Teeth went through bottom lip

When Does a Cut Require Stitches?

Skinned knees, bike accidents, scissors mishaps — the trophies of childhood. As a parent, you’ve no doubt encountered an injury that raised the question: “Does this require stitches?” But how do you know when a cut is serious enough to warrant a trip to the emergency room?

The truth: It’s not always obvious. “It’s a judgment call,” says Ken Haller, MD, an associate professor of pediatrics at Saint Louis University School of Medicine. “Most parents are not doctors and nurses. While we don’t want to risk the child’s health and safety, we also don’t want to subject them — or ourselves — to the stress of a hectic ER.”

Here are some guidelines to help you know when a cut is serious enough to head to the emergency room.

Types of Cuts That Require Stitches

  • What does it look like? “A cut might need stitches if it is deep and gaping,” says Dr. Haller. If you can put your fingers on either side of the cut and gently tug it open, that counts as “gaping.”
  • Does the cut have a flap? “If you see that a part of the skin has been cut into a flap, with a flap of skin kind of popping up, that’s probably a sign that you want to have it looked at,” Haller says. Any deep cut that doesn’t seem to close on its own should probably be looked at by a doctor.
  • Is it still bleeding? “Most thin cuts with no gaping won’t need stitches,” says Haller. “But, if it’s still bleeding several minutes after you’ve been applying pressure, it might be a good idea to have it looked at.” To slow bleeding, apply firm and direct pressure to the cut, using a clean towel or gauze. If possible, elevate the injury above the heart. If blood soaks through the towel, add a new towel without removing the old one.

Cut Locations That Should Get Stitches

  • Face wounds. When it comes to facial cuts, Haller advises that you err on the side of caution. Though not usually more dangerous than other kinds of injuries, facial wounds are more prone to scarring, and facial damage is widely understood to be a source of psychological trauma. He recommends requesting a plastic surgeon to work on face injuries to help avoid scarring.
  • Lip wounds. Even more delicate than facial wounds are cuts through the lip, especially if the cut goes through the lip and into the skin surrounding the lips. “If the vermillion border is cut, it is extremely difficult to match it back up, which can lead to scarring,” Haller says. It’s a good idea to see a plastic surgeon for that type of cut.

Three Tips for Monitoring a Cut

If your child’s injury didn’t warrant a trip to the ER:

  • Keep an eye on how the cut is healing over the next few days.
  • Keep the cut clean and protected.
  • Look for signs of infection, such as redness, warmth, and swelling.

Calling your pediatrician to make sure your child’s tetanus shot is current is also a good idea in the few days after your child is hurt, especially if the injury was deep or caused by something dirty or rusty.

Another good idea: keeping records of your kids’ shots in a handy place. It will make dealing with the trials of childhood a whole lot easier.

Learn more about Kids’ Health.

Cuts and Wounds of the Mouth and Lips

  • Calm your child and let him or her know you can help.

  • Apply pressure with a clean cloth or bandage for several minutes to stop bleeding.

  • Wash your hands well.

  • If the wound is on the lips or outside area of the mouth, wash it well with soap and water, but do not scrub the wound. Remove any dirt particles from the area and let the water from the faucet run over it for several minutes. A dirty cut or scrape that is not well cleaned can cause scarring:

    • Apply an antiseptic lotion or cream.

    • Give your child an ice pop or ice cube to suck on to help reduce bleeding and swelling.

    • Check the area each day and keep it clean and dry.

    • Avoid blowing on the wound, as this can cause germs to grow.

    • Use a sunscreen (sun protection factor, or SPF, at least 15 or greater) on healed cuts and wounds to help prevent scarring.

  • If the wound is inside the mouth, rinse the area well with cool water for several minutes. Remove any dirt particles from the area:

    • Give your child an ice pop or ice cube to suck on to help reduce bleeding and swelling.

    • Check the area each day and keep it clean.

  • Even small lacerations of the lips may cause a noticeable difference in the border or outline of the lips. These wounds may require stitches to keep the borders even and reduce the possibility of scars. Lacerations that occur in the corner of the mouth where the upper and lower lips come together have the potential for very severe bleeding.

  • Bruises, blisters, or swelling on the lips caused by trauma may be treated by sucking on ice pops or ice cubes or by applying a cold pack to the area every one to two hours for 10 to 15 minutes for the first 24 hours.

Cuts: When Stitches Are Needed

Topic Overview

It is important to determine if your wound needs to be closed by a doctor. Your risk of infection increases the longer the wound remains open. Most wounds that require closure should be stitched, stapled, or closed with skin adhesives (also called liquid stitches) within 6 to 8 hours after the injury. Some wounds that require treatment can be closed as long as 24 hours after the injury.

