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Oral cavity

Introduction Trauma

CT is an excellent imaging modality to investigate the The oral cavity is often affected by trauma in dogs and
oral cavity because of the prevalence of high‐attenua- cats, such as injury by other animals or vehicular trauma.
tion structures. CT provides excellent contrast and Structures such as the mandible, maxilla, and teeth may
spatial resolution within the oral cavity. The extent of be fractured or displaced by the traumatic event. CT is
lesion invasion has been shown to be improved with used to increase the diagnostic yield of such injuries
MR imaging compared to CT in a small number of compared to radiographs, especially for the purpose of
cases. Thin‐collimation CT images in bone and soft‐ surgical planning. Multiplanar reformatted images and
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tissue algorithms are ideal for evaluation of both dense 3D images can add information to the transverse 2D
structures and soft tissues of the mouth. Contrast images by displaying the affected structures in relation-
medium is employed when soft tissues are suspected ship to each other. Developing teeth may be damaged in
of being abnormal, and 3D images may be useful for traumatic events, which causes altered development of
surgical planning. The normal structures of the tooth the tooth and occasionally of the adjacent structures
are visible as layers of differing attenuation on thinly (Figures 1.9.3, 1.9.4).
collimated images (Figure 1.9.1).
Inflammatory disorders
Developmental disorders
Dental disease can result in abscess formation around
Congenital anomalies of the teeth are occasionally affected tooth roots and may be observed on CT images
seen on CT images. Supernumerary teeth appear as as contoured or rounded regions of alveolar bone
complete dental structures adjacent to the normal osteolysis surrounding the tooth roots (Figure 1.9.5).
tooth at an abnormal angulation because of displace- Occasionally, the medial wall of the alveolus will be
ment (Figure 1.9.2). These have been reported to occur eroded by the infectious process and cause regional
with high frequency in Greyhounds at the level of rhinitis (Figure 1.9.6). Dental disease may also progress
maxillary P1. The maxillary second premolar and the to frank osteomyelitis, producing regional osteolysis and
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maxillary first molar frequently have fused roots in irregular to smooth periosteal reaction surrounding the
cats and are occasionally absent. 3 affected bone (Figure 1.9.7).
Brachycephalic syndrome has been assessed using Soft tissues of the oral cavity, such as the tongue, can
CT, with increased thickness of the soft palate being be affected by inflammation and abscessation due to
the main associated finding in severely affected trauma or penetrating foreign bodies. On CT and MR
animals. 4 images, abscessation appears as an encapsulated lesion

Atlas of Small Animal CT and MRI, First Edition. Erik R. Wisner and Allison L. Zwingenberger.
© 2015 John Wiley & Sons, Inc. Published 2015 by John Wiley & Sons, Inc.
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