Temporary Skeletal Anchorage Devices Research Articles

Effects of transpalatal arch wire dimension and temporary skeletal anchorage device position on maxillary molar intrusion

ABSTRACT Objectives To investigate the effects of transpalatal (TPA) wire dimension and temporary skeletal anchorage device (TSAD) position on maxillary molar intrusion. Materials and Methods The maxillary molar intrusion measurement system included a maxillary acrylic model, TPA, TSADs, and a three-dimensional Force/Moment (F/M) sensor. The intrusion patterns were categorized into six groups: buccal-mesial, buccal-distal, buccal-mesiodistal, palatal-mesial, palatal-distal, and palatal-mesiodistal. TPA wire dimensions were designed to be 0.7 mm, 0.9 mm, and 1.2 mm. The force and moment loads of the maxillary first molar were measured by the F/M sensor. Results Single buccal or palatal TSADs induced torquing movement, and single mesial or distal TSADs tended to promote tipping movement. Mesiodistal TSADs would have eliminated tipping, but accentuated torquing movement. The TPA significantly reduced the force and moment experienced by the maxillary first molar along three-dimensional axes. The thicker the TPA wire, the smaller the force and moment to which the maxillary first molar was subjected. Conclusions Precise placement of TSADs might have a substantial influence on tooth movement and should be determined in accordance with specific clinical requirements. Increasing the TPA wire dimension could diminish the tipping, torquing, and rotation during TSAD-assisted maxillary molar intrusion, but these tendencies could not be completely eliminated.

Biomechanical and clinical considerations for the correction of Class II anterior open bite

Anterior open bite (AOB) with mild-to-moderate skeletal discrepancies can be camouflaged by an orthodontic tooth movement. Conventional methods can improve occlusal relationships and some profile esthetics, but their mechanics may result in detrimental side effects such as a gummy smile, a high-frequency relapse, and an unfavorable facial profile. The emergence of temporary skeletal anchorage devices (TSADs) has facilitated the treatment of skeletal Class II AOB through intrusion of the posterior teeth and autorotation of the mandible, improving facial esthetics while minimizing the side effects. TSADs can also simplify treatment plans and offer a more predictable treatment result. Finite element studies have identified the location of the center of resistance of the dentition, providing a biomechanical basis for understanding 3-dimensional tooth movement patterns using TSADs. Therefore, biomechanical and clinical considerations are essential for correcting Class II AOB using TSADs.

The Biomechanics of Clear Aligners associated with temporary skeletal anchorage devices (TSADs)

The treatment with aligners is challenging especially because the overall accuracy of tooth movement is reported to be below 50%. Moreover, dental anchorage provided by the CA is critical due to the third law of physics, where for every force action, there is an equal opposite reaction. CA associated with temporary skeletal anchorage devices (TSAD) are an effective treatment protocol for expanding the envelope of movement in complex cases. Extra-alveolar miniscrews associated with CA, are effective for retracting the maxillary (IZC) and mandibular dentition (MBS), while interradicular miniscrews provide excellent anchorage for incisor intrusion.Objective: The objective of the paper was to discuss the current biomechanics principles related to the use of CA associated with TSAD showcasing the treatment of complex cases, such as Class II, Class III, as well as deepbite malocclusions.

Anterior open bite correction via molar intrusion: Diagnosis, advantages, and complications

Anterior open bite can be effectively treated nonsurgically via molar intrusion. This technique, involving the intrusion of posterior teeth using temporary skeletal anchorage devices, prompts counterclockwise rotation of the mandible. This rotation not only corrects anterior open bite but also contributes to a decrease in anterior facial height, improvements in lip incompetency, and forward movement of the chin. For successful outcomes, temporary skeletal anchorage devices, installed on both the buccal and palatal sides, must deliver equivalent intrusion force to the maxillary teeth. Treatment planning should consider factors such as skeletal discrepancies, vertical excess, incisor exposure, and configuration of the occlusal plane. Clinicians are advised to closely monitor periodontal changes and consider overcorrection to ensure lasting stability and maintenance of incisal overlap post-treatment.

