title: Classification of suprabullar pneumatization according to the skull base attachment of the second lamella.
abstract: The skull base attachment of the second lamella and suprabullar pneumatization are likely to be consistent landmarks if they are systematically classified. This study aimed to classify the pneumatization pattern according to the second lamella skull base attachment. A total of 202 computed tomography sides of 101 patients who underwent endoscopic sinus surgery were studied. Suprabullar pneumatization was defined as air cells present above the ethmoid bulla between the second and third lamellae. Its pattern was classified according to the air cell number and location as in the frontal cell classification. Type 0 suprabullar pneumatization was defined as no air cells between the ethmoid bulla and skull base; type 1, as a single suprabullar cell; and type 2, as multiple suprabullar cells above the ethmoid bulla. In type 3 pneumatization, the second lamella extended into the frontal sinus forming a frontal bullar cell. Type 2 was the most prevalent (40.1 %), followed by types 1, 3, and 0 (24.3, 23.3, and 12.4 %, respectively). The distance between the second lamella and anterior ethmoid artery was 8.93, 8.30, 8.50, and 11.25 mm in types 0, 1, 2, and 3 pneumatization, respectively. No patients had intraoperative injuries in the anterior ethmoid artery or lateral lamella. The second lamella skull base attachment and suprabullar pneumatization pattern could be systematically classified and be a consistent landmark to identify the frontal sinus opening.
authors.affiliation: Department of Otorhinolaryngology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Keng Lu
authors.initials: KL
authors.lastname: Tan
authors.affiliation: Department of Otolaryngology, National Police Hospital, Seoul, South Korea.
authors.forename: Woo Hyun
authors.initials: WH
authors.lastname: Lee
authors.affiliation: Department of Otorhinolaryngology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 173 Gumi-ro, Bundang-gu, Seongnam, Gyeonggi-do, 463-707, South Korea. kimemail@snu.ac.kr.
authors.forename: Jeong-Whun
authors.initials: JW
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059925:Anatomic Landmarks; D004724:Endoscopy; D005005:Ethmoid Sinus / Q000033:anatomy & histology* / Q000098:blood supply / Q000000981:diagnostic imaging; D005260:Female; D005626:Frontal Sinus / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D019291:Skull Base / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Anterior ethmoid artery; Chronic rhinosinusitis; Endoscopic sinus surgery; Frontal recess; Suprabullar pneumatization