Cone Beam Tomographic Imaging Anatomy of the Maxillofacial Region
Christos Angelopoulos, DDS, MS
Division of Oral and Maxillofacial Radiology, Columbia University, College of Dental Medicine, PH-7 Stem-134, New York, NY 10032, USA
The main challenge in cone beam CT (CBCT) imaging and diagnosis is the lack of familiarity experienced by most dentalprofessionals with the concept of multiplanar imaging that is oﬀered by this new and exciting technology. Dentists and specialists, with only a few exceptions, have a wide experience in diagnosis using the traditional dental imaging modalities (intraoral radiography and panoramic radiography), and the comfort level in their diagnostic skills with these modalities is high. These imaging modalities have beentaught for several decades in the dental schools and in other training courses. Diagnostic imaging in diﬀerent planes is a new concept and may require a diﬀerent view of the imaging data. It is reminded that multiplanar imaging or reformatting is the ability to generate images in diﬀerent planes, ﬂat or curved. This ability is oﬀered only by some contemporary imaging modalities, such as CBCT,medical CT, MRI, ultrasound, and others. Because a volume of data has been acquired and stored by CBCT, these data can be reformatted or realigned and several diﬀerent types of images can be synthesized in any way the diagnostician requires. With multiplanar imaging, the diagnostician or operator can recreate images in diﬀerent planes (ﬂat or curved) with simple functions. This increases thediagnostic eﬃciency in the hands of the knowledgeable individual in an unparalleled way (Fig. 1). In this article, the author reviews the appearance of several anatomic structures of the maxillofacial region and the head and neck region in general; these structures are revealed in a variety of planes (eg, axial, coronal, sagittal, and more). What may add to the complexity of these images is the fact thatthis technology may demonstrate structures of interest, such as teeth and jaws, in a view that dental professionals have not seen in the past; dentists were never able to view the third dimension of the regions
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ANGELOPOULOSFig. 1. Multiplanar imaging and reformatting. Axial (A), coronal (B), and sagittal (C) sections of the head. The approximate tomographic plane is shown in the three-dimensional images (blue line). These sections can be generated with simple functions using the CBCT scanner’s software applications.
of interest. From the beginning, this may make the images look unfamiliar and diﬀerent. First,as with every other dental diagnostic image, the images are viewed as if the patient under examination were sitting opposite the dentist, as in the dental chair. The structures identiﬁed on the dentist’s right side would represent the anatomic structures on the patient’s left and vice versa. Most of the available software of the various manufacturers properly identiﬁes the right and left sides orthe buccal and lingual sides of the images; thus, orientation is not diﬃcult. The author starts with the evaluation of well-known dental structures in the maxillofacial region in cross sections. Cross-sectional images are generated perpendicular to the arch-form of the maxilla or mandible. The image demonstrated in Fig. 2 is a cross-sectional image (cut or slice) of the maxilla and mandible inthe ﬁrst molar location. In this image, the buccal and palatal or lingual sides are clearly identiﬁed. The maxillary sinus is a pyramidal in shape low-density (black or dark) structure. The appearance of healthy air cavities in the maxillary sinuses is dark (black) because of the fact that air attenuates x-rays minimally. The thin cortical outline of the buccal and medial sinus walls can be...