Oral cancer screening; Procedure and Methods

Oral cancer screening is an examination performed by a dentist or doctor to look for signs of cancer or precancerous conditions in your mouth. The goal of oral cancer screening is to identify mouth cancer early, when there is a greater chance for a cure.

Most dentists perform an examination of your mouth during a routine dental visit to screen for oral cancer. Some dentists may use additional tests to aid in identifying areas of abnormal cells in your mouth.

Medical organizations disagree on whether healthy people without risk factors for mouth cancer need oral cancer screening. No single oral exam or oral cancer screening test is proved to reduce the risk of dying of oral cancer. Still, you and your dentist may decide that an oral exam or a special test is right for you based on your risk factors.

Oral cancer

Oral cancer is divided into two categories – those occurring in the oral cavity (your lips, the inside of your lips and cheeks, teeth, gums, the front two-thirds of your tongue and the floor and roof of your mouth) and those occurring in the oropharynx (middle region of the throat, including the tonsils and base of the tongue).

Why Oral cancer screening is done

The goal of oral cancer screening is to detect mouth cancer or precancerous lesions that may lead to mouth cancer at an early stage — when cancer or lesions are easiest to remove and most likely to be cured.

People with a high risk of oral cancer may be more likely to benefit from oral cancer screening, though studies haven't clearly proved that. Factors that can increase the risk of oral cancer include:

  • Tobacco use of any kind, including cigarettes, cigars, pipes, chewing tobacco and snuff, among others
  • Heavy alcohol use
  • Previous oral cancer diagnosis
  • History of significant sun exposure, which increases the risk of lip cancer

 Risks of oral cancer screening

Oral exams for oral cancer screening have some limitations, such as:

Oral cancer screening could lead to additional tests

Many people have sores in their mouths, with the great majority being noncancerous. An oral exam can't determine which sores are cancerous and which are not.

If your dentist finds an unusual sore, you may go through further testing to determine its cause. The only way to definitively determine whether you have oral cancer is to remove some abnormal cells and test them for cancer by a procedure called a biopsy.

Oral cancer screening can't detect all mouth cancers

It can be difficult to detect areas of abnormal cells just by looking at your mouth, so it's possible that a small cancer or precancerous lesion could go undetected.

Oral cancer screening hasn't been proved to save lives

There's no evidence that routine oral examinations to look for signs of oral cancer can reduce the number of deaths caused by oral cancer. However, screening for oral cancer may help find cancers early — when cure is more likely.

How you prepare

Oral cancer screening doesn't require any special preparation. Oral cancer screening is typically performed during a routine dental

appointment. What you can expect of Oral cancer screening

There are different levels to oral cancer screening, and your dentist is most likely to give you a basic exam that includes a thorough look at all the parts of your mouth, including:

  • Your lips, both outside and inside
  • Your gums
  • Your tongue, from all sides and underneath
  • The insides of your cheeks
  • The roof of your mouth
  • The back of your throat

If you wear dentures, you’ll have to take them out so he can check the tissue beneath them.

He might put one finger in your mouth under your tongue and couple of fingers on the skin under your chin and move them around to feel the tissue between them. Your dentist might also feel underneath your jaw. The exam should take less than 5 minutes.

The goal is to look for lumps and spots and see if anything looks unusual about the spit that covers all the pink parts inside your mouth. If you ever notice any of these things yourself, give your dentist a call.

Your dentist may go a little more in-depth for your oral cancer screening test and have you rinse your mouth with a blue dye before the exam. Any unusual cells in your mouth absorb the dye so it’s easier to see them.

The face

The entire face should be examined. Look for asymmetry, masses, swelling, discoloration, or ulceration. Evaluate for pigmented (red, brown, black), raised, ulcerated, or firm areas of the skin, including the hair-bearing regions of the face and scalp. The facial bones, skeleton, and soft tissue should be palpated, particularly noting asymmetry or masses.

