Comparison of orthodontic tooth movement between adolescents and adults based on implant superimposition

Effect of orthodontic premolar extraction on maxillary teeth angulation and arch dimensions in adolescent patients: A 3-D digital model analysis

Background

Therapeutic orthodontic premolar extraction is a common orthodontic treatment, yet the extent of its impact on the upper dental arch dimensions and teeth angulations is still under exploration. Hypothesis: We postulated that the therapeutic extraction of orthodontic premolars significantly alters the orientation of teeth and the dimensions of the dental arch. Objective: This study assessed the impact of therapeutic orthodontic premolar extraction on dental arch dimensions and tooth angulations.

Material and Methods

We conducted a retrospective cohort study involving 30 patients who underwent bilateral upper premolar extraction and fixed appliance treatment. Pre and post-treatment dental casts were scanned, and changes in tooth angulations and arch dimensions were evaluated using 3D digital maxillary models. Statistical analyses encompassed the application of paired samples t-test.

Results

Significant post-treatment changes were observed, including distal tipping in anterior teeth, minor mesial tipping in first molars, and a reduction in torque for central incisors and canines. Dental arch dimensions were also influenced, with increased width and depth between the canines and decreased width between the second premolars while inter-molar width and overall arch depth significantly reduced post-treatment.

Conclusions

Therapeutic orthodontic premolar extraction significantly affects dental arch dimensions and tooth angulations. These findings have implications for treatment planning and predicting changes associated with orthodontic treatments involving premolar extraction. Key words:3D digital models - orthodontic premolar extraction - teeth angulation - dental arch dimensions.

Comparative analysis of anchorage strength and histomorphometric changes after implantation of miniscrews in adults and adolescents: an experimental study in Beagles

OBJECTIVES

This study aimed to explore the differences in anchorage strength and histomorphometric changes in orthodontic miniscrews between adult and adolescent beagles.

MATERIAL AND METHOD

Six adult beagles and six young beagles were used as experimental subjects, and eight miniscrews were symmetrically placed in the posterior mandible of each dog. Measurement of the displacement (mm) of two adjacent miniscrews after load application was performed to compare the anchorage strength between the adult and adolescent groups. Three intravital bone fluorochromes (oxytetracycline, calcein green, xylenol orange) were administered postoperatively to mark the active bone-forming surface. Subsequently, the mineral apposition rate and bone-implant contact ratio were measured for dynamic and static histomorphometry. Finally, the expression levels of the RANKL/OPG ratio were evaluated by immunohistochemistry.

RESULTS

The average displacement of miniscrews in the adult group was significantly less than that in the adolescent group after load application. For histomorphometry analysis, the mineral exposure rate in the adolescent group was higher than that in the adult group with or without force application. In addition, more fractures and new bone formation but deceased bone-implant contact ratios were observed in the adolescent group than in the adult group. The ratio of RANKL/OPG expression increased more in the adolescent group than in the adult group.

CONCLUSION

Miniscrews do not remain in the same position as skeletal anchors, and the amount of displacement was higher in adolescent group than that in adult group, reflecting the weaker anchorage strength of miniscrews in adolescents due to the higher bone turnover rate and active bone remodelling. Therefore, it is feasible to apply orthodontic loading to the miniscrews in adult patients earlier, even immediately, but it is recommended to wait a period for the adolescents.

Effectiveness of photobiomodulation with low-level lasers on the acceleration of orthodontic tooth movement: a systematic review and meta-analysis of split-mouth randomised clinical trials

