Orthodontic treatment in periodontally compromised patients: a systematic review

Periodontal considerations during orthodontic intrusion and extrusion in healthy and reduced periodontium

In patients with advanced periodontal disease, pathological tooth migration may occur, which may require subsequent orthodontic treatment for both aesthetic and functional purposes. When planning orthodontic treatment mechanics, intrusive or extrusive forces are frequently indicated. Understanding tissue reactions during these movements is essential for clinicians when devising a comprehensive orthodontic-periodontal treatment plan. This knowledge enables clinicians to be fully aware of and account for the potential effects on the surrounding tissues. The majority of our understanding regarding the behavior of periodontal tissues in both healthy and compromised periodontal conditions is derived from animal studies. These studies offer the advantage of conducting histological and other assessments that would not be feasible in human research. Human studies are nevertheless invaluable in being able to understand the clinically relevant response elicited by the periodontal tissues following orthodontic tooth movement. Animal and human data show that in dentitions with reduced periodontal support, orthodontic intrusion of the teeth does not induce periodontal damage, provided the periodontal tissues do not have inflammation and plaque control with excellent oral hygiene is maintained. On the contrary, when inflammation is not fully controlled, orthodontic intrusion may accelerate the progression of periodontal destruction, with bacterial plaque remnants being displaced subgingivally, leading to further loss of attachment. Orthodontic extrusion, on the other hand, does not seem to cause further periodontal breakdown in dentitions with reduced periodontal support, even in cases with deficient plaque control. This is attributed to the nature of the tooth movement, which directs any plaque remnants coronally (supragingivally), reducing the risk of adverse effects on the periodontal tissues. This specific type of tooth movement can be leveraged to benefit periodontal conditions by facilitating the regeneration of lost hard and soft periodontal tissues in a coronal direction. As a result, orthodontic extrusion can be employed in implant site development, offering an advantageous alternative to more invasive surgical procedures like bone grafting. Regardless of the tooth movement prescribed, when periodontal involvement is present, it is essential to prioritize periodontal therapy before commencing orthodontic treatment. Adequate plaque control is also imperative for successful outcomes. Additionally, utilizing light orthodontic forces is advisable to achieve efficient tooth movement while minimizing the risk of adverse effects, notably root resorption. By adhering to these principles, a more favorable and effective combined orthodontic-periodontal approach can be ensured. The present article describes indications, mechanisms, side effects, and histological and clinical evidence supporting orthodontic extrusion and intrusion in intact and reduced periodontal conditions.

Effect of fence tray matching care on excess adhesive and bracket placement accuracy for orthodontic bonding: an in vitro study

OBJECTIVE

This study aimed to evaluate the effect of fence tray matching care (FTMC) in bracket bonding by measuring excess adhesive, as well as linear and angular deviations, and by comparing it with the half-wrapped tray (HWT).

MATERIALS AND METHODS

An intraoral scanner was used to acquire data on the maxillary dental arch of a patient with periodontitis.Furthermore, 20 maxillary dental arch models were 3D printed. Using 3Shape, PlastyCAD software, and 3D printing technology, 10 FTMC (method I) and HWT (method II) were obtained. By preoperative preparation, intraoperative coordination, and postoperative measurement, the brackets were transferred from the trays to the 3D-printed maxillary dental arch models. Additionally, the bracket's excess adhesive as well as linear and angular deviations were measured, and the differences between the two methods were analyzed.

RESULTS

Excess adhesive was observed in both methods, with FTMC showing less adhesive (P< 0.001), with a statistical difference. Furthermore, HWT's vertical, tip and torque, which was significantly greater than FTMC (P< 0.05), with no statistical difference among other respects. The study data of incisors, canines, and premolars, showed that the premolars had more adhesive residue and were more likely to have linear and angular deviations.

CONCLUSIONS

The FTMC had higher bracket bonding effect in comparison to HWT, and the adhesive residue, linear and angular deviations are smaller. The fence tray offers an intuitive view of the precise bonding of the bracket, and can remove excess adhesive to prevent white spot lesions via care, providing a different bonding method for clinical applications.

