The treatment effects of maxillary asymmetric mechanics with the use of the mesial-distalslider: A retrospective study.

INTRODUCTION: This study had 2 objectives: (1) to evaluate the clinical efficacy of the Mesial-Distalslider (MD) appliance when used for simultaneous maxillary molar mesialization and distalization in patients with a maxillary asymmetrical relationship and (2) to compare the outcomes with those achieved using the unilateral Mesialslider (UM) appliance. METHODS: The sample included 40 subjects (25 females and 15 males) with a mean age of 22 years (range, 8-55 years). The patients were divided into 2 groups: 20 patients treated with an MD appliance (group 1) and a group of 20 patients treated with a UM appliance (group 2). Superimposition of digital dental models using regions of interest on the palate was performed to evaluate the 3-dimensional molar movements, the proclination or retroclination of the maxillary incisors, and the displacement of the maxillary midline. RESULTS: At the end of the treatment, the MD group's total movements were 4.5 ± 2.2 mm (sagittal), -0.4 ± 2.4 mm (transverse), and 0.3 ± 0.9 mm (vertical) along the mesialization side and -2.4 ± 1.7 mm (sagittal), -0.5 ± 1.5 mm (transverse), and 0.2 ± 1.4 (vertical) along the distalization side. UM group total movements were 5.5 ± 3.6 mm (sagittal), -0.4 ± 2.7 mm (transverse), and 0.1 ± 2.0 mm (vertical). Incisor displacements were minimal. No statistically significant differences were found between the MD and UM groups for all the parameters. CONCLUSIONS: The use of the MD enables controlled movements in the sagittal direction with negligible dental side effects in the other planes (transverse and vertical). Furthermore, it facilitates asymmetrical movements simultaneously in the desired direction without the patient's compliance and provides good anchorage control.

Dentoskeletal effects of mini-screw assisted, non-surgical palatal expansion in adults using a modified force-controlled polycyclic protocol: a single-centre retrospective study.

OBJECTIVES: This study assessed the dental and skeletal effects of pure bone-borne, non-surgical maxillary expansion, using a modified force-controlled polycyclic protocol. METHODS: Records of 17 adult patients, mean age 24.1 years; range 18-39 years, who had undergone maxillary expansion using a bone-borne Quad-expander (with 4 mini-screws), were analysed. In all patients, 0.17 mm/day of expansion was completed for 1 week, followed by a cyclic protocol of expansion of forward and backward turns until the force needed to turn the expander was below 400 cN, assessed weekly. After this, expansion continued at a rate of 0.17 mm/day until the desired amount of expansion was achieved. Cone beam computer tomography scans were taken pre- and post-expansion. RESULTS: The mid-palatal suture was successfully opened in 100% of patients included in this study. Axially, the amount of skeletal opening at the posterior nasal spine was 61% of the anterior nasal spine. Expansion was pyramidal in the coronal plane. Significant increases at the dental and skeletal levels were achieved, with changes at the skeletal level reaching 73%. The alveolar bone angle increased more than the angular changes at the molars and premolars. LIMITATIONS: This is a retrospective study with short-term results. CONCLUSION: The Quad-expander, with a force-controlled polycyclic expansion protocol, effectively produced a significant increase in maxillary width in skeletally mature subjects in the short term.

Dentoskeletal changes due to rapid maxillary expansion in growing patients with tooth-borne and tooth-bone-borne expanders: A randomized clinical trial.