Although several studies have evaluated the effect of low-level laser therapy (LLLT) on orthodontic movement acceleration, results are still inconsistent. Such inconsistencies may be attributed to the differences in the LLLT application protocols, especially in terms of wavelength ranges. Objective: (i) to assess the clinical effects of LLLT on the acceleration of orthodontic movement and (ii) to establish the most effective LLLT wavelength to accelerate tooth movement during orthodontic treatments. MEDLINE (PubMed), Scopus, ScienceDirect, and LILACS were searched from inception to October 2022. Inclusion criteria: Split-mouth randomised clinical trials (RCTs) on systemically healthy patients reporting the effect of LLLT in accelerating orthodontic movements, specifically retraction of canines. The risk of bias was assessed using RoB-2. A random effect model was applied. Nineteen RCTs met the inclusion criteria for qualitative synthesis, and eighteen RCTs were included in the quantitative synthesis. Seventeen studies were rated as at some concerns of bias and two studies were classified as having a low risk of bias. In general terms, this systematic review and meta-analysis presents a moderate risk of bias. Findings of this systematic review and meta-analysis point to a tendency for faster orthodontic dental movement in the groups receiving LLLT treatment during the first (OR of 0.28 95% CI (0.07 to 0.48)), second (OR of 0.52 95% CI (0.31 to 0.73)), and third (OR of 0.41 95% CI (0.03 to 0.79)) month follow-up. Wavelengths ≤ 810 nm and energy density values ≤ 5.3 J/cm2 were associated with faster orthodontic tooth movement.

Effectiveness of photobiomodulation with low-level lasers on the acceleration of orthodontic tooth movement: a systematic review and meta-analysis of split-mouth randomised clinical trials

Although several studies have evaluated the effect of low-level laser therapy (LLLT) on orthodontic movement acceleration, results are still inconsistent. Such inconsistencies may be attributed to the differences in the LLLT application protocols, especially in terms of wavelength ranges. Objective: (i) to assess the clinical effects of LLLT on the acceleration of orthodontic movement and (ii) to establish the most effective LLLT wavelength to accelerate tooth movement during orthodontic treatments. MEDLINE (PubMed), Scopus, ScienceDirect, and LILACS were searched from inception to October 2022. Inclusion criteria: Split-mouth randomised clinical trials (RCTs) on systemically healthy patients reporting the effect of LLLT in accelerating orthodontic movements, specifically retraction of canines. The risk of bias was assessed using RoB-2. A random effect model was applied. Nineteen RCTs met the inclusion criteria for qualitative synthesis, and eighteen RCTs were included in the quantitative synthesis. Seventeen studies were rated as at some concerns of bias and two studies were classified as having a low risk of bias. In general terms, this systematic review and meta-analysis presents a moderate risk of bias. Findings of this systematic review and meta-analysis point to a tendency for faster orthodontic dental movement in the groups receiving LLLT treatment during the first (OR of 0.28 95% CI (0.07 to 0.48)), second (OR of 0.52 95% CI (0.31 to 0.73)), and third (OR of 0.41 95% CI (0.03 to 0.79)) month follow-up. Wavelengths ≤ 810 nm and energy density values ≤ 5.3 J/cm2 were associated with faster orthodontic tooth movement.

Effectiveness of photobiomodulation with low-level lasers on the acceleration of orthodontic tooth movement: a systematic review and meta-analysis of split-mouth randomised clinical trials

Although several studies have evaluated the effect of low-level laser therapy (LLLT) on orthodontic movement acceleration, results are still inconsistent. Such inconsistencies may be attributed to the differences in the LLLT application protocols, especially in terms of wavelength ranges. Objective: (i) to assess the clinical effects of LLLT on the acceleration of orthodontic movement and (ii) to establish the most effective LLLT wavelength to accelerate tooth movement during orthodontic treatments. MEDLINE (PubMed), Scopus, ScienceDirect, and LILACS were searched from inception to October 2022. Inclusion criteria: Split-mouth randomised clinical trials (RCTs) on systemically healthy patients reporting the effect of LLLT in accelerating orthodontic movements, specifically retraction of canines. The risk of bias was assessed using RoB-2. A random effect model was applied. Nineteen RCTs met the inclusion criteria for qualitative synthesis, and eighteen RCTs were included in the quantitative synthesis. Seventeen studies were rated as at some concerns of bias and two studies were classified as having a low risk of bias. In general terms, this systematic review and meta-analysis presents a moderate risk of bias. Findings of this systematic review and meta-analysis point to a tendency for faster orthodontic dental movement in the groups receiving LLLT treatment during the first (OR of 0.28 95% CI (0.07 to 0.48)), second (OR of 0.52 95% CI (0.31 to 0.73)), and third (OR of 0.41 95% CI (0.03 to 0.79)) month follow-up. Wavelengths ≤ 810 nm and energy density values ≤ 5.3 J/cm2 were associated with faster orthodontic tooth movement.

