Orthodontic tooth movement enhances bone healing of surgical bony defects in rats

Orthodontic tooth movement after periodontal regeneration of intrabony defects

The prevalence of intrabony defects in patients with advanced periodontitis stages III and IV is high. These patients usually need both periodontal treatment and orthodontic therapy, including tooth movement through bone defects, to improve masticatory function, aesthetics, and overall quality of life. Clinical practice guidelines recommend periodontal regenerative surgical interventions to resolve these defects and propose initiating orthodontic tooth movement (OTM) once periodontal therapy goals have been met. Surgical interventions using various regenerative technologies like barrier membranes and enamel matrix proteins, combined or not with bone replacement grafts, have proven effective in regenerating lost periodontal tissues. However, the combination of periodontal and orthodontic treatments requires consideration of how periodontal regenerative therapies influence OTM. Studies suggest that regenerated bone may differ in density, composition, vascularity, and cellular activity, potentially affecting the speed and efficiency of OTM, and potential root resorption of moved teeth. Understanding the sequence and timing of implementing OTM after regenerative periodontal interventions is crucial due to their interlinked processes of bone resorption and formation. This narrative review aims to uncover scientific evidence regarding these combined treatments, examining the impacts of different regenerative technologies on OTM and delineating their advantages, limitations, and best practices.

Long-term stability of regenerative periodontal surgery and orthodontic tooth movement in stage IV periodontitis: 10-year data of a retrospective study

BACKGROUND

This study aimed to evaluate the long-term effectiveness of regenerative treatment of intra-bony defects in combination with consecutive orthodontic therapy (OT) in stage IV periodontitis.

METHODS

Twenty-two patients with a total of 256 intra-bony defects were analyzed after regenerative surgery followed by OT initiated 3 months later. Changes in radiographic bone level (rBL) and probing pocket depths (PPD) were evaluated after 1 year (T1), final splinting (T2), and 10 years (T10).

RESULTS

Mean rBL gain was significant with 4.63 mm (±2.43 mm) after 1 year (T1), 4.19 mm (±2.61 mm) at final splinting (T2), and 4.48 mm (±2.62 mm) after 10 years (T10). Mean PPD was significantly reduced from 5.84 mm (±2.05 mm) at baseline to 3.19 mm (±1.23 mm) at T1, to 3.07 mm (±1.23 mm) at T2, and to 2.93 mm (±1.24 mm) at T10. Pocket closure (PPD ≤ 4 mm) was achieved in 90% of all defects. Tooth loss amounted to 4.5%.

CONCLUSIONS

Within the limitations of this retrospective study design, these 10-year findings suggest that in motivated and compliant patients with stage IV periodontitis and in need of OT an inter-disciplinary treatment can lead to favorable and stable long-term results.

Synergy of Regenerative Periodontal Surgery and Orthodontics Improves Quality of Life of Patients with Stage IV Periodontitis: 24-Month Outcomes of a Multicenter RCT

In stage IV periodontitis patients with pathologic tooth migration (PTM), interdisciplinary treatment includes regenerative periodontal surgery (RPS) with an application of biomaterials and orthodontic therapy (OT) to restore function, esthetics and thereby quality of life (QoL). In a 24-month randomized trial we explored the synergy between regenerative medicine and biomechanical force application. The following methods were used: Forty-three patients had been randomized to a combined treatment comprising RPS and subsequent OT starting either 4 weeks (early OT) or 6 months (late OT) post-operatively. Clinical periodontal parameters and oral health-related QoL (GOHAI) were recorded up to 24 months. We obtained the following results: Mean clinical attachment gain (∆CAL ± SD) was significantly higher with early OT (5.96 ± 2.1 mm) versus late OT (4.65 ± 1.76 mm) (p = 0.034). Pocket closure (PPD ≤ 4 mm) was obtained in 91% of defects with early OT compared to 90% with late OT. GOHAI-scores decreased significantly from 26.1 ± 7.5 to 9.6 ± 4.7 (early OT) and 25.1 ± 7.1 to 12.7 ± 5.6 (late OT). Inconclusion, teeth severely compromised by intrabony defects and PTM can be treated successfully by RPS followed by early OT with the advantage of an overall reduced treatment time. As a result of the combined periodontal-orthodontic therapy, the oral health-related QoL of patients was significantly improved. Early stimulation of wound healing with orthodontic forces had a favorable impact on the outcomes of regenerative periodontal surgery.

