How does the amount of surgical insult affect bone around moving teeth?

The effect of micro-osteoperforations on orthodontic space closure investigated over 12 weeks: a split-mouth, randomized controlled clinical trial

OBJECTIVES

To evaluate the effects of minimally invasive micro-osteoperforations (MOPs) on orthodontic tooth movement and pain.

DESIGN

Prospective, split-mouth, randomized controlled trial.

SETTING

Single-centre, university hospital.

METHODS

Twenty subjects requiring maxillary first premolar extractions were included. Right and left sides of the maxilla were randomly allocated into experimental and controls. Space closure was initiated following alignment on 0.20″ stainless steel archwires, using 150 g force, applied by coil springs on power arms. Nance-TPA was used for anchorage. On the experimental side, two 5 mm deep MOPs in vertical alignment on distal aspect of the maxillary canine mid-root region were performed prior to space closure.

OUTCOMES

The primary outcome was the amount of tooth movement during space closure, measured every 4 weeks for 12 weeks (T1, T2, and T3). Secondary outcome was the pain levels related to MOP, measured using Visual Analogue Scale (VAS) questionnaires. Significance was set at P < 0.01.

RANDOMIZATION

Randomization was generated using a randomization table, and allocation was concealed in sequentially numbered, opaque, sealed envelopes.

BLINDING

Blinding was not possible during the experiment but assessor was blinded during outcome assessment.

RESULTS

All subjects completed the study, with tooth movement measurements available for all 20 patients for T0-T2. In three patients, space was closed on one side at T2. The average tooth movement between sides at three intervals (T0-T1, T1-T2, and T2-T3) were not significantly different. Overall difference following 12 weeks (T0-T3) was 0.69 mm higher on the experimental side (P < 0.001). No harms were observed.

LIMITATIONS

Short-term study, cast measurements done with digital callipers.

CONCLUSION

This 12-week randomized split-mouth controlled clinical trial showed two MOPs that are 5 mm deep, applied once prior to space closure, did not create clinically significant increase in maxillary premolar space closure.

PROTOCOL

The protocol was not published before trial commencement.

REGISTRATION

Trial was not registered.

FUNDING

The Australian Society of Orthodontists Foundation for Research and Education.

Biological Anchorage and Canine Orthodontic Movement Rate with a New Technique for Micro-Osteoperforations

Introduction

The differential management of anchorage and the acceleration of tooth movement are some of the current greatest challenges for orthodontists. Diverse techniques and devices to reinforce anchorage and increase the rate of tooth movement have been proposed. Whether micro-osteoperforations (MOPs) can be used for both purposes is currently investigated.

Objectives

To propose and describe a new technique for biological anchorage, which involves six MOPs performed every four weeks, and to present its results in a clinical case of upper premolar extraction. Intervention. In a dental class II patient who met the selection criteria, three MOPs both on the buccal and palatine sides on the intervention side were performed on the extraction area following the protocol described. No MOPs were performed on the control side. The allocation of the intervention was randomised. The MOPs were performed three times at an interval of four weeks. A 0.019 × 0.025-inch stainless steel wire was activated with calibrated NiTi springs. The three-dimensional movement of the first molars and upper canines was evaluated. In addition, the comfort, periodontal status, and canine root resorption of the patient were evaluated.

Results

Clinical and radiographic results suggest that the MOPs had a positive effect in reducing the loss of biological anchorage of the posterior sector and in the rate of canine tooth movement, without damaging changes in the soft and hard tissues.

Conclusion

The proposed protocol involving six MOPs every four weeks improved the behaviour of biological anchorage and increased distalization on the intervention side in this clinical case.

Effectiveness of platelet rich fibrin versus demineralized bone xenograft in periodontally accelerated osteogenic orthodontics: A pilot comparative clinical study

OBJECTIVES

To compare the rate of extraction space closure between periodontally accelerated osteogenic orthodontics (PAOO) using platelet-rich fibrin (PRF) (Group 1) and PAOO using demineralized bone xenograft (DMBM) (Group 2) and to compare the level of wound healing between the PRF group vs the DMBM group after PAOO.

MATERIALS AND METHODS

A two-arm prospective single blind pilot study with a split-mouth design was used in which 14 patients requiring premolar extraction were divided into two groups: PRF and DMBM. En-masse space closure was carried out with using mini implants after the PAOO procedure. The amount of space closure was measured at five time points with 2-week intervals within 2 months. The gingival healing levels were assessed using early wound healing scores on the first postoperative day.

RESULTS

The rate of extraction space closure was faster in the experimental quadrant at all time points (T1-T4) in the PRF group and at time points (T3, T4) in the DMBM group. Comparison between experimental quadrants showed a significant increase in the rate of space closure in the PRF group T1 to T3 (P < .05). The PRF group showed higher total early healing scores than the DMBM group.

CONCLUSIONS

PRF, when used in the PAOO procedure, produces a faster rate of space closure with better early wound healing than DMBM.

Efficacy of micro-osteoperforation of the alveolar bone by using mini-screw for acceleration of maxillary canine retraction in young adult orthodontic patients: A split-mouth randomized clinical trial

AIM

Acceleration of orthodontic tooth movement (OTM) can decrease the rate of complications. This study aimed to assess the efficacy of micro-osteoperforation (MOP) of the alveolar bone for acceleration of OTM by using mini-screws.

MATERIALS AND METHODS

This split-mouth randomized clinical trial evaluated 25 patients (11 females, 14 males, 16-25 years) with class II division I malocclusion who required canine retraction following the extraction of maxillary first premolar. The patients received similar orthodontic treatment at both sides with MOP on one side (MOP group) and no MOP on the other side (control side). Allocation of MOP to the side of jaw was random using Random Allocation Software in 1:1 distribution and equal numbers. Blinding was not applicable. The rate of canine movement was measured monthly for 5 months and considered as the main outcome. The degree of canine tipping was measured at the end of the intervention as the secondary outcome. All measurements were repeated for 12 patients by the two observers and the intra- and inter-examiner correlation coefficients were found to be 0.946 and 0.925, respectively. Data were analysed by paired t-test and repeated measures ANOVA.

