利用核磁共振影像測量台灣成年人顏面軟組織厚度-臺大醫院病例之回溯性研究

Abstract

顏面重建是利用頭骨重現死者生前容貌的方法，而幾乎所有的顏面重建方法，皆須要有頭骨上不同位點的軟組織厚度的資料。先前研究指出，不同族群的顏面軟組織厚度各不相同，且具有顯著差異。就我們所知，目前臺灣並沒有這方面的資料。本研究的目的，是初步建構台灣地區族群的顏面軟組織厚資料庫。 本研究影像資料來源，是於2012年5月至2013年12月在國立臺灣大學醫學院附設醫院進行頭部核磁共振影像檢查的個案。本研究收集20歲至80歲男性及女性的頭部核磁共振影像資料，以DICOM軟體(RadiAnt DICOM Viewer)進行測量14個顏面中線測量點，及17個顏面側面測量點的軟組織厚度。 本研究共收集135個男性以及133個女性的影像資料的測量結果。受測者男性年齡範圍是24至80歲，平均年齡49.6歲，女性為27至75歲，平均年齡50.3歲。所有測量結果按照不同性別、年齡、身體質量指數（Body Mass Index, BMI）、齒顎顱顏形態(Orthodontic Skeletal Classification)進行分層。研究結果顯示，BMI對顏面軟組織厚度影響最大，每一個測量點的軟組織皆隨著BMI增大而增厚。性別影響方面，男性在大部分的測量點比女性要厚；年齡影響方面，結果並不一致，有些測量點會隨著年齡的增長而增厚(如Glabella、End of nasal、Suborbital、Mid lateral orbit)，有些則隨著年齡的增長而變薄(如Subnasal、Upper lip margin、Lateral glabella、Midphiltrum、Naso-labial ridge)，也有些測量點的軟組織厚度受年齡變化的影響不大。大部分測量點的軟組織厚度不受到齒顎顱顏形態的影響，但我們發現齒顎顱顏形態會影響皮膚表面測量點以及骨骼表面測量點之間的相對位置。另外，我們建立了迴歸公式，表現出不同因素對顏面軟組織厚度的影響。 在這研究中，我們建立了臺灣地區顏面軟組織厚度的資料庫，發現性別、年齡、BMI、齒顎顱顏形態對臉部不同部位的軟組織厚度的影響，並且建立了迴歸公式，使實務上顏面重建時，執業法醫師能更精準預測死者可能的顏面厚度。

Facial reconstruction is the approximation of an antemortem face from human skeletal remains. All of the reconstruction methods require the measurement of average tissue thicknesses at landmark on the face. Previous studies showed that different populations exhibit significant variation in facial tissue thickness. To our knowledge, there are no publications on soft tissue thickness in the Taiwanese population. The aim of this study was to create a reference database of facial tissue thickness in the Taiwanese population. The study material included those who had undergone brain MRI in National Taiwan University Hospital since May, 2012 to December, 2013. Measurements were taken at 14 points at the midline and at 17 points at the bilateral using DICOM software (RadiAnt DICOM Viewer). This study included 135 males (age range, 24-80 years; mean, 49.6 years) and 133 females (age range, 27-75 years; mean, 50.3 years). The measurement results were categorized according to sex, age group, BMI group and orthodontic skeletal classification. BMI value shows the greatest influence on facial soft tissue thickness. The higher BMI value, the thicker soft tissue thickness is at every landmark. Males have greater soft tissue thickness than females at most landmark. Age-related changes in soft tissue thickness are different among the landmarks. Tissue thickness at some landmarks shows decreasing with age (glabella、end of nasal、suborbital、mid lateral orbit) . There are also some landmarks show increasing with age (subnasal、upper lip margin、lateral glabella、midphiltrum、naso-labial ridge), while others presented the same values among different age groups. People of different orthodontic skeletal classes show little difference on tissue thickness at most of landmarks, however, orthodontic skeletal classes may influence the relative position between the soft tissue landmark and the skeletal landmark. We also create a linear regression model to present the various factors that affect facial soft tissue thickness and to estimate the thickness of a specific position. In this study, we not only established a reference database of facial tissue thickness in Taiwanese population, but also presented the influence of sex, age, BMI and orthodontic skeletal classes on facial soft tissue thickness of different facial landmarks. Furthermore, we created a linear regression model to help the practitioners to improve the estimation of individual soft tissue thickness in order to perform better facial reconstructions in real case.