Experimental tooth movement through mature and immature bone regenerates after distraction osteogenesis in dogs

Selection of bone graft material and proper timing of periodontal surgery for orthodontic patients: A systematic review

Introduction

Bone loss progression due to periodontitis can lead to pathologic tooth migration, ultimately compromising the overall structure and function of the oral cavity. In pathologic tooth migration, a periodontal-orthodontic interdisciplinary approach is necessary. The combination of a bone graft and orthodontic treatment has shown promising results for periodontal regeneration. The treatment sequence and selection of a bone graft define the success of the therapy.

Objective

This study aims to discuss the protocol of the interdisciplinary approach to regenerative periodontal surgery in cases of intrabony defects requiring orthodontic treatment.

Material & methods

Literature searches were conducted on four online databases (PubMed, Wiley, ScienceDirect, and Google Scholar). The keywords used were (intrabony defect OR vertical bone defect) AND (bone graft OR periodontal regeneration) AND (orthodontic). Out of 1656 studies that were retrieved initially, 14 full-text articles were checked for eligibility assessment. Finally, a total of seven studies met all of the requirements for inclusion in this study. This study includes two randomized controlled trials (RCTs), which are considered the highest level of evidence, however it is important to note that the overall evidence base is heterogeneous, inclusive of various study designs.

Discussion

Periodontal tissue damage must be addressed before considering orthodontic therapy, including cases with intrabony defects. On the basis of the seven studies, orthodontic therapy can be initiated as early as four weeks after surgery or as late as one year after periodontal surgery. Different types of bone graft materials, such as autografts, allografts, xenografts, and alloplasts, are used in the included studies. Three out of seven studies used autogenous graft combined with xenograft or enamel matrix derivative as the graft material as it is osteoconductive, osteogenic, and osteoinductive. Regular periodontal tissue maintenance therapy should be performed every 2-6 months, before, during, and after orthodontic treatment.

Conclusion

Making a proper diagnosis and treatment sequence is key to the success of a periodontal-orthodontic treatment. In addition, identifying the appropriate timing between periodontal surgery and orthodontic movement, selecting the most suitable bone graft material, and ensuring regular maintenance of periodontal tissue are important considerations.

Evaluation of the Effects of One versus 4 Weeks Activation Intervals on the Rate of Orthodontic Tooth Movement: An Experimental Study

Objectives: To evaluate the effects of one versus four weeks reactivation of the elastomeric chain on the rate of orthodontic tooth movement (OTM) and supporting structures. Methods: The 3rd maxillary premolars of 8 male mongrel dogs were extracted. Custom made appliance was constructed so that the 2nd premolars were allowed to slide bodily. An elastomeric chain with calibrated force of 150g was attached to the hooks of soldered tubes on the 2nd premolar’s crowns. The sample was divided into two groups based on the interval of reactivation of the elastomeric chains used for tooth movement where in group I activation was scheduled every one week versus four weeks in group II. Measurements of the amount and rate of OTM were performed every week for 12 weeks using digital caliper. The animals were then sacrificed and specimens were prepared for decalcified histological examination using Hematoxylin and Eosin stains under light microscope. Results: No remarkable difference in the rate of OTM between the two groups was reported. The total amount of tooth movement in group I was 1.44mm ± 0.5 compared to 1.46mm ± 0.6 in group II. Histological examination revealed a more favorable tissue reaction associated with 4 weeks reactivation as regards the new formed bone, root resorption and periodontal ligament structure. Conclusion: Altering the reactivation interval of the elastomeric chains from four to one week doesn’t have a significant impact on the rate of OTM. However, four weeks reactivation interval showed a more favorable tissue reaction associated with orthodontic tooth movement.

BMP2-Functionalized Biomimetic Calcium Phosphate Graft Promotes Alveolar Defect Healing During Orthodontic Tooth Movement in Beagle Dogs

Background: Grafting of biomaterial in alveolar defect facilitates bone healing and orthodontic treatment. BMP2-functionalized biomimetic calcium phosphate (BioCaP) graft had shown excellent bone defect healing potential in many preclinical studies. In this study, we aimed to investigate the influence of BioCaP graft on surgical alveolar bone defect healing during orthodontic tooth movement (OTM) in beagle dogs.