Effectiveness of photobiomodulation with low-level lasers on the acceleration of orthodontic tooth movement: a systematic review and meta-analysis of split-mouth randomised clinical trials

Although several studies have evaluated the effect of low-level laser therapy (LLLT) on orthodontic movement acceleration, results are still inconsistent. Such inconsistencies may be attributed to the differences in the LLLT application protocols, especially in terms of wavelength ranges. Objective: (i) to assess the clinical effects of LLLT on the acceleration of orthodontic movement and (ii) to establish the most effective LLLT wavelength to accelerate tooth movement during orthodontic treatments. MEDLINE (PubMed), Scopus, ScienceDirect, and LILACS were searched from inception to October 2022. Inclusion criteria: Split-mouth randomised clinical trials (RCTs) on systemically healthy patients reporting the effect of LLLT in accelerating orthodontic movements, specifically retraction of canines. The risk of bias was assessed using RoB-2. A random effect model was applied. Nineteen RCTs met the inclusion criteria for qualitative synthesis, and eighteen RCTs were included in the quantitative synthesis. Seventeen studies were rated as at some concerns of bias and two studies were classified as having a low risk of bias. In general terms, this systematic review and meta-analysis presents a moderate risk of bias. Findings of this systematic review and meta-analysis point to a tendency for faster orthodontic dental movement in the groups receiving LLLT treatment during the first (OR of 0.28 95% CI (0.07 to 0.48)), second (OR of 0.52 95% CI (0.31 to 0.73)), and third (OR of 0.41 95% CI (0.03 to 0.79)) month follow-up. Wavelengths ≤ 810 nm and energy density values ≤ 5.3 J/cm2 were associated with faster orthodontic tooth movement.

Effectiveness of photobiomodulation with low-level lasers on the acceleration of orthodontic tooth movement: a systematic review and meta-analysis of split-mouth randomised clinical trials

Although several studies have evaluated the effect of low-level laser therapy (LLLT) on orthodontic movement acceleration, results are still inconsistent. Such inconsistencies may be attributed to the differences in the LLLT application protocols, especially in terms of wavelength ranges. Objective: (i) to assess the clinical effects of LLLT on the acceleration of orthodontic movement and (ii) to establish the most effective LLLT wavelength to accelerate tooth movement during orthodontic treatments. MEDLINE (PubMed), Scopus, ScienceDirect, and LILACS were searched from inception to October 2022. Inclusion criteria: Split-mouth randomised clinical trials (RCTs) on systemically healthy patients reporting the effect of LLLT in accelerating orthodontic movements, specifically retraction of canines. The risk of bias was assessed using RoB-2. A random effect model was applied. Nineteen RCTs met the inclusion criteria for qualitative synthesis, and eighteen RCTs were included in the quantitative synthesis. Seventeen studies were rated as at some concerns of bias and two studies were classified as having a low risk of bias. In general terms, this systematic review and meta-analysis presents a moderate risk of bias. Findings of this systematic review and meta-analysis point to a tendency for faster orthodontic dental movement in the groups receiving LLLT treatment during the first (OR of 0.28 95% CI (0.07 to 0.48)), second (OR of 0.52 95% CI (0.31 to 0.73)), and third (OR of 0.41 95% CI (0.03 to 0.79)) month follow-up. Wavelengths ≤ 810 nm and energy density values ≤ 5.3 J/cm2 were associated with faster orthodontic tooth movement.