RESULTS

Twenty-five patients (11 females, 14 males, 16-25 years) were evaluated. No significant difference was found between the two groups at different time points in the rate of canine movement (P>0.05). The degree of canine tipping in the MOP group was significantly lower than that in the control group (5.34±3.11° versus 7.08±3.70°; P=0.040). Gender had no significant effect on OTM in any group (P>0.05).

CONCLUSIONS

MOP could not accelerate canine retraction but decreased the degree of canine tipping.

Comparison of the effects of horizontal and vertical micro-osteoperforations on the biological response and tooth movement in rabbits

Objective

This study aimed to compare the amount of tooth movement after multiple horizontal (MH) and single vertical (SV) micro-osteoperforations (MOPs), and evaluate the histological changes after orthodontic force application in rabbits.

Methods

The mandibles of 24 white rabbits were subjected to two experimental interventions: MH and SV MOPs. Defect volume of the MOPs between the two groups was kept similar. A force of 100 cN was applied via a coil spring between the incisor teeth and the first premolars. The amount of tooth movement was measured. Differences in the amount of tooth movement and bone variables at three time points and between the two groups were evaluated using repeated-measures analysis of variance.

Results

The first premolar showed a mesial movement of 1.47 mm in the MH group and 1.84 mm in the SV group, which was significantly different at Week 3 (p < 0.05). No significant difference was observed in bone volume and bone fraction between the groups. Tartrate-resistant acidic phosphatase-positive cell count was also significantly greater at Week 3 than at Week 1 in both the SV and MH groups.

Conclusions

The amount of tooth movement showed significant differences between Weeks 1 and 3 in the SV and MH MOP groups, but showed no differences between the two groups. Therefore, SV MOP could be considered an effective tool for enhancing tooth movement, especially for molar distalization, uprighting, and protraction to an edentulous area.

Comparison of the efficacy of two-time versus one-time micro-osteoperforation on maxillary canine retraction in orthodontic patients: A split-mouth randomized controlled clinical trial

BACKGROUND

Micro-osteoperforation (MOP), a minimally invasive technique for accelerating the rate of orthodontic tooth movement has been research extensively, but with varied clinical results.

OBJECTIVE

To compare the efficacy of one-time versus two-time micro-osteoperforation on the rate of maxillary canine retraction, its influence on anchorage loss, canine angulation and the levels of interleukin (IL-1β) in gingival crevicular fluid (GCF).

MATERIALS AND METHODS

The split-mouth study included 16 patients in which the left and right sides were randomly allocated to the control side (one-time MOP) and experimental side (two-time MOP). MOP was performed on both sides distal to the maxillary canines and canine retraction was carried out using NiTi closed coil springs (150gm) and direct anchorage with miniscrew implants. The second MOP was performed on experimental side one month after the first MOP. The rate of canine movement was assessed using 3D model superimposition over a period of six months. The type of tooth movement, anchorage loss and levels of IL-1β were also evaluated.

RESULTS

Sixteen patients (mean age, 17.87±3.34 years) were analysed for a rate of canine retraction, anchorage loss, and type of tooth movement, while 15 patients were analysed for IL-1β. The rate was significantly higher on two-time MOP side after two months (P<0.001). No statistical difference was found in anchorage loss and controlled tipping of canines was observed. The IL-1β levels immediately after 2^nd MOP were significantly higher than 1^st MOP (P<0.001).

CONCLUSION

The two-time intervention of MOP is more efficacious than one-time MOP in accelerating tooth movement.

Surgical Considerations and Decision Making in Surgically Facilitated Orthodontic Treatment/Periodontally Accelerated Osteogenic Orthodontics

FOCUSED CLINICAL QUESTION

Surgically facilitated orthodontic treatment (SFOT)/periodontally accelerated osteogenic orthodontics (PAOO) has the potential of allowing safer orthodontic treatment in vulnerable periodontium with thin phenotypes. SFOT/PAOO is a phenotype modification therapy (PhMT) approach where thin bone morphotype and/or gingiva are surgically augmented to convert a fragile-thin to a robust-thick periodontal environment. This permits orthodontic treatment in these previously thin phenotype cases to proceed without iatrogenically-induced adverse effects. This is an infrequently performed procedure with few available clinical recommendations.

SUMMARY

In this practical application paper, three clinicians with the collective clinical experience of over 1500 SFOT cases developed a clinical decision-making algorithm outlining the key steps for SFOT. A sample case is provided for clinical appreciation of the procedure. Lastly, this panel reviewed and detailed the critical decision making and surgical approaches associated with the use of SFOT. Though the basic decision making is consistent, individual variations on surgical management are compared. This is summarized in a clinical decision tree along with a sample clinical case. Additionally, the cumulative experience has been organized into tables that provide comparative decision and surgical approaches. There are similarities and differences. Lastly, strategies that have not been individually effective are also noted.

CONCLUSION

SFOT/PAOO is an effective PhMT approach whereby the bone and/or soft tissue phenotype can be surgically modified to permit orthodontic treatment in patients with thin phenotypes. The cumulative experience of three experienced clinicians provides clinical recommendations for SFOT management of PhMT for pre-orthodontic treatment.

Effects of micro-osteoperforations performed with Propel system on tooth movement, pain/quality of life, anchorage loss, and root resorption: a systematic review and meta-analysis

BACKGROUND

The aim of this systematic review was to evaluate the effect of micro-osteoperforations (MOPs) performed with Propel and other mini-screws on the rate of tooth movement, pain/discomfort, periodontal health, anchorage loss, and root resorption in patients undergoing orthodontic retraction compared to a control group.