Methods: Nine Beagle dogs were randomly assigned to three groups: control, deproteinized bovine bone (DBB), and BioCaP. The maxillary second premolars were protracted into the defects of the extracted maxillary first premolar for 8 weeks. The rate of OTM, alveolar remodeling and bone defect healing were evaluated by histology, histomorphometry, and cone beam computed tomography (CBCT) imaging. Periodontal probing depth was analyzed. Gingival cervicular fluid was collected at week 4 and 8, and the IL-1β level was measured by ELISA.

Results: The histological sections of the bone defect showed more newly formed bone in the BioCaP group. The percentage of new bone formation in the BioCaP group was 1.61-, and 1.25-fold higher compared to the control and DBB group, respectively. After 8 weeks of OTM, the resorption rate of BioCaP was 1.42-fold higher compared to DBB. The root resorption index in the DBB group was 1.87-, and 1.39-fold higher compared to the control and BioCaP group, respectively. CBCT images showed 1.92-, and 1.36-fold higher bone mineral density in the BioCaP group compared to the control and DBB group, respectively. There was no significant difference in OTM among the three groups. The distance between the enamel cementum and the crest of the alveolar ridge in the control group was 1.45-, and 1.69-fold higher compared to DBB and BioCaP group, respectively. Periodontal probing depth at week 8 was reduced in the BioCaP group compared to the control. IL-1β concentration in the gingival cervicular fluid was significantly lower in the BioCaP group compared to the control group at week 4 and 8.

Conclusion: BioCaP graft robustly promoted bone regeneration and alveolar bone defect healing without affecting OTM. BioCaP graft caused less alveolar bone recession and root resorption of traction tooth with favorable periodontal attachment level indicating that BioCaP as a bioactive and functional bone filling material for alveolar bone defects during orthodontic treatment.

Apical root resorption after orthodontic treatment in patients with unilateral cleft lip and palate

OBJECTIVES

The aims of this retrospective longitudinal study were to present the incidence of external apical root resorption (EARR) in the maxillary anterior teeth of patients with complete unilateral cleft lip and palate (CUCLP) and to evaluate the influence of orthodontic treatment variables on the development of EARR.

MATERIAL AND METHODS

Forty-one patients with CUCLP participated in the study. Orthopantomograms (OPGs), taken before (T2) treatment with multiband orthodontic appliances (MBA), and periapical radiographs (PAs) of the maxillary anterior teeth taken at the end (T3) of orthodontic treatment (OT) were assessed for EARR.

RESULTS

The incidence of EARR at T3 (97.6%) was considerably higher than at T2 (51.2%). Central incisors and canines on the cleft side showed a significantly higher score (p < 0.01, p < 0.05 respectively) of EARR in comparison to the same group of teeth on the non-cleft side. Preexisting EARR and abnormal root morphology were identified as predisposing factors for EARR.

CONCLUSIONS

Patients with CUCLP treated with MBA have higher incidence of EARR on the maxillary anterior teeth of the cleft side. Severe EARR is rather rare but more often seen on central incisors of the cleft side.

CLINICAL RELEVANCE

As most of the patients with cleft lip and palate undergo a challenging and long-term OT with MBA, it is of importance to identify the predisposing factors related to the special anatomical features of the bone and teeth located in the cleft area, as well as the special OT needs of these patients.

[Symphyseal bone distraction (part 1): benefit / risk ratio. A systematic literature review]

INTRODUCTION

The purpose of this systematic literature review is to evaluate the benefit / risk ratio of mandibular symphyseal distraction osteogenesis.

MATERIALS AND METHODS

Searches were made on Pubmed/Medline and Cochrane for randomized clinical trials and case series involving mandibular symphyseal distraction over the past 20 years with a patient sample greater than or equal to 10.

RESULTS

Of the 92 articles, 25 met the inclusion criteria. A controlled trial was selected, but no randomized trial. The other studies were all case series, 16 retrospective and 8 prospective. Distractors with bone or hybrid anchorage appear to lead to more periodontal and infectious complications due to the buccal position of the jack. Most complications are benign. However, the most difficult event to deal with is distraction device fracture. Symphyseal midline distraction increases the transverse dimension efficiently, reliably and sustainably, and appears to have no demonstrated deleterious effects on the ATMs for the three types of distractors.

DISCUSSION

Tooth-borne devices are recommended in most cases given their benefit / risk ratio. Furthermore, they do not require a second surgical procedure to remove them.

CONCLUSION

Mandibular symphyseal distraction osteogenesis is a reliable therapy whose exact limits and reproducibility remain to be defined by future prospective studies.