Effectiveness of photobiomodulation with low-level lasers on the acceleration of orthodontic tooth movement: a systematic review and meta-analysis of split-mouth randomised clinical trials

Although several studies have evaluated the effect of low-level laser therapy (LLLT) on orthodontic movement acceleration, results are still inconsistent. Such inconsistencies may be attributed to the differences in the LLLT application protocols, especially in terms of wavelength ranges. Objective: (i) to assess the clinical effects of LLLT on the acceleration of orthodontic movement and (ii) to establish the most effective LLLT wavelength to accelerate tooth movement during orthodontic treatments. MEDLINE (PubMed), Scopus, ScienceDirect, and LILACS were searched from inception to October 2022. Inclusion criteria: Split-mouth randomised clinical trials (RCTs) on systemically healthy patients reporting the effect of LLLT in accelerating orthodontic movements, specifically retraction of canines. The risk of bias was assessed using RoB-2. A random effect model was applied. Nineteen RCTs met the inclusion criteria for qualitative synthesis, and eighteen RCTs were included in the quantitative synthesis. Seventeen studies were rated as at some concerns of bias and two studies were classified as having a low risk of bias. In general terms, this systematic review and meta-analysis presents a moderate risk of bias. Findings of this systematic review and meta-analysis point to a tendency for faster orthodontic dental movement in the groups receiving LLLT treatment during the first (OR of 0.28 95% CI (0.07 to 0.48)), second (OR of 0.52 95% CI (0.31 to 0.73)), and third (OR of 0.41 95% CI (0.03 to 0.79)) month follow-up. Wavelengths ≤ 810 nm and energy density values ≤ 5.3 J/cm2 were associated with faster orthodontic tooth movement.

Effectiveness of photobiomodulation with low-level lasers on the acceleration of orthodontic tooth movement: a systematic review and meta-analysis of split-mouth randomised clinical trials

Although several studies have evaluated the effect of low-level laser therapy (LLLT) on orthodontic movement acceleration, results are still inconsistent. Such inconsistencies may be attributed to the differences in the LLLT application protocols, especially in terms of wavelength ranges. Objective: (i) to assess the clinical effects of LLLT on the acceleration of orthodontic movement and (ii) to establish the most effective LLLT wavelength to accelerate tooth movement during orthodontic treatments. MEDLINE (PubMed), Scopus, ScienceDirect, and LILACS were searched from inception to October 2022. Inclusion criteria: Split-mouth randomised clinical trials (RCTs) on systemically healthy patients reporting the effect of LLLT in accelerating orthodontic movements, specifically retraction of canines. The risk of bias was assessed using RoB-2. A random effect model was applied. Nineteen RCTs met the inclusion criteria for qualitative synthesis, and eighteen RCTs were included in the quantitative synthesis. Seventeen studies were rated as at some concerns of bias and two studies were classified as having a low risk of bias. In general terms, this systematic review and meta-analysis presents a moderate risk of bias. Findings of this systematic review and meta-analysis point to a tendency for faster orthodontic dental movement in the groups receiving LLLT treatment during the first (OR of 0.28 95% CI (0.07 to 0.48)), second (OR of 0.52 95% CI (0.31 to 0.73)), and third (OR of 0.41 95% CI (0.03 to 0.79)) month follow-up. Wavelengths ≤ 810 nm and energy density values ≤ 5.3 J/cm2 were associated with faster orthodontic tooth movement.

Effectiveness of photobiomodulation with low-level lasers on the acceleration of orthodontic tooth movement: a systematic review and meta-analysis of split-mouth randomised clinical trials