MATERIALS AND METHODS

PubMed, Cochrane, Web of Science, LILACS, Google Scholar, Scopus, and OpenGrey were searched without restriction. A manual search was also carried out. Only randomized clinical trials (RCT) were included. The risk of bias (RoB) was assessed using RoB 2.0 and the certainty of evidence through the GRADE tool.

RESULTS

Among the twelve RCTs reviewed, five used the Propel system. Overall, the RoB was classified as low (4), moderate (5), and high (3). Two RCTs with moderate and one with a low RoB using the Propel system reported mild increases on rate of tooth movement associated with MOPs. One RCT with a moderate and another with high RoB did not find a significant effect of Propel on orthodontic movement. Regarding tooth movement, a subgroup meta-analysis found no differences between control and Propel movement (95% CI = - 0.01 to 0.75) or other mini-screws (- 0.02 to 0.31) related to rate of tooth movement per month. There was no effect of MOPs on root resorption, periodontal health, anchorage loss, and a mild effect on pain and oral health related to quality of life regardless of mini-screw type. The level of certainty was graded as low for the rate of tooth movement and pain/discomfort, as moderate for anchorage loss, and high for root resorption.

CONCLUSION

A low certainty of evidence supports that MOPs performed with Propel seem to have no significant effect on the rate of tooth movement. Moreover, this intervention does not seem to cause an increase in root resorption, periodontal heath, pain/discomfort, or anchorage loss. Thus, the Propel system does not appear to produce different results from those observed for other mini-screws.

Assessment of bone density changes following two-jaw surgery using multidetector computed tomography: A pilot study

Objective

The aim of this retrospective study was to evaluate the pre- and postsurgical bone densities at alveolar and extra-alveolar sites following two-jaw orthognathic surgery.

Methods

The sample consisted of 10 patients (mean age, 23.2 years; range, 18.0–27.8 years; 8 males, 2 females) who underwent two-jaw orthognathic surgery. A three-dimensional imaging program (Invivo 5) was used with multidetector computed tomography images taken pre- and postoperatively (obtained 32.3 ± 6.0 days before surgery and 5.8 ± 2.6 days after surgery, respectively) for the measurement of bone densities at the following sites: (1) alveolar bone in the maxilla and mandible, (2) extra-alveolar sites, such as the top of the head, menton (Me), condyle, and the fourth cervical vertebrae (C4).

Results

When pre- and postsurgical bone densities were compared, an overall tendency of decrease in bone density was noted. Statistically significant reductions were observed in the densities of cancellous bone at several areas of the maxillary alveolar bone; cortical and cancellous bone in most areas of the mandibular alveolar bone; cortical bone in Me; and cancellous bone in C4. There was no statistically significant difference in bone density in relation to the depth of the alveolar bone. In a comparison of the bone densities between groups with and without genioplasty, there was almost no statistically significant difference.

Conclusions

Accelerated tooth movement following orthognathic surgery may be confirmed with reduced bone density. In addition, this study could offer insights into bone metabolism changes following orthognathic surgery, providing direction for further investigations in this field.

Effect of mini-screw-facilitated micro-osteoperforation on the rate of orthodontic tooth movement: a single-center, split-mouth, randomized, controlled trial

Objective

The present study aimed to evaluate the effect of MOP over a 3-month period and to determine the influence of the number of perforations on the rate of canine retraction. In addition, the amount of pain and discomfort caused by the MOP method was evaluated.

Trial design

A single-center, split-mouth, triple-blind, randomized, controlled trial was conducted.

Methods

The clinical trial was conducted from December 2018 to July 2019 in the Orthodontic Clinic, Shiraz Dental School. Twenty-eight patients (range from16.3 to 35.2 years) who need fixed orthodontic treatment were recruited and randomly assigned to MOP1 and MOP2 groups. In each patient one side of the mouth worked as a control side which received no MOPs. Four months after first premolars extraction, patients in MOP1 group received 3 MOPs on the buccal surface of alveolar bone in the experimental side to accelerate canine retraction whereas patients in MOP2 group received 3 buccal MOPs and 3 palatal MOPs in the experimental side. The amount of canine retraction was measured every 28 days at three intervals on both sides of the mouth. Pain perception was also measured on the day of MOP procedure and subsequently at 24 h. Randomization was performed using online software RANDOM.ORG; the recruited patients were divided into two parallel groups with a 1:1 allocation ratio then the side of MOPs intervention in each subject was randomly determined with coin tossing. Triple blinding design was employed.

Results

The result of the intra-examiner reliability using ICC was 0.97 (P <  0.001), indicating excellent repeatability and reliability of the measurements. The baseline characteristics between the groups were similar (P > 0.05). There was a significant difference in the rate of canine retraction between the MOP groups and the contralateral control sides, as well as between the MOP1 and MOP2 groups (P <  0.05).

Conclusion

The MOP procedure was effective in accelerating orthodontic tooth movement, although the amount of acceleration was not clinically significant in the case of canine retraction. An increase in the number of MOPs resulted in a significant acceleration of the canine retraction.

Trial registration

The trial was registered 30 November 2018 at the Iranian Registry of Clinical Trials (IRCT20181121041713N1).

Evaluating the Efficacy of a Modified Piezo-Puncture Method on the Rate of Tooth Movement in Orthodontic Patients: A Clinical Study

Objective

Owing to the increasing demand from orthodontic patients for a more rapid treatment, many studies have focused on accelerated tooth movement. Currently, one of the prevalent methods to achieve accelerated tooth movement is piezo-puncture. The aim of the present study was to evaluate the effect of a modified piezo-puncture method on tooth movement rate and type during canine retraction.