Biomechanical and clinical considerations in deep bite treatment using temporary skeletal anchorage devices

Deep bite is usually treated by intrusion of the anterior teeth, extrusion of the posterior teeth, or a combination thereof. Various traditional methods have been used to correct deep bites, but they can cause negative side effects. Recently, temporary skeletal anchorage devices (TSADs) have been used to intrude the anterior teeth simply and efficiently without side effects. The amount of incisal exposure at rest should be considered as the first factor in determining which tooth segment should be intruded to correct a deep bite. The center of resistance of the anterior teeth should be considered to achieve the proper biomechanics when intruding them. The location of TSADs should be determined to ensure sufficient interradicular bone to achieve the desired tooth movement. Therefore, clinicians should understand the biomechanical and clinical considerations to correct a deep bite using TSADs.

Orthodontic considerations in hypodivergent craniofacial patterns

This article examines the characteristics of hypodivergent craniofacial patterns and explores treatment modalities in response to these features. It discusses the impact of robust masticatory muscles, which produce heavy occlusal forces. In addition, it examines the use of Botox or splints to reduce gonial angles in individuals with a square face. A nonextraction treatment approach supported by temporary skeletal anchorage devices is recommended; however, if anatomical limitations persist, extraction may be necessary when arch expansion, molar distalization, incisor proclination, or interproximal reduction cannot create the necessary space. In hypodivergent cases where a nonextraction approach is impractical, a single-arch extraction strategy may be considered to prevent a reduction in the vertical dimension. Emphasizing esthetics, particularly maxillary incisor display, a protocol of total arch extrusion of the maxillary dentition assisted with temporary skeletal anchorage device, bite raisers, and interarch elastics is suggested.

Current status of the biomechanics of extra-alveolar miniscrews

Temporary skeletal anchorage devices such as miniscrews are frequently used nowadays. Compared to miniplates, miniscrews are much less expensive and technically easier to place and remove; they are popular and can be easily placed by an orthodontist. Extra-alveolar miniscrews offer benefits compared to inter-radicular miniscrews, such as reduced risk of root damage and the lack of interference with the mesiodistal tooth movement. They are particularly useful for addressing anchorage loss issues and enabling specific tooth movements such as total arch maxillary and mandibular retraction, posterior distalization, molar protraction, molar intrusion, occlusal plane control, and midline correction. The present paper discusses the current biomechanics principles related to the use of extra-alveolar miniscrews placed in the infrazygomatic and mandibular buccal shelf.

Nonextraction Orthodontic Treatment of Severely Impacted Maxillary Canines through Transalveolar Transplantation in a 10-Year-Old Patient: A Case Report with a 6-Year Follow-Up Period

Objective: This case report describes the interdisciplinary treatment of a 10-year-old girl with asymmetric Class III malocclusion, severe maxillary crowding, and bilaterally impacted maxillary canines. Clinical considerations: The clinical decision-making factors regarding treatment alternatives and the final treatment plan are discussed. A two-phase nonextraction therapy was implemented to relieve severe crowding, eliminate the maxillary canine impactions, and compensate for skeletal Class III malocclusion. The first treatment phase involved aligning the left canine through conventional orthodontic traction, while the more deeply horizontally impacted right canine was corrected through transalveolar transplantation. In the second phase, the Class III dental relationship was corrected through mandibular molar retraction. The effective use of various temporary skeletal anchorage devices such as modified c-palatal plates and mini-implants was illustrated. Conclusions: At the end of the treatment, esthetic dental alignment was achieved, along with improved facial balance. The transplanted maxillary right canine showed good health and a favorable long-term prognosis over six years after the procedure.

Evaluation of the Patient-Reported Outcome Measures (PROMs) With Temporary Skeletal Anchorage Devices in Fixed Orthodontic Treatment: A Systematic Review.

