Mouth Guards in Sports: A Necessary Piece of Equipment

Youth and adolescent sports participation has grown steadily over the years. It is estimated that 20 to 25 million youths participate in competitive sports. As a result of this growth in participation levels, incidence of injury has also increased. Some have reported sports to account for approximately 36% of all unintentional injuries to children and adolescents. Of those injuries, 10-20% of all sports related injuries are maxillofacial injuries according to the American Dental Association.

The National Youth Sports Foundation for Safety reports dental injuries as the most common type of orofacial injury sustained during sports participation. They contend that an athlete is 60 times more likely to sustain damage to the teeth when not wearing a protective mouthguard. Often times these injuries will result in permanent damage to oral structures which require medical intervention.

Types of Dental Injuries

Injuries to the teeth can be grouped in three different categories with care specific to each type.

• Fracture

  • Can be classified as a root fracture, broken tooth or chipped tooth. If possible, stabilize portion of tooth still in mouth by gently biting on towel to control bleeding. Athlete and tooth fragments should be transported immediately to a dentist. Best methods of transport of the tooth are in Hank's Balanced Salt Solution, milk, saline soaked gauze, or under the athlete's tongue

• Avulsion

  • Entire tooth, including root, knocked out. Do not handle tooth by the root (tooth should be handled by the crown). Do not brush, scrub, or sterilize tooth. If tooth is dirty, gently rinse with water. If possible, place tooth back in socket and have athlete gently bite down on towel. If unable to reimplant tooth, transport tooth with the athlete as described above to the dentist immediately

• Luxation

  • Tooth in socket, but in wrong position.

  • Extruded Tooth- tooth appears longer than surrounding teeth.

  • Lateral Displacement- tooth pushed back or pulled forward

  • For extruded or laterally displaced teeth, provide the following care: The tooth will need to be repositioned in socket using firm finger pressure. This is best done by trained dental/medical personnel. Have the athlete gently bite down on a towel and transport immediately to a dentist

  • Intruded tooth - tooth looks short, pushed into gum

  • Do not attempt to reposition tooth. Transport athlete immediately to a dentist

It is important to remember time is critical when handling dental injuries. Do not allow the athlete to wait until the end of the game to seek treatment for a dental injury. Transport them to a dentist within 2 hours for the best outcomes.

Prevention of Dental Injuries

Dental injuries are easily prevented. Some experts recommend that mouthguards be worn by athletes in competitive and recreational sports in which impact, contact and collision are likely to occur.

The American Dental Association recommends wearing custom mouthguards for the following sports: acrobats, basketball, boxing, field hockey, football, gymnastics, handball, ice hockey, lacrosse, martial arts, racquetball, roller hockey, rugby, shot putting, skateboarding, skiing, skydiving, soccer, squash, surfing, volleyball, water polo, weightlifting, and wrestling. Other experts include baseball and softball infielders on that list. They further recommend the mouthguard to be worn during all practices and competition.

Selecting a Mouth Guard

• There are three types of mouthguards:

• Ready-made or stock mouthguard

• Mouth-formed "boil and bite" mouthguard

• Custom-made mouthguard (made by a dentist)

These mouthguards vary in price and comfort, yet all provide some protection. According to the American Dental Association, the most effective mouthguard should be comfortable, resistant to tearing, and resilient. A mouthguard should fit properly, be durable, easily cleaned, and not restrict speech or breathing.

It is important to remember damaged teeth do not grow back. Protect that perfect smile - wear a mouthguard.

Nationwide Children’s Hospital Sports Medicine specializes in diagnosing and treating sports-related injuries in youth, adolescent, and collegiate athletes. Services are available in multiple locations throughout central Ohio. To make an appointment, call 614-355-6000 or request an appointment online.

A gentler strategy for avoiding childhood dental decay

The combination of a carb-heavy diet and poor oral hygiene can leave children with early childhood caries (ECC), a severe form of dental decay that can have a lasting impact on their oral and overall health.

A few years ago, scientists from Penn's School of Dental Medicine found that the dental plaque that gives rise to ECC is composed of both a bacterial species, Streptococcus mutans, and a fungus, Candida albicans. The two form a sticky symbiosis, known scientifically as a biofilm, that becomes extremely virulent and difficult to displace from the tooth surface.

Now, a new study from the group offers a strategy for disrupting this biofilm by targeting the yeast-bacterial interactions that make ECC plaques so intractable. In contrast to some current treatments for ECC, which use antimicrobial agents that can have off-target effects, potentially harming healthy tissues, this treatment uses an enzyme specific to the bonds that exist between microbes.