Methods

A total of 17 patients who required fixed orthodontic treatment with extraction of the maxillary first premolars were included in the study. Following a split-mouth design, upper canines were retracted with Ni-Ti coil spring that applied 150 g of force on each side (piezo-puncture on one side and contralateral side served as the control). Then, the rates of tooth movement, canine angulation and rotation, and anchorage loss were evaluated at T0 (before the intervention), T1 (1 month after the intervention), and T2 (2 months after the intervention). For calculating the canine movement rate, either the distance between the canine and the lateral incisor or the space between the second premolar and the canine was measured. In addition, pain perception was documented by Visual Analog Scale. Data were analyzed using the Kolmogorov-Smirnov normality test, Spearman correlation test, paired sample t-test, and Wilcoxon signed-rank test.

Results

No significant acceleration was observed in canine movement, canine tipping, rotation, or anchorage loss of molar in different times.

Conclusion

Considering the limitations of the study, the application of piezo-puncture employing the protocol used in the present study failed to accelerate tooth movement and to decrease the unfavorable tipping, rotation, and molar anchorage loss.

Effectiveness and Safety of Minimally Invasive Orthodontic Tooth Movement Acceleration: A Systematic Review and Meta-analysis

Doctors and patients attempt to accelerate orthodontic tooth movement with a minimally invasive surgery approach. The purpose of this systematic review was to evaluate the evidence of accelerated tooth movement in minimally invasive surgery and the adverse effects from it. A systematic search of the literature was performed in the electronic databases of PubMed, CENTRAL (Cochrane Central Register of Controlled Trials), Embase, Scopus, Web of Science, Science Direct, and Medline and was complemented by a manual search until February 2019. The inclusion criteria were prospective clinical studies of patients treated with a fixed appliance, and the intervention was accelerated orthodontic treatment with minimally invasive surgery. Nineteen articles (538 participants) were included in the review: 9 studies assessed the rate of upper canine movement; 5 considered the treatment time; 1 evaluated the en masse retraction time; and 4 studied adverse effects. We performed a meta-analysis for the rate of canine movement and treatment time and described the results for the adverse effects in a systematic review. The results of the subgroup analysis according to micro-osteoperforation and piezocision were included in the study. No accelerated tooth movement was found in the micro-osteoperforation group. After flapless corticotomy procedures, increased tooth movement rates were identified by weighted mean differences of 0.63 (95%CI = 0.22, 1.03, P = 0.003) and 0.64 (95% CI, −25 to 1.53; P = 0.16) for 1 and 2 mo, respectively. The mean treatment time was 68.42 d (95% CI, −113.19 to −23.65; P = 0.003) less that than for minimally invasive surgery. Moreover, no significant adverse effect was found. Because of the high heterogeneity of the meta-analysis, the results must be validated by additional large-sample multicenter clinical trials. There is not sufficient evidence to support that the single use of micro-osteoperforation could accelerate tooth movement, and there is only low-quality evidence to prove that flapless corticotomy could accelerate tooth movement.

Comparative Evaluation of Effects of Different Corticotomy Designs on Velocity of Upper Canine Retraction: A Finite Element Study

Purpose: Understanding the effects of different corticotomy designs on the velocity of maxillary canine retraction.

Materials and Method: The 3-dimensional model of maxillary dentition was constructed and 3 corticotomy designs were compared with the conventional approach of canine retraction. 4 models were constructed for the present study: 1 with no corticotomy cuts (model 1), 1 with vertical cuts on both buccal and palatal side (model 2), other with cuts only on buccal side (model 3), and 1 with circular holes (model 4). Stress intensity and force distribution were evaluated after applying 150 gm of orthodontic forces on maxillary canine.

Results: Models with corticotomy approaches exhibited approximately twice the displacement when compared with conventional noncorticotomy procedure. The stresses were mainly concentrated on the distal side of the canine in all the models. The rate of canine retraction was the highest in model with buccal and palatal corticotomy compared to other designs.

Conclusions: Corticotomies help orthodontists to alter the biomechanical responses of dentoalveolar structures during maxillary canine retraction and accelerate tooth movement. Clinically, buccal corticotomy is a better choice for the patients as it is less traumatic and more acceptable to patients.

The effect of autologous leukocyte platelet rich fibrin on the rate of orthodontic tooth movement: A prospective randomized clinical trial

Objective:

The aim of this study was to evaluate the effect of LPRF, placed in extraction sockets, on orthodontic tooth movement (OTM).

Materials and Methods:

Thirty extraction sockets from eight patients (five males, three females, with a mean age of 17.37 years; range 12–25 years) requiring extraction of first premolars based on their orthodontic treatment plan participated in this split-mouth clinical trial. In one randomly selected quadrant of each jaw, the extraction socket was preserved as the experimental group by immediate placement of LPRF in the extraction socket. The other quadrant served as the control group for secondary healing. Immediately, the teeth adjacent to the defects were pulled together by a NiTi closed-coil spring with constant force. A piece of 0.016 × 0.022-inch stainless steel wire was used as the main arch wire. The amount of OTM was measured on the study casts at eight time points with 2-week intervals for 3 months. Analysis of random effect model was performed for the purpose of comparison between the experimental and control groups.

Results:

According to the random effect model, a statistically significant difference was found between the experimental and control group in rate of OTM (P = 0.006).

Conclusion:

According to the results, application of LPRF, as an interdisciplinary approach combining orthodontics and surgery, may accelerate OTM, particularly in extraction cases.

Alveolar restoration following rapid maxillary expansion with and without corticotomy: A microcomputed tomography study in sheep

Objective

This study examined bone microstructure restoration after rapid maxillary expansion (RME) with and without corticotomy over multiple retention periods.

