Ultrasonic Diagnosis of Maxillary Sinus Diseases

Abstract

The patterns of 145 cases of patients who had received ultrasonic A-scans at the Osaka Dental University Hospital were compared with radiographic and operative findings.
The following results were obtained.
1) Normal echo patterns (N-type) were seen only in the initial echo. The correct diagnosis was obtained in 33 (82.5%) of the 40 normal maxillary sinuses. Seven (17.5%) of the patterns were false positive.
2) Typical cystic echo patterns (C-type) consisting of two peaks were seen between the initial and back wall echos. The correct diagnosis was obtained in 84.1% (69/82) of the postoperative maxillary cysts while 13 (15.9%) of the patterns were false negative.
3) The correct diagnosis was obtained in 90% (18/20) of the odontogenic cysts.
4) A back wall echo of the E-type was observed in cases of maxillary sinusitis with mucosal thickening and fluid retention. In mucosal thickening without fluid retention, a mucosal echo was observed due to the mucosa/air interface, and the back wall echo of the M-type disappeared. The correct diagnosis was obtained in 77.3% (17/22) of the cases of maxillary sinusitis.
5) Multiple and irregular echos were observed in one case of maxillary carcinoma.
6) Back wall echos were found in cases of normal maxillary sinuses. This was probably due to a small amount of fluid and slight mucosal thickening which could not be demonstrated by radiographic examination.
7) The negative findings in cases of postoperative maxillary cysts were caused by the specific location of the cyst, air in the sinus, and curved cyst walls.
From the above results it was determined that the use of ultrasonic A-scans is a useful adjunct in diagnosing maxillary sinus diseases.