"We thought this could be a new way of approaching the problem of ECCs that would intervene in the synergistic interaction between bacteria and yeast," says Geelsu Hwang, an assistant professor in Penn Dental Medicine and senior author on the study, published in the journal mBio. "This offers us another tool for disrupting this virulent biofilm."

The work builds off findings from a 2017 paper by Hwang and colleagues, including Hyun (Michel) Koo of Penn Dental Medicine, which found that molecules call mannans on the Candida cell wall bound tightly to an enzyme secreted by S. mutans, glycosyltransferases (Gftb). In addition to facilitating the cross-kingdom binding, Gftb also contributes to the stubbornness of dental biofilms by manufacturing gluelike polymers called glucans in the presence of sugars.

While some cases of ECC are treated with drugs that kill the microbes directly, potentially reducing the number of pathogens in the mouth, this doesn't always effectively break down the biofilm and can have off-target effects on "good" microbes as well as the soft tissues in the oral cavity.

Hwang and colleagues wanted to try a different approach that would directly target the insidious interaction between yeast and bacteria and opted to target the mannans in the Candida cell surface as a point of contact.

Using three different mannan-degrading enzymes, they applied each to a biofilm growing on a tooth-like surface in a human saliva medium and left it for five minutes. Following the treatment, they noted that the overall biofilm volume was reduced. Using powerful microscopy, they also observed drastic reductions in the biofilm thickness and interactions between bacteria and yeast. The pH of the surrounding medium was higher when exposed to the enzymes, indicating an environment that is not as acidic and thus less conducive to tooth decay.

They also measured how easy it was to break up the biofilm after treatment, using a device that applies a stress, akin to tooth brushing.

"The biofilm structure was more fragile after the enzyme treatment," Hwang says. "We were able to see that the biofilms were more easily removed."

To confirm the mechanism of their approach -- that the mannan-degrading enzymes were weakening the binding between yeast and bacteria -- the team used atomic-force microscopy to measure the bonds between Candida and Gftb. The therapy, they found, reduced this binding force by 15-fold.

Finally, they wanted to get a sense of how well-tolerated these enzymes would be when used in the oral cavity, especially since children would be the patient group targeted.

Applying the enzymes to human gingival cells in culture, they found no harmful impact, even when they used a concentrated form of the enzymes. In addition, they observed that the treatment didn't kill the bacteria or yeast, a sign that it could work even if the microbes developed mutations that would lend them resistance against other types of therapies.

The researchers kept the application time relatively short at five minutes though they hope to see activity in an even shorter time, like the two minutes that is recommended for tooth brushing. Hwang says they may consider a non-alcohol-based mouthwash with these enzymes added that could be used by children as a preventive measure against ECC.

The researchers hope to continue pursuing this possibility with additional follow up, including testing these enzymes in an animal model. With more successes, they aim to add another tool for fighting the public health threat of ECC.

The study was supported in part by the National Institutes for Dental and Craniofacial Research (grants DE027970 and DE025220) and Josephine and Joseph Rabinowitz Award.

What exercises can help relieve TMJ pain?

People experiencing pain due to a temporomandibular joint (TMJ) disorder can try a range of exercises to relieve it. These exercises can improve jaw strength and mobility.

TMJ disorders are a group of conditions affecting the muscles and bones of the jaw. They cause pain in the joint that connects the jaw to the skull and allows a person to open and close their mouth. The pain can stem from the muscles responsible for moving the joint or the joint itself.

Noninvasive or conservative therapies can reduce pain and stiffness from TMJ disorders. These might include exercises that can help improve the strength or function of the jaw.

This article explains what TMJ disorders are and details some exercises that can help alleviate the symptoms.

What causes TMJ disorders?

The TMJ, or the temporomandibular joint, allows the jaw to move when a person is eating, talking, or yawning. The joints, muscles, and ligaments that control the jaw are on either side of it.

According to the American Dental Association, each joint has a disk inside that provides cushioning as the jaw moves. Any misalignment in the system of muscles, ligaments, and the disk can cause pain, stiffness, or discomfort in the TMJ.

The TMJ Association states that common causes of TMJ disorders include:

• trauma to the jaw

• dental surgery

• the insertion of a breathing tube during surgery

• autoimmune disease

• infections

• Other possible causes include arthritis and clenching or grinding the teeth.

