title: Characteristics of intranasal structures for endonasal dacryocystorhinostomy in asians.
abstract: OBJECTIVE
  To describe the anatomic characteristics of structures adjacent to the lacrimal sac fossa and the standardized osteotomy method for endonasal dacryocystorhinostomy in Asians.
  
  
  METHODS
  Retrospective noncomparative observational case series study.
  
  
  METHODS
  One hundred fifty-two eyes of 76 patients who had normal orbit computed tomographic scans were enrolled. The relationships of the uncinate process, the operculum of the middle turbinate, and the agger nasi cell to the lacrimal sac fossa were analyzed. Bone thickness and proportion of the frontal process of the maxilla in the lacrimal sac fossa was also evaluated.
  
  
  RESULTS
  The uncinate process was attached to the lacrimal sac fossa in 152 cases (100%) at the lower level of the fossa. The operculum of the middle turbinate was attached to the lacrimal sac fossa in 142 cases (93.4%), with wide positional variation. The agger nasi cell was adjacent to the lacrimal sac fossa in 118 cases (77.6%). The descent of the operculum of the middle turbinate relative to the lacrimal fossa had a strong correlation with the descent of the agger nasi cell (P < .001). The height and length of the nasal bone had a significant negative correlation with the thickness of the frontal process of the maxillary bone (P < .001).
  
  
  CONCLUSIONS
  The uncinate process, operculum of the middle turbinate, and agger nasi cell should be removed for sufficient osteotomy in a significant portion of Asian patients during dacryocystorhinostomy. A thick frontal process of the maxilla can be anticipated for the patient with a low nasal bridge. Further studies on the variation in intranasal procedures and the success rate of endonasal dacryocystorhinostomy need to be established.
authors.affiliation: Department of Ophthalmology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Korea.
authors.forename: Kyung In
authors.initials: KI
authors.lastname: Woo
authors.affiliation: Department of Ophthalmology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Korea.
authors.forename: Hyo-Sung
authors.initials: HS
authors.lastname: Maeng
authors.affiliation: Department of Ophthalmology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Korea. Electronic address: ydkimoph@skku.edu.
authors.forename: Yoon-Duck
authors.initials: YD
authors.lastname: Kim
mesh_terms: D000328:Adult; D044466:Asian People; D003608:Dacryocystorhinostomy; D005260:Female; D006801:Humans; D007723:Korea; D008297:Male; D008437:Maxilla / Q000000981:diagnostic imaging; D009295:Nasal Bone / Q000000981:diagnostic imaging; D009296:Nasal Cavity / Q000000981:diagnostic imaging; D009301:Nasolacrimal Duct / Q000000981:diagnostic imaging*; D009915:Orbit / Q000000981:diagnostic imaging*; D010030:Ostomy; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014420:Turbinates / Q000000981:diagnostic imaging; D055815:Young Adult