Wash the wound well and stop the bleeding, then pinch the sides of the wound together. If the edges of the wound come together and it looks better, you may want to consider seeing your doctor for treatment. If treatment may be needed, do not use an antiseptic until after a doctor has examined the wound.

The location and type of wound also affects how soon it should be treated.

  • Wounds that have an increased risk of infection, such as dirty cuts or crush injuries, are usually closed within 6 hours after the injury. Occasionally a wound that has an increased risk of infection will not be closed until after 24 hours, or may not be stitched at all, so that adequate cleaning and antibiotic treatment can be done initially to prevent infection.
  • A cut with a clean object, such as a clean kitchen knife, may be treated from 12 to 24 hours after the injury depending on the location of the cut.
  • A facial wound may be treated to reduce scarring.

Treatment by a doctor is more likely to be needed for:

  • Wounds that are more than 0.25 in. (6.5 mm) deep, that have jagged edges, or that gape open.
  • Deep wounds that go down to the fat, muscle, bone, or other deep structures.
  • Deep wounds over a joint, especially if the wound opens when the joint is moved or if pulling the edges of the wound apart shows fat, muscle, bone, or joint structures.
  • Deep wounds on the hands or fingers.
  • Wounds on the face, lips, or any area where you are worried about scarring (for cosmetic reasons). Wounds on the eyelids often need treatment for both functional and cosmetic reasons.
  • Wounds longer than 0.75 in. (20 mm) that are deeper than 0.25 in. (6.5 mm).
  • Wounds that continue to bleed after 15 minutes of direct pressure.

The types of wounds listed above usually need an evaluation by a doctor but may not always need to be closed by a doctor.

Treatment by a doctor may not be needed for:

  • Wounds with smooth edges that stay together during normal movement of the affected body part.
  • Shallow wounds less than 0.25 in. (6.5 mm) deep and less than 0.75 in. (20 mm) long.
  • Most puncture wounds.
    • The wounds tend to be smaller, and treatment does not speed healing or reduce scarring.
    • The wounds tend to be deeper, narrower, and harder to clean. Closing a puncture wound with stitches, staples, or skin adhesive may seal bacteria into it, which increases the risk of infection.
    • If a puncture wound becomes infected, it will usually drain better and heal faster if it is not closed with stitches, staples, or skin adhesive.

Mouth Injury

Is this your child’s symptom?

  • Injuries to the lips and mouth
  • Includes inner cheeks and the roof of the mouth (hard and soft palate)
  • Front of the mouth includes the tongue. Also, includes the flap under the upper lip (frenulum).
  • Back of the mouth includes the tonsils and the throat
  • Tooth injuries are not covered here

Types of Mouth Injuries

  • Tongue. Cuts of the tongue or inside of the cheeks are the most common mouth injury. Usually, due to accidentally biting them during eating. Bites of the tongue rarely need sutures. Even if they gape open a little, the cuts usually heal quickly. If the edges come together when the tongue is still, it needs no treatment.
  • Upper Lip. Cuts and bruises of the upper lip are usually due to falls. The piece of tissue joining the upper lip to the gum is the frenulum. A tear of the upper frenulum is very common. It always heals without sutures. However, it will rebleed every time you pull the lip out to look at it.
  • Lower Lip. Cuts of the lower lip are usually caused by the teeth. They occur when catching the lip between the upper and lower teeth while falling. Most of these cuts do not connect (don’t go through the lip). These do not need sutures unless the outer cut is gaping.
  • Serious injuries are those to the tonsil, soft palate, or back of the throat. Examples of these injuries include falling with a pencil or toothbrush in the mouth. Puncture wounds here can cause a deep space infection in the neck.

When to Call for Mouth Injury

Call 911 Now

  • Major bleeding that can’t be stopped
  • Trouble breathing
  • You think your child has a life-threatening emergency

Call Doctor or Seek Care Now

  • Gaping cut of tongue or inside the mouth that may need stitches
  • Gaping cut of the lip that may need stitches
  • Severe pain and not better 2 hours after taking pain medicine
  • Trouble swallowing fluids or spit
  • Can’t fully open or close the mouth
  • Fever and mouth looks infected. Signs are increasing pain or swelling after 48 hours. Note: it’s normal for a healing wound in the mouth to be white.
  • You think your child has a serious injury
  • You think your child needs to be seen, and the problem is urgent

Call Doctor Within 24 Hours

  • Mouth looks infected and no fever
  • You think your child needs to be seen, but the problem is not urgent

Call Doctor During Office Hours

  • You have other questions or concerns

Self Care at Home

  • Minor mouth injury

Seattle Children’s Urgent Care Locations

If your child’s illness or injury is life-threatening, call 911.