Correlation between alveolar cleft morphology and the outcome of secondary alveolar bone grafting for unilateral cleft lip and palate

Background

Secondary alveolar bone grafting (SABG) is an integral part of the treatment for cleft lip and alveolus and cleft lip and palate. However, the outcome of SABG was not satisfactory as expected, factors that affecting the outcome were still controversial. The aims of this study were to summarize a new method for the classification of alveolar cleft morphology in patients with unilateral cleft lip and alveolus or unilateral cleft lip and palate, to evaluate the correlation between the morphology and SABG outcomes, to identify factors that might predict the outcomes.

Methods

The characteristics of the cleft morphologies of 120 patients who underwent SABG were observed using the preoperative Cone-Beam Computed Tomography (CBCT) images. 52 patients who had CBCT scans performed at least 6 months after SABG were included for the evaluation of outcomes. Both categorical and continuous evaluation methods were measured. Correlations between cleft morphology and SABG outcomes were assessed using the Pearson correlation coefficient in SPSS 27.0.0.

Results

A new method for the classification of cleft morphology was summarized:type I, prism type (labial defect size ≥ palatal defect size; nasal defect size ≥ occlusal defect size); type II, prism’ type (labial defect ≥ palatal defect; nasal defect < occlusal defect); type III, inverted prism type (palatal defect ≥ labial defect); type IV, funnel type (presented as a significantly narrow defect area in the middle towards the vertical dimension); and type V, undefinable (extremely irregular morphology can’t be defined as any of the above types). Categorical evaluation showed 8 failure, 11 poor, 12 moderate, and 21 good results, while the average bone filling rate was 59.24 ± 30.68%. There was a significant correlation between the cleft morphology and categorical/continuous evaluation outcome (p < 0.05).

Conclusion

The new method for the classification of alveolar cleft morphology summarized in this study was comprehensive and convenient for clinical application. Both categorical and continuous methods should be used for radiographic assessments in patients undergoing SABG. The chances of a successful procedure might be better when the patient has type I or IV morphology, in which the shape is like a funnel in the relatively palatal or occlusal area towards the vertical dimension. A relatively great amount of bone resorption was observed in most patients.

Trial registration Chinese clinical trial registry; registration number: ChiCTR2100054438.

Effect of orthodontic treatment on periodontal health of periodontally compromised patients: A randomized controlled clinical trial

OBJECTIVES

To evaluate the effect of fixed orthodontic treatment on periodontal parameters in periodontally compromised adult orthodontic patients.

MATERIALS AND METHODS

This was a prospective, randomized, controlled clinical trial. Thirty-six periodontally compromised adult patients (mean age: 29.67 ± 4.8 years) were randomly allocated to either test (perio-ortho) or control group (perio). After periodontal stabilization in both groups, orthodontic treatment was started in the test group, whereas the control group remained on periodontal maintenance only. Evaluation and comparison of clinical parameters (plaque index [PI]; gingival index [GI]; bleeding on probing [BOP]; probing depth [PD]; clinical attachment level [CAL]) of both groups was assessed at three time intervals: T0 (base line), T1 (at start of orthodontic treatment), and T2 (1 year after start of orthodontic treatment). Radiological parameters (alveolar bone levels [ABL]) were recorded using CBCT at T1 and T2.