[Symphyseal bone distraction (part 2): which protocol in 2018? A systematic literature review]

INTRODUCTION

The aim of this systematic literature review is to propose a clinical protocol in 2018 by comparing therapeutic efficacy and undesirable effects of the technique.

MATERIALS AND METHODS

Searches were made on Pubmed/Medline and Cochrane for randomized clinical trials and case series involving mandibular symphyseal distraction over the past 20 years with a patient sample greater than or equal to 10.

RESULTS

Of the 92 articles, 25 met the inclusion criteria. A controlled trial was selected, but no randomized trial. The other studies were all case series, 16 retrospective and 8 prospective. Dental crowding over 7 mm, with or without compensation, is an indication for mid-symphyseal distraction. Pre-surgical orthodontic treatment ensures root divergence between the mandibular incisors. Tooth-borne devices are recommended in first intention. Surgical intervention (ambulatory) under local anesthesia and intravenous sedation is considered. The latency period before activation of the jack is 6 days. Activations are performed by the orthodontist and subsequently by the patient at a rate of 1 mm per day, with four activations daily. Orthodontic movements are resumed two weeks after activations are discontinued. The distractor is removed within two to three months after installation.

CONCLUSION

Although the main features of the mid-symphyseal distraction protocol were drawn up essentially in the light of expert opinion, they still need to be refined by controlled trials.

Treatment outcomes of archwise distraction osteogenesis in mandibular dentoalveolar retrognathia cases

The aim of this study was to describe the treatment of class II malocclusion by sagittal advancement of the alveolar bone in the symphyseal area using an intraoral archwise distractor device and to determine the effects of this method on the dentoalveolar complex. Fifteen patients (10 female, five male) aged 16-20 years with a class II division 2 malocclusion, characterized by mandibular dentoalveolar retrusion and a prominent chin, underwent archwise alveolar distraction in the anterior mandible. Lateral cephalometric radiographs were obtained before distraction (T0), after 6 weeks of consolidation (T1), and after debonding (T2). Linear and angular skeletal, dental, and soft tissue measurements were performed. Forty-seven parameters were measured for each of the 15 subjects on pre- and postoperative lateral cephalometric radiographs (T0, T1, and T2). The distraction protocol was successful in all patients. Skeletally, the mandible showed a clockwise rotation. B-point moved forward significantly (P<0.05). Overjet decreased significantly (P<0.001). The total profile angle was unaffected, and the improvement in the submental fold was highly significant (P<0.001). The intraoral archwise distraction force that is applied through brackets and archwires is sufficiently effective for alveolar advancement. This procedure is simple and effective in the treatment of specific adult patients with a class II division 2 malocclusion, characterized by a prominent chin and severe mandibular dentoalveolar retrusion.

Alternate rapid maxillary expansion-constriction and tooth-borne symphyseal distraction osteogenesis : A case report demonstrating treatment of a patient with severe crowding

Surgically assisted rapid mandibular expansion is a contemporary treatment alternative to enable genuine skeletal mandibular widening. Mandibular widening via a tooth-borne distractor is a practical and noninvasive clinical approach. Recently, to expand and protract the maxilla, the alternate rapid maxillary expansion-and-constriction procedure was suggested. In this case report, we describe a female patient (12 years 7 months old) having severe maxillary and mandibular crowding who underwent repeated alternate rapid maxillary expansion and constriction in combination with tooth-borne symphyseal distraction osteogenesis.

Dentate transport discs can be used to reconstruct large segmental mandibular defects

PURPOSE

This study tested the use of a dentate transport segment for the reconstruction of a large U-shaped defect in the anterior segment of the canine mandible using a novel curved reconstruction plate. The quality and quantity of bone regenerate formed by dentate versus edentulous transport segments were compared.

MATERIALS AND METHODS

In 5 adult foxhound dogs, a defect of 70 to 75 mm was created in the canine mandible by excising the mandible anterior to the right and left fourth premolars. Reconstruction was performed by trifocal distraction osteogenesis using a bone transport reconstruction plate (BTRP-02), with 2 transport units being activated simultaneously, one on either side of the defect, 1 dentate and 1 edentulous. Bilateral distraction proceeded at a rate of 1 mm/day until the segments docked against each other in the midline. After 39 to 44 days of consolidation, the animals were euthanized. The quantity and quality of bone regeneration on the 2 sides were compared using micro-computed tomography.