Methods

Eighteen male Dorper sheep were randomly distributed into three groups (n = 6 each group): group 1, RME with corticotomy on the buccal and palatal sides; group 2, conventional RME treatment; and group 3, no treatment. Post-RME, trabecular bone microstructure and new bone formation were evaluated by using microcomputed tomography (microCT) and histomorphometry after a 4- or 12-week retention period. Intergroup differences in bone quality and bone remodeling were analyzed by using two-way analysis of variance with Bonferroni post-hoc test.

Results

The bone volume fraction (bone volume [BV]/total volume [TV]) values relative to the control in groups 1 and 2 were 54.40% to 69.88% after the 4-week retention period and returned to approximately 80% after the 12-week retention period. The pooled BV/TV values of the banded teeth in groups 1 and 2 were significantly lower than those of the control after the 4-week retention period (p < 0.05). However, after the 12-week retention period, the pooled BV/TV values in group 2 were significantly lower than those in groups 1 and 3 (p < 0.05). Histomorphological analysis showed that the new bone formation area in group 1 was approximately two to three times of those in group 2 and control.

Conclusions

Corticotomy significantly enhanced the restoration of bone quality after the retention periods for banded teeth. This benefit might result from the increased new bone formation after corticotomy.

Comparison of tooth movement and biological response in corticotomy and micro-osteoperforation in rabbits

Objective

The aim of this study was to evaluate the amount of tooth movement and histologic changes with different corticotomy designs and micro-osteoperforation in rabbits.

Methods

The sample consisted of 24 rabbits divided into three experimental groups (triangular corticotomy [TC] and indentation corticotomy [IC] with flap, and flapless micro-osteoperforations [MP]) and a control. A traction force of 100 cN was applied by connecting the first premolars to the incisors. The amount of tooth movement was measured. Kruskal-Wallis test was used to assess differences in tooth movement between the groups. Micro-computed tomography, hematoxylin and eosin staining, and tartrate-resistant acidic phosphatase (TRAP) analysis were performed. Analysis of variance was applied to assess differences in TRAP-positive osteoclast count between the groups.

Results

The amount of tooth movement increased by 46.5% and 32.0% in the IC and MP groups, respectively, while the bone fraction analysis showed 69.7% and 8.5% less mineralization compared to the control. There were no significant intergroup differences in the number of TRAP-positive osteoclasts.

Conclusions

The micro-osteoperforation group showed no significant differences in the amount of tooth movement compared to the corticotomy groups, nor in the TRAP-positive osteoclast count compared to both corticotomy groups and control.

Biological events related to corticotomy-facilitated orthodontics

Corticotomy-facilitated orthodontics is a clinical treatment modality comprising the application of conventional orthodontic forces combined with selective decortication of the alveolar process of the bone, which generates a localized process of bone remodeling (turnover) that enables accelerated orthodontic tooth movement. Compared with conventional orthodontic treatment, corticotomy-facilitated orthodontics is associated with reduced treatment time and reduces the frequency of apical external root resorption; however, this modality increases morbidity and financial costs. Although the clinical outcomes of corticotomy-facilitated orthodontics appear favorable, no results of evidence-based investigations of long-term outcomes are available in the literature, and the long-term effects of corticotomy-facilitated orthodontics on the teeth and periodontium are unclear. This narrative review discusses the biological events associated with corticotomy-facilitated orthodontics. Authoritative articles found in relevant databases were critically analyzed and the findings were integrated and incorporated in the text.

Localizing the osseous boundaries of micro-osteoperforations

INTRODUCTION

The aim of this work was to determine how far the effects of micro-osteoperforations (MOPs) extend within bone by quantifying the damage caused and the short-term bony adaptations that occur in and around the injury site.

METHODS

With the use of a split-mouth design, 34 MOPs (Propel) were randomly placed in the mandibular furcal bone of 13 beagle dogs either 2 or 4 weeks before killing them. The control side received no treatment. Vickers hardness microindentation, microscopic computed tomography, and histologic analyses were performed to evaluate the bone surrounding the MOPs.

RESULTS

Microfractures produced during insertion extended ∼0.6 mm from the MOP sites. Cortical and trabecular bone were significantly less dense on the experimental than on the control side up to 4.2 mm from the edge of the MOP, but side differences were small (<5%) beyond 1.5 mm from the MOP. Experimental cortical bone was significantly softer than the control bone up to 0.8 mm from the MOP after 2 weeks of healing, and up to 0.5 mm from the MOP after 4 weeks of healing. Hematoxylin and eosin stained sections of cortical and trabecular bone showed small areas of woven bone within the MOP sites after 2 weeks, and acellular areas of bone extending ∼0.5 mm from the MOP. After 4 weeks of healing, there were greater amounts of woven bone, as well as early signs of lamellar bone, in and around the MOP sites. Markedly increased TRAP activity extending up to 2.5 mm from the MOP was evident after 2 weeks, but not after 4 weeks. Vital fluorescence staining showed diffuse bone deposition on the experimental side up to 1.5 mm from the MOP margin.

CONCLUSIONS

When MOPs are performed in beagle dogs, demineralization is transient and healing of the injured area, as well as remineralization of bone affected by MOP placement, begins during the first 2 weeks. Although the transient effects extend farther, the principal effects extend only ∼1.5 mm from the MOP site.

Effects of micro-osteoperforations on tooth movement and bone in the beagle maxilla

PURPOSE

The purpose of this study was to determine how micro-osteoperforations (MOPs) affect tooth movements, bone turnover, bone density, and bone volume.

METHODS

A split-mouth experimental design with 7 beagle dogs was used to evaluate bone surrounding maxillary second premolars that had been retracted for 7 weeks. One month after the maxillary third premolars were extracted, 8 MOPs (1.5 mm wide and 7 mm deep) were created without flaps with the use of the Propel device (6 were placed 3 mm distal to the second premolar and 2 were placed in the premolar furcation) on one randomly chosen side. The maxillary second premolars were retracted bilaterally with the use of 200 g nickel-titanium closed coil springs. Tooth movements were measured intraorally and radiographically. Microscopic computed tomography was used to evaluate the material density and volume fraction of bone distal to the premolars. Hematoxylin and eosin-stained and fluorescent sections were used to examine the bone remodeling.