RESULTS

Intragroup analysis showed statistically significant improvement in all clinical and radiological periodontal parameters in both groups (P ≤ .05). Intergroup comparison revealed improvement in the periodontal parameters was not statistically significant between the groups (P ≥ .05). Subgroup analysis showed reduction in the number of moderate and severe periodontitis sites in both groups with significant more gains in ABL in the test group compared to the control group.

CONCLUSIONS

Orthodontic treatment after periodontal stabilization does not have any detrimental effect on periodontal health in adult periodontally compromised orthodontic patients and may add to the benefits achieved by periodontal treatment alone.

Long-Term Assessment of Periodontal Tissues after Corticotomy-Assisted Orthodontic Arch Expansion

OBJECTIVES

The aim of the study was the long-term assessment of the condition of periodontal tissues after corticotomy-assisted orthodontic expansion in patients with transverse maxillary deficiency.

MATERIALS AND METHODS

The study included a group of 18 adults (9 women, 9 men) aged between 24 and 40 years who were at least 5 years post treatment. The following parameters were assessed: the full mouth plaque index (FMPI), full mouth bleeding on probing (FMBOP), probing depth (PD), clinical attachment level (CAL), gingival recession height (GR), recession width (RW), papilla height (PH), papilla width (PW), bone sounding (BS), phenotype, and KT.

RESULTS

During examination performed at least 5 years after the completion of orthodontic treatment, the values of PD and CAL were found to be considerably decreased compared to the examination one year post treatment (PD: -0.23; 95% Cl: -0.29, -0.16) (CAL: -0.04; 95% Cl: -0.17, 0.10). The other parameters-FMPI, FMBOP, GR, RW, PH, PW, BS, phenotype, and KT-did not change significantly.

CONCLUSIONS

Corticotomy-assisted orthodontic arch expansion does not have a negative effect on the periodontium in long-term observations.

CLINICAL RELEVANCE

Orthodontic arch expansion can lead to bone dehiscence and gingival recession. Long-term observations revealed that corticotomy-assisted orthodontic expansion of the upper arch is not followed by negative changes in periodontal status.

Timing of orthodontic tooth movement in bone defects repaired with synthetic scaffolds: A scoping review of animal studies

OBJECTIVE

The optimal timing of orthodontic tooth movement (OTM) could allow earlier tooth movements across alveolar bone defects while minimizing the adverse effects. The objective of this scoping systematic review was therefore designed to review pre-clinical animal studies on the ideal protocol for the timing of orthodontic traction across alveolar defects augmented with synthetic scaffolds.

DESIGN

Following the PRISMA-ScR guidelines, three electronic databases were searched (Pubmed, Scopus and Web of Science).

RESULTS

A total of twelve studies were included in the final review that reported on small-animal (rats, guinea pigs, rabbits) and large-animal (dogs and goats) models. Based on the grafting biomaterials, eight papers used cell-free scaffolds, four articles utilised cell-based scaffolds. The timing protocol for the initiation of OTM employed in the studies ranged from immediate to 6 months after surgical grafting. Only four studies included autologous bone graft (gold standard) as positive control. Most papers reported positive results with regards to the rate of OTM and bone augmentation effects while only a few reported side effects such as root resorptions. Overall, the included articles showed a massive heterogeneity in terms of the animal bone defect model characteristics, scaffold materials, study designs, parameters of OTM and methods of analysis.

CONCLUSION

Since there was inadequate evidence to identify the optimal protocol of OTM, optimization of animal bone defect models and outcome measurements is needed to improve the translational ability of future studies.

The effect of timing of orthodontic therapy on the outcomes of regenerative periodontal surgery in patients with stage IV periodontitis: A multicenter randomized trial

AIM

To compare the outcomes after early (4 weeks post surgery) or late (6 months post surgery) orthodontic therapy (OT) following regenerative surgery of intra-bony defects (IDs).

