Assessment of the outcomes and stability after mandibular incisor extraction in orthodontic patients: A systematic review and meta-analysis.

Background: This study assessed the stability of the outcomes after mandibular incisor extraction (MIE) using intercanine width and peer assessment rating (PAR) scores in orthodontic patients. Methods: PubMed, Cochrane Library, Science Direct, Google Scholar, Ovid, and SciELO were systematically searched without restrictions until August 2022. A risk of bias assessment was performed using Newcastle-Ottawa Scale (NOS). The Grading of Recommendations, Assessment, Development, and Evaluation tool was used to assess the quality of evidence. Random effects meta-analysis was performed using RevMan software. Results: Seven retrospective studies met the inclusion criteria and were included. Meta-analysis identified a statistically significant reduction in intercanine width with MIE after the retention period. The mean difference in post-retention changes concerning intercanine width (MD=0.14, 95% CI: -2.17-1.89; P<0.00001) was significantly higher in premolar extraction (PE) compared to incisor extraction and significantly less in non-extraction compared to incisor extraction (MD=0.72, 95% CI: -0.59-2.03; P<0.00001). Improvements in PAR scores from the start of treatment to the retention period indicated a high outcome standard (>70%) with MIE treatment, with no significant difference in the reduction percentage compared to premolar and non-extraction groups. Conclusion: With the existing retrospective studies of limited evidence, treatment outcomes with MIE were found to show good improvements in PAR scores. Some reduction in the intercanine width was evident after the retention period, which was observed even with the other two treatment modalities that were compared. Hence, with careful evaluation, MIE could be considered a valid treatment option.

Effect of placement angle, diameter, length and bone density on the pull-out strength of orthodontic mini-implants: An in vitro study.

OBJECTIVE: To evaluate the effect of the placement angle, diameter, length and bone density on the mechanical stability of orthodontic mini-implants by measuring their pull-out strengths. DESIGN: A total of 120 mini-implants of four different dimensions made from titanium were used. They measured 1.3 × 6.0mm, 1.3 × 8.0 mm, 1.5 × 6.0 mm and 1.5 × 8.0 mm. Synthetic polyurethane bone blocks (Saw Bones, USA) in two different densities were used. SETTING: Each size of mini-implant was inserted equidistantly into synthetic bone blocks of two different densities, in three different insertion angles of 30°, 60° and 90°. This resulted in 24 test groups with five mini-implants allocated to each group. METHODS: The pull-out strength was measured using an Instron Universal Testing Machine exerting a vertical force parallel to the long axis of the mini-implant until removal or failure occurred. Peak load at failure of the mini-implant was recorded in kN. RESULTS: Showed that mini-implants placed at an insertion angle of 30° offered least resistance to pull-out. Mini-implants 6.0 mm in length showed less pull-out strength compared to the longer 8.0-mm mini-implants. Mini-implants 1.3 mm in diameter provided similar pull-out values as 1.5-mm mini-implants. Bone densities of 0.20 g/cc and 0.32 g/cc did not affect the pull-out strength of mini-implants. CONCLUSION: From the study, it was concluded that a logical choice of mini-implant dimension and prudent use of placement technique can help achieve the treatment goals with a reduced hazard of mini-implant failure.

Assessment of relapse of skeletal open bite treatment in adult patients treated with molar intrusion using temporary anchorage devices and orthognathic surgery - a systematic review / Avaliação da recidiva do tratamento da mordida aberta esquelética em pacientes adultos tratados com intrusão molar utilizando dispositivos de ancoragem temporária e cirurgia ortognática - uma revisão sistemática

Objetivo: O objetivo deste estudo é avaliar sistematicamente as evidências disponíveis para recidiva do tratamento da mordida aberta esquelética usando dispositivos de ancoragem temporária e cirurgia ortognática. Material e Métodos: Cinco bases de dados eletrônicas como MEDLINE, COCHRANE, SCIELO, GOOGLE SCHOLAR, EMBASE foram pesquisadas sistematicamente até junho de 2020. Os estudos de qualidade metodológica foram classificados por meio da Ferramenta de Avaliação de Qualidade do Projeto de Práticas de Saúde Pública Eficazes (EPHPP). Resultados: No total, 1.005 estudos foram identificados para triagem e 6 estudos foram elegíveis. O instrumento de avaliação da qualidade apresentou qualidade moderada para todos os estudos. A correção imediata pós-tratamento da mordida aberta foi melhor nos estudos cirúrgicos do que nos estudos tratados com TADs. Conclusão: A estabilidade dos resultados do tratamento da mordida aberta anterior foi comparável nos casos tratados em ambas as modalidades de tratamento. A recidiva da mordida aberta anterior foi associada a casos em que a sobremordida pós-tratamento foi mínima. A sobremordida parece ser mais estável quando apenas a maxila foi operada do que com cirurgias bimaxilares. A rotação anti-horária da mandíbula com subsequente redução da altura facial anterior foi melhor na correção cirúrgica do que através de TADs (AU)

Objective: The purpose of this study is to systematically assess the available evidence for relapse of skeletal open bite treatment using temporary anchorage devices and orthognathic surgery. Materials and Methods: Five electronic databases such as MEDLINE, COCHRANE, SCIELO, GOOGLE SCHOLAR, EMBASE were systematically searched up to June 2020. Methodological quality studies were graded by means of the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool. Results: In total, 1005 studies were identified for screening, and 6 studies were eligible. The quality assessment tool showed moderate quality for all the studies. The immediate post treatment correction of open bite was better in the surgical studies than in the studies treated with TADs. Conclusion: Stability of treatment results of anterior openbite was comparable in cases treated in both the treatment modalities. Relapse of anterior open bite was associated with cases in which the posttreatment overbite was minimal. Overbite seems to be more stable when only the maxilla has been operated on than with bi-maxillary surgeries. Counterclockwise rotation of the mandible with subsequent reduction of anterior facial height was better in surgical correction than through TADs. (AU)