The National Institute of Dental and Craniofacial Research (NIDCR) adds that the exact cause of TMJ disorders is not always clear, noting that some injuries can cause them. These injuries may affect the:

• joint itself

• disk within the joint

• muscles or ligaments responsible for moving the jaw

6 exercises for relieving TMJ pain

Some people might find that certain exercises that stretch or strengthen the jaw reduce pain from TMJ disorders.

Below, we list six exercises that might help minimize symptoms and explain how to perform them.

However, it is best to discuss exercises with a doctor or physical therapist before starting. A person should always stop performing any exercise if it worsens the pain or discomfort.

1. Resisted mouth closing: Resisted mouth closing involves applying some pressure to the chin while closing the mouth. To perform the exercise: Place the thumbs under the chin. Place the index fingers between the ridge of the mouth and the bottom of the chin. Use the fingers and thumbs to apply gentle downward pressure to the chin while closing the mouth.

2. Resisted mouth opening: A person can also apply gentle pressure to the chin while opening their mouth. To perform the exercise: Place two fingers under the chin and open the mouth slowly while applying gentle pressure with the fingers. Hold for 3–6 seconds. Slowly close the mouth.

3. Side-to-side jaw movement : This exercise involves moving the jaw from side to side to strengthen the muscles: Gently bite down with the front teeth on an object that is about one-quarter of an inch thick, such as two tongue depressors. Slowly move the jaw from side to side. Increase the thickness of the object once the exercise becomes easier.

4. Tongue up: The tongue up exercise involves slowly opening and closing the mouth while maintaining contact with the roof of the mouth. A person should repeat this movement several times.

5. Forward jaw movement: This exercise also requires a thin object. A person can follow these steps: Gently hold an object that is about one-quarter of an inch thick between the front teeth. Move the jaw forward so that the bottom teeth are in front of the top teeth. As the exercise becomes easier, replace the object with a thicker one.

6. Oxford University Hospitals Exercise: Oxford University Hospitals recommends the following routine to strengthen the jaw muscle and prevent clicking in the jaw joint. A person can perform this exercise sequence for 5 minutes, twice a day: Close the mouth and let the teeth touch without clenching them. Place the tip of the tongue on the palate right behind the upper front teeth. Run the tip of the tongue back toward the soft palate until it cannot reach further while keeping the teeth together. Hold the tongue here against the soft palate and slowly open the mouth until the tongue starts to pull away. Hold the position for 5 seconds, then close the mouth and relax. Repeat the steps for 5 minutes.

When to contact a doctor

People experiencing pain from TMJ disorders should talk with a doctor about possible treatment options. A doctor can recommend a physical therapist, who can work with the person to develop a tailored exercise program for improving jaw strength and flexibility.

Some people will not find these exercises effective in relieving pain. In these cases, doctors may suggest medications or other therapies to alleviate the pain. In severe cases, they might recommend surgery, although they tend to view this as a last resort.

The NIDCR warns that the possible benefits of surgery might not outweigh the risks, which include permanent jaw damage and replacement joints breaking or not functioning properly.

Summary

Exercises for TMJ pain are generally safe and can reduce symptoms for some people. They are easy for a person to perform at home each day.

It is best to talk with a doctor or physical therapist for more guidance on what exercises are suitable. Doctors may also recommend medical treatments if the exercises do not reduce symptoms.

More Evidence Ties Gum Disease With Heart Disease

The ongoing Swedish study previously found that gum disease ("periodontitis") was much more common in first-time heart attack patients than in a group of healthy people.

In this follow-up study, the researchers examined whether gum disease was associated with an increased risk of new heart problems in both heart attack survivors and healthy people the same age and sex, and living in the same area.

"The risk of experiencing a cardiovascular event during follow-up was higher in participants with periodontitis, increasing in parallel with the severity. This was particularly apparent in patients who had already experienced a [heart attack]," said study author Giulia Ferrannini, from the Karolinska Institute in Stockholm.

The researchers suspect that damage to the gum tissue in people with gum disease may allow germs to enter the bloodstream. "This could accelerate harmful changes to the blood vessels and/or enhance systemic inflammation that is harmful to the vessels," Ferrannini added.

In total, the study included nearly 1,600 participants with an average age of 62. Dental examinations between 2010 and 2014 showed that 985 had good dental health, 489 had moderate periodontitis and 113 had severe periodontitis.

During an average follow-up of just over six years, people with gum disease were 49% more likely to die from any cause, have a nonfatal heart attack or stroke, or to develop severe heart failure.

The risk of those outcomes increased with the severity of gum disease, according to the study presented Friday at a virtual meeting of the European Society of Cardiology. Such research is considered preliminary until published in a peer-reviewed journal.