OBJECTIVES: To compare, using cone-beam computed tomography, the dentoskeletal changes in rapid maxillary expansion with tooth-bone-borne (Hybrid Hyrax) and tooth-borne (Hyrax) appliances. SETTING AND SAMPLE POPULATION: Forty-two patients who met the eligibility criteria (aged 11-14 years; transverse maxillary deficiency, posterior crossbite, and presence of upper first premolars and molars) were screened and allocated into two groups: HHG (treatment with Hybrid Hyrax) and HG (treatment with Hyrax). MAIN OUTCOME MEASURES: The primary outcomes included nasomaxillary dimensional changes. CBCT was performed before and 3 months after the activation phase. Measurements were performed using Dolphin® . Baseline data were compared using one-way ANOVA. For intergroup comparison, ANCOVA was used to analyze the initial age, appliance activations (mm), and mid-palatal suture maturation data as covariates. Statistical significance was set at 5%. RESULTS: The premolar region in HHG showed increased skeletal changes than in HG, with the difference being 1.5 mm (0.5; 2.6) in the nasal cavity (P = .004), 1.4 mm (0.3; 2.5) in the nasal floor (P = .019), and 1.1 mm (0.2; 2.1) in the maxilla (P = .022). The molar region in HHG showed increased skeletal changes with the difference being 0.9 mm (0.2; 1.5) in the nasal cavity (P = .005), and 0.9 mm (0; 1.8) in the maxilla (P = .042) than in HG. Premolar inclination was higher in HG. CONCLUSION: Hybrid Hyrax showed more skeletal changes and fewer dental side effects, especially in the first premolar region. The amount of activation influenced the higher nasal skeletal changes in the Hybrid hyrax group.

Treatment of maxillary transversal deficiency by using a mini-implant-borne rapid maxillary expander and aligners in combination.

Bone-borne rapid maxillary expansion distraction devices are used to achieve a more skeletal expansion and to avoid dental side effects of conventional expanders such as tipping of anchorage teeth. In this article, we report the use of a prefabricated expander fixed on 2 mini-implants in the anterior palate. This allows for the insertion of the mini-implants and the expander to occur without the need for an impression or any laboratory procedures. Especially when aligners are going to be used, the use of a mini-implant-borne expander seems to be reasonable because the expander can be left in place as a skeletal retainer during the aligner finishing.

Maxillary molar mesialization with the use of palatal mini-implants for direct anchorage in an adolescent patient.

A unique clinical challenge presents when dealing with a compromised first permanent molar. A compelling treatment option for consideration is the removal of a nonrestorable first permanent molar, with the subsequent "replacement" through controlled mesial tooth movement of viable second and third molars. To reinforce the anchorage support associated with such a planned movement, indirect or direct implant-supported mechanics may be used. With the use of direct anchorage, orthodontic brackets are not required and space closure can be commenced immediately. In this article, we report the clinical procedure and design of direct-anchorage mechanics used for the successful closure of a maxillary first permanent molar space with the use of an implant-supported appliance (Mesialslider). Treatment was completed in just under 12 months, with successful mesial movement of the maxillary second and third molars without the need for the bonding of orthodontic brackets on the anterior dentition. The result was determined to be stable over a 3-year period.

CAD-CAM-fabricated mini-implant insertion guides for the delivery of a distalization appliance in a single appointment.

This article reports on the technical aspects of using a computer-aided design-computer-aided manufacturing (CAD-CAM) insertion guide for the placement of orthodontic mini-implants used for the purpose of providing anchorage support for maxillary molar distalization. A 10-year-old girl presented with a bilateral full-step Angle Class II molar relationship in the permanent dentition, with anterior arch-length insufficiency and blocked out maxillary canine teeth. The primary treatment objective was to provide an esthetic and functional occlusal outcome, and secondarily to avoid the removal of multiple premolar teeth. The patient was initially treated with an implant-supported distalization device, and the occlusion was subsequently detailed with preadjusted fixed orthodontic appliances. The CAD-CAM procedure facilitates the safe and precise insertion of mini-implants in the anterior palate, potentially broadening the scope of use of palatal mini-implants for less experienced clinicians. The illustrated protocol allows for the insertion of mini-implants and fitting of a prefabricated appliance in a single office appointment.

Is there an ideal insertion angle and position for orthodontic mini-implants in the anterior palate? A CBCT study in humans.