Analysis of patient-reported outcome measures(PROMs) is essential to ensure that the skeletal and traditional anchoring methods are appropriately and effectively utilized in the context of patient acceptance and satisfaction. This review's objective was to assess the available data on the levels of discomfort, soft-tissue irritation, functional impairment, and other patient-reported outcomes related to the usage of mini-implants in the context of fixed orthodontic treatment for adult patients. A total of seven electronic bibliographic databases were searched between January 1995 and February 2022. Moreover, a manual search was done in the selected orthodontic journals. This systematic review (SR) covered cohort studies, retrospective studies, randomized clinical trials (RCTs), and controlled clinical trials (CCTs) that studied the use of mini-implants, mini-plates, or onplants as anchorage devices on patients receiving orthodontic treatment. The risk of bias was assessed using Cochrane's risk of bias tool (RoB2 tool). Three RCTs and two cohorts were included in this SR with a total of 468 patients. Three of the four included studies were at high risk of bias. The pain level was in the "mild-to-moderate" category on the first day following the insertion of mini-implants, then decreased to a mild level from the fifth day to the seventh day of insertion (mean values are 36.61, 16.36, and 11.33, respectively). The levels of functional impairments were found to be located between the "mild-to-moderate" and "moderate" categories after the placement of mini-plates and intermaxillary fixation screws, while they experienced a mild level with mini-implants. The greatest pain levels were found after the insertion of the temporary anchorage devices (TADs) and then decreased until they became mild or disappeared completely after one month. Speaking, chewing, and cleaning difficulties were more problematic when using TADs compared to conventional anchorage. To obtain good evidence in this area, more high-quality RCTs are needed.

Correction of anterior open bite malocclusion with a temporary skeletal anchorage device–supported appliance

To evaluate the dental and skeletal changes using a novel miniscrew-supported bite-closing appliance (MBCA) to correct anterior open bite. A novel MBCA that uses nickel-titanium springs connected to miniscrews combined with a biteplate and a low-hanging transpalatal arch to intrude posterior teeth was used. Using cone-beam computed tomography (CBCT) and cephalograms, skeletal and dental changes were measured and discussed in 25 patients with open bites consecutively treated with this appliance. The MBCA significantly decreased the open bite (2.9 ± 0.1 mm; P <0.0001). Relative to FH, intrusion was achieved on the maxillary second premolars (−2.0 ± 1.5 mm; P <0.0001), first (−2.3 ± 1.8 mm; P <0.0001), and second molars (−1.9 ± 1.6 mm; P <0.0001). This was supported by the results from the CBCT superimpositions that showed intrusion of the maxillary second premolar (−3.2 ± 1.6 mm) and the maxillary first and the second molars (−2.8 ± 1.5 mm and −2.1 ± 1.6 mm, respectively). This resulted in favorable skeletal changes exhibited by a significant decrease in FMA (−1.4 ± 2.2°; P <0.005), SN-MP (−1.8 ± 2.4°; P <0.005), and an increase in PFH (1.2 ± 1.4 mm; P <0.05) and SN-NPog (1.4 ± 2.2°; P <0.05). These results are consistent with the counterclockwise rotation of the mandible. A mandibular lingual holding arch resulted in better vertical control of the mandibular posterior teeth (P <0.05). Follow-up on patients with available posttreatment CBCTs (n = 8) suggests some dental relapse at the second premolar (1.5 ± 3.0 mm) and the first (1.7 ± 2.4 mm) and second molars (1.7 ± 2.4 mm), but the skeletal changes were maintained. Visual assessment of patients with posttreatment photographs (n = 18) showed that positive overbite was maintained in all subjects. MBCA can provide satisfactory correction of the anterior open bite through counterclockwise rotation of the mandible.

Pain, Discomfort, and Functional Impairments When Retracting Upper Anterior Teeth Using Two-Step Retraction With Transpalatal Arches Versus En-Masse Retraction With Mini-implants: A Randomized Controlled Trial.

Background This study aimed to evaluate the levels of pain and discomfort associated with employing mini-implants as a temporary skeletal anchorage device compared to the traditional transpalatal arches (TPAs) during upper anterior teeth retraction in patients with upper dentoalveolar protrusion and to determine the level of acceptance of both techniques among patients. Methodology The study sample consisted of 38 patients (29 women and nine men) with an average age of 21.7 years. The patients were randomly and equally distributed into two groups. In the first group: upper anterior teeth were en-masse retracted using mini-implants (the TAD group), whereas, in the second group, TPAs were used during the two-step retraction of upper anterior teeth (the TPA group). Standardized questionnaires were distributed to all patients after 24 hours of mini-implant application. The questionnaire asked the patients to rate their pain perception, swelling sensation, eating difficulties, talking impairments, and cleansing difficulties on a four-point Likert scale on the third-day, one-week, two-week, and one-month follow-ups after the anchorage application. Wilcoxon matched-pairs signed-rank tests were used to evaluate intragroup changes, whereas Mann-Whitney U tests were employed to examine intergroup differences. Results Patients in the TAD group had higher pain and swelling levels than those in the TPA group, and differences were statistically significant at the first three assessment time points. The differences between the two groups were statistically insignificant regarding eating and talking difficulties, whereas differences were statistically significant for brushing difficulties. These impairments decreased to almost normal levels after one month of treatment initiation. Conclusions TPAs, when used for anchorage in the two-step retraction technique, were less problematic compared to mini-implants withen-masseretraction, where the sensation of pain or swelling around the mini-implants did not last for more than a week. The difficulties of cleaning, chewing, and speaking in the presence of mini-implants were temporary and mostly disappeared within two weeks of mini-implant application.