When assessed separately, the relationship between gum disease severity and the risk of negative outcomes was significant only for those who had experienced a heart attack in the past.

"Our study suggests that dental screening programs including regular check-ups and education on proper dental hygiene may help to prevent first and subsequent heart events," Ferrannini concluded in a meeting news release.

Rare mineral from rocks found in mollusk teeth

Northwestern University researchers have, for the first time, discovered a rare mineral hidden inside the teeth of a chiton, a large mollusk found along rocky coastlines. Before this strange surprise, the iron mineral, called santabarbaraite, only had been documented in rocks.

The new finding helps understand how the whole chiton tooth -- not just the ultrahard, durable cusp -- is designed to endure chewing on rocks to feed. Based on minerals found in chiton teeth, the researchers developed a bio-inspired ink for 3D printing ultrahard, stiff and durable materials.

"This mineral has only been observed in geological specimens in very tiny amounts and has never before been seen in a biological context," said Northwestern's Derk Joester, the study's senior author. "It has high water content, which makes it strong with low density. We think this might toughen the teeth without adding a lot of weight."

The study will be published the week of May 31 in the Proceedings of the National Academy of Sciences.

Joester is an associate professor of materials science and engineering in Northwestern's McCormick School of Engineering. Linus Stegbauer, a former postdoctoral fellow in Joester's laboratory, is the paper's first author. At Northwestern during the research, Stegbauer is now a principal investigator at the Institute of Interfacial Process Engineering and Plasma Technology of the University of Stuttgart in Germany.

One of the hardest known materials in nature, chiton teeth are attached to a soft, flexible, tongue-like radula, which scrapes over rocks to collect algae and other food. Having long studied chiton teeth, Joester and his team most recently turned to Cryptochiton stelleri, a giant, reddish-brown chiton that is sometimes affectionately referred to as the "wandering meatloaf."

To examine a tooth from Cryptochiton stelleri, Joester's team collaborated with Ercan Alp, a senior scientist at Argonne National Laboratory's Advanced Photon Source, to use the facility's synchrotron Mössbauer spectroscopy as well as with Paul Smeets to use transmission electron microscopy at the Northwestern University Atomic and Nanoscale Characterization and Experiment (NUANCE) Center. They found santabarbaraite dispersed throughout the chiton's upper stylus, a long, hollow structure that connects the head of the tooth to the flexible radula membrane.

"The stylus is like the root of a human tooth, which connects the cusp of our tooth to our jaw," Joester said. "It's a tough material composed of extremely small nanoparticles in a fibrous matrix made of biomacromolecules, similar to bones in our body."

Joester's group challenged itself to recreate this material in an ink designed for 3D printing. Stegbauer developed a reactive ink comprising iron and phosphate ions mixed into a biopolymer derived from the chitin. Along with Shay Wallace, a Northwestern graduate student in Mark Hersam's laboratory, Stegbauer found that the ink printed well when mixed immediately before printing.

"As the nanoparticles form in the biopolymer, it gets stronger and more viscous. This mixture can then be easily used for printing. Subsequent drying in air leads to the hard and stiff final material," Joester said. Joester believes we can continue to learn from and develop materials inspired by the chiton's stylus, which connects ultra-hard teeth to a soft radula.

"We've been fascinated by the chiton for a long time," he said. "Mechanical structures are only as good as their weakest link, so it's interesting to learn how the chiton solves the engineering problem of how to connect its ultrahard tooth to a soft underlying structure. This remains a significant challenge in modern manufacturing, so we look to organisms like the chiton to understand how this is done in nature, which has had a couple hundred million years of lead time to develop."

The study, "Persistent polyamorphism in the chiton tooth: From a new biomaterial to inks for additive manufacturing," was supported by the National Science Foundation (award numbers DMR-1508399 and DMR-1905982), National Institutes of Health (award number NIH-DE026952), Air Force Research Laboratory (award number FA8650-15-2-5518) and Deutsche Forschungsgemeinschaft (award number STE2689/1-1).

Predicting tooth loss

Tooth loss is often accepted as a natural part of aging, but what if there was a way to better identify those most susceptible without the need for a dental exam?

New research led by investigators at Harvard School of Dental Medicine suggests that machine learning tools can help identify those at greatest risk for tooth loss and refer them for further dental assessment in an effort to ensure early interventions to avert or delay the condition.

