INTRODUCTION: The objective of this trial was to compare, in a 3-week follow-up, patients' perceptions of recovery, surgery time, and complications related to surgical exposure of palatally displaced canines (PDCs) with either the closed or the open techniques.

METHODS: This study was a 2-center, 2-arm parallel randomized clinical trial with a 1:1 allocation ratio. A total of 100 participants with PDC from 2 university clinics, aged <16 years, with unilateral or bilateral PDCs with cusp tip position in sectors II-IV, were randomly allocated to either closed-exposure or open-exposure techniques. Outcomes related to surgery and surgery/dressing removal interventions were analyzed by blinded assessors. Patients' perceptions during both interventions and the week postinterventions were evaluated using take-home questionnaires, which included 3 question types: visual analog scale (VAS) questions about pain/discomfort, binary questions about analgesic intake, and open questions about complications. Surgical duration and professional-reported complications were assessed in patient journals. Mixed models with random intercepts were used to examine the effects of treatment on VAS scores (Gaussian model) and the use of analgesics (logistic model). Linear regression was used to examine the effect of the treatment on the operation. Statistical significance was set at <0.05.

RESULTS: A total of 92 participants were included with no baseline differences between the intervention groups. There were no significant differences in patient perceptions between the centers. The open approach showed higher VAS scores for pain (coefficient, 8.58 [95% confidence interval, 2.29-14.88]; P <0.01) and discomfort (coefficient, 9.15 [95% confidence interval, 2.33-15.98]; P <0.01) from the exposure operation onwards, with nonsignificantly higher scores for patients with bilateral than unilateral PDCs. No pain/discomfort score differences were observed between treatment groups or between patients with bilateral or unilateral PDCs at surgery/dressing removal intervention. There were no differences in analgesic intake after surgery, but there was significantly more consumption after suture/dressing removal with the closed technique. Overall, a shorter duration was observed for the open technique, particularly when no flap surgeries were performed. Few complications were detected and were more common in the open group.

CONCLUSIONS: There was more pain and discomfort in the open group during surgery and the following week; however, no difference was observed during suture/dressing removal or the week after. There was increased analgesic intake in the closed group after suture dressing removal. Open surgical exposure required a shorter time, particularly when no flap surgery was performed. Complications were sparse and more common in the open group.

REGISTRATION: ClinicalTrials.gov (NCT05067712) PROTOCOL: Published before trial commencement.

FUNDING: University of Oslo.

OBJECTIVES: To evaluate treatment time and patient perception of two surgical methods to expose a palatally displaced canine (PDC) into the oral cavity.

MATERIAL AND METHODS: A total of 30 consecutive patients between 11 and 18 years, with maxillary displaced canines were recruited. After gaining informed consent from the patients and custodians, the patients were randomized into two groups by an independent person. Both groups received a chain attached to the crown of the canine: in group A (control group) the chain was placed under the mucoperiosteal flap to an incision on the alveolar crest and in group B (test group), the chain penetrated the mucoperiosteal flap inferiorly to the crown of the canine. Outcome measures where time to expose the PDC into the oral cavity and the patient's experience of pain and discomfort during the treatment.

RESULTS: Twenty-six patients full-filled the trial, mean age was 12.9 years, (SD 1.6 years). The time to expose the canines for the control group was 11.9 months (SD 6.5) and for the test group 6.7 months (SD 3.2) The conventional method showed less pain on the day of surgery.

CONCLUSION: The method used in the test group resulted in a 5-month shorter time to expose the canine compared to the control group, and higher pain level on the day of surgery. For generalizability of the results, larger studies are needed.

AIMS: To identify if lower incisor movements after orthodontic treatment are due to the relapse of the orthodontic treatment or due to natural growth. SUBJECTS AND METHODS: The subjects consisted of 92 patients who have had orthodontic treatment, divided into three groups, group 1: 38 individuals had no retainer in the lower jaw. Group 2: 24 individuals had a retainer 0.028 inch, a spring hard wire bonded to the mandibular canines only. Group 3: 30 individuals had a 0.0195-inch Twist-Flex wire, bonded to all mandibular incisors and canines. Study models before orthodontic treatment (T0), immediately after orthodontic treatment (T1), 6 years after orthodontic treatment (T2), and 12 years after orthodontic treatment (T3) were used for the measurements. The wires in groups 2 and 3 were removed after mean 2.6 years (SD 1.49). Little Irregularity Index (LII), inter-canine distance, available mandibular anterior space, and number of crowded incisors were registered. A Tooth Displacement Index (TDI) was developed to measure the tooth displacement directions at T0 and T3. RESULTS: The LII showed equal values before treatment (T0) and at the follow-up registrations (T2 and T3). But about 25 per cent of the tooth displacements at T2 and T3 did not exist before treatment, at T0. This indicates usual growth changes and not relapse of the orthodontic treatment. CONCLUSION: As about 25 per cent of the displaced incisors can be considered as an effect of natural growth, not a relapse of the orthodontic treatment, it is valuable to use a displacement index in combination with other variables for investigations of stability after orthodontic treatment. Importance of the present study is that it is possible to differ between relapse and usual growth changes.