Although several studies have evaluated the effect of low-level laser therapy (LLLT) on orthodontic movement acceleration, results are still inconsistent. Such inconsistencies may be attributed to the differences in the LLLT application protocols, especially in terms of wavelength ranges. Objective: (i) to assess the clinical effects of LLLT on the acceleration of orthodontic movement and (ii) to establish the most effective LLLT wavelength to accelerate tooth movement during orthodontic treatments. MEDLINE (PubMed), Scopus, ScienceDirect, and LILACS were searched from inception to October 2022. Inclusion criteria: Split-mouth randomised clinical trials (RCTs) on systemically healthy patients reporting the effect of LLLT in accelerating orthodontic movements, specifically retraction of canines. The risk of bias was assessed using RoB-2. A random effect model was applied. Nineteen RCTs met the inclusion criteria for qualitative synthesis, and eighteen RCTs were included in the quantitative synthesis. Seventeen studies were rated as at some concerns of bias and two studies were classified as having a low risk of bias. In general terms, this systematic review and meta-analysis presents a moderate risk of bias. Findings of this systematic review and meta-analysis point to a tendency for faster orthodontic dental movement in the groups receiving LLLT treatment during the first (OR of 0.28 95% CI (0.07 to 0.48)), second (OR of 0.52 95% CI (0.31 to 0.73)), and third (OR of 0.41 95% CI (0.03 to 0.79)) month follow-up. Wavelengths ≤ 810 nm and energy density values ≤ 5.3 J/cm2 were associated with faster orthodontic tooth movement.

Methods of Anterior Torque Control during Retraction: A Systematic Review

Background: There are various methods of controlling the inclination of the incisors during retraction, but there is no evidence as to the advantages of some methods over others. The purpose of this systematic review and meta-analysis was to determine the effectiveness of the methods used to control torque during anterior teeth retraction. Methods: In accordance with the PRISMA guidelines, the main research question was defined in the PICO format [P: patients with complete permanent dentition; I: the maxillary incisor torque after (I) and before I retraction with straight-wire appliance and different modes of torque control; O: statistically significant differences in torque values of the upper incisors after orthodontic treatment]. The MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases were searched for keywords combining: retraction orthodontics, torque control orthodontics, torque orthodontics, inclination orthodontics, torque control retraction. The articles were subjected to risk of bias and quality analyses with the ROBINS-I protocol and the modified Newcastle–Ottawa QAS, respectively. Meta-analyses were performed with both fixed- and random-effects models. Results: 13 articles were selected in which total number of 580 subjects took part. In all studies, incisors were retroclined during retraction by 2.46° (mean difference), which was statistically significant. Considering the articles separately, the differences in torque between the study group and the control group were statistically significant in six articles. The Q statistic was 36.25 with p = 0.0003 and I2 = 66.9%, which indicated a high level of study heterogeneity. Conclusion: Both properly performed corticotomy and en-masse retraction using orthodontic microimplants seem to be the most effective and scientifically validated methods of torque control. Further high-quality research is needed to perform better quality analyses and draw more reliable conclusions.

Efficacy and safety of piezocision in accelerating maxillary anterior teeth en-masse retraction: study protocol for a randomized controlled trial

BACKGROUND

Orthodontic treatment is commonly more time-consuming in adults than in teenagers, especially when it comes to the maxillary en-masse retraction, which may take 9 months or even longer. As to solve this concern, orthodontists have been striving to seek new methods for shortening orthodontic treatment time. Piezocision, as a popular alternative treatment, has been widely used in different types of tooth movement. However, its effect on en-masse retraction of maxillary anterior teeth remains unclear. This randomized controlled trial intends to figure out the role piezocision plays in accelerating en-masse retraction.

METHODS

This protocol is designed for a prospective, single-center, assessor-blinded and parallel-group randomized controlled trial. Twenty adult patients aged from 18 to 40 whose orthodontic treatment required bilateral maxillary first premolars extraction will be randomly assigned to the piezocision group and the control group at a ratio of 1:1. The piezocision group will undergo en-masse retraction immediately after the piezo surgery, while the control group will start en-masse retraction directly. Both groups will be followed up every 2 weeks to maintain the retraction force until the end of space closure. The space closing time is set as the primary endpoint. Meanwhile, the secondary endpoints include the change of root length, labial and palatal alveolar bone thickness, vertical bone height, probing depth of maxillary anterior teeth, cephalometric measurements, visual analogue scale, and postoperative satisfaction questionnaire.