RESULTS

Neither the intraoral (P = 0.866) nor radiographic (P = 0.528) measures showed statistically significant side differences in tooth movements. There also were no statistically significant differences in the density (P = 0.237) or volume fraction (P = 0.398) of bone through which the premolars were being moved. Fluorescent and histologic evaluations showed no apparent differences in osteoblasts, osteoclasts, or mineralization of bone near the teeth being moved. Bone healing was evident in and near the MOP sites, which had nearly but not completely healed after 7 weeks. Regions of acellular bone were evident extending ∼0.8 mm from the MOP sites.

CONCLUSIONS

MOPs placed 3 mm away from teeth do not increase tooth movements and have limited and transitory effect on bone.

Three-dimensional finite element analysis to evaluate biomechanical effects of different alveolar decortication approaches on rate of canine retraction

INTRODUCTION

The aim of this study was to compare different corticotomy approaches and determine their biomechanical effects on rate of canine displacement when compared to conventional orthodontics.

METHOD

Three-dimensional Finite Element Models with conventional non-corticotomy approach (model 1) and three corticotomy approaches ensuing buccal and palatal vertical cuts (model 2), interseptal bone reduction (model 3), buccal vertical cuts (model 4) were fabricated. Displacement of the canine and von Mises stresses in the canine and trabecular bone were calculated and compared under a distal retraction force of 1.5N.

RESULTS

The maximum displacement of canine with minimum anchorage loss was seen in model 3 followed by model 2, model 4 and model 1. The maximum equivalent (von Mises) stress was concentrated mainly on the distal side of canine in model 3 and had a uniform distribution of stresses on entire root surface.

CONCLUSIONS

Corticotomy approaches effectively accelerated maxillary canine retraction, exhibiting twice the rate of canine movement with minimum anchorage loss when compared to non-corticotomy approach. Corticotomy with interseptal bone reduction was most effective in terms of canine displacement and stress distribution.

A rodent model using skeletal anchorage and low forces for orthodontic tooth movement

INTRODUCTION

Nonhuman animal models have been used extensively to study orthodontic tooth movement (OTM). However, rodent models have disadvantages, including a reported reduction in bone volume during OTM. The purpose of this study was to determine the viability of a skeletal anchorage and the effect of low force (∼3 cN) on interradicular bone volume during OTM.

METHODS

Ninety Sprague-Dawley rats were divided into 5 time points. A miniscrew and a nickel titanium coil spring placed a load of 3 cN (experimental) or 0 cN (sham) on the maxillary first molar in a split-mouth design. Displacement of the first molar and bone volume/total volume (BV/TV) in the interradicular region were quantified.

RESULTS

The success rate of the miniscrew was 98.9% (89 out of 90). Linear and angular tooth movement increased steadily (mean 0.1 mm/wk, 0.48 mm at 40 days). BV/TV was significantly reduced between the tooth movement and non-tooth movement sides in the 3 cN group: by 13%, 23%, 15%, 23%, and 16% at 3, 7, 14, 28, and 40 days, respectively.

CONCLUSIONS

Our model resulted in efficient OTM without skeletal anchorage failure. BV/TV reduction was lower than in previous reports. This novel validated model is likely to be the basis for future studies.

Corticotomy affects both the modus and magnitude of orthodontic tooth movement

Objective

To analyze whether the decreased bone density due to the manipulation of bone remodeling rate has an influence on the type of the planned tooth movement.

Materials and methods

A finite element model of a lower incisor has been developed. The density of the alveolar bone surrounding the tooth has been assumed to simulate the one occurring after corticotomy to increase tooth movement rate. Moment-to-force ratios corresponding to three different types of movements have been simulated; uncontrolled tipping, translation, and root movement. The three tooth movements have been analyzed in both corticotomized and non-corticotomized simulations, and the final effects on the amount and type of tooth movement analyzed. The stress and strain levels in the periodontal ligament have been analyzed too.

Results

The amount of tooth movement obtained in case of lower bone density is higher in all types of movement simulations. The centre of rotation of the movement shifts more apically in case of translation, controlled and uncontrolled tipping. In the corticotomy simulations, the compressive stresses in the periodontal ligament decreased while the tensile stresses increased.

Conclusion

A decreased bone density influences not only the amount of tooth movement, but also its type. This study suggests that the moment-to-force ratios used in conventional orthodontics should be modified in case of techniques that decrease bone density to enhance tooth movement rate.

Three-dimensional assessment of the effect of micro-osteoperforations on the rate of tooth movement during canine retraction in adults with Class II malocclusion: A randomized controlled clinical trial

INTRODUCTION

The purpose of this split-mouth trial was to investigate the effect of micro-osteoperforations (MOPs) on the rate of tooth movement.

METHODS

Thirty-two patients (24 female, 8 male; mean age, 19.26 ± 2.48 years) who required fixed orthodontic treatment and maxillary first premolar extractions participated in this trial with MOPs randomly allocated to either the right or left sides distal to the maxillary canines. Eligibility criteria included Class II Division 1 malocclusion, healthy periodontal condition, no smoking, and no systemic disease. Miniscrews were used to support anchorage and retract the canines with the aid of closed-coil nickel-titanium springs with 150 g of force. Randomization was accomplished with block randomization with a permuted block size of 2 with a 1:1 allocation ratio to either right or left with allocations concealed in opaque, sealed envelopes. Blinding was used at the data collection and analysis stages. Three MOPs were performed using miniscrews (5 mm depth, 1.5 mm width) on the buccal bone distal to the canines on the randomly selected side. The primary outcome was the rate of canine retraction measured from 3-dimensional digital models superimposed at the rugae area from the baseline to the first, second, and third months. The following secondary outcomes were examined: anchorage loss, canine tipping, canine rotation, root resorption, plaque index, and gingival index. Pain level, pain interference with the patients' daily life, patients' satisfaction with the procedure and degree of ease, willingness to repeat the procedure, and recommendation to others were also evaluated.

