eRadiograph Volume 7: Imaging of Oral Cavity | Page 19

bone, nasal cavity. Invasion of maxillary sinus may be difficult to differentiate from
mucosal disease inflammatory disease. T2 weighted images should allow to
diffrentiate. Contrast enhanced images would not be useful as inflammation and
neoplasm, would both enhance. There may be perineurial extension along the lesser
and greater palatine nerves. The greater palatine foramen is located medial to the third
molar, within the lateral border of the hard palate. The incisive canal is found posterior
to the incisor teeth; nasopalatine nerve and arteries runs through this foramen. From
these nerves, tumor can spread to V2 and consequently intracranially via the foramen
of rotunda or via the vidian nerve in the vidian canal. Perineurial spread is seen as
erosion of the foramen, asymmetric size of foramen, involved size larger enlargement
of nerve, asymmetric enhancement of the nerve. There may be also loss of fat in the
pteryrgopalatine fossa. From these nerves the tumor can spread along V2 via foramen
of rotundum to the cavernous sinus or superiorly or inferiorly into the inferior and
superior orbital fissures. There may be posterior extension to the vidian nerve canal.
The vidian canal is very well demonstrated on CT as a sclerotic marginated canal. Loss
of this sclerotic margin is easily appreciated indicating invasion.
Oropharynx
Anatomy
This is the part of pharynx located posterior to the oral cavity between nasopharynx and
hypopharynx.

The oropharynx has 4 sub sites:
• Base of tongue, including glossoepiglottic and pharyngoepiglottic folds
• Palatine tonsils, including tonsillar fossa, anterior and posterior tonsilar pillars
• Ventral soft palate, including uvula
• Posterior and lateral pharyngeal walls at the oropharyngeal level.
Pharyngeal Tongue
Pharyngeal tongue lies parallel to oropharyngeal posterior wall, limited anteriorly by
circumvallate papillae, laterally by glossotonsillar sulci, which is covered by lymphatic
tissue, representing lingual tonsil. The anterior aspect of the suprahyoid epiglottis is
connected to base of the tongue by medial and lateral glossoepiglottic folds, which
enclose the valleculae.
Neoplasms of base of tongue manifest with dysphagia,odynophagia sensation of a

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Imaging of Oral Cavity

The anatomic boundaries of the oropharynx are the circumvallate papillae anteriorly,
the posterior pharyngeal wall posteriorly, the soft palate superiorly and the
hypopharynx inferiorly demarcated at the level of the superior border of hyoid bone.
Anteriorly the oropharynx communicates with the oral cavity, superiorly with the
nasopharynx and inferiorly with the hypopharynx and supraglottic larynx.