INTRODUCTION: Orthodontic mini-implants are frequently used to provide additional anchorage for orthodontic appliances. The anterior palate is frequently used owing to sufficient bone quality and low risk of iatrogenic trauma to adjacent anatomical structures. Even though the success rates in this site are high, failure of an implant will result in anchorage loss. Therefore, implants should be placed in areas with sufficient bone quality. The aim of the present study was to identify an optimal insertion angle and position for orthodontic mini-implants in the anterior palate. METHODS: Maxillary cone-beam computed tomographic (CBCT) scans from 30 patients (8 male, 22 female, age 18.6 ± 12.0 years) were analyzed. To assess the maximum possible length of an implant, a 25-reference-point grid was defined: 5 sagittal slices were extracted along the median plane and bilaterally at 3 mm and 6 mm distances, respectively. Within each slice, 5 dental reference points were projected to the palatal curvature at the contact point between the cuspid (C) and first bicuspid (PM1), midpoint of PM1, between PM1 and PM2, midpoint of PM2, and between PM2 and the first molar (M1). Measurements were conducted at -30°, -20°, -10°, 0°, 10°, 20°, and 30° to a vector placed perpendicular to the local palatal curvature. Statistical analysis was conducted with the use of R using a random-effects mixed linear model and a Tukey post hoc test with Holm correction. RESULTS: High interindividual variability was detected. Maximum effective bone heights were detected within a T-shaped area at the midpoint of PM1 and contact point PM1-PM2 (P < 0.01). Within the anterior region a posterior tipping was advantageous, whereas in the posterior regions an anterior tipping was beneficial (P < 0.01). In the middle of the median plane, tipping did not reveal a significant influence. No gender- or age-related differences were observed. CONCLUSIONS: Within the limitations of this study, optimal insertion positions were found within a T-shaped area at the height of PM1-PM2 in the anterior palate. In general, a posterior tipping was beneficial at anterior positions, and an anterior tipping appeared beneficial at posterior positions. High interindividual variation was found and should be carefully considered by the clinician.

Impact of manual control point selection accuracy on automated surface matching of digital dental models.

OBJECTIVES: Treatment outcomes are frequently evaluated based on the superimposition of digital dental models. However, errors from surface matching may distort these findings. The aims of this study were (i) to develop a simulation unit to mimic point set registrations and (ii) to evaluate the impact and clinical relevance of manual landmark selection errors on registration accuracy. MATERIAL AND METHODS: Ten randomly selected dental casts were digitized using a 3D laser scanner, and were loaded by an in-house developed simulation unit (MATLAB R2014a). First, the models were digitally duplicated and one surface was rotated and translated at random. Landmark-based registration was performed with 3 to 15 landmarks, and Gaussian noise was increased iteratively from 0 to 2 mm which simulated CP selection inaccuracy. Iterative closest point (ICP) matching was performed with and without addition of Gaussian noise. Finally, root-mean-squared (RMS) errors and Hausdorff distances were calculated, and averaged for each matching algorithm and noise level. RESULTS: Selection of 10 control points provided reliable registration even in the presence of noise. ICP improved registration results, but noise above 0.5 mm clearly worsened the outcomes. CONCLUSION: Reliable superimposition of digital dental models is possible if 10 carefully selected control points with deviation below 0.5 mm are used for initial landmark-based registration. CLINICAL RELEVANCE: Potential registration errors should be considered carefully whenever superimposed digital dental models are interpreted.

CAD-CAM design and 3-dimensional printing of mini-implant retained orthodontic appliances.

The objective of this article was to illustrate the digital process in the custom fabrication of metallic mini-implant supported appliances. An implant-supported appliance was produced for a patient using a CAD-CAM procedure without a physical impression or a printed model. The work flow consisted of mini-implant insertion into the palate, recording an intraoral digital scan, digital design with incorporation of a scanned expansion mechanism, direct 3-dimensional metal printing via laser melting, laser welding of the hyrax mechanism, insertion, and activation of the appliance. The favorable clinical outcome demonstrated that this procedure is an efficient and viable method for constructing an implant-supported palatal metallic appliance.

Wear-time recording during early Class III facemask treatment using TheraMon chip technology.

Successful intervention in a developing Class III malocclusion with facemask protraction therapy depends on a patient's ability to adhere to the recommendations for duration of appliance wear. In this article, we report the introduction of a novel approach for tracking of the duration of application of a protraction facemask, with the incorporation of a "FaceMon" sensor (TheraMon, microelectronic system; MC Technology GmbH, Hargelsberg, Austria) to track wear time. A 9-year-old boy with a Class III malocclusion was successfully treated with a modified alternate rapid maxillary expansion and constriction protocol and intermittent application of a hybrid hyrax-protraction facemask combination. The average duration of wear of the facemask was measured at 10.8 hours per day. The use of an objective measuring device may have implications for the development of treatment strategies, since patient responses may be able to calibrated in relation to compliance.

