Despite its clinical importance, the surface anatomy of the pterion is inconsistently reported. This study reappraises the surface marking of the pterion and its relationship to the middle meningeal artery (MMA). The position and morphology of the pterion were analyzed in the Frankfurt plane in 76 adult skulls and 50 adult cranial cone beam CT scans. Relationship to the anterior branch of the MMA was examined in the skulls. Measurement reproducibility was assessed in a 20% randomly selected sample. In the skulls, the majority of pteria were sphenoparietal (78%), followed by epipteric (16%) and frontotemporal (5%). The center of the pterion was a mean of 26 ± 4 mm behind and 11 ± 4 mm above the posterolateral margin of the frontozygomatic suture; measurements were reproducible and consistent between sides and genders. Distances from the frontozygomatic suture were slightly greater (29 and 16 mm, respectively) in cranial CTs. A one centimeter circle centered on the midpoint of the pterion overlapped the anterior branch of the MMA in 68% of skulls; the artery was a few millimeters posterior in the remainder. Mean skull thickness at the midpoint of the pterion was 4.4 mm compared to 1 mm at its thinnest point in the squamous temporal bone. In conclusion, in most adults, the pterion lies within a one centimeter diameter circle 2.6 cm behind and 1.3 cm above the posterolateral margin of the frontozygomatic suture (which is easily palpable in vivo). This region overlaps the anterior branch of the MMA in two-thirds of cases.

This study measured and assessed facial soft tissue depths (FSTDs) in adult female Chinese and New Zealand (NZ) Europeans (Caucasoids). Ultrasound was used to obtain depths at nine landmarks on 108 healthy subjects (51 Chinese, 57 NZ European), erect positioned, of same age group (18-29 years). Height and weight were also recorded. Statistical analysis focused on comparison of tissue depth between the two ancestry groups and the influence of Body Mass Index (BMI) (kg/m2). Results showed mean depth differences at Supra M2 and Infra M2 landmarks significantly greater for Chinese than Caucasoid women for all three BMI Classes (BMI<20, 20≤BMI<25, 25≤BMI<30), even BMI<20. For both groups BMI positively correlated with FSTD values at all landmarks except Labrale superius. This study enabled ancestry and BMI influence on FSTDs to be observed and compared for two distinct groups. Results add to knowledge about facial tissue depth variation.

The head is positioned erect for an approximation; yet most facial soft tissue depths (FSTD) used are measured from supine subjects. Depth difference might be significant, but there is a paucity of data to verify. This study compared erect and supine values for 17 landmarks from 30 healthy New Zealand (European population affinity) women (18-30 or 40-55 years) in erect then supine positions. Height, weight, and sonographic FSTD data, totaling 1020 measurements, were obtained. Three midline and seven averaged bilateral values were compared using ANOVA, p values, and Pearson's correlations. Correlative strength of age and body mass index, BMI (kg/m(2) ), was determined by values. Results showed averaged erect and supine differences were significant for four of ten FSTDs. Between individuals, difference was various and not unidirectional. In conclusion, depth differences were observed but not all significant or unidirectional, BMI significantly influenced nine FSTD values, but age group did not.