Note any external swelling that may represent enlargement of a major salivary gland. A significantly enlarged parotid gland will alter the facial contour and may lift the ear lobe; an enlarged submandibular salivary gland (or lymph node) may distend the skin over the submandibular triangle. With minimal manipulation of the patient’s lips, tongue, and cheeks, note the presence of any salivary pool, and note whether the mucosa is moist, covered with scanty frothy saliva, or dry.
To evaluate parotid gland function, dry the cheek mucosa around the orifice of each parotid duct, and massage or “milk” the gland and duct externally, observing the amount and character of any excreted material. With a normal gland, clear and freely flowing saliva will be readily apparent; a limited flow (usually only one or two drops) of viscous saliva, cloudy or frankly purulent discharges, or the absence of flow are abnormal and indicate the need for additional evaluation of the salivary glands. When salivary flow is reduced, there may be a brief flow of viscous or cloudy saliva, followed by a small amount of apparently normal saliva; this emphasizes the need for careful observation of the initial flow. Psychic stimuli (such as asking the patient to think of a cold refreshing lemon drink on a hot day) may also be used to increase the flow of parotid saliva during the examination. Palpate any suspected parotid swelling externally at this time, recording texture and any tenderness or nodularity; distinguish parotid enlargement from hypertrophy and spasm of the masseter muscle.
For the submandibular and sublingual glands, use bimanual palpation (insert the gloved index finger beside the tongue in the floor of the mouth and locate the two salivary glands and any enlarged submandibular lymph nodes, using a second finger placed externally over the gland); note the location, texture, and size of each gland and any tenderness or nodules. Dry the orifices of both Wharton’s ducts and note the amount and character of the excreted saliva as one and then the other submandibular glands and ducts are “milked.” Palpate Wharton’s duct on each side for any salivary calculi. When either the parotid or the submandibular/sublingual salivary flow appears minimal, flow may often be stimulated by either gustatory stimuli (such as lemon juice swabbed on the tongue dorsum) or painful stimuli (eg, pricking the gingiva with an explorer). With stimulation of the salivary flow, minor salivary gland function can be demonstrated by the appearance of multiple small beads of saliva on the dried upper- and lower-lip mucosa. (See Chapters 9, Salivary Gland Disease and 3, Maxillofacial Imaging for descriptions of more detailed evaluation of salivary function and imaging of the salivary glands.)