Anchorage Efficacy of Palatally-inserted Miniscrews in Molar Distalization with a Periodontally/Miniscrew-anchored Distal Jet

Abstract

Titanium miniscrews with a polished surface, 1.6 mm in diameter and 8-9 mm long, do not provide stationary anchorage in molar distalization with the periodontally/miniscrew-anchored Distal Jet. When subjected for several months to load from forces that act in reciprocity to the force systems occurring during molar distalization, they fail to remain completely stationary in position in the palatal locations in which they were inserted. However, the combined anchorage setup is sufficient, intraorally and regardless of patient compliance, to largely compensate for the mesially-acting forces that occur reciprocal to molar distalization.

Skeletal versus conventional intraoral anchorage for the treatment of class II malocclusion: dentoalveolar and skeletal effects

“…Our findings are in agreement with those of Kinzinger et al [17] who, utilizing a distal jet supported by two palatally inserted miniscrews, reported a mean anchorage loss of 0.71 ± 0.78 mm at the level of the first premolar and 0.36 ± 0.32 mm at the level of the central incisors.…”

“…There are various possible reasons for this. As reported by Kinzinger et al [17] and Liou et al [18], palatal miniscrews may, due to absence of osseointegration and the elasticity of the bone, show small movements when stressed by orthodontic forces. Another important factor to consider is the reduced stiffness of the anchoring system to which the miniscrews are connected.…”

Optimal force magnitude loaded to orthodontic microimplants: A finite element analysis

“…Liou et al 7 found significant screw displacement after applying immediate forces of 400 g. Others found displacement to occur at even lower force levels. 8,9 Wang et al 10 found that screw displacement was not correlated with force magnitudes of 200 g to 425 g and that beyond this range, other consequences might ensue. When an excessive load is applied, partly osseointegrated microimplants can become extremely mobile and eventually fail.…”

Avaliação cefalométrica comparativa do tratamento da má oclusão de Classe II com o distalizador first class em ancoragem convencional e esquelética e aparelho extrabucal cervical seguidos de aparelho fixo

“…A ancoragem sempre foi considerada um desafio no tratamento com os distalizadores intrabucais (BAE et al, 2002;PROFFIT, 1995) visto que a utilização do botão de Nance, um dispositivo intrabucal e dentomucossuportado, na ancoragem convencional não é suficiente para impedir que os efeitos de reação das forças distalizadoras atuem nos dentes de suporte promovendo perda de ancoragem ARAÚJO et al, 2006;BOLLA et al, 2002;BRICKMAN;SINHA;BUSSICK;DARENDELILER, 1997;CHIU;FRANCHI, 2005;FORTINI et al, 2004;FUZIY et al, 2006;NANDA, 1996b;GULATI;PARKASH, 1998;HAYDAR;UNER, 2000;HILGERS, 1992;WHITE, 1992;SEZEN, 2003;KINZINGER et al, 2008;BOWMAN, 2006;MAVROPOULOS et al, 2005;MAVROPOULOS et al, 2006;NGANTUNG;BOWMAN, 2001;PATEL et al, 2009;RUNGE;MARTIN;BUKAI, 1999;TOROĞLU et al, 2001).…”

“…Estudos recentes se propuseram a combinar os diferentes aparelhos distalizadores com ancoragem em mini-implantes (ESCOBAR et al, 2007;GELGOR et al, 2004;SEZEN, 2003;KINZINGER et al, 2008;KIRCELLI, 2006;KYUNG et al, 2003;OBERTI et al, 2009;ÖNÇAĞ et al, 2007;LEE;KWON, 2005;TSUBONO, 2005), mostrando resultados animadores, pois não houve perda de ancoragem (GREC et al, 2013).…”