Introduction: The aim of this work was to analyze the dental and skeletal changes in patients treated with fixedorthodontic appliances with or without retention appliances, and to compare the changes with untreated sub- jects. 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.

Agenesis of mandibular second premolar is reported to be 2.4-4.5%. The diagnosis can be set on at average 9 years of age. Early treatment in the form of extraction of the second primary molar and in some cases also the remaining three second premolars and comprehensive orthodontic treatment are often a good treatment solution. In vertical deep bite cases, cases with spacing in the dental arch, mandibular posterior rotation and for extractions disadvantageous growth pattern, a treatment with retaining of the primary molar must be taken in consideration. When there is no or minor infraocclusion, root resorption less than half of the root length, and no caries or fillings at the age of 12-13 years, there is a good prognosis for longtime survival of the primary molar.

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.

INTRODUCTION: The aim of this longitudinal 32-year follow-up investigation was to analyze the very long-term effects of Herbst treatment on the dentoskeletal structures. We followed 14 patients from a sample of 22 with Class II Division 1 malocclusions who were consecutively treated with the banded Herbst appliance at ages 12 to 14 years. The subjects were reexamined after therapy at the ages of 20 years (when the radius epiphysis/diaphysis plate was closed) and 46 years. METHODS: Lateral head films were analyzed from before (T1) and after (T2) treatment, and at 6 years (T3) and 32 years (T4) after treatment. RESULTS: (1) In the standard analysis (angular measurements) during the T2 to T3 period of 6 years, significant skeletal changes were the following: increase of the SNB (1.0°; P <0.01), decrease of the ANB (0.9°; P <0.01), and decrease of the ML/NSL (2.5°; P <0.001). During the T3 to T4 period of 24 years, no further significant angular changes occurred. (2) In the analysis of the sagittal changes in the occlusion (linear measurements) during the T2 to T3 period of 6 years, the mandible (6.1 mm; P <0.001) and the maxilla (3.0 mm; P <0.01) grew forward. During the T3 to T4 period of 24 years, the mandible (2.8 mm; P <0.01) and the maxilla (3.1 mm; P <0.01) continued to grow forward. Thus, during the total posttreatment (T2-T4) period of 32 years, there was continuous forward growth of the mandible (8.9 mm; P <0.001) and the maxilla (6.1 mm; P <0.001). (3) The analysis of superimposed lateral head films showed in all 14 subjects large amounts of sagittal and vertical skeletofacial growth during T3 to T4. CONCLUSIONS: In all 14 subjects, large amounts of sagittal and vertical skeletofacial growth occurred after the age of 20 years. However, the question of when, during the period from 20 to 46 years, growth had come to an end remains open. Closure of the radius epiphysis/diaphysis plate is not useful as an indicator for completed skeletofacial growth. Our findings indicate the importance of considering late adult skeletofacial growth in dentofacial orthopedics, orthognathic surgery, and tooth implantology with respect to treatment timing, posttreatment retention, and relapse.

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.

Objective:  To analyze radiographic signs of temperomandibular joint (TMJ) osteoarthritis and clinical TMJ symptoms in patients 6 years and 32 years after treatment with a Herbst appliance. Materials and Methods:  Fourteen patients were derived from a sample of 22 with Class II division 1 malocclusions consecutively treated with a banded Herbst appliance at the age of 12–14 years old (T1-T2). The subjects were reexamined after therapy at the ages of 20 years (T3) and 46 years (T4). The TMJs of the 14 patients were analyzed radiographically (conventional lateral tomography at T3 and cone-beam computed tomography at T4) and clinically/anamnestically at T3 and T4. Results:  Six years after Herbst therapy, signs of osteoarthritis were seen in one patient. At the 32-year follow-up, two additional patients had developed signs of osteoarthritis. At the 6-year follow-up, TMJ clicking was present in two patients, though none of the patients reported TMJ pain. At the 32-year follow-up, six patients had TMJ clicking and one patient had TMJ pain. Conclusions:  This longitudinal very-long-term follow-up study after Herbst therapy revealed only minor problems from the TMJ. The TMJ findings 6 years and 32 years after Herbst treatment corresponded to those in the general population. Thus, in the very long term, the Herbst appliance does not appear to be harmful to the TMJ.