MATERIALS AND METHODS

In a multi-center, parallel-group, randomized clinical trial, 43 patients with stage IV periodontitis were randomized to receive either early (n = 23) or late OT (n = 20) following regenerative surgery of IDs. Primary outcome was change in clinical attachment level (CAL) in one target ID at 12 months after surgery. Secondary outcomes were changes of probing pocket depth (PPD), bleeding on probing (BOP), and frequency of pocket closure.

RESULTS

No statistically significant differences between groups could be observed for CAL gain (5.4 mm [±2.1 mm] for early; 4.5 mm [±1.7 mm] for late OT). PPD was reduced by 4.2 mm (±1.9 mm) in the early group and by 3.9 mm (±1.5 mm) in the late group (p > .05). Pocket closure (PPD ≤ 4 mm) was obtained in 91% of defects in early compared to 85% in late OT.

CONCLUSION

In the inter-disciplinary treatment of periodontitis stage IV, OT can be initiated already 4 weeks after regenerative surgery of IDs with favourable results, thus reducing the overall treatment time.

Factors associated with alveolar bone depth mesial to the mandibular third molars after orthodontic protraction

INTRODUCTION

The objective of this research was to study the factors associated with the alveolar bone depth mesial to the mandibular third molars (M8) after the mandibular second (M7) and third molars were protracted into the space of the mandibular first molars (M6), which were newly extracted for orthodontic treatment or extracted more than 1 year before treatment.

METHODS

This retrospective study included 57 adult patients (mean age 23.40 ± 4.40 years) in whom M6 were newly extracted for orthodontic treatment or extracted more than 1 year before treatment. The alveolar bone depth mesial to M8 was measured on posttreatment panoramic radiographs. The vertical, horizontal, and angular changes of M8 were measured on both pre- and posttreatment panoramic radiographs. Linear correlation and regression analyses were conducted to explore the factors associated with the alveolar bone depth mesial to M8.

RESULTS

The alveolar bone conditions of M6 (R= -0.391, P <0.001) and the vertical movement directions of M8 (R= -0.433, P <0.001) were significant factors associated with the alveolar bone depth mesial to M8 after orthodontic protraction.

CONCLUSIONS

Without considering the pretreatment periodontal status of M8, patients with M6 extracted exceeding 1 year before treatment and with M8 extruded after orthodontic protraction may exhibit deeper alveolar bone depth mesial to M8.

Regenerative periodontal surgery and orthodontic tooth movement in stage IV periodontitis: A retrospective practice-based cohort study

AIM

Evaluation of the effectiveness of regenerative treatment of intra-bony defects in combination with consecutive orthodontic tooth movements in stage IV periodontitis.

MATERIAL AND METHODS

A total of 526 intra-bony defects in 48 patients were analysed after regenerative therapy using collagen-deproteinized bovine bone mineral with or without collagen membrane or enamel matrix derivative followed by orthodontic tooth movement initiated 3 months after surgery. Changes in radiographic bone levels (BL) and probing pocket depths (PPD) were evaluated after 1 year and up to 4 years.

RESULTS

Tooth loss amounted to 0.57%. Mean BL gain was 4.67 mm (±2.5 mm) after 1 year and 4.85 mm (±2.55 mm) after up to 4 years. Mean PPD was significantly reduced from 6.00 mm (±2.09 mm) at baseline to 3.45 mm (±1.2 mm) after 1 year, and to 3.12 mm (±1.36 mm) after 2-4 years. Pocket closure (PPD ≤4 mm) was accomplished in 87% of all defects. Adjunctive antibiotic therapy did not show any statistically significant impact on treatment outcomes.

CONCLUSIONS

Within the limits of this retrospective study design, the findings suggest that the combination of regenerative treatment and consecutive orthodontic tooth movements resulted in favourable results up to 4 years.

Timing of force application on buccal tooth movement into bone-grafted alveolar defects: A pilot study in dogs

INTRODUCTION

The aim of this pilot study was to evaluate the effect of the timing of postoperative orthodontic force application on bone remodeling during tooth movement into surgical alveolar defects with bone grafts in beagle dogs.