DISCUSSION

This study will attempt to provide more convincing evidence to verify whether piezocision will shorten the time of en-masse retraction or not. Distinguished with previous studies, our study has made some innovations in orthodontic procedure and primary outcome measurement, aiming to clarify the efficacy and safety of piezocision-assisted en-masse retraction in Chinese population.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR 1900024297 . Registered on 5 July 2019.

Evaluation of the stability of the palatal rugae using the three-dimensional superimposition technique following orthodontic treatment

OBJECTIVES

To determine the uniqueness and stability of the palatal rugae after orthodontic treatment.

METHODS

Cast models of untreated subjects (n=50) were obtained twice at intervals of 8-30 months. Cast models of patients who received non-extraction (n=50) and extraction (n=50) orthodontic treatment were obtained before and after treatment at intervals of 11-41 months and 14-49 months, respectively. All 300 cast models were scanned digitally. The palatal rugae were manually extracted and transformed into 3D point clouds using reverse engineering software. An iterative closest point (ICP) registration algorithm based on correntropy was applied, and the minimum point-to-point root mean square (RMS) distances were calculated to analyze the deviation of palatal rugae for scans of the same subject (intrasubject deviation [ISD]) and between different subjects (between-subject deviation [BSD]). Differences in ISD between each group and the deviation between ISD and BSD of all 150 subjects were evaluated.

RESULTS

Significant differences were found in the 150 ISD and 1225 BSD in each group, as well as the 150 ISD and 11175 BSD across all groups. The mean values of ISD in untreated, non-extraction and extraction group were 0.178, 0.229 and 0.333 mm, respectively. When the first ruga was excluded in the extraction group, the mean ISD decreased to 0.241 mm, which was not significantly different from that in the non-extraction group (p=0.314).

CONCLUSIONS

Orthodontic treatment can influence the palatal rugae, especially in cases of extraction. Furthermore, variation mainly existed in the first ruga in cases of extraction. However, palatal rugae are still unique and may be used as a supplementary tool for individual identification.

CLINICAL SIGNIFICANCE

This study indicates that palatal rugae might be applied in the evaluation of orthodontic tooth movement and forensic individual identification. The registration algorithm based on correntropy provides a credible, precise, and convenient method for palatal rugae superimposition.

The risk for infraposition of dental implants and ankylosed teeth in the anterior maxilla related to craniofacial growth, a systematic review

BACKGROUND

The aim of the study was to evaluate a potential association between individuals with different craniofacial types or other exposures, and the risk of infraposition due to continued growth/eruption of adjacent teeth in the anterior maxilla.

MATERIALS AND METHODS

This is a systematic review in which primary studies as well as other systematic reviews are scrutinised. A search of PubMed (Medline), Scopus, Web of science and Health technology assessment (HTA) organisations and a complementary handsearch was carried out. Selected studies were read in full-text by several reviewers. The quality of the included primary studies was assessed using a protocol for assessment of risk of bias in exposure studies.

RESULTS

The literature search resulted in 3,296 publications. Title and abstract screening yielded 25, whereof one systematic review, potential publications allocated for full-text inspection. The quality assessment resulted in a total of seven studies with a low/moderate risk of bias and four studies with a high risk of bias.

CONCLUSION

In conclusion, a long-term risk for infraposition of dental implants, or ankylosed teeth, among natural teeth can be observed in some cases. The predisposing factors are still not fully understood since the current scientific evidence is very limited.

