An old dental filling or infrequent visits to your dentist could lead to a painful interruption of your holiday plans.

According to dentists in the United Kingdom and the United States, a tiny air bubble around a deteriorating filling, cracked tooth or undetected infection can expand and become painful when flying.

Amid the busy holiday travel season, this means more people, especially seniors with decades of dental care, could experience pain from pressure changes during flights above 9,000 feet.

Barodontalgia, as it is known, also can occur when people scuba dive.

“For people our age, finding more time to travel, we try to make sure they are aware of [the possibility of tooth pain],” said Dr. Terry Buckenheimer, 63, a dentist with a 37-year practice in South Tampa, Fla.

“It can be a fun time in life,” he said, “but these episodes could ruin it.”

Because most commercial airlines fly at 30,000 feet or above, cabin pressure changes are subtle but inevitable. Dental pain can be caused by several different conditions, including a cracked tooth or air pockets around a filling or crown, according to Buckenheimer. “If they have any symptoms while biting, chewing, or pressures, or if their sinuses are bothering them (which could be an upper tooth), they should go to a dentist.”

Usually, if there is pain as the plane pressurizes, it will go away once the plane lands, Buckenheimer said. But on long-haul flights, that can be hours.

The best protection, Buckenheimer said, is to report to your dentist any discomfort before a trip and possibly get a “full mouth X-ray series to look at the roots.”

The risk of dental pain while flying has been known to military pilots for years. They call it “tooth squeeze,” according to Dr. Richard Coates, who has practices in Sunderland and Newcastle, England.

When it comes to travel, “People could be putting themselves at risk of searing pain even before they make it to their holiday destination,” he said, adding that it “can ruin a holiday before it has even begun.”

Coates advises anyone who is planning a long trip to see a dentist a couple of months before leaving.

As we get older, there is increased potential for old fillings to deteriorate and for teeth to be damaged by age and wear.

Buckenheimer suggests that people carry an over-the-counter anti-inflammatory with them when they travel. If a person needs to travel after a recent root canal or dental infection, Buckenheimer said he would prescribe an antibiotic ahead of time.

As with pilots, barodontalgia can be a significant risk for people who dive for a living, Coates noted, due to underwater pressure changes.

“I am a diver myself,” Coates said, “and have treated many commercial divers who have experienced the problem, which has risked their careers.

“Of course, this can affect recreational divers also,” he said, adding that studies suggest up to 40 percent of divers experience dental problems when diving.