METHODS

Six beagle dogs underwent surgery for buccal dehiscence-type defects (width, 5 mm; height, 6 mm) on the distal root of maxillary second premolars bilaterally for 12 defects. After 1-month healing, bone-augmentation procedures were undertaken at the dehiscence defects. The second premolars were protracted buccally for 6 weeks into the surgical sites immediately (F-0), at 4 weeks (F-4), or 8 weeks (F-8) after grafting. Orthodontic tooth movement was monitored using digital models. Remodeling of alveolar bone was evaluated by histology, histomorphometry, immunohistochemistry, microcomputed tomography, and fluorescence microscopy.

RESULTS

Group F-0 showed significant expansion (mean, 2.42 mm) and tipping (mean, 9.03°) after completing orthodontic tooth treatment. The vertical bone defect was significantly lower in groups F-4 and F-8 than that in group F-0 (mean, 2.1, 2.7, and 4.5 mm, respectively). In group F-4, the formation of new bone and mineralization were significantly greater than those in groups F-0 and F-8 (P <0.05). Group F-4 showed a minimal amount of bone-material remnants. Immunohistochemistry showed the highest expression of collagen-1 and osteopontin in group F-4, followed by group F-8 and group F-0, which demonstrated high osteoblast activity and enhanced bone remodeling in group F-4.

CONCLUSIONS

Orthodontic force application at 4 weeks after an augmentation procedure provided the best functional stimulation for an alveolar bone graft. This strategy enhanced new-bone regeneration and degradation of bone substitutes and, eventually, promoted bone remodeling in the bone-grafted area.

Magnitude-dependent response of osteoblasts regulated by compressive stress

The present study aimed to investigate the role of magnitude in adaptive response of osteoblasts exposed to compressive stress. Murine primary osteoblasts and MC3T3-E1 cells were exposed to compressive stress (0, 1, 2, 3, 4, and 5 g/cm2) in 3D culture. Cell viability was evaluated, and expression levels of Runx2, Alp, Ocn, Rankl, and Opg were examined. ALP activity in osteoblasts and TRAP activity in RAW264.7 cells co-cultured with MC3T3-E1 cells were assayed. Results showed that compressive stress within 5.0 g/cm2 did not influence cell viability. Both osteoblastic and osteoblast-regulated osteoclastic differentiation were enhanced at 2 g/cm2. An increase in stress above 2 g/cm2 did not enhance osteoblastic differentiation further but significantly inhibited osteoblast-regualted osteoclastic differentiation. This study suggested that compressive stress regulates osteoblastic and osteoclastic differentiation through osteoblasts in a magnitude-dependent manner.

Orthodontic treatment in periodontitis-susceptible subjects: a systematic literature review

The aim is to evaluate the literature for clinical scientific data on possible effects of orthodontic treatment on periodontal status in periodontitis-susceptible subjects. A systematic literature review was performed on studies in English using PubMed, MEDLINE, and Cochrane Library central databases (1965-2014). By manually searching reference lists of selected studies, we identified additional articles; then we searched these publications: Journal of Periodontology, Periodontology 2000, Journal of Clinical Periodontology, American Journal of Orthodontics and Dentofacial Orthopedics, Angle Orthodontist, International Journal of Periodontics & Restorative Dentistry, and European Journal of Orthodontics. Search terms included randomized clinical trials, controlled clinical trials, prospective and retrospective clinical studies, case series >5 patients, periodontitis, orthodontics, alveolar bone loss, tooth migration, tooth movement, orthodontic extrusion, and orthodontic intrusion. Only studies on orthodontic treatment in periodontally compromised dentitions were included. One randomized controlled clinical trial, one controlled clinical trial, and 12 clinical studies were included. No evidence currently exists from controlled studies and randomized controlled clinical trials, which shows that orthodontic treatment improves or aggravates the status of periodontally compromised dentitions.

