True vertical validation in facial orthognathic surgery planning

Abstract

Objectives: To validate the effectiveness of the original standards of True Vertical (TV) Subnasal Line in orthognatic surgery planning. The present study evaluates the changes occurring in patients with skeletal Class II alterations programmed for orthognathic surgery with a view to improving their facial profile. Study design: We showed a series of black profiles (composed by a first control group of subjects with normal occlusion, and another two additional groups comprised patients before –Group 2- and after orthognatic surgical correction of Class II malocclusion -Group 3-) for three groups of observers (orthodontists, surgeons and laypeople). The facial images became black silhouettes in order to determine a series of parameters (including aesthetic assessment) by means of the observers. Their observation were assessed using a 5-point Likert scale. Results: The sample was composed of 52 profile’s subjects who were tested for a total of 72 observers. Aesthetic assessment yielded mean scores of 2.57, 1.67 and 2.46 for groups 1, 2 and 3, respectively. There was a statistically significant difference (p<0.001) between group 1 versus group 2. There were no significant differences in terms of observer assessment of aesthetics, with the exception of a wider perception range among the orthodontists. Regarding the studied profile measures, significant differences were recorded for point B’ and Pg’ (p<0.02) between groups 2 and 3 (i.e., pre- versus post-surgery). Conclusions: The results of our study suggest the subnasale vertical and sagittal measures of the lower third of the face are decisive in facial aesthetics, and therefore also for the planning of orthognathic surgery. Consequently, these aesthetic parameters can be used as an objective tool for the planning of orthodontic treatment. Key words:Facial profile, Class II, orthognathic surgery, cephalometric analysis, facial soft tissue, subnasale vertical.

Association between Lateral Cephalometric Changes in X-Y Coordinate System and Profile Changes among Skeletal Class III Patients after Orthognathic Surgery

“…In the Espinar study (class II patients), only horizontal displacements of points Ils and Pog’ had the most effect on the profile. 8 In the present study, we observed that the higher the B point, the lower the PNS point, and the more the anterior point A, the better the profile would be. In the study of Marchiori et al , participants’ profile was not correlated with magnitude of NLA angle.…”

“…In Espinar et al's research (Class II patients), the highest displacements were in the lower third of the face; and Ils, Li, and Pog' points showed the most significant changes (horizontal dimension). 8 In a study by Altung Atac et al (double-jaw surgery for Class III patients), the most changes were in the horizontal and vertical dimensions in the mentolabial angle and the chin. On the other hand, nose and upper lip areas had the least changes in these surgeries and questioned the necessity of maxillary surgery in the patients.…”

“…In Espinar et al ’s research (Class II patients), the highest displacements were in the lower third of the face; and Ils, Li, and Pog’ points showed the most significant changes (horizontal dimension). 8 …”

Orthodontic camouflage versus orthodontic-orthognathic surgical treatment in class II malocclusion: a systematic review and meta-analysis

“…Compared to other reference lines for the lip position, the E-line appears very convenient due to its anterior location, although it has limitations in terms of consistency and sensitivity 37 . Therefore, the true vertical subnasal line may be preferable, due to its independence from the position of the chin and also because it overcomes the limitations of other reference planes 38 . Future studies should include this type of reference for sagittal aesthetic measurements.…”

Orthodontic–surgical strategy in 2016

“…-To account for the transversal and vertical dimensions of treatment with their relative functional importance. This is being proposed more often and allows a more systematic correction even for slight anomalies 15,21,26,30 .…”