incisors (P = 0.04). Significant median ABL gain was found on the lingual surface of maxillary incisors, which were retroclined more than 8.6 degree and intruded more than 1.6 mm. CONCLUSIONS: ABL changes after periodontal-orthodontic treatment in patients with periodontal disease were small. ABL gain was more observed on mesial and distal surfaces and ABL loss on buccal and lingual surfaces. Larger orthodontic movements of maxillary incisors influenced ABL gain.

Outcome of orthodontic treatment in subjects with periodontal disease. Part III: a CBCT study of external apical root resorption.

BACKGROUND: No evidence is present on the risk for external apical root resorption (EARR) during orthodontic treatment (OT) of adult patients with periodontal disease. AIM: To examine EARR after OT in subjects with periodontal disease and to analyse how intrusion and change in inclination of the most proclined maxillary incisors influence EARR. METHODS: The study included 50 patients with periodontal disease. Sub-gingival debridement by ultrasonic instrumentation supplemented with hand instruments was performed by experienced dental hygienist after baseline examination for all patients. For the control group, final periodontal treatment (PT) was performed before orthodontic tooth movement. For the test group patients, final PT was performed after levelling and alignment phases were finished, before the active space closure with elastic chain and/or inter-arch elastic traction for sagittal correction was started. OT was performed with a straight-wire appliance. Micro-implants or implants were used for posterior anchorage. Cone beam computed tomography examinations were performed before and after OT. EARR of all single-rooted teeth were measured. EARR of the most proclined maxillary incisor was related to intrusion and change in inclination angle. RESULTS: EARR after OT was observed in median 80.7 per cent (interquartile range 22.02) of single-rooted teeth [mean 1.2 (standard deviation 0.44) mm]. In 82.3 per cent of teeth, EARR was 2 mm or less. Severe EARR was found in 8 per cent of patients and five maxillary incisors (less than 1 per cent of all teeth). The amount of intrusion and change in inclination angle of the most proclined maxillary central incisor influenced the extent of EARR. Mean EARR was significantly higher when OT lasted more than 18 months (P = 0.02). CONCLUSIONS: OT in conjunction with PT in periodontal patients resulted in EARR in 81 per cent of all single-rooted teeth. Intrusion and change in inclination angle of the most proclined maxillary central incisor influenced the extent of EARR, as did longer OT.

Are panoramic radiographs good enough to render correct angle and sector position in palatally displaced canines?

OBJECTIVES: The early interceptive treatment of palatally displaced canines (PDCs) has for decades been based on their position in panoramic radiographs. In the 1990s, cone-beam computed tomography (CBCT) started to become popular in cases with PDCs. The aims of this prospective study were to evaluate the agreement of PDC sector position and angle to midline between panoramic radiographs and CBCT scans. METHODS: PDC sector and angle to midline were measured in panoramic radiographs and CBCT scans in 58 consecutive patients with 64 PDCs. Kappa with linear weighting was used to assess the agreement between the measurements of PDC sector position and Bland-Altman limits of agreement to assess the agreement between the PDC angular measurements in the 2 methods. RESULTS: PDC sector position and angle to midline had systematically higher values in panoramic radiographs compared with those in the CBCT scans. The agreement of sector position between the methods was fair: weighted kappa 0.36 (95% CI 0.24-0.49). The mean difference in angle was almost 7° (95% CI 5.9°-7.9°) higher in panoramic radiographs compared with CBCT. CONCLUSIONS: Panoramic radiographs overestimate PDC sector and angle to midline position, compared with the use of CBCT scans, but clinically the differences are quite modest. Panoramic radiographs could be considered good enough for rendering PDC position when the need for 3D information is not crucial for treatment planning.

Mandibular incisor alignment in untreated subjects compared with long-term changes after orthodontic treatment with or without retainers.

INTRODUCTION: The aim of this work was to analyze the dental and skeletal changes in patients treated with fixed orthodontic appliances with or without retention appliances, and to compare the changes with untreated subjects. Specifically, mandibular incisor irregularity was analyzed. METHODS: A total of 105 children who had undergone orthodontic treatment with fixed appliances in both jaws were examined in 2 groups: 64 had a lingual mandibular retainer and 41 had no retainer. Retention time was 2.7 ± 1.5 years. The untreated group consisted of 25 subjects. Measurements were done on study casts and lateral head radiographs before and after treatment and 6 and 12 years after treatment. The Little irregularity index (LII) was the most important variable. RESULTS: No differences were found in LII 12 years after treatment between the group that had a retainer and the group without a retainer after treatment. In the untreated group, LII was increased over time, but not to the same extent as in the treated groups. Correction of overjet and overbite was stable long-term. At the last examination, the amount of overjet was almost the same in all 3 groups. CONCLUSIONS: The routine use of mandibular retainers for 2 to 3 years does not appear to prevent long-term relapse. If the patient wants to constrain natural development and changes, lifelong retainers are needed.

