Normative Findings for Periocular Anthropometric Measurements among Chinese Young Adults in Hong Kong

Measurement of periocular structures is of value in several clinical specialties including ophthalmology, optometry, medical and clinical genetics, oculoplastic surgery, and traumatology. Therefore we aimed to determine the periocular anthropometric norms for Chinese young adults using a noninvasive 3D stereophotography system. Craniofacial images using the 3dMDface system were acquired for 103 Chinese subjects (51 males and 52 females) between the ages of 18 and 35 years. Anthropometric landmarks were identified on these digital images according to standard definitions, and linear distances between these landmarks were calculated. It was found that ocular measurements were significantly larger in Chinese males than females for intercanthal width, biocular width, and eye fissure lengths. No gender differences were found in the eye fissure height and the canthal index which ranged between 43 and 44. Both right and left eye fissure height-length ratios were significantly larger in females. This is the first study to employ 3D stereophotogrammetry to create a database of anthropometric normative data for periocular measurements. These data would be useful for clinical interpretation of periocular pathology and serve as reference values when planning aesthetic and posttraumatic surgical interventions

Stereophotogrammetry-based facial depth measurements: a novel method for quantifying facial projection

BACKGROUND: Orthognathic surgery leads to alteration of the spatial relationship of the mandible and maxilla resulting changes in the degree of facial projection. Traditional 2-dimensional cephalometry and photographic techniques do not provide data on facial depth. Though stereophotogrammetry can be used as a noninvasive method for evaluating facial depth, the unavailability of ethnicity-specific norms hinder its routine use in clinical practice. The objectives of this study were to (a) generate an analytic scheme suitable for evaluating facial depth using stereophotogrammetry and (b) create normative data for the facial depth measurements for young Hong Kong Chinese adults. METHODS: Stereophotographic images from 41 male and 45 female ethnic Chinese young adults without facial deformities were analyzed. Facial depth measurements were performed based on standard anthropometric landmarks, with the aid of 3dMDVultus software. RESULTS: All facial depth measurements were found in absolute terms to be significantly higher in males. In contrast, the upper face, maxillary, and sublabial depth indices were significantly higher in females, whereas no significant gender differences emerged for lower facial and maxillomandibular indices. CONCLUSIONS: A novel method of using stereophotographic images for quantifying facial depth was evaluated. Normative facial depth measurements for young Hong Kong Chinese adults were established. This gender-specific database can be used as a reference in the diagnosis, treatment planning, or evaluation of outcomes after surgical correction of facial deformities

How Accurate Are the Fusion of Cone-Beam CT and 3-D Stereophotographic Images?

Abstract Background: Cone-beam Computed Tomography (CBCT) and stereophotography are two of the latest imaging modalities available for three-dimensional (3-D) visualization of craniofacial structures. However, CBCT provides only limited information on surface texture. This can be overcome by combining the bone images derived from CBCT with 3-D photographs. The objectives of this study were 1) to evaluate the feasibility of integrating 3-D Photos and CBCT images 2) to assess degree of error that may occur during the above processes and 3) to identify facial regions that would be most appropriate for 3-D image registration

Are neoclassical canons valid for southern Chinese faces?

BACKGROUND: Proportions derived from neoclassical canons, initially described by Renaissance sculptors and painters, are still being employed as aesthetic guidelines during the clinical assessment of the facial morphology. OBJECTIVE: 1. to determine the applicability of neoclassical canons for Southern Chinese faces and 2. to explore gender differences in relation to the applicability of the neoclassical canons and their variants. METHODOLOGY: 3-D photographs acquired from 103 young adults (51 males and 52 females) without facial dysmorphology were used to test applicability of four neoclassical canons. Standard anthropometric measurements that determine the facial canons were made on these 3-D images. The validity of the canons as well as their different variants were quantified. PRINCIPAL FINDINGS: The neoclassical cannons seldom applied to these individuals, and facial three-section and orbital canons did not apply at all. The orbitonasal canon was most frequently applicable, with a frequency of 19%. Significant sexual dimorphism was found relative to the prevalence of the variants of facial three-section and orbitonasal canons. CONCLUSION: The neoclassical canons did not appear to apply to our sample when rigorous quantitative measurements were employed. Thus, they should not be used as esthetic goals for craniofacial surgical interventions

3-D hard and soft tissue images generated by Cone-beam CT.

<p>3-D hard and soft tissue images generated by Cone-beam CT.</p

The <i>3dMDface</i> stereophotograhic system.

<p>The <i>3dMDface</i> stereophotograhic system.</p

The matching of Cone-beam CT soft tissue and stereophotograhic images during registration.

<p>Initial manual aligning (a) is followed by automated registration (b).</p