The study, published June 18 in PLOS ONE, compared five algorithms using a different combination of variables to screen for risk. The results showed those that factored medical characteristics and socioeconomic variables, such as race, education, arthritis, and diabetes, outperformed algorithms that relied on dental clinical indicators alone.

"Our analysis showed that while all machine-learning models can be useful predictors of risk, those that incorporate socioeconomic variables can be especially powerful screening tools to identify those at heightened risk for tooth loss," said study lead investigator Hawazin Elani, assistant professor of oral health policy and epidemiology at HSDM.

The approach could be used to screen people globally and in a variety of health care settings even by non-dental professionals, she added.

Tooth loss can be physically and psychologically debilitating. It can affect quality of life, well-being, nutrition, and social interactions. The process can be delayed, even prevented, if the earliest signs of dental disease are identified, and the condition treated promptly. Yet, many people with dental disease may not see a dentist until the process has advanced far beyond the point of saving a tooth. This is precisely where screening tools could help identify those at highest risk and refer them for further assessment, the team said.

In the study, the researchers used data comprising nearly 12,000 adults from the National Health and Nutrition Examination Survey to design and test five machine-learning algorithms and assess how well they predicted both complete and incremental tooth loss among adults based on socioeconomic, health, and medical characteristics.

Notably, the algorithms were designed to assess risk without a dental exam. Anyone deemed at high risk for tooth loss, however, would still have to undergo an actual exam, the researchers added.

The results of the analysis point to the importance of socioeconomic factors that shape risk beyond traditional clinical indicators.

"Our findings suggest that the machine-learning algorithm models incorporating socioeconomic characteristics were better at predicting tooth loss than those relying on routine clinical dental indicators alone," Elani said. "This work highlights the importance of social determinants of health. Knowing the patient's education level, employment status, and income is just as relevant for predicting tooth loss as assessing their clinical dental status."

Indeed, it has long been known that low-income and marginalized populations experience a disproportionate share of the burden of tooth loss, likely due to lack of regular access to dental care, among other reasons, the team said.

"As oral health professionals, we know how critical early identification and prompt care are in preventing tooth loss, and these new findings point to an important new tool in achieving that," said Jane Barrow, associate dean for global and community health and executive director of the Initiative to Integrate Oral Health and Medicine at HSDM. "Dr. Elani and her research team shed new light on how we can most effectively target our prevention efforts and improve quality of life for our patients."

The research was done in collaboration with researchers at the Harvard T.H. Chan School of Public Health, the University of São Paolo in Brazil, and the University of Otago Faculty of Dentistry in New Zealand.

Co-investigators included André F. M. Batista, W. Murray Thomson, Ichiro Kawachi, and Alexandre D. P. Chiavegatto Filho.

This work was supported by the National Institute on Minority Health And Health Disparities (grant K99MD012253) and CNPq (grant 308731/2018-2).

A link between childhood stress and early molars

Early in her career neuroscientist Allyson Mackey began thinking about molars. As a researcher who studies brain development, she wanted to know whether when these teeth arrived might indicate early maturation in children.

"I've long been concerned that if kids grow up too fast, their brains will mature too fast and will lose plasticity at an earlier age. Then they'll go into school and have trouble learning at the same rate as their peers," says Mackey, an assistant professor in the Department of Psychology at Penn. "Of course, not every kid who experiences stress or [is] low income will show this pattern of accelerated development."

In the Proceedings of the National Academy of Sciences, Mackey, with doctoral student Cassidy McDermott and colleagues from Penn's School of Dental Medicine and the University of Missouri-Kansas City, shows that children from lower-income backgrounds and those who go through greater adverse childhood experiences get their first permanent molars earlier. The findings, generated initially from a small study and replicated using a nationally representative dataset, align with a broader pattern of accelerated development often seen under conditions of early-life stress.

"It's really important for us to understand how to detect early maturation sooner," Mackey says. "Right now, we're relying on seeing when kids hit puberty, which might be too late for some meaningful interventions. If we can inexpensively see that a child is experiencing this maturation earlier, we might be able to direct more intervention resources toward them."

A novel rating system

Broadly speaking, Mackey's lab studies how the brain changes and grows as people learn. It's well-established that stress during childhood speeds up maturation and that children who hit puberty earlier are at greater risk for both physical and mental health problems in adulthood.

Beyond that, in studies across primate species, molar eruption has been used to measure childhood length and correlates with a number of other developmental events. Similarly, for humans, the timing of dental events often plays a role in estimating biological age.

"That all made molar eruption a compelling developmental indicator," says McDermott, who is training to be a clinical psychologist.