Rehabilitation of Dentofacial Asymmetry Secondary to Unilateral Temporomandibular Joint Ankylosis with Dual Distraction and Fixed Orthodontics - Stability at Three-year Follow-up.

Optimal rehabilitation of asymmetric dentofacial deformity secondary to unilateral temporomandibular joint (TMJ) ankylosis is often a challenge. The purpose of this case series is to present an insight into esthetic, occlusal and functional rehabilitation of two patients with varying degree of asymmetric Class II dentofacial deformities secondary to long-standing unilateral TMJ ankylosis. The patients were treated with one-stage surgical protocol employing simultaneous dual distraction technique along with interpositional arthroplasty. Dual distraction technique entailed the simultaneous use of two distractors which allowed for proper control of proximal condylar segment during the course of distraction and lowering the risk of ankylosis recurrence. Thereafter, comprehensive fixed orthodontic mechanotherapy involving the use of temporary anchorage devices was instituted to align and level the compensated dentition. Post-treatment records showed significant improvements in skeletal disharmony and functional stability with good functional occlusion. At the three-year follow-up, the morphological and functionally acceptable results were reasonably well-maintained, with no signs of relapse. Through the two cases reported here, we would like to highlight that one-stage concurrent arthroplasty and dual distraction technique is a safe, stable, and reliable approach for surgical and functional rehabilitation of an adult asymmetric dentofacial deformity secondary to unilateral TMJ ankylosis. Meticulously executed comprehensive orthodontic manipulations involving use of acrylic bite-blocks, elastic traction, and temporary skeletal anchorage device play a crucial role in enhancing the final occlusal outcomes.

An Orthodontic Treatment Case of a TMD Patient with Maxillary Posterior Intrusion Using TSADs

The orthodontic treatment of patients having temporomandibular disorders are some of the most complicated cases to treat. The positions of the mandibular condyles are often unstable, which means clinicians find it difficult to have definite criteria for making an accurate and reliable orthodontic diagnosis. This article reports the orthodontic treatment of a patient showing skeletal Class II and temporomandibular disorders with condylar resorption. To stabilize her condylar position and to relieve her symptoms in the temporomandibular joint, a stabilization splint was used before orthodontic tooth movement. After the splint therapy, the patient exhibited significantly increased open bite and a more severe Class II occlusal relationship as her mandibular condyles were seated anteriorly and superiorly in the articular fossae. The occlusion and facial esthetics of the patient were improved by orthodontic camouflage treatment with the proper use of temporary skeletal anchorage devices and treatment mechanics.

Clinical Application and Biomechanics of Various Lingual Retractors with Temporary Skeletal Anchorage Devices: A Narrative Review

The lingual retractor is an appliance with esthetic advantages and biomechanical superiority in the retraction of anterior teeth, when used in combination with temporary skeletal anchorage devices (TSADs). These appliances can address the patients’ chief complaint during the early stages of bialveolar protrusion treatment. This narrative review presents the clinical applications and biomechanics of various lingual retractors with TSADs.This review includes all research and case reports related to various lingual retractors such as the C-lingual retractor (CLR), double J retractor (DJR), and antero-posterior lingual retractor (APLR). Anterior torque and vertical control can be achieved with all three types of lingual retractors by changing the length of the lever arms and the position of the TSADs. Torquing springs in DJR are designed to slide along palatal mini-implants or to apply intermaxillary elastics to counteract retroclination of the incisors during space closure. APLR allows three-dimensional control of the anterior tooth movement with anterior lever arms, guide bars, posterior tubes, and position of TSADs. Various lingual retractors with TSADs are effectively proper anterior torque and vertical control.

