Tomography in the Region of the Maxillary Sinuses

Abstract

The purpose of this paper is to present the normal tomographic landmarks in the region of the maxillary antra and to compare them with certain abnormalities of these parts. The work now reported is part of a more complete study to be published later. Although tomograms do not give distinct and detailed views of bony structures, they have the advantage of disclosing features which are obscured in ordinary roentgenograms by overlying and underlying bony structures and by certain soft tissues. Especially is this true in the field of cancer. While serving as a visiting fellow of the Chicago Tumor Institute in 1938, Felix Leborgne of Montevideo, Uruguay, constructed a simple tomographic apparatus similar to one he had designed and previously described. The main features of this unit are its simplicity and economy. So far as we know, it was the first equipment of this type installed in this country. A review of the literature of tomography discloses numerous publications, but for the most part these are limited to case reports. Leborgne (1, 2, 3) was the first to publish comprehensive studies of tomography with reference to abnormalities in a limited anatomical field, namely, cancer of the larynx. Caulk (4) has also contributed to the subject. Moore (5, 6, 7) has written extensively on the value of this type of roentgenography and is a pioneer in the field. In dental radiography the value of the tomogram has been demonstrated in temporomandibular joint abnormalities by Costen (8), Peyrus and Aubert (9), and Pippin and his associates (10). Cone, Moore, and Dean (11) have reported on the use of tomography of the paranasal sinuses in ocular disorders due to disease of these chambers. Epstein (12) has recently published a report on the tomographic study of skull abnormalities. Abnormalities of the skull, larynx, and lungs are especially well shown by this technic. We have made a series of tomographic films at 0.5-cm. levels through the head of an adult cadaver in the anteroposterior projection. A similar study was made in the lateral projection, on another cadaver head. The present paper is concerned only with anteroposterior views at the level of the mid-portion of the maxillary sinuses. Obviously, a clear conception of the features demonstrable by tomography can be obtained only by a comparison of successive adjacent levels. In this manner, a pathologic process can be followed from the point where it is first evident to the area where it is lost in normal bone architecture. Normal Tomography Figure 1, taken 5.0 cm. from the table top, is at the level of the central and lateral incisor teeth. The floors of both atria are well outlined and rather sharp in detail. The anterior maxillary sinus septa are readily seen. The shadow cast by the lateral wall of the posterior portion of the maxilla is seen to bisect each antrum (designated here and in films to follow as the “H” line). It is not a septal image, with which it is sometimes confused.