It helped that more than 100 children, ages 4 to 7, had been participating in two Penn brain development studies, which included structural and functional MRI scans. "There's one type of MRI scan called a T2 weighted scan where you can visualize the morphology of the tooth pretty well," McDermott says. These scans -- typically used to look at the brain -- showed the researchers just how close these molars were to breaking through the gum line.

Once Mackey and McDermott realized this, they partnered with Katherine Hilton, then a student in Penn Dental Medicine, and Muralidhar Mupparapu, a professor in the Department of Oral Medicine, who developed a novel scale to precisely rate each tooth's position.

"The scale ranges from 1 to 4," McDermott says. "At the low end of the scale is 1, which is before the tooth has really developed at all. As the tooth emerges, there are intermediate stages, and the highest rating, a 4, is when the tooth is fully in the mouth and parallel with the other teeth." Four molars each received a score, which then got averaged, leaving a single score per individual.

Controlling for factors like age and gender, the researchers then looked for associations between early environment and molar eruption. "What we found is that income and adverse childhood experiences are both individually associated with molar eruptions status," McDermott says.

Replicating the findings

Those findings derived from just 117 participants, so although the correlation was clear, Mackey and McDermott hoped to replicate what they'd seen.

Collaborators at the University of Missouri-Kansas City told them about a large population-representative dataset called the National Health and Nutrition Examination Survey (NHANES), which is publicly available and includes dental data, demographic data, and family income, among other measures.

"Because our sample is only from one city and is much smaller than a population-representative study like that," McDermott says, "we saw it as an opportunity to verify that the findings exist outside of what we had collected in Philadelphia."

Though some facets differed -- NHANES measures dental development a little differently, for example -- the models showed similar results, indicating a connection between lower family income and earlier first molars.

Whether this overall trend is new or just now coming to light is something Mackey wants to study further. She's also curious about when the rate of maturation gets set. "Is it as early as in utero or is it dynamically adjusted based on stressors in the world?" she says. "If it's the latter, that tells you there are more opportunities to intervene."

Present implications, future work

There are still significant unknowns, as well as findings that need further examination, Mackey says. For example, the research team found racial disparities in this timing, with first molars emerging in Black children sooner than in white children.

"These race differences in molar eruption have been known for a long time, but no one thought critically about where they came from," she says. "It's consistent with higher levels of stress due to structural racism. This is a clear indication that it's not just speculation that experiences with racism can cause stress and early aging. They are having an effect on kids that we can't ignore."

For all children, a year-plus of pandemic-driven grief and social isolation most certainly amplified stress levels, making it even more important to understand who is at greatest risk for early maturation, Mackey says.

Yet she and McDermott emphasize that molar timing shouldn't become another parental fear. "What I really don't want is for parents to either worry or feel complacent just based on when their kids got their molars," says Mackey. "We don't have those data yet."

The Penn researchers are working on it. In the future, they hope to collaborate with dental offices to recruit children into studies based on their molar-eruption status. The goal would be to follow them into adulthood, to get more information on what precisely early first molars may indicate. "If this is the meaningful discovery that I think it is," Mackey says, "I would love for many scientists to jump on board and test these hypotheses."

Funding for this research came from the Jacobs Foundation, National Institute on Drug Abuse (Grant 1R34DA050297-01), and National Science Foundation.What would help, she thought, was a scalable, objective way -- a physical manifestation, of sorts -- to indicate how children embodied and responded to stresses in their world. Eruption timing of the first permanent molars proved to be just that.

Could Losing Your Wisdom Teeth Enhance Your Sense of Taste?

So claims a new study that challenges previous research on the issue.

"Prior studies have only pointed to adverse effects on taste after extraction, and it has been generally believed that those effects dissipate over time," said study senior author Richard Doty. He is director of the Smell and Taste Center at the University of Pennsylvania, in Philadelphia.

"This new study shows us that taste function can actually slightly improve between the time patients have surgery and up to 20 years later," Doty said in a Penn Medicine news release. "It's a surprising but fascinating finding that deserves further investigation to better understand why it's enhanced and what it may mean clinically."

For the study, the investigators analyzed data from 1,255 people who were evaluated at the smell and taste center over 20 years. Of those, 891 had undergone wisdom tooth extraction and 364 had not.

The participants were tested on their ability to detect sweet, salty, sour or bitter tastes. For all four tastes, the wisdom tooth extraction group outperformed the control group, according to the study published recently in the journal Chemical Senses.