Occlusal Plane Changes after Maxillary Molar Distalization Using Temporary Skeletal Anchorages Devices: A Narrative Review and Preliminary Study

Background: We conducted a narrative review of studies analyzing the occlusal and mandibular plane angles after maxillary molar distalization using temporary skeletal anchorage devices (TADs). An original preliminary investigation was conducted on the occlusal and mandibular plane angle changes according to the design of TAD-supported distalization. Methods: We included 51 participants stratified into three groups (buccal TAD, lingual arch TAD, and pendulum TAD) who underwent lateral cephalography before and after treatment. The paired t-test and ANOVA were used to analyze the significant differences among the groups. Results: The pterygoid vertical to maxillary second molar (p &lt; 0.01) significantly differed before and after treatment within each group (group 1, 1.29 ± 1.73 mm; group 2, 2.01 ± 1.46 mm; group 3, 1.12 ± 1.43 mm). The angle between the Frankfort horizontal and anatomical occlusal plane increased by 1.96 ± 2.88° (p &lt; 0.05) and 2.51 ± 2.57° (p &lt; 0.01) in groups 2 and 3, respectively. Conclusions: The measured variables did not significantly differ among the three groups. The Frankfort-mandibular plane angle and functional occlusal plane did not change after maxillary molar distalization. The anatomical occlusal plane is influenced by the anterior teeth and may be unrelated to maxillary molar distalization. Further studies are required to verify the exact relationship between maxillary molar distalization and occlusal plane angle.

Torque and vertical control of maxillary incisors for an esthetic smile using TSADs implanted in various areas: Biomechanical considerations

Esthetic smiles are an increasingly important focus of orthodontic treatment. Factors related to maxillary incisors, such as smile arc, maxillary gingival exposure, and maxillary crown torque, are related to esthetic smiles. It is very important to consider these factors during orthodontic treatment. However, with conventional orthodontic treatment using traditional anchorage, torque and vertical control of maxillary incisors, which are closely related to esthetic smile, were significant challenges, but with the introduction of temporary skeletal anchorage devices (TSADs), control of maxillary incisors has become easier to accomplish along with premolar extractions. Importantly, the various clinical applications and biomechanics of TSADs must be understood because of the variety of sites where the TSADs can be implanted. In general, the torque and vertical position of the maxillary incisors can be controlled by adjusting the line of action of force by changing the length of the lever arm and the vertical position of the TSADs. In this article, we classify TSADs for esthetic control of the maxillary incisors into anterior labial TSADs, posterior buccal TSADs, and palatal TSADs according to the implant sites, presenting various cases and discussing the biomechanics associated with them. Esthetic smiles are an increasingly important focus of orthodontic treatment. Factors related to maxillary incisors, such as smile arc, maxillary gingival exposure, and maxillary crown torque, are related to esthetic smiles. It is very important to consider these factors during orthodontic treatment. However, with conventional orthodontic treatment using traditional anchorage, torque and vertical control of maxillary incisors, which are closely related to esthetic smile, were significant challenges, but with the introduction of temporary skeletal anchorage devices (TSADs), control of maxillary incisors has become easier to accomplish along with premolar extractions. Importantly, the various clinical applications and biomechanics of TSADs must be understood because of the variety of sites where the TSADs can be implanted. In general, the torque and vertical position of the maxillary incisors can be controlled by adjusting the line of action of force by changing the length of the lever arm and the vertical position of the TSADs. In this article, we classify TSADs for esthetic control of the maxillary incisors into anterior labial TSADs, posterior buccal TSADs, and palatal TSADs according to the implant sites, presenting various cases and discussing the biomechanics associated with them.

Improved facial profile with non-extraction treatment of severe protrusion using TSADs

Extraction has traditionally been necessary to correct bimaxillary and lip protrusion with proclined maxillary and mandibular incisors. However, non-extraction treatment using temporary skeletal anchorage devices (TSADs) is now an option for severe overjet or full-step Class II malocclusions. It is possible to treat bimaxillary protrusion with non-extraction, but for successful non-extraction treatment in bimaxillary patients, the amount of total arch distalization of the mandibular dentition is crucial.For maximum total mandibular arch distalization in protrusion patients, it is recommended to extrude and distalize the molars simultaneously, which results in more posterior movement of the mandibular dentition without gingival impingement. Therefore, this paper presents efficient biomechanics, a strategy, and the anatomy of the retromolar area for total arch distalization using TSADs to improve facial profile without extracting premolars in Class II maxillary and bimaxillary protrusion patients.

