Background: Serial 3D models can be used to analyze changes, but correct superimposition is crucial before measurements can be assessed. Earlier studies show that every palatal structure changes due to growth or treatment. Here, we describe a new method that uses an algorithm-based analysis to perform superimpositions and measurements in maxillary 3D models. This method can be used to identify deformations. In a second step, only unchanged areas are used for superimposition. Objectives: This study investigates the validity and reliability of this novel method. Methods: Digital 3D models from 16 cases were modified by an independent 3D engineer to simulate space closure and growth. True values for tooth movements were available as reference. Measurements and repeated measurements were performed by four observers. Results: The total tooth movement had an absolute mean error of 0.0225 mm (SD 0.03). The intraclass correlation coefficient (ICC) was 0.9996. Rotational measurements had an absolute mean error of 0.0291 degrees (SD 0.04 degrees) and an ICC of 0.9999. Limitations: Serial models need to be taken with a moderate interval (1 to 2 years). Obvious changed areas in the palate need to be cropped before processing the models. Conclusion: The tested method is valid and reliable with excellent accuracy and precision even when changes through growth or orthodontic treatment occur.

Objective: To investigate and compare the experience of pain and discomfort between insertion of miniscrews and premolar extractions in adolescent patients. Materials and Methods: A total of 80 adolescents were recruited and randomized into groups A and B. Both groups were treated with extraction of the upper first premolars and fixed appliance. Beyond the fixed appliance, patients in group A received anchorage reinforcement with miniscrews. Miniscrews were inserted buccally between the second premolar and first molar when space closure started. Space closure was performed as en masse retraction with immediate loading by 150-g coil springs. Pain, discomfort, impact on daily activities, and functional jaw impairment were assessed with patient-reported questionnaires. Questionnaires were filled in at baseline, the evening after tooth extraction, 1 week after tooth extraction, the evening after screw placement, and 1 week after screw placement. Results: Patients reported significantly lower levels of pain (P < .001) and discomfort (P = .012) after screw placement compared with premolar extractions. The ability to drink (P = .035) and the ability to take a big bite (P < .001) were also significantly less disturbed in the evening after screw placement. During the first week after screw placement, the impact on leisure time activities was significantly lower (P = .015) compared with premolar extractions. Conclusion: The use of miniscrews in adolescents can be recommended from a pain and discomfort perspective.

Introduction: Anchorage can be reinforced in many ways. Due to the variety of anchorage concepts, only a few general conclusions can be drawn. Therefore, more research is needed to investigate specific concepts with specific indications. The objective of this trial was to compare the anchorage capacities of miniscrews and molar blocks. Methods: This randomized controlled trial was conducted on 2 parallel arms. The trial was conducted at the Public Dental Service Orthodontic Clinic in Gavle, Sweden. Participants were adolescents who needed orthodontic treatment with a fixed appliance, extraction of the maxillary first premolars, and anchorage reinforcement. In group A, miniscrews were used as direct anchorage during space closure. In group B, molar blocks were used as anchorage reinforcement during leveling and alignment and space closure. The primary outcome was loss of anchorage assessed as maxillary first molar movement. Random allocation was maintained with a simple randomization stratified by sex. The observer was blinded to the allocations during the measurements. Results: Forty participants each were randomized to groups A and B. Results were analyzed on an intention-to-treat basis, meaning that all participants, successful or not, were included in the analysis. Group A showed a mean anchorage loss of 1.2 mm during leveling and alignment. During space closure with miniscrews, no significant anchorage loss was found. Group B showed mean anchorage losses of 1.4 mm during leveling and alignment and 2.4 mm during space closure. No serious harms were detected. The first molar rotation, torque, and tipping showed different characteristics during the treatment phases. Conclusion: Miniscrews can be recommended for anchorage reinforcement. Depending on the need for anchorage reinforcement, miniscrews can be inserted at the beginning of treatment or when space closure starts. Molar blocks cannot be recommended for anchorage reinforcement. Protocol: The protocol was published after trial commencement.

Objective: To analyse cost-effectiveness of anchorage reinforcement with buccal miniscrews and with molar blocks. We hypothesized that anchorage with miniscrews is more cost-effective than anchorage with molar blocks. Trial design: A single-centre, two-arm parallel-group randomized controlled trial. Methods: Adolescents (age 11–19 years) in need of treatment with fixed appliance, premolar extractions, and en masse retraction were recruited from one Public Dental Health specialist centre. The intervention arm received anchorage reinforcement with buccal miniscrews during space closure. The active comparator received anchorage reinforcement with molar blocks during levelling/alignment and space closure. The primary outcome measure was societal costs defined as the sum of direct and indirect costs. Randomization was conducted as simple randomization stratified on gender. The patients, caregivers, and outcome assessors were not blinded. Results: Eighty patients were randomized into two groups. The trial is completed. All patients were included in the intention-to-treat analysis. The median societal costs for the miniscrew group were €4681 and for the molar block group were €3609. The median of the difference was €825 (95% confidence interval (CI) 431–1267). This difference was mainly caused by significantly higher direct costs consisting of material and chair time costs. Differences in chair time costs were related to longer treatment duration. No serious harms were detected, one screw fractured during insertion and three screws were lost during treatment. Generalizability and limitations: The monetary variables are calculated based on a number of local factors and assumptions and cannot necessarily be transferred to other countries. Variables such as chair time, number of appointments, and treatment duration are generalizable. Owing to the study protocol, the benefit of miniscrews as a stable anchorage has not been fully utilized. Conclusions: When only moderate anchorage reinforcement is needed, miniscrews are less cost-effective than molar blocks. The initial hypothesis was rejected. Miniscrews provide better anchorage reinforcement at a higher price. They should be used in cases where anchorage loss cannot be accepted. Trial registration: NCT02644811