The eyes

Extra ocular movements should be checked in each direction to test for cranial nerve involvement. Any swelling of the eye or periorbital area should be noted and can be a late sign of a tumor. Drainage from the lacrimal system (epiphora) may be a sign of an obstructing mass in the maxillary sinus, nose, or facial soft tissue.

The ears and nose

Nasal examination should include palpation of the external nose and paranasal region overlying the maxilla and maxillary sinus. Hearing should be tested by talking with the patient during the physical exam and assessing the integrity of the acoustic nerve. Carefully inspect the auricle, noting any pigmented, erythematous, or ulcerous lesions. Note that skin cancers often appear on the superior, sun-exposed portion of the auricle.

The neck

The patient should be positioned at the dentist eye level. Bimanually palpate the neck, comparing both sides simultaneously for signs of enlargement of lymph nodes. Examine the jugular chain first. With two deeply placed fingers, palpate along the course of the sternomastoid muscles, underneath the mandible, and down to the clavicle. Palpate the supraclavicular spaces on either side. Examine the parotid groups lying anterior and inferior to the ears, the submental, and finally the sub maxillary chain. To palpate a mass in the submaxillary area, insert a gloved finger in the patient’s mouth and press structures against your other hand, positioned under the chin. Next, palpate along the course of the larynx for signs of immobility or enlargement.

The thyroid

First inspect the thyroid gland and then palpate, because the thyroid gland is often difficult to feel. Some clinicians prefer to palpate the thyroid while positioned behind their patients, but it is perfectly acceptable to examine the gland from the front as well. Attempt to palpate the entire gland, and note the characteristics of any nodules or masses. Having the patient swallow while your fingers are positioned adjacent to the gland will elevate the thyroid gland and may facilitate your examination. Note and record any tenderness. After the lobe has been palpated, and with the fingers still, the doctor will ask the patient to swallow. The gland will move upward during swallowing and any abnormality will become more apparent. On swallowing, the inferior pole of the lobes is elevated and can be outlined. Inability to palpate the inferior pole may suggest sub sternal extension of the thyroid gland on that side. Examine each lobe in this manner.

The lips

The lips should be evaluated with the mouth open and closed, noting any abnormalities in symmetry, contour, color, or texture. Attention to the vermilion border of the lower lip is warranted as this is a prime site for oral cancers. First, revert the lower lip and inspect the inner surface. The labial mucosa should be smooth and uniform in color. Notice the frenum of the lip in the midline. Note any signs of smokeless tobacco use (ulcers, red or white discolorations, texture variations) on the labial mucosa. With the lip still retracted, one can also inspect the gingiva labial sulcus, the gingival mucosa, and the teeth. Next, palpate the lip with your thumb and index finger, noting any firm or nodular sub mucosal areas. Repeat these steps for the upper lip.

Buccal mucosa

Move the buccal mucosa away from the teeth and gingiva to visualize the vestibule. Examine one side and then the other. It is not uncommon to see a white line (linea alba) from biting the cheek. Any irregularity in texture or color or other signs listed above should be noted. Be sure to examine the entire buccal mucosa from the labial commissure back to the anterior tonsillar pillar. Stenson’s duct from the parotid gland is a small protrusion in this area opposite the upper second molar and should secrete clear saliva from both sides when the parotid gland is milked. This area is easy to examine when two tongue blades are used to spread the lining from the gingiva or gauze is used to pull the lips apart. With your index and middle fingers inside the patient’s mouth on the buccal mucosa and with your thumb on the cheeks, carefully pull laterally and inspect along the upper and lower jaws. Next, gently pinch the cheek between your fingers and thumb; this allows you to palpate the buccal mucosa for any hidden masses.