The efficacy of Hybrid Hyrax-Mentoplate combination in early Class III treatment: a novel approach and pilot study.

INTRODUCTION: The aim of the present study was to assess the skeletal, dental and soft tissue effects of a specific treatment protocol in consecutively treated patients who presented with a Class III malocclusion. Treatment involved the use of a Hybrid Hyrax (HH) in the maxilla, a Mentoplate in the mandible and the application of continuous intra-oral Class III elastics. METHOD: The treated group was comprised of seven males and seven females (mean pretreatment age 10.4 ± 1.7 yr, range 7.8-12.9 yr). Treatment changes were analysed on lateral cephalograms taken 6-12 months prior to commencing treatment (T1) and at the finish of the orthopaedic phase (T2). Where a normality assumption was met, a parametric paired-sample t-test was used to assess the change differences at T1 and T2. For non-normal data, a non-parametric Wilcoxon sign rank test for related samples was used to assess T1 and T2 differences. The level of statistical significance was set at p < 0.05 (2-tailed). RESULTS: The average sagittal changes showed an improved SNA angle of 2.1 ± 2° (p = 0.002), an ANB angle of 1.9 ± 1.8° (p = 0.002), a Wits improvement of 3.4 ± 2.7 mm (p < 0.001) and an overjet reduction of 2.0 ± 2.2 mm (p = 0.005). There were no statistically significant correlations found between the age at T1, age at treatment start and age at T2 and the changes identified in the cephalometric variables (T2-T1). CONCLUSION: The HH-Mentoplate Class III treatment protocol induced a mean Wits improvement of 3.4 mm in the maxillary and mandibular sagittal base relationship at the functional occlusal level. This was primarily achieved by sagittal maxillary skeletal protraction with negligible effects on the mandible, facial vertical dimension and the incisor angulations. A controlled clinical study with larger sample sizes and longer follow-up times is needed.

Mini-implant-anchored Mesialslider for simultaneous mesialisation and intrusion of upper molars in an anterior open bite case: a three-year follow-up.

BACKGROUND: The present case report describes the orthodontic treatment and long-term follow-up of an adult female patient (27 years) who was diagnosed with a mild Class III malocclusion characterised by an anterior and lateral open bite and three periodontally-compromised first permanent molars. AIM: The aim of treatment was to provide an acceptable aesthetic and functional occlusion while, at the same time, improving the periodontal prognosis. METHODS: The patient was treated with fixed orthodontic appliances utilising direct and indirect skeletal anchorage derived from two mini-screws placed in the palate and one mandibular buccal mini-screw. RESULTS: The objectives of good aesthetics, a functional occlusion, a healthy periodontium and a balanced profile were achieved. The total treatment time was 31 months, which comprised 13 months of maxillary fixed labial appliances and 25 months of mandibular fixed labial appliances. The three-year follow-up records showed stability of the Class ILL correction.

Closure of an open bite using the 'Mousetrap' appliance: a 3-year follow-up.

Recently, skeletal anchorage devices have been used as anchorage units for upper molar intrusion as a way of correcting an anterior open bite malocclusion. To avoid the surgical procedures associated with the placement of miniplates in the zygomatic area, mini-implants may be inserted palatally or buccally in the alveolar process. However, consideration must be given to the potential risks of root damage and a higher failure rate associated with the placement of temporary anchorage devices (TADs) in the interradicular area. The anterior hard palate provides a safer and more stable alternative for TAD placement. The current paper describes the biomechanical principles and the clinical procedures of 'Mousetrap' mechanics using mini-implants in the anterior palate for upper molar intrusion. The stomatognathic response of maxillary molar intrusion is an autorotation of the mandible and so the sagittal implications for each patient must be considered. The presented patient demonstrates successful correction and stability of the treatment result at a three-year review.