Bitewings are a type of dental X-ray that captures the upper and lower back teeth in a single image, showing the crowns of your teeth and the bone level between them. They’re the most common X-ray taken at routine dental checkups, primarily because they’re the best tool for finding cavities hiding between teeth where your dentist can’t see or probe directly.
How Bitewings Work
The name comes from the original technique, which required patients to bite down on a small wing-shaped tab attached to a film packet. Modern versions use a plastic holder with three parts: a clip that keeps the sensor parallel to your teeth, a flat bite platform you clamp down on, and an aiming device that helps position the X-ray beam. Your dental team will place the holder between your upper and lower back teeth and ask you to close firmly. The whole process takes a few seconds per image, and a standard set includes two to four images covering both sides of your mouth.
The bite platform holds the sensor in place at just the right angle to capture the crowns of your premolars and molars, along with a strip of the surrounding jawbone. This positioning is what makes bitewings so effective at revealing problems that develop in the tight spaces between teeth.
What Bitewings Detect
Bitewings are the go-to for spotting interproximal cavities, the kind that form on the surfaces where two teeth touch. These are notoriously difficult to catch during a visual exam because they’re hidden from direct view, and a dental explorer often can’t reach them either. Bitewing X-rays have higher sensitivity than panoramic X-rays for detecting these lesions in molars and premolars, making them the radiological test of choice for this purpose.
Cavities show up on a bitewing as dark spots in the tooth structure. When decay is still limited to the enamel (the hard outer layer), your dentist may monitor it or recommend preventive measures. When it has reached the deeper dentin layer underneath, treatment is typically needed. Bitewings can catch decay at the enamel stage, often before you’d notice any symptoms, which means smaller fillings and less damage to the tooth.
Beyond cavities, bitewings also reveal early bone loss around your teeth, a hallmark of gum disease. The image captures the crest of bone between teeth, so your dentist can see whether that level has dropped. Bitewings can also show tartar buildup below the gumline, overhanging edges on old fillings, and decay forming underneath existing dental work.
Bitewings vs. Other Dental X-Rays
Bitewings focus on the crowns of your teeth and the bone just below the gumline. Periapical X-rays, by contrast, capture the entire tooth from crown to root tip, including the surrounding bone. That makes periapicals better for evaluating root infections, abscesses, and deeper bone loss. Your dentist chooses between them based on what they’re looking for: bitewings for routine cavity screening, periapicals when a specific tooth needs closer investigation.
Panoramic X-rays capture your entire jaw in one wide image. They’re useful for assessing wisdom teeth, jaw fractures, or orthodontic planning, but they lack the detail needed to reliably find small cavities between teeth. That’s why bitewings remain the standard for decay detection even when a panoramic has been taken.
How Often You Need Them
The American Dental Association’s guidelines tie bitewing frequency to your cavity risk. If you have no active cavities and aren’t at elevated risk for developing them, posterior bitewings every 24 to 36 months are sufficient. If you do have cavities or factors that raise your risk (a history of frequent decay, dry mouth, heavy sugar intake, or certain medical conditions), the recommendation shortens to every 6 to 18 months.
Your dentist determines which category you fall into based on your dental history, current oral health, and lifestyle factors. The goal is to catch problems early without exposing you to X-rays more often than necessary.
Bitewings for Children
Children don’t automatically get bitewings at their first dental visit. The American Academy of Pediatric Dentistry recommends an individualized approach: if a child still has baby teeth with open spaces between them (where the dentist can visually inspect the surfaces), X-rays may not be needed at all. Bitewings become more relevant once those gaps close and the contact points between teeth can no longer be examined visually or with a probe. For many children, this means their first set of bitewings happens around age 5 or 6, though timing varies based on how their teeth are developing and their individual cavity risk.
Radiation Exposure
A single bitewing X-ray delivers roughly 0.005 millisieverts of radiation, comparable to the exposure you’d get from a short airplane flight. For context, the average American absorbs about 3 millisieverts per year from natural background radiation (cosmic rays, radon in soil, and trace radioactive elements in food). A full set of four bitewings adds less than 1% of that annual background dose.
Digital sensors, which most dental offices now use, require less radiation than traditional film to produce a clear image. Lead or thyroid aprons provide additional shielding during the exposure. For the vast majority of patients, the diagnostic benefit of catching a cavity early, before it reaches the nerve or requires a crown, far outweighs the minimal radiation involved.
What the Experience Feels Like
The most common complaint about bitewings is discomfort from the sensor or holder pressing into the floor of your mouth or against your palate. The sensor is a rigid rectangle, and if you have a small mouth, a sensitive gag reflex, or inflamed gums, it can feel awkward. Biting down firmly on the platform, as your dental team will ask you to do, actually helps stabilize the holder and often reduces the discomfort compared to biting lightly. Each image takes only a second or two of actual exposure time, though positioning the holder may take a bit longer. A full set of four bitewings is typically finished within a few minutes.