Glabellar vertical line as a reference goal for anteroposterior maxillary position

Carruitero, Marcos J.; Ambrosio-Vallejos, Ximena M.; Flores-Mir, Carlos

doi:10.1590/2177-6709.24.3.45.e1-5.onl

ABSTRACT

Objective:

The aim of this study was to evaluate the use of glabellar vertical line (GVL) as the anteroposterior maxillary position goal.

Methods:

A cross-sectional study was conducted assessing 129 participants (20.21 ± 1.99 years): 67 women (20.16 ± 1.99 years), and 62 males (20.26 ± 2.06 years). The facial profile photographs were taken with a posed smile in natural head position. The linear distance from the most facial convexity of the upper central incisor (FA) to the goal anterior-limit line (GALL) and also from FA to GVL were measured and compared. Wilcoxon signed-ranks test was applied. To determine the correlation between the distances, Spearman’s correlation coefficient was used. Simple and multiple linear regression were also performed.

Results:

The GALL-GVL separation was 0.54 ± 1.14 mm (95%CI: 0.34-0.74). A strong correlation between FA-GALL and FA-GVL distances (Spearman’s rho=0.983 [95%CI: 0.976-0.988], p< 0.01) was identified. The FA-GVL distance explains almost all the total variation of FA-GALL (R²=95.84%, p< 0.01). The FA-GALL distance can be predicted by using the formula: FA-GALL=0.5+0.9*(FA-GVL).

Conclusion:

These findings suggest that GVL could be used as an easier-to-use treatment goal to determine the maxillary anteroposterior position, compared to GALL, to improve facial harmony profile goals in cases where the maxillary incisors are properly positioned anteroposteriorly.

Keywords:
Facial profile; Diagnosis; Orthodontics; Orthognathic surgery

[1] Contact address:
Marcos J. Carruitero Antenor Orrego Private University, School of Stomatology América Sur Av. #3145 Monserrate, Trujillo, Peru E-mail: mcarruiteroh@upao.edu.pe, m_carruitero@hotmail.com

Variable	Calibration	Statistical test	95% confidence interval	P value
		Kappa
Type of forehead	Intraexaminer	0.836	(0.444-1.000)	<0.001*
Type of forehead	Interexaminer	1.000	(1.000-1.000)	<0.001*
		ICC
FA-GVL distance	intraexaminer	0.929	(0.729-0.982)	<0.001*
FA-GVL distance	interexaminer	0.959	(0.837-0.990)	<0.001*
FFA -FA distance	intraexaminer	0.962	(0.853-0.990)	<0.001*
FFA -FA distance	interexaminer	0.976	(0.905-0.994)	<0.001*
Forehead inclination	intraexaminer	0.998	(0.991-1.000)	<0.001*
Forehead inclination	interexaminer	0.996	(0.985-0.999)	<0.001*
FA-GVL distance	intraexaminer	0.928	(0.596-0.983)	<0.001*
FA-GVL distance	interexaminer	0.960	(0.844-0.990)	<0.001*
FA-GALL distance	intraexaminer	0.998	(0.991-1.000)	<0.001*
FA-GALL distance	interexaminer	0.996	(0.985-0.999)	<0.001*

Groups		Distance	n	Mean (mm)	SD	Mean difference (FA-GALL) - (FA-GVL)/GALL-GVL distance	SD of the mean difference	95% Confidence Interval of the difference	P value	Spearman correlation coefficient	95% Confidence Interval of the correlation	P value
Total		FA-GALL	129	0,09	4,78	0.54	1.14	(0.34-0.74)	<0.001^ⱡ	0.983	(0.976 -0.988)	<0.001*
		FA-GVL	129	-0,44	5.26
Sex	Female	FA-GALL	67	-0,28	5,08	0,64	1,25	(0.33-0.94)	<0.001^ⱡ	0.981	(0.969-0.988)	<0.001*
		FA-GVL	67	-0,92	5,63
	Male	FA-GALL	62	0,5	4,43	0,44	0,99	(0.18-0.70)	<0.001^ⱡ	0.993	(0.972-0.990)	<0.001*
		FA-GVL	62	0,86	4,83
Age groups	18 to 21 years	FA-GALL	87	-0,3	4,81	0,56	1,13	(0.31-0.80)	<0.001^ⱡ	0.980	(0.969 -0.987)	<0.001*
		FA-GVL	87	-0,86	5,3
	22 to 24 years	FA-GALL	42	0,91	4,66	0.51	1,16	(0.15-0.87)	0.002^ⱡ	0.986	(0.975 -0.993)	<0.001*
	FA-GVL	42	0,4	5,16