Assessing the Interdental Septal Thickness in Alveolar Bone Grafting Using Cone Beam Computed Tomography

OBJECTIVE

To assess the interdental septal thickness of grafted bone bridges using cone beam computed tomography (CBCT).

PATIENTS

Of 71 patients with cleft lip and/or palate having undergone alveolar bone grafting for the first time at least 6 months previously, 52 patients with 57 grafted sites rated type I or II based on the Bergland scale using occlusal radiographs were selected.

INTERVENTIONS

CBCT was performed for each bone-grafted alveolar cleft within 1 week after the occlusal radiographs were taken.

MAIN OUTCOME MEASURES

The thickness of the grafted bone bridge was evaluated using CBCT according to the relationship between crest thickness and the root width of cleft-adjacent teeth, and the results were classified into four categories, with scores of 1 to 4 indicating that the thickness of the bony bridge was ≥100%, ≥75%, ≥50%, and <50% of the root width of the cleft-adjacent teeth, respectively.

RESULTS

Of the 34 grafted sites rated type I on the Bergland scale, 15 (44.12%), 10 (29.41%), 4 (11.76%), and 5 (14.71%) clefts were scored 1 to 4 on interdental septal thickness using CBCT, respectively. Of the 23 cases of type II, 3 (13.04%), 9 (39.13%), 1 (3.45%), and 10 (43.48%) clefts were scored 1 to 4, respectively.

CONCLUSIONS

The interdental septal thickness of grafted bone bridges with clinically successful heights based on the Bergland scale (type I or II) using occlusal radiographs varied significantly in the evaluation using CBCT.

Periodontal responses to augmented corticotomy with collagen membrane application during orthodontic buccal tipping in dogs

This prospective randomized split-mouth study was performed to examine the effects of absorbable collagen membrane (ACM) application in augmented corticotomy using deproteinized bovine bone mineral (DBBM), during orthodontic buccal tipping movement in the dog. After buccal circumscribing corticotomy and DBBM grafting into the decorticated area, flaps were repositioned and sutured on control sides. ACM was overlaid and secured with membrane tacks, on test sides only, and the flaps were repositioned and sutured. Closed coil springs were used to apply 200 g orthodontic force in the buccolingual direction on the second and third premolars, immediately after primary flap closure. The buccal tipping angles were 31.19 ± 14.60° and 28.12 ± 11.48° on the control and test sides, respectively. A mean of 79.5 ± 16.0% of the buccal bone wall was replaced by new bone on the control side, and on the test side 78.9 ± 19.5% was replaced. ACM application promoted an even bone surface. In conclusion, ACM application in augmented corticotomy using DBBM might stimulate periodontal tissue reestablishment, which is useful for rapid orthodontic treatment or guided bone regeneration. In particular, ACM could control the formation of mesenchymal matrix, facilitating an even bone surface.

Interdisciplinary treatment of a periodontally compromised adult patient with multiple missing posterior teeth

This article reports the comprehensive, interdisciplinary treatment of a 50-year-old periodontally compromised adult patient with multiple missing posterior teeth. After initial periodontal treatment, the maxillary first molars and right central incisor were intruded orthodontically. Miniscrews were used to intrude the maxillary first molars by 3 mm. The mandibular arch was restored with a tooth-supported overdenture. Root coverage of the maxillary right central incisor was performed using Alloderm (Biohorizons, Birmingham, Ala). At the end of the interdisciplinary therapy, the results were esthetically pleasing, with the patient's oral functions restored to the optimum. The emphasis of this report is to highlight the importance of integrating various specialties such as periodontics, orthodontics, endodontics, and restorative dentistry toward a common goal of improving the patient's oral health, function, and esthetics.

