Every parent has witnessed it: A toddler takes a bad tumble, a youngster flies off their bike, a Little Leaguer has an unfortunate encounter with an errant baseball. Ideally, it’s nothing a Band-Aid, some ice, and a big kiss can’t make better.

Sometimes, though, it’s more severe, and that can include an injury to the teeth and mouth. Up to one-third of children and teenagers experience what is known as “dental trauma” at some point as they grow up, whether to their primary (“baby”) or permanent teeth. Falls are the most common culprit, followed by sports injuries, car accidents, fights, and biting on hard objects. And there can be long-term consequences, especially if a permanent tooth is knocked out.

“There are few true emergencies in dentistry. A permanent tooth that’s knocked out is one of them,” says Zameera Fida, chair of the Department of Endodontics at Tufts University School of Dental Medicine. A tooth stands the best chance of being able to be reattached if it’s been outside the mouth for less than an hour, so time is of the essence.

One of the best things parents can do to speed reaction time and reduce anxiety can happen before an injury even occurs: Discuss emergency procedures with a dentist ahead of time, says Fida, who is trained and board certified in both endodontics and pediatric dentistry.

“Have a good relationship with your dentist, and find out what sorts of emergency services they provide,” she says. “So if you do end up in this situation, especially after hours or on a weekend, you can get help.”

Fida talked with Tufts Now about what parents and other caregivers should do when there’s an injury to a child’s mouth, and how these accidents can affect future oral health.

When are kids most likely to experience a traumatic dental injury?

There’s a peak in trauma around age two to three, when toddlers are more mobile. They’re curious, but they might not be totally stable. And then we see a second peak in the 8 to 11 age range, when kids have their permanent teeth but they’re becoming more adventurous, trying new activities, and their dental occlusion, or how their teeth are growing in, is not quite stable yet.

What can parents and other adults do to try and prevent these injuries?

For sports, be mindful of the activity the child is participating in and use the right kind of protective gear, which could include not just mouth guards but also helmets to protect the head and neck. For sports where there’s less of a head injury potential, have that mouth guard in so the teeth, lips, and gums can be protected.

Aside from sports injuries, there are accidents that you can’t really account for. The best thing you can do is be as safe as possible. Wear your seat belts.

Also, kids with different dental appearances will be at different risks. A child whose upper jaw is a little bit more pronounced, where the teeth are a little bit more visible, is going to be at higher risk than a child who has a flatter face.

What are the most common types of dental injuries in children?

It’s more common to have injuries where the teeth are fractured or broken. It could be the enamel, or even in the deeper layers of the tooth structure—the middle layer, called the dentin, which is a little softer, and the innermost layer, the pulp, which is composed of nerve and blood vessels and other kinds of tissue.

The deeper the crack or fracture, the more involved the treatment of it might be. The closer the crack or fracture gets to the pulp, then the higher the likelihood for pain, discomfort, and sensitivity, and the higher the likelihood that the tooth might need to have a root canal treatment.

What is a root canal?

If the pulp is damaged, it can become a source of infection. The purpose of the root canal treatment is to remove that damaged or infected pulp tissue and replace it with a biocompatible material. A root canal treatment in an 8- to 11-year-old may look very different than in an older adult. It will be helpful to find out if your dentist is comfortable in managing the differences.

What if a tooth is knocked out completely?

The best thing a parent or anybody can do is to get that permanent tooth back into the socket where it was knocked out, as soon as possible. This works for patients of any age, including adults.

But if you can’t get the tooth back into the socket, you want to make sure that it’s not dry, that it stays hydrated in some capacity. Milk is a great liquid to put the tooth in and one that most people have at home. You could do something like saline solution. Water is not ideal, because the chemical composition of water could potentially be disruptive to the cells of the tooth. But use water if that is all you have; it’s better than the tooth being dry.

What if the tooth is dirty?

It’s really important that even if you’re concerned about the tooth being dirty that you manipulate the root structure as little as possible. So if you’re picking up the tooth, pick it up and hold it by the crown, the part that we see when somebody smiles.

If it’s dirty you can take the tooth, hold it, and gently agitate it in water. You want to minimize having forceful water on the tooth, because that would disrupt those cells that we’re trying to protect.

What next?

If an adult can get that tooth back in the socket, they could then have the child bite down on a piece of gauze or something similar to hold it in place until they’re able to see a dentist to stabilize it.

If you’re not able to get to a dentist, you can try the emergency room. Some emergency rooms will have dentists on staff, or the emergency room physician might be able to help stabilize it. The tooth has to be stabilized with a splint, which looks kind of like a form of braces, to keep the tooth stable until everything heals and reattaches properly.

How long can a tooth be out of the mouth?

Research suggests that if a tooth is out of the mouth for more than an hour, we won’t get the healing of that nerve and blood supply. However, we want to get that tooth back into the socket even if it’s later than an hour. We have newer techniques in dentistry to help manage any complications.

What if a baby tooth falls out from a fall or accident?

If a baby tooth is knocked out, or otherwise lost early through an injury, we don’t want to put that baby tooth back in. We just want to say, OK, the tooth fairy is coming a little bit early.

So that’s the first thing you have to determine: Are you confident it’s a baby tooth?

What if the baby tooth is damaged, but not completely knocked out?

It really depends on the extent of the injury, and the child’s ability to cooperate, because younger children are going to have very different abilities to tolerate treatment than an older child will. Oftentimes, when a baby tooth is injured, we may just monitor it. If the tooth has moved out of position and it’s interfering with how the teeth bite down, or if the child can’t close their mouth all the way properly, we might think about removing the baby tooth completely.

What if a parent isn’t sure how extensive the injury is? Mouth injuries can be bloody.

When there’s a little bit of blood mixed with a mouthful of saliva, it’s going to look like a lot of bleeding, so it can be scary, but try not to panic. Just get to the right health care professional, whether it’s the emergency department or your dentist, for an evaluation.

Any trauma to the teeth can be considered head and neck trauma, so a child needs to be evaluated for any neurologic concerns. The biggest red flag is if a child loses consciousness. Any loss of consciousness is concerning in a child and should be evaluated by a medical professional. If you have any concerns, the neurologic issues should be addressed first, followed by dental care once the child is stable.