RESULTS

The defect reconstruction was successful. The amount and quality of bone formed by the transport segments were similar on the 2 sides. There were no major differences in the bone volume fraction and density of the regenerate bone formed by the 2 transport segments. The bone volume fraction and density of the regenerate bone were considerably lower than those of the host bone in the distal segments, likely owing to the short consolidation period.

CONCLUSIONS

Bone transport remains a viable option in reconstructing anterior segmental defects in the mandible. The use of dentate or edentulous transport segments for reconstruction provides options for the surgeon in often highly compromised patients requiring these surgeries.

Treatment of alveolar cleft with distraction osteogenesis using anchorage with a tooth-microimplant joint in a dog model

Our aim was to investigate the efficacy of correction of an alveolar cleft with distraction osteogenesis using anchorage with a tooth-microimplant joint in a canine model, which was established in 12 adult mongrel dogs that were subsequently randomised into two groups (n=6 in each). The first group comprised dogs that had osteogenesis using anchorage with a tooth (tooth group), while in the second, anchorage with tooth-microimplant joint (microimplant group) was used. All animals were killed one month after completion of distraction. Samples were collected for gross observation and histological examination. There was a significant difference in the degree of movement of the anchorage teeth in the transport discs between the 2 groups (p<0.01). There was less prominent inclination and shift of the natural teeth in the transport disc and less bony resorption around the root in the microimplant group than in the tooth group. These changes were less remarkable in the microimplant group. Treatment of alveolar cleft by distraction osteogenesis using anchorage with a tooth-microimplant joint is practical, and yields better results.

The Effects of Hyperbaric Oxygen on Tooth Movement into the Regenerated Area after Distraction Osteogenesis

Objective

To analyze the effect of hyperbaric oxygen on newly formed bone in distracted areas surrounding the root of a moving tooth by histological and radiological analysis. It was hypothesized that the application of hyperbaric oxygen to a tooth moving into the distracted area would accelerate ossification and vascularization of newly formed bone in the distracted space.

Design

Ten dogs were used. After creating a 10-mm-long bone defect, a bony segment was prepared and translocated into the defect area at a rate of 1 mm/d for 10 days. Following the distraction period, tooth movement was started and the dogs were divided into two groups. The HBO group received hyperbaric oxygen; whereas, the control group did not. At 150 days after tooth movement, the distracted area around the moving tooth was evaluated radiologically and histologically. Differences between groups were confirmed by a Mann-Whitney U test.

Results

Trabecular bone density and cortical and subcortical bone areas measured by peripheral quantitative computed tomography in the HBO group were significantly higher than those in the control group. Histological observations revealed regenerated bone and blood vessels formation in the tension site of the moving tooth in the HBO group. The regenerated bone structure measured by bone histomorphometry was larger and more active in bone formation in the HBO group than in the control group.

Conclusions

Applying hyperbaric oxygen to tooth movement into a distracted area appears to accelerate ossification and vascularization of regenerated bone in the that area.

Biologic response of rapid tooth movement with periodontal ligament distraction

INTRODUCTION

Length of treatment is a complaint of many orthodontic patients. The purpose of this study was to evaluate the security and feasibility of rapid tooth movement with periodontal ligament distraction.

METHODS

Eight male beagles, aged 13 to 16 months, were used in this study. Extraction of the mandibular second premolar and alveolar surgery to reduce the osteal resistance on the mesial side of the extraction socket were performed on the experimental side. Then a device was placed to distract the first premolars distally on the experimental side; on the control side, the first premolars were distalized with nickel-titanium coil springs. The beagles were killed in the first, second, fourth, and eighth weeks after orthodontic force application.

RESULTS

The first premolar on the experimental side moved more rapidly than that on the control side (P <0.05). Histologic data indicated that more new bone was deposited on tension area of the experimental side than on the control side. Active and extensive bone resorption in the compressive area and bone deposition in the tension area were observed on the experimental side.

CONCLUSIONS

These results suggest that the periodontal ligament can be rapidly distracted without complications. The rapid orthodontic tooth movement by distracting the periodontal ligament cannot be emulated by current conventional orthodontic concepts and methods.

