Fibrous Dysplasia-Like Appearance of the Frontal Process of the Maxilla on CT: Prevalence in North China

Abstract

SUMMARY:The frontal process of the maxilla occasionally shows a localized FD-like appearance. The purpose of this study was to determine its prevalence and findings on CT. A retrospective study of 1000 consecutive paranasal sinus CT scans was preformed on outpatients without a history of trauma or previous surgery in our hospital during 6 months. CT images were interpreted independently by 2 experienced head and neck radiologists on a PACS system in a bone window setting. Of the 1000 patients (546 males; 454 females), 51 (5.1%,41 males and 10 females) had an FD-like appearance in the frontal process of the maxilla. There was a statistically significant difference between sexes (P Ͻ .001). Twenty-nine (56.9%) entities arose from the right frontal process and 22 (43.1%) from the left frontal process. These entities, with well-defined margins, were located at the base of the frontal process of the maxilla, appearing as an ovoid or triangular configuration on axial-plane CT and as a spindle or elliptic shape on the coronal plane. The mean maximal diameter was 9.8 mm (range, 3.6 -16.1 mm). These entities exhibited a pagetoid appearance (type I) in 37 (72.5%), a ground-glass appearance (type II) in 8 (15.7%), and a cyst-like appearance (type III) in 6 (11.8%) patients on CT. The FD-like appearance of the frontal process of the maxilla is not rare and can be readily detected by CT. ABBREVIATIONS: FD ϭ fibrous dysplasia During the past 10 years, we have incidentally encountered a few people with an FD-like appearance of the frontal process of the maxilla by paranasal sinus CT in our daily practice. These individuals usually presented to the ear, nose, and throat clinic with rhinosinusitis symptoms and underwent paranasal sinus CT scans. On the basis of outpatient medical records, they had no facial deformities on physical examination. To the best of our knowledge, no relevant studies on the subject have been reported in the literature to date.1-6 Knowledge of the osseous appearance in this region could help radiologists and clinicians increase their awareness of the variant or asymptomatic FD, avoiding confusion with tumor or infection. For us, there has been some recent interest in the appearance of the frontal process of the maxilla. This prompted our study to determine the prevalence and features of it on paranasal sinus CT scans of outpatients in North China. Materials and Methods PatientsThis study was approved by the institutional review board. A retrospective review of paranasal sinus CT scans of 1000 consecutive outpatients who were consecutively selected by a PACS system in our hospital between August 1, 2008, and January 31, 2009, was performed. All these patients were referred for CT due to clinical symptoms, presumably rhinosinusitis. Their clinical medical records were reviewed, and they had no history of trauma or prior surgery. CT TechniqueCT images were acquired in both the axial and coronal planes by using a Brilliance 64-section CT scanner (Philips Healthcare, Best, the Netherlands). The imaging parame...

Fibrous dysplasia of the paranasal sinuses: case report

“…Albright described fibrous dysplasia (FD) for the first time in 1937 as a condition where normal bone is progressively replaced by fibrous tissues resulting in bone weakness that makes it fragile and prone to fractures. 1 It is a congenital, non-hereditary, chronic disorder that affects the skeletal system. The disease shows no gender predilection as it affects equally both males and females.…”

“…Most cases, about 75%, are reported in young individuals aged under 30 years. 1 The disease occurs mainly among children as it begins in the childhood and continues throughout puberty and adolescence. It was believed that the disease goes dormant in early adult life, but recent research seems to support the idea that fibrous dysplasia may progress to adulthood.…”

Endoscopic endonasal open reduction for fractures of the frontal process of the maxilla

“…4,5 The FPM covers the anterior half of the lacrimal sac and contributes to the osseous part of the nasolacrimal duct. 1,6 Therefore, severe FFPM have the potential to cause damage to adjacent structures, inducing ophthalmic diseases such as acute dacryocystitis. 7 FFPM may also be combined with nasal bone fractures (NBF).…”

“…The frontal process of the maxilla (FPM) is an irregularly shaped extension of the maxilla. 1 It is connected medially to the nasal bone by a fibrous aponeurosis, which is also the composite part of the complex structure of the nasal pyramid. 2,3 Fractures of the FPM (FFPM) can cause severe facial deformities such as traumatic telecanthus.…”