People who've had wisdom teeth extracted typically have an average 3% to 10% long-term improvement in their ability to taste, the researchers concluded.

There are two possible explanations, the study authors suggested.

Wisdom tooth extraction may damage nerves that control taste buds in the front of the mouth, which releases restrictions on nerves that control taste buds in the back of the mouth, boosting whole-mouth sensitivity.

The second possibility is that nerve damage from wisdom tooth extraction may cause taste hypersensitivity, according to the report.

"Further studies are needed to determine the mechanism or mechanisms behind the extraction-related improvement in taste function," Doty said. "The effects are subtle, but may provide insight into how long-term improvement in neural function can result from altering the environment in which nerves propagate."

How teeth sense the cold

"It's a unique kind of pain," says David Clapham, vice president and chief scientific officer of the Howard Hughes Medical Institute (HHMI). "It's just excruciating."

Now, he and an international team of scientists have figured out how teeth sense the cold and pinpointed the molecular and cellular players involved. In both mice and humans, tooth cells called odontoblasts contain cold-sensitive proteins that detect temperature drops, the team reports March 26, 2021, in the journal Science Advances. Signals from these cells can ultimately trigger a jolt of pain to the brain.

The work offers an explanation for how one age-old home remedy eases toothaches. The main ingredient in clove oil, which has been used for centuries in dentistry, contains a chemical that blocks the "cold sensor"protein, says electrophysiologist Katharina Zimmermann, who led the work at Friedrich-Alexander University Erlangen-Nürnberg in Germany.

Developing drugs that target this sensor even more specifically could potentially eliminate tooth sensitivity to cold, Zimmermann says. "Once you have a molecule to target, there is a possibility of treatment."

Mystery channel

Teeth decay when films of bacteria and acid eat away at the enamel, the hard, whitish covering of teeth. As enamel erodes, pits called cavities form. Roughly 2.4 billion people -- about a third of the world's population -- have untreated cavities in permanent teeth, which can cause intense pain, including extreme cold sensitivity.

No one really knew how teeth sensed the cold, though scientists had proposed one main theory. Tiny canals inside the teeth contain fluid that moves when the temperature changes. Somehow, nerves can sense the direction of this movement, which signals whether a tooth is hot or cold, some researchers have suggested.

"We can't rule this theory out," but there wasn't any direct evidence for it, says Clapham a neurobiologist at HHMI's Janelia Research Campus. Fluid movement in teeth -- and tooth biology in general -- is difficult to study. Scientists have to cut through the enamel -- the hardest substance in the human body -- and another tough layer called dentin, all without pulverizing the tooth's soft pulp and the blood vessels and nerves within it. Sometimes, the whole tooth "will just fall to pieces," Zimmermann says.

Zimmerman, Clapham, and their colleagues didn't set out to study teeth. Their work focused primarily on ion channels, pores in cells' membranes that act like molecular gates. After detecting a signal -- a chemical message or temperature change, for example -- the channels either clamp shut or open wide and let ions flood into the cell. This creates an electrical pulse that zips from cell to cell. It's a rapid way to send information, and crucial in the brain, heart, and other tissues.

About fifteen years ago, when Zimmermann was a postdoc in Clapham's lab, the team discovered that an ion channel called TRPC5 was highly sensitive to the cold. But the team didn't know where in the body TRPC5's cold-sensing ability came into play. It wasn't the skin, they found. Mice that lacked the ion channel could still sense the cold, the team reported in 2011 in the journal Proceedings of the National Academy of Sciences.

After that, "we hit a dead end," Zimmermann says. The team was sitting at lunch one day discussing the problem when the idea finally hit. "David said, 'Well, what other tissues in the body sense the cold?' Zimmermann recalls. The answer was teeth.

The whole tooth

TRPC5 does reside in teeth -- and more so in teeth with cavities, study coauthor Jochen Lennerz, a pathologist from Massachusetts General Hospital, discovered after examining specimens from human adults.

A novel experimental set up in mice convinced the researchers that TRPC5 indeed functions as a cold sensor. Instead of cracking a tooth open and solely examining its cells in a dish, Zimmermann's team looked at the whole system: jawbone, teeth, and tooth nerves. The team recorded neural activity as an ice-cold solution touched the tooth. In normal mice, this frigid dip sparked nerve activity, indicating the tooth was sensing the cold. Not so in mice lacking TRPC5 or in teeth treated with a chemical that blocked the ion channel. That was a key clue that the ion channel could detect cold, Zimmermann says. One other ion channel the team studied, TRPA1, also seemed to play a role.