[Not Available]

Facing a dental crowding, the orthodontist has several therapeutic options. If maxillary expansion is often used, mandibular orthodontic expansion is proscribed because of its tendency of inefficiency and relapse. Mandibular symphyseal distraction osteogenesis allows to remove this proscription. This therapeutic protocol consists in a pre-surgery orthodontic preparation phase followed by surgery (symphyseal osteotomy and placement of the distraction device), a latency period (five to seven days), then an activation period (most of the time 1 mm/day in two steps) followed by a consolidation period (three months) during which the orthodontic treatment can be resumed. Skeletal and alveolar expansion corrects dental crowding. This surgical technique is versatile, minimally invasive, and stable with time. Major indications are hypoplastic symphysis, anterior crowding, relapse of orthodontic treatments and some syndromes. This method can also be an answer to aesthetic concerns or an alternative for treatment of dental crowding. Face à un encombrement dentaire, l'orthodontiste dispose de plusieurs options thérapeutiques. Si au maxillaire, l'expansion est fréquemment utilisée, l'expansion mandibulaire orthodontique est proscrite, car inefficace et récidivante. La distraction symphysaire permet de lever cet interdit. Ce protocole thérapeutique comprend : une préparation orthodontique pré-chirurgicale, une chirurgie (ostéotomie symphysaire et pose du distracteur), une période de latence (cinq à sept jours), puis une période d'activation (le plus souvent 1 mm/j en deux fois) suivie d'une période de consolidation (trois mois) pendant laquelle le traitement orthodontique peut être repris. L'expansion basale et alvéolaire corrige l'encombrement dentaire. Cette technique est polyvalente, peu invasive et stable dans le temps. Ses indications majeures sont l'hyposymphysie, l'encombrement incisif, la récidive de traitements orthodontiques et certains grands syndromes. Cette méthode peut aussi être proposée pour répondre à des préoccupations esthétiques ou comme alternative aux traitements classiques de l'encombrement dentaire.

Mandibular Symphyseal Distraction Osteogenesis Using a Bone-Supported Distractor

Increases in mandibular width by symphyseal distraction osteogenesis have recently been shown to be an acceptable and stable treatment option for transverse deficiencies. This case report presents the application of symphyseal distraction osteogenesis for increasing mandibular width using a bone-supported distractor as part of the orthodontic treatment of a 14-year-old male with a tapered shaped mandible and severe mandibular anterior crowding.

Rapid orthodontic tooth movement aided by alveolar surgery in beagles

INTRODUCTION

It has been reported that oral surgery can accelerate orthodontic tooth movement. The purpose of this study was to evaluate the effects of alveolar surgery that undermines interseptal bone in orthodontic tooth movement.

METHODS

Ten male beagles, aged 12 to 15 months, were used in this study. Extraction of the mandibular second premolar and alveolar surgery to reduce the osteal resistance on the mesial side of the extraction socket were performed on the experimental side; on the control side, only the second premolar was extracted. The first premolars were distalized against the third premolars with orthodontic nickel-titanium coil springs on the both sides. The beagles were killed in the first, second, third, fourth, and eighth weeks after orthodontic force application.

RESULTS

The first premolar on the experimental side moved more rapidly than that on the control side (P <.01). Tissue slices were obtained for histological evaluation. No obvious root resorption and no irreversible injury to the pulp were observed on either side. Active and extensive bone resorption in the compressive area and bone deposition in the tension area were observed on the experimental sides.

CONCLUSIONS

Self-fluorescence checks showed that more new bone was deposited in the tension area of the experimental side than on the control side (P <.05). These results suggest that alveolar surgery might be an effective and safe way to aid orthodontic tooth movement.

Osteoclastogenic activity during mandibular distraction osteogenesis

Mandibular distraction osteogenesis is a well-developed clinical modality for the treatment of craniofacial deformities and dental arch discrepancies, in combination with orthodontic treatment. However, in our previous study, orthodontic tooth movement into the distraction gap caused severe root resorption. The present study aimed to clarify the osteoclastogenic activity of cells in the distraction gap. We hypothesized that the gene expression of osteoclastogenic- and osteoclast-supporting molecules in osteoblasts and stromal cells would increase at distraction sites during the consolidation period. An animal model experiment involving rabbits was designed for mandibular distraction osteogenesis and subjected to in situ hybridization analysis. The number of osteoclasts was larger in the distraction gap during the early consolidation period than in normal controls, due to an increase of gene expression for osteoclastogenic cytokines in osteoblasts. It was concluded that osteoclastogenic and osteoclastic activities are stimulated at distraction sites during the early consolidation period.