Treatment of missing maxillary lateral incisors: a clinical and aesthetic evaluation.

OBJECTIVE: The aim of this study was to evaluate whether implant therapy or orthodontic space closure was the best treatment option for patients with missing maxillary lateral incisors. SUBJECTS AND METHODS: The implant group (I group) consisted of 22 patients aged <26 years who had one or both maxillary lateral incisors substituted by a single implant-supported crown. The space-closure group (SC group) consisted of patients matched with I group patients based on diagnosis, gender, and number. Examinations were performed by one examiner and occurred at least 5 years after the prosthetic therapy or orthodontic treatment was finished. Clinical examination of the 44 patients involved assessing the aesthetics and gingival conditions of the implant-supported crown and the replacement canine, the occlusal morphology and the extraoral characteristics. Both the patient and examiner answered a question about their satisfaction with the aesthetic result. RESULTS: Of the 12 variables analysed by the examiner, one variable was significantly improved in the I group and five variables were improved in the SC group. There were no significant differences between the treatment groups for the remaining six variables. Gingival colour and crown length were better in the SC group, and crown colour was better in the I group. There were no significant differences between the groups with regards to the patient's and examiner's overall aesthetic satisfaction of the maxillary anterior teeth or between the patient's and examiner's opinion. CONCLUSION: If both treatment alternatives are available, space closure is preferable.

Closed vs open surgical exposure of palatally displaced canines: surgery time, postoperative complications, and patients' perceptions: a multicentre, randomized, controlled trial.

Background: Closed and open surgical techniques are two different main approaches to surgical exposure of palatally displaced canines (PDCs). Because there is insufficient evidence to support one technique over the other, there is a need for randomized controlled trials. Objectives: To compare surgery time, complications and patients' perceptions between closed and open surgical techniques in PDCs. Trial design: The trial was a multicentre, randomized, controlled trial with two parallel groups randomly allocated in a 1:1 ratio. Material and methods: Study participants were 119 consecutive patients from 3 orthodontic centres, with PDCs planned for surgical exposure, randomly allocated according to a computer-generated randomization list, using concealed allocation. Full-thickness mucoperiosteal flap was raised, and bone covering the canine was removed in both interventions. In closed exposure, an attachment with a chain was bonded to the canine and the flap was sutured back with the chain penetrating the mucosa. In open exposure, a window of tissue around the tooth was removed and glass ionomer cement placed on the canine crown, to prevent gingival overgrowth during spontaneous eruption. Patient perceptions were assessed with two questionnaires, for the evening on the day of operation and 7 days post-surgery. Blinding: It was not possible to blind either patients or care providers to the interventions. The outcome assessors were blinded and were unaware of patients' intervention group. Results: Seventy-five girls and 44 boys, mean age 13.4 years (SD 1.46) participated in the study and got either of the interventions (closed exposure, n = 60; open exposure, n = 59). Surgery time did not differ significantly between the interventions. Complications though were more severe in bilateral cases and the patients experienced more pain and impairment in the open group. Conclusion: There were no statistically significant differences regarding surgery time between the groups. Postoperative complications were similar between the groups in unilateral PDCs, but more common in the open group in bilateral cases. More patients in the open group experienced pain and impairment compared to the closed group. Trial registration: Trial registration: ClinicalTrials.gov, ID: NCT02186548 and Researchweb.org, ID: 127201.

Orthodontic treatment simultaneous to or after periodontal cause-related treatment in periodontitis susceptible patients. Part I: Clinical outcome. A randomized clinical trial.

AIM: To compare two treatment strategies regarding the effect of orthodontic treatment on periodontal status in patients with plaque-induced periodontitis. SUBJECTS AND METHODS: This was a randomized clinical trial. Fifty periodontal patients were randomly assigned to the test or control groups according to periodontal treatment timing. All patients received supra- and subgingival debridement following baseline examination. Control group patients received cause-related periodontal treatment before the start of orthodontic treatment and which was performed simultaneous to orthodontic treatment for the test group patients. RESULTS: No difference between the test and control groups was found regarding change of clinical attachment level (CAL) after periodontal-orthodontic treatment. Fewer sites with initial pocket depth (PD) of 4-6 mm healed after periodontal-orthodontic treatment in the test group (20.5%, IQR = 11.9%) in comparison with controls (30.4%, IQR = 27.1%) (p = .03). Anterior teeth [OR 2.5] and teeth in male patients [OR 1.6] had a greater chance for PD improvement ≥2 mm. Total periodontal-orthodontic treatment duration was significantly longer for the control group (p < .01). CONCLUSIONS: Both groups showed a gain of CAL and a reduction in sites with PD ≥ 4 mm. Orthodontic treatment, simultaneously to the periodontal treatment, could be used in the routine treatment of patients with plaque-induced periodontitis.

