Few phrases more reliably set British teeth on edge than this one: "British teeth" -- the disobliging characterisation of what our American friends imagine to be the grisly state of our nation's gnashers. Like "British food", another snobbish pejorative, it's not only irritating it's outdated. British food has been transformed in the past few decades, and so have the teeth with which we chew it.

Perhaps the children of my generation, raised in the 1970s and '80s, were the last of the dentist dodgers. The elaborate oral hygiene routines of our transatlantic cousins, and the early-interventionist techniques of their healthcare professionals, had not been so widely adopted over here in my snaggle-toothed youth as they have today.

I have British teeth. They are uneven and off-off-white. (They're yellow.) My mouth has never seen the inside of an orthodontist's surgery and, as a result, no orthodontist has ever seen the inside of my mouth. Neither, until just the other day, had I suffered the attentions of a hygienist.

Full disclosure: it's been 20 years since I visited a dentist. (You can save the "euww!" and the "gross!" for further down the scroll.)

A connection between gum disease and neurodegenerative disorders can't be ruled out

In July, for the first column in what we are calling the Longevity Project, HTSI sent me to a Swiss clinic for a detox that included a battery of tests, scans and assessments. Happily, it turned out that in most respects I am in borderline acceptable condition for a man of my age (I'm 52), background and inclinations. But if I am to give myself a chance at a long and contented senescence, I need to make some changes, specifically around diet and exercise.

One of the more unexpected red flags raised in Switzerland, a land of red flags, concerned my mouth. Not my teeth so much as my gums, which are receding and inflamed. The man who photographed them told me I should immediately seek out the services of a gum expert.

What did this have to do with longevity? Turns out, quite a lot. "Gum health is general health," according to Dr Reena Wadia, a leading gum specialist. She told me this at a conference table in her Harley Street four-surgery clinic, RW Perio. Then she smiled, revealing rows of pearly whites as blinding as a head torch, set in Pantone-pink gums.

The scientific literature backs her up. A study published in The British Medical Journal in 2021 found that the gum diseases gingivitis and periodontitis -- the first, if untreated, often a precursor to the latter -- can potentially lead to increased risk of chronic illnesses, including cardiovascular, cardiometabolic and autoimmune disease. There is evidence that gum disease can lead to mental ill-health. And that it can increase the risk of type 2 diabetes.

A link to Alzheimer's has also been suggested. That is unproven. But some connection to neurodegenerative disorders can't be ruled out. And studies quoted in a 2021 paper from The Economist Intelligence Unit show that three out of four adults with periodontitis don't know they have the disease. My gums don't bleed when I brush. I'm not in pain. I'm aware I'm no Julia Roberts in the Hollywood smile department -- I'm no Julia Roberts in any department -- but I hadn't ever been overly worried about my oral health.

Gum disease, Dr Wadia explains, is inflammation of the gum and tissues that surround the teeth caused by the build-up of plaque, which can lead to bone loss. Diseased gums detach from the teeth, creating pockets into which bacteria can penetrate and enter the bloodstream. I need to sort my pockets out. A week after I saw Dr Wadia, I was booked in for an assessment with one of her colleagues. Dr Devan Raindi, another gum specialist, another owner of a winning smile, took a series of 10 X-rays, while I stared up at a ceiling-mounted video screen showing time-lapse photos of plants coming into flower, even more beautiful in their maturity -- but aren't we all? -- than in their early development.

We sat at Dr Raindi's computer and looked, with gritted teeth in my case, at his photos of my mouth. First, the bad news. There are signs of "moderate" periodontitis. It's not my fault, he said. It's genetic. (He was being nice.)

Bacteria has gathered in my pockets, under my gumline. The trouble with this -- increased risk of chronic diseases aside -- is that as the bacteria gets closer to the bone, so the bone recedes, the gum follows, the teeth loosen, they become painful and the result can be tooth loss. The good news: Dr Raindi can help. He can't cure the periodontitis, but he can help control it. But only if I commit to a new and more robust oral-health regime.

He prescribed an initial programme of treatment, including two appointments with an advanced hygienist and two with gum specialists to clean and disinfect above and below my gumline, "disrupting" and removing the bacteria.

"Mama wipe the blood outta my face," sang Bob, as Dr Sajni Panchal got busy with the anaesthetic wand. After that I went next door to meet my hygienist, the miracle-working Hiba Malik. The following day I was back with Dr Raindi for more plaque removal.

My teeth and gums look better already. But the most important treatments are being carried out by me. My formerly abrupt routine -- twice-daily brushing with a manual toothbrush and the occasional sluice of mouthwash -- has expanded. No longer do I just brush and go.

The morning is not so different, although like Bob Dylan at the Newport Folk Festival, I've gone electric. Malik recommends the Oral-B iO2 series, so that's what I've gone for. First the gums, then the teeth. Then spit but don't rinse.

The evening ritual is more involved. I scrub between each tooth with snug-fitting interdental brushes. Then I use a gum brush to target hard-to-reach areas around the back teeth. Then I brush. Then I use a tongue scraper to remove the bacteria and toxins that gather there. Apparently this is an ancient Ayurvedic practice, though my stainless-steel number, from Dr Wadia's own brand, looks pleasingly modern. All together, it takes about 15 minutes.

I'm going back to Harley Street soon for another session with Malik and a reassessment with Dr Raindi. I won't be asking for Dylan next time. There's an Oasis tune more appropriate to this project.

RW Perio specialist assessment, from £250; complete package for patients with periodontitis, from £2,650

Could my British teeth be killing me?