The Effect of Upper Incisor Anteroposterior Position Changes on the Lip Profile in Class I Malocclusion

DOI

10.2991/idcsu-17.2018.56How to use a DOI?

Keywords

Class I malocclusion, lip position, upper incisor position, pterygomaxillary vertical (PMV)

Abstract

Soft tissue analysis has always been an integral part of the diagnosis and planning of orthodontic treatment. Treatment plans in Class I malocclusions, with or without the extraction of the first four premolars are still debated, since the perceived premolar extraction effect will be "flattening face". The Pterigomaxillary Vertical (PMV) reference line is used for evaluation of soft-tissue and hard-tissue position changes in this study. Cross-sectional research design of the cephalogram before and after treatment of forty subjects measured the linear change of incisor position and then evaluated its effect on lip position. There is a change in the position of the upper incisor over the lip position in the non-extraction treatment of Class I malocclusions and by the extraction of the first four premolar treatments, which also affect the nasolabial angle. In non-extraction Class I malocclusion treatment, 1 mm of incisor retractions will change the position of the lips posteriorly as far as 0.034 mms and increase the nasolabial angle of 1.79°. In the treatment of Class I malocclusion with the extraction of the first four premolars, 1 mm of incisor retractions will change the position of the lips posteriorly as far as 0.067 mms and increase the nasolabial angle of 2.87°. The anteroposterior upper incisor position change not only affects the position of the upper lip alone, but also influences the nasolabial angle. In this study, changes in lip position on S-Line were unaffected by the changes of the incisor positions before and after treatment.

Copyright

© 2018, the Authors. Published by Atlantis Press.

Open Access

This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

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TY  - CONF
AU  - Okky Windyasari
AU  - Muslim Yusuf
PY  - 2018/02
DA  - 2018/02
TI  - The Effect of Upper Incisor Anteroposterior Position Changes on the Lip Profile in Class I Malocclusion
BT  - Proceedings of the International Dental Conference of Sumatera Utara 2017 (IDCSU 2017)
PB  - Atlantis Press
SP  - 215
EP  - 218
SN  - 2468-5739
UR  - https://doi.org/10.2991/idcsu-17.2018.56
DO  - 10.2991/idcsu-17.2018.56
ID  - Windyasari2018/02
ER  -