The dentist will ask the patient to stick out his or her tongue and move it from side to side. It should move easily and completely to both sides without spasm or asymmetry. Note any masses, ulceration, or swelling. When there is a nerve paralysis of the hypoglossal nerve, the tongue will usually deviate to the side of the lesion. Observe the dorsum of the tongue, noting any discolorations, irregularities, or limitations to movement, all of which may be a sign of cancer. Notice the circumvallate papillae and lingual tonsils, which are often mistaken for pathologic lesions. One of the most common sites of oral cancer is on the lateral border of the tongue, and it must be evaluated completely. This often requires using gauze to pull the tongue out and roll it from side to side while retracting the cheek with a tongue blade. A dental mirror may be necessary to visualize the base of the tongue (part of the oropharynx). This area is best viewed by pulling the tongue forward while holding it with 2X2 gauze, rolling it up into a position that enables a clearer view. Next, palpate the dorsum and lateral margins of the tongue, paying special attention to any masses or firm/fixated areas. Being careful not to gag the patient, palpate the lingual tonsils. Finally, have the patient touch the roof of the mouth with the tip of his or her tongue. This will allow the examiner to inspect the ventral surface of the tongue.

Floor of the mouth

The floor of the mouth is the U-shaped area that extends from the alveolar ridge of the mandible to the ventral aspect of the tongue. Inspect this area while the tongue is elevated. If needed, wrap a piece of gauze around the tip of the tongue and pull the tongue gently forward and to one side. With the other hand, use a tongue blade or gloved finger to push the middle of the tongue up and out of the way. Notice the frenulum in the midline and the ducts from the submandibular glands symmetrically on either side. Also note the sublingual glands. It is helpful to first dry this area with a gauze before looking for any surface abnormalities. Next, insert a gloved finger beneath the tongue, and another under the chin on the exterior skin, and bimanually palpate the submandibular glands and the entire sub mental region. Keep in mind that this one of the most common places for oral cancers.

Hard and soft palate

Have the patient open wide and tilt his or her head backward to provide an adequate view of the hard and soft palate. If needed, depress the base of the tongue with a tongue blade to provide a better view of the soft palate. Loose teeth, red spots (figure 3), white spots, ulcerations, rough areas, asymmetry, growths, or other masses may be the first sign of a cancer in this area as in all areas of the head and neck. The uvula should hang down in the midline. Its deviation may indicate a vagal nerve palsy. Some patients have a torus palatinus, or bony outgrowth, from the midline of their hard palate. This variation of normal should not be mistaken for a malignancy.


Ask the patient to open wide, relax, and slowly breathe in and out saying, “Ahh.” This relaxes the tongue and offers a view of the oropharynx. It may be necessary to press down on the back of the tongue to get a full view of the oropharynx. Simply depressing the tongue with a tongue blade and having the patient say “ahh” often gives only a superficial view of the oropharynx, and many early cancers may go unnoticed. The palatine tonsils can be seen on both sides behind the retromolar trigone. Examine the anterior and posterior tonsillar pillars and tonsillar fossa for any exophytic mass, asymmetry, ulceration, or redness.

Additional tests for oral cancer screening

Some dentists use special tests in addition to the oral exam to screen for oral cancer. It's not clear if these tests offer any additional benefit over the oral exam. Special oral cancer screening tests may involve:

  • Rinsing your mouth with a special blue dye before an exam. Abnormal cells in your mouth may take up the dye and appear blue.
  • Shining a light in your mouth during an exam. The light makes healthy tissue appear dark and makes abnormal tissue appear white.


A screening for oral cancer is not just a medical exam; it's an opportunity for a person to talk to the doctor or dentist about fears and concerns, and to ask for advice about reducing his risk.

If your dentist discovers any signs of mouth cancer or precancerous lesions, he or she may recommend:

  • A follow-up visit in a few weeks to see if the abnormal area is still present and note whether it has grown or changed over time.
  • A biopsy procedure to remove a sample of cells for laboratory testing to determine whether cancer cells are present. Your dentist may perform the biopsy, or you may be referred to a doctor who specializes in oral cancer diagnosis and treatment.