Most of us hardly notice our wisdom teeth coming through, but at some point in between middle school and university, many people living in the US or Australia are told we need to get them taken out.

Depending on whether the teeth are impacted - meaning they're trapped under the gum line - the surgery can involve general anaesthetic, stitches, and a week or two of bed rest and pudding. For a lot of us, it can be a pretty brutal introduction to adulthood.

But more and more experts are beginning to question whether the majority of these surgeries are even necessary. And a growing body of research indicates that we might be putting people through the risk of expensive tooth removal for no reason.

To be clear, not all wisdom teeth removals are unnecessary. Wisdom teeth can become infected, cause tooth decay or cysts, damage neighbouring teeth, and cause a huge amount of pain if left in people's jaws.

In these cases, the evidence is clear that it's far better for a patient to have these 'third molars' - the official name for wisdom teeth - removed.

But it's the other cases that researchers are beginning to question - the cases where wisdom teeth are impacted but are otherwise healthy, or don't have any symptoms at all.

The UK gave up on routinely removing wisdom teeth without solid evidence back in 1998, after a study at the University of York concluded that there was no scientific evidence to support it.

That same year, the Royal College of Physicians of Edinburgh said that for patients who don't have a condition related to third molars, removal is "not advisable".

Still, in many countries, including the US and Australia, routine wisdom teeth removal remains the standard procedure. The reason given is that leaving them in is simply putting off the inevitable, because patients with wisdom teeth will face infection or complications later on.

Based on that logic, in 2011, 10 million wisdom teeth were removed from Americans' mouths, and a 2015 study estimated that seven times more people are hospitalised for the removal of impacted wisdom teeth in Australia than in the UK.

But new research suggests that it might be overkill.

"Everybody is at risk for appendicitis, but do you take out everyone’s appendix?" Greg J. Huang, chairman of orthodontics at the University of Washington in Seattle told Rony Carin Rabin over at The New York Times.

"I’m not against removing wisdom teeth, but you should do an assessment and have a good clinical reason."

So what does the research say? The more recent evidence to support getting wisdom teeth out "just in case" comes from a 2014 review that looked at seven papers examining what happened when young adults left their wisdom teeth in. And while, overall, the study showed that leaving wisdom teeth in did lead to an increased risk of complications later on, that wasn't the full story.

"The review concluded that the risk of having to undergo removal appeared to increase as subjects aged," Rob Wile explains for Fusion.

"But at least one of the studies in the [review] concluded no such thing. Rather, the British study found that 83.13 percent of patients survived the one-year study period symptom-free, and just 5 percent had to have teeth removed."

Rabin over at The New York Times also notes that while several studies have linked keeping wisdom teeth in with ongoing problems, "There does not appear to be a single randomised clinical trial - the gold standard for scientific proof - comparing similar patients who have and have not undergone prophylactic wisdom teeth removal."

On the other hand, there's a solid and growing body of research showing the opposite - that a lot of wisdom teeth removal is unnecessary.

A 2011 study of more than 6,000 patients in Greece who'd had their wisdom teeth out found that only 2.8 percent of the teeth had a cyst or tumour.

And a frequently cited 1988 study showed that only 12 percent of 1,756 middle-aged people who didn't have their impacted wisdom teeth removed experienced a complication.

Even more damming, in 2008 the American Public Health Association (APHA) dismissed many of the arguments typically made for removing wisdom teeth, such as adjacent teeth getting damaged or wisdom teeth harbouring bacteria that could cause periodontal disease.

"The few studies of long-term retention of impacted teeth have shown little risk of harm," the association concluded.

The APHA also approved a policy that year saying the concerns of leaving wisdom teeth in don't justify the risk of surgery - which aren't small. Aside from associated risks of anaesthetic, the surgery can lead to possible nerve damage, loss of the sense of taste, and sometimes even death.

Knowing all that, why are dentists still recommending that so many people have their wisdom teeth extracted? It all comes down to uncertainty.

"The trick is that clinicians still don’t have all the tools and data available that would make them comfortable with a sit-and-wait approach," Julia Boughner, a cell biologist from the University of Saskatchewan in Canada, who's been following the debate closely, told Fusion.

So what should you do if your dentist recommends you have your wisdom teeth out? Rabin recommends trying to understand if it's truly worth the risk of surgery in your case, and whether there are any less invasive treatments you could pursue first.

In other words, getting a second or third opinion before you say yes to surgery definitely can't hurt.

But when is it worth the risk?

"The general consensus among critics of routine extraction is that recurrent gum infection, or pericoronitis; irreparable tooth decay; an abscess; cysts; tumours; damage to nearby teeth and bone; or other pathological conditions justify the procedure," writes Rabin.

Whatever you decide, the most important thing is to make sure you're regularly seeing your dentist for check ups and cleaning, because dental health is not something to be taken lightly. Especially for young adults at the start of their life.