The team traced TRPC5's location to a specific cell type, the odontoblast, that resides between the pulp and the dentin. When someone with a a dentin-exposed tooth bites down on a popsicle, for example, those TRPC5-packed cells pick up on the cold sensation and an "ow!" signal speeds to the brain.

That sharp sensation hasn't been as extensively studied as other areas of science, Clapham says. Tooth pain may not be considered a trendy subject, he says, "but it is important and it affects a lot of people."

Zimmermann points out that the team's journey towards this discovery spanned more than a decade. Figuring out the function of particular molecules and cells is difficult, she says. "And good research can take a long time."

People with severe gum disease may be twice as likely to have increased blood pressure

Adults with periodontitis, a severe gum infection, may be significantly more likely to have higher blood pressure compared to individuals who had healthy gums, according to new research published today in Hypertension, an American Heart Association journal.

Previous studies have found an association between hypertension and periodontitis, however, research confirming the details of this association is scarce. Periodontitis is an infection of the gum tissues that hold teeth in place that can lead to progressive inflammation, bone or tooth loss. Prevention and treatment of periodontitis is cost effective and can lead to reduction of systemic markers of inflammation as well as improvement in function of the endothelium (thin membrane lining the inside of the heart and blood vessels).

"Patients with gum disease often present with elevated blood pressure, especially when there is active gingival inflammation, or bleeding of the gums," said lead study author Eva Muñoz Aguilera, D.D.S., M.Clin.Dent., senior researcher at UCL Eastman Dental Institute in London, United Kingdom. "Elevated blood pressure is usually asymptomatic, and many individuals may be unaware that they are at increased risk of cardiovascular complications. We aimed to investigate the association between severe periodontitis and high blood pressure in healthy adults without a confirmed diagnosis of hypertension."

The study included 250 adults with generalized, severe periodontitis (≥50% of teeth measured with gum infection) and a control group of 250 adults who did not have severe gum disease, all of whom were otherwise healthy and had no other chronic health conditions. The median age of the participants was 35 years, and 52.6% were female. The research was completed in collaboration with the department of dentistry at the Universitat Internacional de Catalunya in Barcelona, Spain.

All participants underwent comprehensive periodontal examinations including detailed measures of gum disease severity, such as full-mouth dental plaque, bleeding of the gums and the depth of the infected gum pockets. Blood pressure assessments were measured three times for each participant to ensure accuracy. Fasting blood samples were also collected and analyzed for high levels of white blood cells and high sensitivity C-reactive protein (hsCRP), as both are markers of increased inflammation in the body. Additional information analyzed as confounders included family history of cardiovascular disease, age, body mass index, gender, ethnicity, smoking and physical activity levels.

The researchers found that a diagnosis of gum disease was associated with higher odds of hypertension, independent of common cardiovascular risk factors. Individuals with gum disease were twice as likely to have high systolic blood pressure values ?140 mm Hg, compared to people with healthy gums (14% and 7%, respectively). Researchers also found:

The presence of active gum inflammation (identified by bleeding gums) was associated with higher systolic blood pressure.

Participants with periodontitis exhibited increased glucose, LDL ("bad" cholesterol), hsCRP and white blood cell levels, and lower HDL ("good" cholesterol) levels compared to those in the control group.

Nearly 50% of participants with gum disease and 42% of the control group had blood pressure values for a diagnosis of hypertension, defined as ?130/80 mmHg.

"This evidence indicates that periodontal bacteria cause damage to the gums and also triggers inflammatory responses that can impact the development of systemic diseases including hypertension," said corresponding author Francesco D'Aiuto, D.M.D., M.Clin.Dent., Ph.D., professor of periodontology and head of the periodontology unit at the UCL Eastman Dental Institute. "This would mean that the link between gum disease and elevated blood pressure occurs well before a patient develops high blood pressure. Our study also confirms that a worryingly high number of individuals are unaware of a possible diagnosis of hypertension."

D'Aiuto added, "Integration of hypertension screening by dental professionals with referrals to primary care professionals and periodontal disease screening by medical professionals with referrals to periodontists could improve detection and treatment of both conditions to improve oral health and reduce the burden of hypertension and its complications. Oral health strategies such as brushing teeth twice daily are proven to be very effective in managing and preventing the most common oral conditions, and our study's results indicate they can also be a powerful and affordable tool to help prevent hypertension."

This study did not account for other factors that may also impact blood pressure, such as abdominal obesity, salt intake, use of anti-inflammatory medications, hormone treatments or stress, or any other oral health conditions.