title: [Two efferent ducts of frontal sinuses--an antomical variant].
mesh_terms: D005004:Ethmoid Bone / Q000002:abnormalities / Q000196:embryology; D005626:Frontal Sinus / Q000002:abnormalities* / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000196:embryology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D014054:Tomography
vernacular_title: Zweifache Ausführungsgänge der Stirnhöhlen--eine anatomische Variante.