Effect of Micro Implant Anchorage on Hard Tissue and Soft Tissue Indexes in the Treatment of Class II 1 Malocclusion

  • Xuelian Yin
Keywords: Micro Implant Anchorage, class II Division 1 malocclusion (occlusion), hard tissue, soft tissue

Abstract

To investigate the effect of Micro Implant Anchorage on the hard and soft tissue indexes in the treatment of
class II 1 malocclusion. 118 patients with class II Division 1 malocclusion (occlusion) treated in our hospital
from March 2016 to April 2018 were randomly divided into experimental group and control group, 59 cases in
each group. Patients in the control group were treated with traditional external arch anchorage, while patients in
the experimental group were treated with micro implant anchorage. Record and analyze the treatment time of
both groups, and compare the changes in hard tissue related indexes [(SNA, SNB, ANB, GoGn-SN,
OP-SN)],soft tissue related indexes [lip protrusion, lip protrusion, vertical distance from the point of upper lip
protrusion to E-line (U lip - E), vertical distance from the lower lip point to the E-line (L lip - E), the angle
between the tangent line of the chin front point and the upper and lower lip point and the plane of the eye and
ear (Z angle)], tooth-related indexes [angle between the long axis of the upper central incisor and the Sn plane
(u1-sn), vertical distance from the cutting edge of the upper central incisor to the line Na (u1-na), vertical
distance from the APG line to the cutting edge of the upper central incisor (apg-u1), vertical distance from
posterior edge of the pterygoid maxillary fissure to the distal and middle adjacent surfaces of the upper
molar(PTM - U6)] as well as relevant indicators for model measurement {Anterior teeth coverage (OJ), overlap
(occlusion) [OB]} before and after the treatment. Compared with the control group, the treatment time of the
experimental group was significantly shorter (P < 0.05). Compared with the pre-treatment group, the op-sn of
both groups decreased significantly (P < 0.05), and compared with the control group, the op-sn of the
experimental group decreased significantly (P < 0.05) after the treatment. There was no significant difference in
SNA, SNB, anb and gogn Sn between both groups (P > 0.05). Compared with the control group, the soft tissue
indexes of both groups were significantly lower in the upper lip protrusion and lower lip protrusion, and the Z
angle was significantly higher (P < 0.05) after the treatment; compared with the control group, the experimental
group was significantly lower in the upper lip protrusion and lower lip protrusion, and the Z angle was
significantly higher (P < 0.05). There was no significant difference between both groups (P > 0.05) after the
treatment. Compared with the control group, u1-na, apg-u1 and ptm-u6 in the experimental group decreased
significantly (P < 0.05). There was no significant difference in u1-sn between both groups (P > 0.05) after the
treatment. Compared with the conditions before the treatment, OJ and OB were significantly reduced in both
groups after the treatment (P <0.05). The OJ and OB related parameters were significantly lower in the
experimental group than in the control group after treatment (P <0.05). The clinical effect of implant anchorage
in the treatment of class II Division 1 malocclusion is ideal. It can significantly improve the facial profile,
shorten the operation time, and reduce the pain of patients. It is worthy of clinical application and promotion.

Published
2020-02-01