β-TCP versus autologous bone for repair of alveolar clefts in a goat model

OBJECTIVE

The aim of this study in goats was to test the hypothesis that a novel synthetic bone substitute beta tricalcium phosphate (β-TCP) can work as well as autologous bone harvested from the iliac crest for grafting and repair of alveolar clefts.

DESIGN

Ten adult Dutch milk goats (Capra hircus) were used in a split-mouth study design.

MAIN OUTCOME MEASURES

Volumetric histologic assessment of new bone formation and radiographic measurement of orthodontic movement of teeth in a formerly created alveolar cleft.

CONCLUSIONS

The synthetic bone substitute β-TCP was shown to result in bone healing similar to that of iliac crest bone. The surgical, orthodontic, and histologic results now warrant the testing of β-TCP in the human cleft situation.

Repair of a defect following the removal of an impacted maxillary canine by orthodontic tooth movement: a case report

This case report describes a 13-year-old boy with alveolar bony defect resulted from surgical removal of impacted upper canine transposed in the anterior region. The boy had a normal occlusion with malposition of upper central and lateral incisors. The treatment objectives were to align teeth, close spaces by mesial movement of the buccal segments in the upper jaw to repair bone loss. Fixed appliance with palatal root torque was used for the mesial movements, levelling, and alignment of teeth.

Orthodontic tooth movement consisted of a sequence of root movement in a direction to increase the thickness of the labial cortical plate of bone, could ensure healthier periodontium. A healthier periodontium prior to space closure ensured repair of alveolar bony defect after surgical intervention. Orthodontic tooth movement should be added to our armamentarium for the repair of alveolar bony defect.

Orthodontic tooth movement enhancing bony apposition in alveolar bony defect: a case report

INTRODUCTION

Prevalence of complications from orthognathic surgery is relatively low but if it happens it is vital to manage the post complication bony defect appropriately.

CASE PRESENTATION

This case report describes a 20-year-old gentleman who suffered from a complication from a bimaxillary orthognathic surgery. A bone grafting was carried out to repair the bony defect from the surgery but it was unsuccessful. A non-invasive technique employing the use of very light orthodontic force with a laceback stainless steel ligature is described and a successful space closure with an improvement in the periodontal condition and bone apposition has been shown.

CONCLUSION

This technique can be considered if orthodontic tooth movement is needed across a deficient alveolar ridge.

Orthodontic movement after periodontal regeneration of class II furcation: a pilot study in dogs

PURPOSE

The effect of orthodontic movement on the periodontal tissues of maxillary second pre-molars, after regenerative treatment for class II furcations, was evaluated in four mongrel dogs.

MATERIAL AND METHODS

Class II furcation lesions were created. After 75 days they were treated with bovine bone mineral matrix and guided tissue regeneration with absorbable membrane. After 2 months of daily plaque control, each of the dog's furcation pre-molars was randomly assigned to a test or control group. Orthodontic appliances were placed on both sides of the maxilla using third pre-molars and canines as anchorages. In the test group, bodily orthodontic movement of the second pre-molars was performed in the mesial direction for 3 months while control pre-molars remained unmoved. The dogs were sacrificed for histometric and histologic analyses.

RESULTS

There were no statistically significant differences between the two groups in total bone and biomaterial areas or linear extension of periodontal regeneration on the radicular surfaces. In the test group, however, there was a tendency to a greater quantity of bone and a lesser quantity of biomaterial.

CONCLUSION

The orthodontic movement was not pre-judicial to the results obtained with the regenerative periodontal treatment.

Interdental papilla augmentation procedure following orthodontic treatment in a periodontal patient

BACKGROUND

The absence of the interdental papilla is a situation that may alter patients' esthetics. Recession of interproximal gingival tissues may be a consequence of periodontal disease, but in some cases it may also be a consequence of periodontal therapy, as a result of surgical or non-surgical procedures.

METHODS

The authors present a new multidisciplinary approach for the treatment of migrated maxillary incisors presenting infrabony defects, extrusion, and loss of the interdental papilla.

