title: Geometrical interpretation for abnormal facial behaviour with possible correction of angle S-N-A and S-N-B.
abstract: The orientation of the sella nasion (SN) line in lateral skull radiographs is important for accurate assessment of antero-posterior and vertical facial relationship. Lateral skull radiographs of a random sample were traced and digitized to produce a mean shape template of the sample, with the craniofacial centroid line (CFC) used as a base for superimposition of the sample. A geometrical triangle was formed using the sella nasion line, craniofacial centroid line and the mandibular plane as the sides of the triangle. Simple geometric calculations were done to re-orient both the mandibular plane and sella nasion line in cases with balanced clinical profiles, while the S-N-A and S-N-B measurements indicate otherwise.
authors: Department of Orthodontics, King Saud University College of Dentistry, Riyadh, Kingdom of Saudi Arabia.
authors: O A
authors: OA
authors: Sarhan
authors: K M
authors: KM
authors: al-Balkhi
mesh_terms: D002508:Cephalometry / Q000592:standards*; D002648:Child; D005147:Facial Bones / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D011859:Radiography; D012016:Reference Values; D012399:Rotation; D012886:Skull / Q000033:anatomy & histology* / Q000000981:diagnostic imaging