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

The biological effects of Piezocision™ on bone for accelerated tooth movement: A systematic review of animal studies

OBJECTIVES

This systematic review aimed to assess the biological response at tissue, cellular, and molecular levels following Piezocision™ surgery, and its efficacy in accelerating orthodontic tooth movement.

MATERIAL AND METHODS

A systematic review of the literature was conducted across 4 databases following the PRISMA guidelines up to May 2022. Prospective controlled animal studies involving healthy animals under active orthodontic treatment assisted by corticotomy performed with a piezotome (Piezocision™) published in the English language without time restrictions were included. The article selection, data extraction and risk of bias assessment (SYRCLE tool) were performed by two independent blinded review authors.

RESULTS

Out of 738 articles screened, 10 studies were included with various level of bias. Biological responses were categorized into tissue, cellular, and molecular levels. Tissue-level changes included a global decrease in bone mineral content post-Piezocision™. At the cellular level, increased bone turnover activity was noted. Molecularly, elevated RANKL and OPG expression, along with increased TRAP+ and cytokines, were observed after Piezocision™. Studies confirmed Piezocision's efficacy, reporting 1.35 to 3.26 times faster tooth movements, peaking between the 3rd and 50th day post-surgery. Biological responses were transient, reversible, and proportional to surgical insult, with reactivation possible through a second Piezocision™.

CONCLUSIONS

After Piezocision™ surgery, a transient and reversible biological response was described at the tissue, cellular and molecular levels, which induced faster orthodontic tooth movements. This biological response could be re-activated by an additional Piezocision™ and is proportional to the surgical injury.

SYSTEMATIC REVIEW REGISTRATION

Prospero CRD42022303237.

Influence of the Curve of Spee on Tooth Displacement Patterns: A Finite Element Analysis at Varying Implant Heights

Background Monocortical mini-screw-type temporary anchorage devices (TADs), or mini-screws, have significantly impacted orthodontic treatment strategies, especially in severe crowding and protrusion cases. These devices offer flexibility in placement sites, but the chosen location can considerably influence tooth displacement patterns. Key factors include the 'line of force' and the biomechanical properties of orthodontic tools. By analyzing tension distribution and three-dimensional displacements, the finite element method (FEM) provides a thorough means to comprehend these patterns. The Curve of Spee (COS) is a crucial factor potentially affecting displacement. Objective This study aimed to leverage finite element analysis (FEA) to understand the impact of varying mini-implant heights (10 mm, 13 mm, and 16 mm) on the displacements of different tooth types under a consistent force of 150 gm and compare these displacements both in the presence and absence of the COS. Materials and methods A CAD model of the jaw and teeth was developed using CT scan data and a Rexcan III 3D White Light Scanner. This model was meshed in Altair HyperMesh using tetrahedral elements, resulting in a Finite Element Model. The model incorporated various components, including teeth, the periodontal ligament (PDL), alveolar bone, brackets, a titanium mini-screw, and an archwire measuring 0.019 x 0.025 inches. Unique material properties were assigned to the PDL, and the assembly accurately replicated the clinical alignment of the archwire and brackets. Subsequently, stress and strain analyses were conducted on the model using the FEM. Results The displacement patterns of various teeth at implant heights of 10 mm, 13 mm, and 16 mm under a 150-gm force were analyzed in relation to the COS. Notably, for the central incisor, the COS significantly affected displacements in the Y and Z directions. Similarly, the Lateral Incisor and Canine exhibited marked changes in the Z direction with the presence of the COS. The Second Premolar's apex displacement showed significant variation due to the COS, while the First Molar displayed notable changes in the X direction. Generally, the presence of the COS either maintained or slightly increased Z-directional displacements across teeth, particularly at the apices. Conclusion The presence of COS significantly influences tooth displacement patterns when using mini-screws at different implant heights. Central incisors, lateral incisors, and canines are particularly sensitive to changes in the Z direction with the COS. The biomechanical analysis emphasizes the importance of considering COS in treatment planning for optimal results with mini-implants in orthodontics.

Comparative Efficacy of Traditional Corticotomy and Flapless Piezotomy in Facilitating Orthodontic Tooth Movement: A Systematic Review and Meta-Analysis

Background and Objectives: This study aimed to perform a meta-analysis comparing the effects of corticotomy and flapless piezocision on accelerated tooth movement. Materials and Methods: A comprehensive search using a combination of controlled vocabulary (MeSH) and free-text terms was undertaken by two reviewers to identify published systematic reviews. Three major electronic databases (Medline via PubMed, Cochrane Database, and Embase) were searched up to 2 June 2023. Results: The results of the meta-analysis showed that the pooled standardized mean difference values of accumulative movement distances for flapless piezocision were 1.43 (95% CI, 0.38 to 2.48; p < 0.01), 1.09 (95% CI, -0.08 to 2.26; p = 0.07), and 0.73 (95% CI, -0.58 to 4.02; p = 0.14). The results of the meta-analysis demonstrated that the pooled SMD values of accumulative movement distances for the corticotomy were 2.76 (95% CI, 0.18 to 5.34; p = 0.04), 1.43 (95% CI, -1.10 to 3.96; p = 0.27), and 4.78 (95% CI, -4.54 to 14.10; p = 0.32). Although the test for overall effectiveness was significant for piezocision and corticotomy, there were no significant differences between piezocision and corticotomy. Conclusions: The study determined that both conventional corticotomy and flapless piezosurgery are effective as adjuncts to orthodontic treatment. Moreover, no significant difference was observed in the short-term effectiveness of canine retraction acceleration between conventional corticotomy and flapless piezocision. While piezocision may be a favorable option for orthodontic treatment, corticotomy can be considered in cases requiring additional procedures such as bone grafting.