Perception of orthodontic treatment need among Swedish children, adolescents and young adults.

OBJECTIVE: Perceptions of orthodontic treatment need and perceptions of dental aesthetics was investigated among subjects ages 10, 15 and 19. MATERIALS AND METHODS: A total of 489 subjects completed a questionnaire after inspecting 10 photographs in the Aesthetic Component scale of the Index of Orthodontic Treatment Need to (i) reveal the lower limit for orthodontic treatment need and (ii) rate their dental aesthetics by selecting the most similar photo. RESULTS: The mean lower limit for orthodontic treatment need was significantly higher (and closer to literature-based standards) among subjects, age 10 (4.2 ± 1.5), than among subjects, age 15 (3.6 ± 1.2) (p = .0009), and subjects, age 19 (3.5 ± 1.2) (p = .00002). Among subjects ages 15 and 19, the lower limit for orthodontic treatment need was lower in groups with (i) self-perceived orthodontic treatment need (p = .002 and .001, respectively) and (ii) previous orthodontic treatment (p = .005 and .035, respectively). Self-perceived orthodontic treatment need was present in more than one-third of subjects, age 19, who had previously received orthodontic treatment. Subjects of foreign origin reported that their dental aesthetics were worse (p = .002) and those same subjects, age 19, set the lower limit for orthodontic treatment lower (p = .047) than Swedes, age 19. CONCLUSIONS: The lower limit for orthodontic treatment need among subjects, age 10, was higher - compared to subjects, ages 15 and 19 - and closer to literature-based standards. Subjects with self-perceived orthodontic treatment need, subjects with previous orthodontic treatment, and subjects age 19 of foreign origin, have higher aesthetic demands.

Twelve-year follow-up of mandibular incisor stability: Comparison between two bonded lingual orthodontic retainers.

OBJECTIVE: To compare the long-term outcome 9 years after removal of two different types of fixed retainers used for stabilization of the mandibular anterior segment. MATERIALS AND METHODS: Sixty-four children who had undergone orthodontic treatment with fixed appliances in both arches were divided into two groups depending on which kind of retainer being used. Twenty-eight of the patients had a canine-to-canine retainer bonded to the canines and 36 had a bonded twistflex retainer 3-3, bonded to each tooth. Measurements were made on study models and lateral head radiographs, before and after treatment, 6 years after treatment, and 12 years after treatment, with a mean of 9.2 years after removal of the retainers. RESULTS: No significant differences were found between the two groups at the long-term follow-up according to Little's Irregularity Index or available space for the mandibular incisors. The overjet and overbite were reduced after treatment in both groups and stayed stable throughout the observation period. Also, no differences in bonding failures between the two retainers were found. CONCLUSIONS: Both a canine-to-canine retainer bonded only to the canines and a twistflex retainer 3-3 bonded to each tooth can be recommended. However, neither of the retention types prevented long-term changes of mandibular incisor irregularity or available space for the mandibular incisors after removal of the retainers.

Orthodontic treatment in periodontitis-susceptible subjects: a systematic literature review.

The aim is to evaluate the literature for clinical scientific data on possible effects of orthodontic treatment on periodontal status in periodontitis-susceptible subjects. A systematic literature review was performed on studies in English using PubMed, MEDLINE, and Cochrane Library central databases (1965-2014). By manually searching reference lists of selected studies, we identified additional articles; then we searched these publications: Journal of Periodontology, Periodontology 2000, Journal of Clinical Periodontology, American Journal of Orthodontics and Dentofacial Orthopedics, Angle Orthodontist, International Journal of Periodontics & Restorative Dentistry, and European Journal of Orthodontics. Search terms included randomized clinical trials, controlled clinical trials, prospective and retrospective clinical studies, case series >5 patients, periodontitis, orthodontics, alveolar bone loss, tooth migration, tooth movement, orthodontic extrusion, and orthodontic intrusion. Only studies on orthodontic treatment in periodontally compromised dentitions were included. One randomized controlled clinical trial, one controlled clinical trial, and 12 clinical studies were included. No evidence currently exists from controlled studies and randomized controlled clinical trials, which shows that orthodontic treatment improves or aggravates the status of periodontally compromised dentitions.