To intrude or not to intrude? A systematic review of the controversy surrounding orthodontic intrusion on reduced periodontium

OBJECTIVE

The main objective of this review was to evaluate the effects of orthodontic intrusion on patients with reduced periodontium. Additionally, this review aims to explore the potential for attachment gain and tissue regeneration in these patients and identify optimal therapeutic conditions to mitigate any negative effects of intrusion.

METHODS

A systematic review was conducted according to the PRISMA 2020 statement. Duplicate electronic searches of the PubMed, Cochrane, EMC Premium, and Science Direct databases were performed by two independent reviewers. Data extraction and quality assessments, including risk of bias evaluation using the Cochrane and ROBINS-I tools were conducted.

RESULTS

From an initial pool of 418 articles, 29 were selected after title and abstract screening for full-text review. Following thorough full-text reading, 15 studies were ultimately included in the analysis. The total number of patients included in the studies is 528, who underwent orthodontic intrusion on reduced periodontium. Studies indicated a decrease in periodontal pocket depth and an increase in clinical attachment with ortho-periodontal treatment. Alveolar bone level outcomes varied, showing both increases and losses. Authors generally observed improved papillary regeneration and reduced gingival recessions.

CONCLUSION

Clinical studies involving combined ortho-periodontal treatment showed that orthodontic intrusion on a reduced but healthy periodontium can be considered a beneficial treatment for the periodontium, provided that potential adverse effects are carefully monitored.

Osteocyte Mechanotransduction in Orthodontic Tooth Movement

PURPOSE OF REVIEW

Orthodontic tooth movement is characterized by periodontal tissue responses to mechanical loading, leading to clinically relevant functional adaptation of jaw bone. Since osteocytes are significant in mechanotransduction and orchestrate osteoclast and osteoblast activity, they likely play a central role in orthodontic tooth movement. In this review, we attempt to shed light on the impact and role of osteocyte mechanotransduction during orthodontic tooth movement.

RECENT FINDINGS

Mechanically loaded osteocytes produce signaling molecules, e.g., bone morphogenetic proteins, Wnts, prostaglandins, osteopontin, nitric oxide, sclerostin, and RANKL, which modulate the recruitment, differentiation, and activity of osteoblasts and osteoclasts. The major signaling pathways activated by mechanical loading in osteocytes are the wingless-related integration site (Wnt)/β-catenin and RANKL pathways, which are key regulators of bone metabolism. Moreover, osteocytes are capable of orchestrating bone adaptation during orthodontic tooth movement. A better understanding of the role of osteocyte mechanotransduction is crucial to advance orthodontic treatment. The optimal force level on the periodontal tissues for orthodontic tooth movement producing an adequate biological response, is debated. This review emphasizes that both mechanoresponses and inflammation are essential for achieving tooth movement clinically. To fully comprehend the role of osteocyte mechanotransduction in orthodontic tooth movement, more knowledge is needed of the biological pathways involved. This will contribute to optimization of orthodontic treatment and enhance patient outcomes.

Does orthodontic treatment using clear aligners and fixed appliances affect periodontal status differently?

DESIGN

Systematic review and meta-analysis of clinical trials, and prospective or retrospective cohort. The protocol of the study was registered in advance on PROSPERO.

DATA SOURCES

An electronic search in MEDLINE (PubMed), Web of Science, Scopus, and The Cochrane Library was conducted by two independent authors up to September 2022. Additionally, OpenGrey and www.greylit.org were searched for gray literature, whereas ClinicalTrials.gov was searched for detecting any relevant unpublished data.

STUDY SELECTION

The review question was defined in PICOS format as follows: population (P), patients undergoing orthodontic therapy; intervention (I), orthodontic therapy with clear aligner (CA); comparison (C), orthodontic therapy with fixed appliances (FA); outcome (O), periodontal health status and development of gingival recession; studies (S), randomized clinical trials (RCTs), controlled clinical trials, and retrospective or prospective cohort studies. Cross-sectional studies, case series, case reports, studies without a control group, and studies with less than 2 months follow-up were excluded.