RESULTS

There was no statistically significant difference in the rates of tooth movement between the MOP and the control sides at all time points (first month: P = 0.77; mean difference, 0.2 mm; 95% CI, -0.13, 0.18 mm; second month: P = 0.50; mean difference, -0.08 mm; 95% CI, -0.33, 0.16 mm; third month: P = 0.76; mean difference, -0.05 mm; 95% CI, -0.40, 0.29 mm). There were also no differences in anchorage loss, rotation, tipping, root resorption, plaque index, periodontal index, and pain perception between the MOP and control sides at any time point (P >0.05). MOPs had no effect on the patients' daily life except for a feeling of swelling on the first day (P = 0.05). Level of satisfaction and degree of easiness of the procedure were high. A significant percentage of patients were willing to repeat the procedure and recommend it to others. No serious harm was observed.

CONCLUSIONS

Three MOPs were not effective in accelerating tooth movement at any time point. Other secondary parameters evaluated were not different between the MOP and control sides except for the feeling of swelling on day 1 on the MOP side. Patients were highly satisfied with the MOP procedure, and many considered MOPs an easy procedure and were willing to repeat and recommend it to friends.

REGISTRATION

This trial was registered at Clinicaltrials.gov with identifier number NCT02473471.

PROTOCOL

The protocol was not published before trial commencement.

FUNDING

This work was supported by Jordanian University of Science and Technology (grant number 20150263). No conflict of interest is declared.

Accelerated orthodontic treatment - what's the evidence?

The demand and accessibility of orthodontic care has increased but has also been accompanied by patient requests for shorter treatment times. Longer orthodontic treatment increases the risk of decalcification, gingival recession, and root resorption and so shorter treatment times have multiple advantages as well as appealing to patient's desires. Numerous techniques and materials have been suggested to reduce treatment times but, in most cases, are based upon selected case reports with no prospective clinical trials to validate claims. The present review examines many of the current options purported to accelerate orthodontic tooth movement and the level of evidence presently available. There is some evidence to suggest that low-level laser therapy and a corticotomy involving the raising of a muco-periosteal flap are associated with accelerated orthodontic tooth movement; however, the current level of evidence is low to moderate in quality. For this reason, further research is required before routine application could be recommended.

Effect of Piezoelectric Sutural Ostectomies on Accelerated Bone-Borne Sutural Expansion

PURPOSE

The present study investigated the effect of piezoelectric sutural ostectomies on accelerated bone-borne sutural expansion.

MATERIALS AND METHODS

Sixteen male New Zealand white rabbits (20 to 24 weeks old) were randomly divided into 4 experimental groups (n = 4): group 1, conventional rapid sutural expansion; group 2, accelerated sutural expansion; group 3, accelerated sutural expansion with continuous ostectomy; and group 4, accelerated sutural expansion with discontinuous ostectomy. All sutural ostectomies were performed using a piezoelectric instrument (Woodpecker DTE, DS-II, Guangxi, China) before expander application with the rabbits under anesthesia. Modified hyrax expanders were placed across the midsagittal sutures of the rabbits and secured with miniscrew implants located bilaterally in the frontal bone. The hyrax expanders were activated 0.5 mm/day for 12 days (group 1) or with a 2.5-mm initial expansion, followed by 0.5 mm/day for 7 days (groups 2 to 4). After 6 weeks of retention, the bone volume fraction, sutural separation, and new bone formation were evaluated using micro-computed tomography and histomorphometry. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U tests and Spearman's rho correlation (P < .05).

RESULTS

Ranking of the median sutural separation was as follows: group 1, 3.05 mm; group 2, 3.97 mm; group 4, 4.78 mm; and group 3, 5.66 mm. The least and most bone formation were observed in groups 1 (63.63%) and 3 (75.93%), respectively. Spearman's correlation showed a strong, positive, and significant correlation (r = 0.932; P < .01) between the new sutural bone formation and amount of sutural separation.

CONCLUSIONS

Piezoelectric sutural ostectomies increased the rate of sutural separation and promoted new sutural bone formation/osteogenesis. Continuous ostectomy gave better results than discontinuous ostectomy.

Elevation of a full-thickness mucoperiosteal flap alone accelerates orthodontic tooth movement

INTRODUCTION

Our objective was to determine whether the elevation of a full-thickness mucoperiosteal flap alone, without cortical cuts, decreases the amount of bone around teeth and accelerates mesial tooth movements.

METHODS

The mandibular second premolars of 7 beagle dogs were extracted, and on a randomly selected side, a full-thickness mucoperiosteal buccal flap extending from the distal aspect of the third premolar to the mesial aspect of the first premolar was elevated. The other side did not receive flap surgery. The mandibular third premolars were protracted with orthodontic appliances. Tooth movements were analyzed biweekly over an 8-week period with calipers and radiographs. The amount and density of bone were analyzed using microcomputed tomography; bone remodeling was evaluated with histologic sections.

RESULTS

Experimental tooth movements measured intraorally between cusp tips were significantly greater (25.3%) than control tooth movements. The approximate center of resistance measured radiographically also moved significantly more (about 31%) on the experimental than on the control side. The experimental premolar tipped more than the control premolar (10.5° vs 8.7°), but the difference was not statistically significant. The medullary bone volume fraction mesial to the third premolar was significantly less (9.1%) and the bone was significantly less dense (9%) on the experimental side than on the control side. Histology showed no apparent side differences in the numbers of osteoclasts and osteoblasts evident in the medullary bone.

