Three-dimensional Analysis of Nasolabial Soft Tissues While Smiling Using stereophotogrammetry (3dMDTM)

Abstract

The nasolabial region is the central esthetic unit of the face and is considered one of the most important determinants of the facial esthetic. The facial morphometry of soft tissues is a very important tool in facial surgery. Advances have been made recently in the capture and analysis of 3D images, which offer great development potential in the diagnosis and treatment of facial deformities. The aim of this study was to characterize the nasolabial region of patient candidates for orthognathic surgery using 3D facial captures. A study was conducted to characterize the width of the nasal base and the nasolabial angle in adult patients through 3D photographs. 30 subjects were included, taking two 3D photos each, one in a resting position and the other smiling. The three-dimensional capture was done with the 3dMDface System. The measurements were taken with the 3dMD Vultus software. The length of the alar base was an average of 34.3 ± 2.6 mm at rest, and 39.1 ± 2.9 mm smiling. The mean of the nasolabial angle was 104.6 ± 9.6° at rest and 105.4 ± 14.3º smiling. Additionally, the distance of the alar base smiling compared to its distance at rest increased an average of 4.83 mm, whereas the nasolabial angle smiling increased an average of 0.8º compared to at rest. In this study, the nasolabial angle did not present any significant changes so that its assessments in the case of facial modifications can be standard; the width of the nasal base is significantly modified with the smile and thus a more intense study of any type of modification in this area is required.

Photographic Parameters in Three-Dimensional Facial Image Acquisition. A Scoping Review

“…Despite the considerable quantity of image acquisition systems presently employed for 3D photography, research use for this type of imaging is limited to a handful of devices, of which 2 are the most extensively utilized. First, we found that the most used system was the 3dMD, 10,[12][13][14][15][16][17][18][19][20][21][22][23][24] which consists of 2 groups of 3 cameras, each located at 45 degrees to the right and left side target, and was used by 52% of the authors, followed by the Vectra M3, [25][26][27][28][29][30][31][32] which consists of a device composed of 3 groups of 2 cameras each and was used by 28% of the authors. In contrast, some other systems were used by some authors.…”

“…In contrast, most of the authors used chairs with high backs to improve back support, reducing variations due to mobility or changes in body posture. [12][13][14][15][16]18,19,25,[27][28][29][30][31][32][33]36,37,41 Head Posture Riml et al (2011) 42 showed the influence of head position on facial analysis, noting that different postures yield different results in measurements on facial photographs. In this study, most authors describe the positioning of the head for image acquisition as: "natural head position," (NHP) noting that this is a reproducible and proven position, described as "the head positioned in a relaxed manner while the person observes a fixed point on the horizon."…”

“…Parra et al (2021) 20 evaluated the changes that occur in the middle third of the face during smiling. 13 Riml et al (2011) 42 showed the influence of some expressions on the measurements made on the facial photographs, observing some differences depending on the facial expression. In this study, some authors agree that the facial expression should be neutral and relaxed, with the lips gently closed.…”

Avaliação da morfologia do mento após cirurgia ortognática bimaxilar: estudo retrospectivo utilizando estereofotogrametria

“…Embora, alcançar a precisão adequada seja difícil, a análise com essa tecnologia 3D pode gerar bons resultados além de permitir melhores abordagens (PARRA M et al,2019).…”

“…Dentre os métodos existentes, a estereofotogrametria ou foto 3D é um método não invasivo que permite uma reprodução tridimensional precisa das estruturas faciais. Embora, alcançar a precisão adequada seja difícil, a análise com essa tecnologia 3D pode gerar bons resultados além de permitir melhores abordagens (PARRA M et al, 2019).…”