Macroscopic and microscopic evaluation of flapless alveolar perforations on experimental tooth movement.

Jose Luis Munoz Pedraza,Matilde Da Cunha Gonçalves Nojima,Lincoln Issamu Nojima,Mariana Marquezan

doi:10.1590/2177-6709.23.6.073-079.oar

Abstract

Objective: The aim of this study was to evaluate a flapless surgical technique as an alternative to traditional alveolar corticotomy used to accelerate orthodontic tooth movement (OTM). Methods: To induce OTM in Wistar rats, 40 cN of orthodontic force were applied to the maxillary left first molars. Forty rats were distributed into control groups (CG1, CG3, CG7 and CG14) and experimental groups (n= 5), in which alveolar perforations were made using a spear-shaped guide bur (EG1, EG3, EG7, EG14). Euthanasia dates were set at 1, 3, 7 and 14 days, respectively, after tooth movement began. The amount of OTM was measured with a caliper, and osteoclasts present in the periodontal ligament of the mesial root of the moved tooth were counted by means of histological evaluation (tartrate-resistant acid phosphatase staining, TRAP). Results: Although there was no difference in the amount of OTM within subgroups of corresponding experimental periods (p> 0.05), when EG14 and CG14 were compared, a larger number of osteoclasts was counted in the experimental group (p< 0.00). Conclusion: The authors concluded that flapless cortical alveolar perforations led to more intense osteoclastic activity on the fourteenth day; nevertheless, no evidence of accelerated OTM could be noted.

Highlights

In some clinical situations, orthodontic tooth movement (OTM) can be a complex task due to the severity of malocclusions, or to diminish the biologic responses commonly seen in periodontally compromised adults and patients with general health problems.[1,2] there is demand for therapeutic approaches that facilitate OTM whenever a factor involving difficulty is associated, reducing the time of active orthodontic treatment
Selective alveolar bone corticotomy before beginning with orthodontic treatment is outstanding among the available alternatives,[3,4,5,6,7,8,9] because increased local tissue metabolism in response to surgical trauma can accelerate OTM.[5,10]
Histological analysis demonstrated a significant difference in the number of osteoclasts between control and experimental subgroups on the fourteenth day after tooth movement began, with increased quantities of osteoclasts in EG14 (p < 0.000) (Table 1)

Summary

Introduction

Orthodontic tooth movement (OTM) can be a complex task due to the severity of malocclusions, or to diminish the biologic responses commonly seen in periodontally compromised adults and patients with general health problems.[1,2] there is demand for therapeutic approaches that facilitate OTM whenever a factor involving difficulty is associated, reducing the time of active orthodontic treatment. Selective alveolar bone corticotomy before beginning with orthodontic treatment is outstanding among the available alternatives,[3,4,5,6,7,8,9] because increased local tissue metabolism in response to surgical trauma can accelerate OTM.[5,10]. Ever since it was first reported, the success of alveolar corticotomy was related to outlining the bone blocks connected by cancellous bone only, thereby offering less resistance to orthodontic forces.[11]

Methods

Results

Conclusion