CONCLUSIONS

Elevation of a full-thickness mucoperiosteal flap alone (ie, without injury to bone) decreases the amount and density of medullary bone surrounding the tooth and accelerates tooth movement. Due to its limited effects, elevation of a flap alone to increase tooth movements may not be justified.

Miniscrew-assisted slow expansion of mature rabbit sutures

INTRODUCTION

In this study, we experimentally evaluated whether complex, mature sutures can be separated using skeletal anchorage and light, continuous forces.

METHODS

Twelve adult, 8- to 9-month-old female New Zealand white rabbits were randomly assigned to 1 control group and 2 experimental groups. Open-coil nickel-titanium springs delivered constant forces of 100 g across the sagittal suture to miniscrew implants placed bilaterally in the frontal bone. Sutural separation was measured biweekly. Separation was also measured with microcomputed tomography. Bone formation (mineral apposition) was measured with fluorescent labels. Qualitative histologic analyses of the suture tissues were performed using hematoxylin and eosin staining; osteoclasts were evaluated with tartrate resistant acid phosphatase staining.

RESULTS

All 24 miniscrew implants remained stable throughout the experiment. There was no statistically significant sutural separation in the control group. In the experimental groups, sutural separation was significant (P <0.05) at all time points after the initial records were taken. The rate of separation was linear during the first 42 days. There were moderate correlations (R = 0.59-0.89; P <0.05) between miniscrew implant separation and bone marker separation. Mineral apposition rate, which was not measureable in the control group, was significant in the experimental group. The mineral apposition rate was greater between 14 and 28 days than between 28 and 38 days, and it was greater on the ectocranial than on the endocranial surface. Based on the microcomputed tomography analysis, 3-dimensional sutural volume of the experimental group increased significantly (P = 0.02), but surface area did not (P = 0.26).

CONCLUSIONS

It is possible to separate the sagittal suture of mature rabbits. Sutural separation is limited, indicating involvement of other articulations.

Progressive changes in patients with skeletal Class III malocclusion treated by 2-jaw surgery with minimal and conventional presurgical orthodontics: A comparative study

INTRODUCTION

In this study, we aimed to compare treatment efficacy and postsurgical stability between minimal presurgical orthodontics and conventional presurgical orthodontics for patients with skeletal Class III malocclusion.

METHODS

Forty patients received minimal presurgical orthodontics (n = 20) or conventional presurgical orthodontics (n = 20). Lateral cephalograms were obtained before treatment, before orthognathic surgery, and at 1 week, 3 months, 6 months, and 12 months after surgery.

RESULTS

Changes of overjet and mandibular incisal angle before surgery were greater in the conventional presurgical orthodontics group than in the minimal presurgical orthodontics group. Postsurgical horizontal changes in Points A and B, overjet, and mandibular incisal angle showed significant differences among the time points. Most of the horizontal and vertical relapses in the maxilla and the mandible occurred within the first 6 months in both groups.

CONCLUSIONS

Minimal presurgical orthodontics and conventional presurgical orthodontics showed similar extents and directions of skeletal changes in patients with Class III malocclusion. However, orthodontists and surgeons should preoperatively consider the postsurgical counterclockwise rotation of the mandible when using minimal presurgical orthodontics. Close and frequent observations are recommended in the early postsurgical stages.

Minimal presurgical orthodontics for a skeletal Class III patient with mandibular asymmetry

A 19-year-old man with a skeletal Class III malocclusion was treated using minimal presurgical orthodontics. Orthodontic appliances and miniscrews were placed at the beginning of treatment, and the double-jaw-surgery was performed once the maxillary right and left first premolars were intruded, without worsening the concave profile and facial asymmetry presurgically. Different from the traditional combined orthodontic-orthognathic surgery, the jaw discrepancy was corrected first, followed by the orthodontic tooth movement. Miniscrews were used to intrude the premolars presurgically because of their interference and to provide the skeletal anchorage for intermaxillary elastics after the operation. The patient was pleased with the treatment results and satisfied with his facial and dental appearance, as well as his oral function. The 1-year follow-up photographs show a stable result both esthetically and functionally.

An interview with Peter H. Buschang

Dr. Peter Buschang is regent professor and director of orthodontic research. He has been at Texas A&M University Baylor College of Dentistry since 1988. Dr. Buschang received his PhD in 1980 from the University of Texas at Austin; he spent 3 years as a NIDR postdoctoral fellow at the University of Connecticut, and five years as a FRSQ scholar at the University of Montreal. Every year, Dr. Buschang teaches in 16 different courses, 7 of which he directs. In addition to more than 100 lecture hours per year, he spends hundreds of hours mentoring students. For his teaching efforts, Dr. Buschang was awarded the Robert E. Gaylord Award of Excellence in Orthodontic education in 1992, 1998, 2004, and 2010. He also gives 1-2 day evidence-based CE courses throughout the world. The residents he has taught recently honored him by pledging to fund the Peter H. Buschang Endowed Professorship of Orthodontics. His research interests pertain to craniofacial growth and assessment of treatment effects. Dr. Buschang has been funded regularly over the years by the Medical Research Council of Canada, Fonds de le Recherche en Santé du Québec, the NIH, and the American Association of Orthodontics Foundation. He has mentored over 140 Master's and PhD students, and 49 dental students. Dr. Buschang has published over 250 peer-reviewed articles, 15 book chapters and 198 abstracts. He has given over 150 invited talks and lectures in 14 different countries. For his work with the American Board of Orthodontics, Dr. Buschang was awarded the Earl E. and Wilma S. Shepard Award. Dr. Buschang is the only non-orthodontist ever to have been made an honorary member of both the American Association of Orthodontics (2005) and the Edward H. Angle Society of Orthodontics (2009), the two most prestigious orthodontic groups.