Paranasal Sinus CT Scans Analysis of the Primary Maxillary Sinus Hypoplasia / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Identification of primary maxillary sinus hypoplasia (PMSH) is important diagnostically and therapeutically. Recently, the clinical significance of associated abnormalities in PMSH has been suggested. The aim of this study is to investigate the incidence of PMSH, their associated abnormalities and relationship of anatomical variations and paranasal sinusitis. MATERIALS AND METHODS: We evaluated radiologic diagnostic criteria of PMSH and analyzed the relationship of the anatomical variations of nasal cavity and paranasal sinuses in paranasal sinus CT scans, retrospectively. We measured the volume estimated ratio (VER) in PMSH cases. RESULTS: The incidence of unilateral and bilateral PMSH were 11 cases (5.9%) and 10 cases (5.3%). respectively. According to the Bolger's classification, there were 13 sites (41.9%) of type I with the mean VER of 0.71, 14 sites (45.2%) of type II with the mean VER 0.50, and 4 sites (12.9%) of type III with the mean VER of 0.27. The most common anatomical anomalies in both of the unilateral and bilateral PMSH were zygomatic (90.3%) and alveolar pneumatization (90.3%); the second most common abnormal finding was high maxillary sinus floor (77.4%). Of the anatomical variations, the frequency of uncinate process abnormalities (41.9%), paradoxical middle turbinate (32.3%) and Haller's cell (19.4%) were statistically significant. CONCLUSION: These results suggest that zygomatic and alveolar pneumatization, and high maxillary sinus floor are additionally important anatomical abnormalities associated with PMSH. Careful preoperative assessment of anatomical variations in the paranasal sinus CT scans may be essential to avoid incidental iatrogenic complications during functional endoscopic sinus surgery (FESS) or Caldwell-Luc operation in patients with PMSH.

Natural Dehiscence of Lamina Papyracea with Prolapse of Orbital Content: Radiologic Evaluation / 대한이비인후과학회지

BACKGROUND: Orbital complications may be occured by means of surgical injury to lamina papyracea during endoscopic sinus surgery or intranasal ethmoidectomy. The frequency of orbital complications increases when the natural dehiscence of lamina papyracea(NDLP) with or without prolapse of orbital content into ethmoid sinus is present. OBJECTIVES: The aim of this study is to evaluate the incidence and radiologic characteristics of NDLP, and to evaluate association NDLP with anatomical variations of nasal cavity and paranasal sinuses. MATERIALS AND METHOD: The axial and coronal paranasal sinus CT scans of 183 patients with chronic paranasal sinusitis(366 sides) who had undergone endoscopic sinus surgery were retrospectively reviewed and analyzed. The incidence and radiologic features of NDLP, and the association NDLP with anatomical variations of paranasal sinus and nasal cavity were analyzed. RESULTS: The NDLP was found in 18 patients(9.8%, n=183 patients) or 22 sides(6.0%, n=366 sides). The most common site of NDLP was superior portion(45.5%) in coronal image of paranasal sinus CT scans and anterior ethmoid sinus area(68.2%) in axial image. Grade 1 of NDLP(86.4%) was observed most commonly. NDLP was not associated with anatomical variations of paranasal sinus. CONCLUSION: The incidence of NDLP with prolapse of orbital content is far beyond general expectation, and close preoperative evaluation of paranasal sinus CT scans is important to avoid possible orbital complications.