Inferior oblique muscle origin: horizontal location in relation to ala nasi and its gender difference.
We studied the horizontal location of the inferior oblique muscle (IOM) origin in relation to the ipsilateral ala nasi and compared the results between genders in 76 orbits of 38 Japanese cadavers. Consequently, the IOM origin was located 1.2 mm laterally to the vertical line through the lateral margin of the ipsilateral ala nasi. No significant difference was noted between genders (males, 1.3 mm; females, 0.9 mm; P = 0.257, Student t test) or between sides (right, 1.1 mm; left, 1.3 mm; P = 0.570, Student t test). In contrast, the mean interalae-nasi distance was 39.8 mm and was significantly greater in males than that in females (males, 40.8 mm; females, 38.6 mm; P = 0.049, Student t test). The ala nasi can be used as a reference point irrespective of gender or side for identifying the IOM origin during oculoplastic surgery.
Department of Ophthalmology, Aichi Medical University, Nagakute, Aichi, Japan.
Yasuhiro
Y
Takahashi
Hirohiko
H
Kakizaki
Kiwamu
K
Kohjima
Takashi
T
Nakano
Ken
K
Asamoto
Akihiro
A
Ichinose
Masayoshi
M
Iwaki
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000033:anatomy & histology*; D009915:Orbit / Q000033:anatomy & histology*; D010781:Photography; D012737:Sex Factors