A cone-beam computed tomography study on strategic uprighting of mandibular molars using a biocreative reverse curve system.

ObjectiveTo analyze the overall treatment effects in terms of the amount of uprighting with changes in the three-dimensional positions of the mandibular posterior teeth after applying the biocreative reverse curve (BRC) system.MethodsThirty-four patients (mean age, 20.5 ± 8.56 years) were treated using the BRC system (mean period, 8.17 ± 2.19 months). Cone-beam computed tomography was performed before treatment and after treatment with the BRC system. The three-dimensional movement of each tooth was analyzed in the coordinate system at points on the crown and root apex. A paired t-test was used to analyze the treatment effects of the BRC system.ResultsThe application of the BRC system spanning from the first premolar to the second molar resulted not only in buccal and distal uprighting, but also in increased buccal and distal tipping of the teeth. The premolars and the first molar were extruded, and the second molar was intruded.ConclusionsWhen the BRC system is applied, simultaneous distal and buccal uprighting of the premolars and molars can be achieved bilaterally using a temporary skeletal anchorage device without unnecessary movement of the anterior teeth.

Treatment effects after maxillary total arch distalization using a modified C-palatal plate in patients with Class II malocclusion with sinus pneumatization

The purpose of this study was to evaluate the treatment effects after molar distalization using modified C-palatal plates in patients with Class II malocclusion with maxillary sinus pneumatization. This study consisted of 70 lateral cephalograms derived from cone-beam computerized tomography images of 35 patients with Class II malocclusion (mean age 22.3 ± 7.4 years) who had undergone bilateral total arch distalization of the maxillary dentition using modified C-palatal plates. The samples were divided into 2 groups according to sinus pneumatization; group 1 (n= 40), cephalograms with sinus pneumatization and group 2 (n= 30) cephalograms without sinus pneumatization. Paired t tests and independent-sample t tests were used to compare the changes in each group and between groups. The distal movement of the maxillary first molars was 4.3 mm for group 1 and 3.5 mm for group 2, with the intrusion of 1.4 mm and 2.5 mm, respectively. There was no statistically significant difference between the 2 groups. Group 1 showed 3.5° of distal tipping of the maxillary second molars, which was significantly greater than the 0.2° in group 2 (P<0.05). The total treatment period, including distalization, was 2.2 years for group 1 and 1.9 years for group 2, but the difference was not significant. There was no significant difference in the amount of distal movement and intrusion of the maxillary first molars between groups 1 and 2. Therefore, these results suggest that regardless of sinus pneumatization, molar distalization using temporary skeletal anchorage devices in Class II patients can be performed as a nonextraction treatment.

Biomechanical features of tooth movement from a lingual appliance in comparison with a labial appliance during space closure in sliding mechanics

The objectives of this study were to simulate long-term orthodontic tooth movement in en-masse retraction using the finite element method and investigate the effects of power arms on tooth movements when using a lingual appliance in comparison with a labial appliance. A 3-dimensional finite element model of the maxillary dentition was constructed with 0.018-in brackets and 0.016 × 0.022-in stainless steel archwire. An en-masse retraction was performed by applying retraction force at various lengths of the power arm (4, 6, 8, and 10 mm) to the second molar tube, and long-term tooth movements with the lingual and labial appliances were analyzed using the finite element method. Although lingual crown tipping of the incisor was more marked with the lingual appliance than with the labial appliance in the early phase of space closure, only a slight difference was evident after space closure. Although the power arm was effective for achieving better-controlled tooth movement and reducing vertical and transverse bowing effects, bodily movement of the incisor could not be achieved, and bowing effects could not be eliminated. To provide better torque control of the incisor or prevent a vertical bowing effect, the incorporation of extra torque into brackets of incisors was recommended, and the use of power arms for the lingual appliance. To prevent a transverse bowing effect, incorporation of the antibowing bend or application of retraction force from both buccal and lingual sides or temporary skeletal anchorage devices was recommended.