DATA ANALYSIS

Periodontal health status was assessed as a primary outcome and it was measured in terms of pocket probing depth (PPD), gingival index (GI), plaque index (PI) and bleeding on probing (BoP). Gingival recession (GR) was assessed as secondary outcome, and was measured as the development or progression of GR, shown by the apical migration of the gingival margin occurring between pre- and post-orthodontic treatment. Each periodontal index was assessed in three-time points; short-term (2-3 months from baseline), mid-term (6-9 months from baseline), and long-term (12 months or more from baseline). A descriptive analysis of included articles was performed. Pairwise meta-analyses were conducted to compare outcomes assessed in FA and CA groups and were only performed when studies reported similar periodontal indices at similar follow-ups.

RESULTS

12 studies (3 RCTs, 8 prospective cohort studies, 1 retrospective cohort study) were included in the qualitative synthesis, of which, 8 studies were included in the quantitative synthesis (meta-analysis). A total of 612 patients (321 treated with buccal FA and 291 with CA) were assessed. Results from meta-analyses favored CA in regards to PI, demonstrating a significant difference in the mid-term follow-up (number of studies = 4, standardized mean difference [SMD] = -0.99, 95% confidence interval [CI] = -1.94 to -0.03, I2 = 99%, P = 0.04). There was a tendency to report better GI values with CA, specifically in long-term (number of studies = 2, SMD = -0.46 [95% CI, -1.03 to 0.11], I2 = 96%, P = 0.11). However, no statistical significance between the two treatment modalities was shown for any follow-up intervals (P > 0.05). As for PPD, the long-term follow-up showed statistical significance favoring CA (SMD = -0.93 [95% CI, -1.06 to 0.7], P < 0.0001), whereas short- and mid-term follow-ups did not show significant differences between FA and CA. Overall, patients treated with CA showed better values of BoP and less GR when compared to patients treated with FA.

CONCLUSIONS

Available evidence is still not enough to conclude the superiority of clear aligner therapy in terms of periodontal status during orthodontic treatment compared to fixed appliances.

Levels of Pro-Inflammatory and Bone-Resorptive Mediators in Periodontally Compromised Patients under Orthodontic Treatment Involving Intermittent Forces of Low Intensities

During orthodontic treatment, diverse cytokines, enzymes, and osteolytic mediators produced within the teeth surrounding periodontal tissues determine the rate of alveolar bone remodeling and consequent teeth movement. In patients with teeth presenting reduced periodontal support, periodontal stability should be ensured during orthodontic treatment. Thus, therapies based on the application of low-intensity intermittent orthodontic forces are recommended. To determine if this kind of treatment is periodontally well tolerated, this study aimed to analyze the production of receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), interleukin (IL)-6, IL-17A, and matrix metalloproteinase (MMP)-8 in periodontal tissues of protruded anterior teeth with reduced periodontal support and undergoing orthodontic treatment. Patients with periodontitis-associated anterior teeth migration received non-surgical periodontal therapy and a specific orthodontic treatment involving controlled low-intensity intermittent orthodontic forces. Samples were collected before periodontitis treatment, after periodontitis treatment, and at 1 week to 24 months of the orthodontic treatment. During the 2 years of orthodontic treatment, no significant differences were detected in the probing depth, clinical attachment level, supragingival bacterial plaque, and bleeding on probing. In line with this, the gingival crevicular levels of RANKL, OPG, IL-6, IL-17A, and MMP-8 did not vary between the different evaluation time-points of the orthodontic treatment. When compared with the levels detected during the periodontitis, the RANKL/OPG ratio was significantly lower at all the analyzed time-points of the orthodontic treatment. In conclusion, the patient-specific orthodontic treatment based on intermittent orthodontic forces of low intensities was well tolerated by periodontally compromised teeth with pathological migration.