Accuracy and reliability of maxillary digital model (MDM) superimposition in evaluating teeth movement in adults compared with CBCT maxillary superimposition

Superimposition of 3D maxillary digital dental models of different time points based on palatal vault region has been used to evaluate tooth movement during orthodontic treatment. This study evaluated the accuracy and reliability of 3D maxillary digital model (MDM) superimposition in adults by comparing it with CBCT maxillary superimposition. In CBCT maxillary superimposition, voxel-based superimposition was firstly conducted, and MDMs were matched with corresponding CBCT models (CBCT-MDM superimposition). MDM superimposition (palatal vault regional superimposition) were performed on another pair of pre- and posttreatment MDMs. The position and orientation of upper first molars (U6s) and upper central incisors (U1s) on the posttreatment MDMs were compared to assess the accuracy of the MDM superimposition methods. The reliability was validated in both MDM superimposition and CBCT maxillary superimposition. In terms of accuracy, the average linear deviations in U6 and U1 positions were less than ± 0.3 mm, the average angular deviations of U6s and U1s were less than ± 0.2°, both have no significant difference from zero. The ICCs for MDM superimposition ranged from 0.85 to 0.99. The ICCs for CBCT-MDM superimposition were larger than 0.99 in all items. MDM superimposition was an efficient, accurate and reliable method for evaluating teeth movement in adults, although its reliability is slightly lower than CBCT maxillary superimposition.

Reliability and validity of miniscrews as references in cone-beam computed tomography and intraoral scanner digital models: study on goat heads

Background

Miniscrews have been used to superimpose three-dimensional (3D) craniofacial images as well as explore stable structures in jaws. Our purpose was to evaluate the reliability and validity of linear and angular measurements made with miniscrews on a 3D cone-beam computed tomography (CBCT) at two voxel sizes and compared to models created by an intraoral scanner (IOS).

Methods

Altogether, 64 miniscrews were placed in 12 goat jaws. The jaws were scanned by CBCT machine at 0.12 mm and 0.3 mm voxels and by the IOS. Linear and angular measurements between miniscrews on CBCT at the two voxel settings and the IOS were compared with actual measurements and with each other.

Results

An intra-and inter-class correlation of 0.961–1.000 were obtained by each method. Linear measurements showed significant overestimations of 0.27 ± 0.24, 0.14 ± 0.22 and 0.15 ± 0.26 mm, and angular measurements showed non-significant differences of 0.11 ± 1.97°, 0.15 ± 2.79° and 0.41 ± 2.34° for the CBCT at 0.12-mm, 0.3-mm voxels and the IOS, respectively. Equal magnification of linear measurements was on homolateral and contralateral sides using CBCT, whereas significantly greater magnification on the homolateral side than on the opposite was observed using the IOS. There was no significant difference with angular measurements between digital CBCT models at two voxels and IOS. In addition, all angular measurements were comparable to actual measurement results.

Conclusions

Miniscrews in CBCT and IOS are reliable and clinical valid when used as a reference measuring tooth movement. However, when miniscrews are involved in high precision measurement in CBCT or IOS image, systematic error should be taken into consideration. When comparing CBCT images, using the same voxel size is recommended for miniscrew related measurements to reduce error.

Dentoskeletal and soft tissue changes associated with miniscrew anchorage in customized lingual orthodontics

Objectives

The goal of this study was to analyze skeletal, dental, and soft tissue changes of patients treated with customized lingual systems and to evaluate the clinical effectiveness of miniscrew anchorage.

Methods

Nine upper first premolar extraction patients who were treated with customized lingual appliances were included in this study. Miniscrews were used for reinforcement of molar anchorage. Cephalometric films and study models were obtained before treatment (T1), after alignment (T2), and after treatment (T3). Treatment effects were analyzed by cephalometric radiographs and study models.

Results

The upper anterior teeth were retracted significantly at T2 and T3 (4.41 ± 4.14 mm and 5.51 ± 2.48 mm, respectively). During space closure, the upper first molars showed slight mesial movement (1.50 ± 1.97 mm). The intercanine width of the upper arch increased at T2 (1.59 ± 1.81 mm), but decreased at T3 (0.11 ± 1.00 mm). The sella-nasion-A, A-nasion-B, and mandibular plane angles were not significantly changed at T3. The upper lip showed continuous retraction at both T2 and T3 (1.40 ± 1.46 mm and 2.32 ± 2.48 mm, respectively).

Conclusions

By using miniscrew anchorage for lingual orthodontics, patients’ dental and soft tissue changes considerably improved and molar anchorage was reinforced.