title: An investigation of the variability between the optic plane and Frankfort horizontal.
abstract: Frankfort horizontal is commonly constructed on a lateral cephalogram from the top of the ear rod to orbitale. Ear rod positioning and identification of orbitale present obvious variables with such a reference plane. The optic plane has been proposed as a more accurate representation of Frankfort horizontal. Using fifty dry skull cephalograms and fifty cephalograms of patients, this study investigated whether the optic plane is more reliable than ear rod to orbitale Frankfort horizontal in determining anthropologic Frankfort horizontal on a lateral cephalogram. The optic plane was found to be significantly different from anthropologic Frankfort horizontal and was not found to be significantly less variable than ear rod to orbitale Frankfort horizontal.
mesh_terms: D000885:Anthropology, Physical; D002508:Cephalometry / Q000379:methods*; D004431:Ear, External / Q000033:anatomy & histology; D005123:Eye / Q000033:anatomy & histology; D006801:Humans; D009915:Orbit / Q000033:anatomy & histology