RESULTS AND CONCLUSION

The proposed clinical protocol may reconstruct the interproximal soft tissue, with esthetic improvement of the papillary level, together with resolution of the periodontal defects.

Overeruption without root exposure of third molars and periodontal health in the mandible

Bone formation is seen around the third molar even when the tooth is exposed to the oral environment due to overeruption. To determine if overeruption of the third molar with or without root exposure is related to the status of the exposure of other teeth in the mandible, using orthopantomographs, 424 third molars were studied in 371 patients who were over 41 years of age. The rate of overeruption and root exposure in third molars was measured, and its relationship to the number of teeth lost and the rate of root exposure in other teeth in the mandible was analyzed. Tooth loss in the group of third molars with overeruption without root exposure was greater than in that without overeruption or root exposure in men, whereas the relationship was not seen in women. We found that root exposures of other teeth in the group of third molars with overeruption without root exposure were significantly smaller than in those with root exposure in both genders. Third molars with overeruption without root exposure, in which bone formation was easy to observe for radiographic diagnosis, were correlated with periodontal health in the mandible, suggesting a component of precision determination for predicting resistance to periodontitis.

Bone Apposition in Surgical Bony Defects Following Orthodontic Movement: A Comparative Histomorphometric Study Between Root- and Periodontal Ligament-Damaged and Periodontally Intact Rat Molars

BACKGROUND

The influence of orthodontic tooth movement with diminished periodontal support is unclear. The aim of the present study was to evaluate bone healing in surgical defects following orthodontic tooth movement with and without periodontal ligament (PDL) and root surface damage.

METHODS

The study comprised 33 adult male Wistar rats, divided into two groups: group 1 (n = 14) with bony defect and no root damage and group 2 (n = 19) with periodontal bony defect including root/PDL damage on the mesial root of the maxillary first molar. One week after a surgical defect was created, orthodontic protraction of the right maxillary first molar was initiated in both groups. After 2 weeks of protraction, retention of 1 week was established; at the end of this period block sections were made. Histomorphometric analysis through light microscopy of decalcified tissue was performed. Results were statistically analyzed using independent samples t test and analysis of variance (ANOVA) with repeated measures.

RESULTS

Differences between groups in total area of bone defect and bone apposition were not statistically significant. Bone apposition calculated as percentage of the bone defect was significantly (t-test) greater (P = 0.002) in group 2 (46.21%) than in group 1 (24.95%). Within each group, area of bone apposition was significantly (ANOVA) greater in the distal than in the mesial quadrants of the bony defect (P = 0.006) and in the apical than the occlusal ones (P = 0.021).

CONCLUSION

Following orthodontic tooth movement, periodontal bony defects showed enhanced bony healing compared with alveolar bone defects with no direct association with the periodontal attachment apparatus.

Combined bone grafting and orthodontic treatment of an iatrogenic periodontal defect: a case report with clinical reentry

BACKGROUND

This case report discusses the treatment of an iatrogenic periodontal defect caused by an inadequate orthodontic appliance in a 9-year-old girl.

METHODS

The multidisciplinary approach to this case consisted of periodontal treatment using a bone grafting technique to restore the 10 mm bone dehiscence. Three months later orthodontic treatment was initiated to straighten and level the central incisors. Six months later mucogingival surgery was performed to cover 2 to 3 mm gingival recession.

RESULTS

The bony defects were completely filled and the 10 mm dehiscence was reduced to 4 mm. The connective tissue graft resulted in a complete coverage of the recessions and a thickening of the keratinized gingiva. The patient is still undergoing orthodontic treatment. So far, straightening of the upper central incisors and closure of the diastema are satisfactory.

CONCLUSIONS

Inadequate orthodontic appliances can cause iatrogenic periodontal defects. A multidisciplinary approach in a well-defined sequence can restore lost periodontal tissue, thus achieving comfort, function, and esthetics.