Care Advice for Minor Mouth Injuries

  1. Upper Lip and Frenulum Bleeding – How To Stop:
    • Cuts of the inside of the upper lip are very common.
    • Often, the piece of tissue that connects the upper lip to the upper gum is torn. This tissue is called the upper labial frenulum.
    • The main symptom is oozing tiny amounts of blood.
    • This cut always heals perfectly without sutures.
    • For bleeding from the frenulum, use direct pressure. Press the outer lip against the teeth for 10 minutes.
    • Caution: Once bleeding has stopped, don’t pull the lip out to look at it. Reason: The bleeding will start up again.
    • It’s safe to look at it after 3 days.
  2. Lower Lip Bleeding – How to Stop:
    • Most children who fall and bite their lower lip have 2 cuts. They have cuts to both the outside and inside of the lip.
    • Catching the lower lip between the upper and lower teeth causes the 2 cuts. This tends to happen in children with an overbite.
    • Most of these small cuts do not connect with each other.
    • For bleeding from the lip, use direct pressure. Press the outer lip against the teeth for 10 minutes.
  3. Tongue Bleeding – How to Stop:
    • Bites of the tongue rarely need sutures.
    • Even if they gape open a little, tongue cuts usually heal quickly. If the edges come together when the tongue is still, it needs no treatment.
    • For tongue bleeding, try to press on the bleeding site with a sterile gauze. You can also use a piece of clean cloth. Do this for 5 minutes if it’s practical.
    • Cuts of the tongue normally tend to ooze a little blood for several hours. This is due to the rich blood supply in the mouth.
    • For constant oozing of blood, can use a moistened tea bag for 10 minutes. (Reason: tannic acid released from the tea bag may stop the oozing).
  4. Cold for Pain:
    • Put a piece of ice or popsicle on the spot that was injured.
    • You can also use a cold wet washcloth.
    • Do this for 20 minutes.
  5. Pain Medicine:
    • To help with the pain, give an acetaminophen product (such as Tylenol).
    • Another choice is an ibuprofen product (such as Advil).
    • Use as needed.
  6. Soft Diet:
    • Try to get your child to drink adequate fluids.
    • Goal: Keep your child well hydrated.
    • Cold drinks, milk shakes, popsicles, slushes, and sherbet are good choices.
    • Solids. Offer a soft diet. Also avoid foods that need much chewing. Avoid citrus, salty, or spicy foods.
    • Rinse the wound with warm water right away after meals.
  7. What to Expect:
    • Small cuts and scrapes inside the mouth heal up in 3 or 4 days.
    • Infections of mouth injuries are rare.
  8. Call Your Doctor If:
    • Pain becomes severe
    • Mouth looks infected (mainly increasing pain or swelling after 48 hours)
    • Fever occurs
    • You think your child needs to be seen
    • Your child becomes worse

And remember, contact your doctor if your child develops any of the ‘Call Your Doctor’ symptoms.

Disclaimer: this health information is for educational purposes only. You, the reader, assume full responsibility for how you choose to use it.

Last Reviewed: 02/01/2020

Last Revised: 03/14/2019

Copyright 2000-2019 Schmitt Pediatric Guidelines LLC.

Traumatic Injuries of the Lips and Tongue

What Is It?

Trauma to the lips, tongue and the inside of the mouth is quite common. The soft flesh of the lips and their exposed location make them vulnerable to injury. A blow to the face can crush your lips against your teeth, causing bruising or cuts. Your teeth can cut the inside of your lip or puncture your skin. A fall or blow may cause you to bite your tongue.

Any cut inside the mouth usually bleeds heavily because of the rich supply of blood to the area.


Symptoms include bruising, swelling, bleeding or cuts on the lips or tongue.


Your dentist or physician will ask about what happened to cause your recent trauma and do a thorough physical exam of the area. If the lips are injured, he or she will check the teeth and bone for damage, and look for pieces of chipped tooth.

Expected Duration

The healing time for a lip or tongue injury will depend on how badly it is cut. However, the mouth has many blood vessels, which promotes quick healing.


Many lip and tongue injuries occur during sports or other active pastimes. They often could be prevented through the use of a safety mouth guard. Mouth guards are made of soft plastic that is adapted to fit the shape of the upper teeth. Guards made for heavier contact sports may cover both the upper and lower teeth. Mouth guards protect both the lips and teeth by providing a shield in front of the teeth and a softer biting surface for the back teeth. Preformed guards are available in sporting goods stores. A dentist can create a custom-fit guard.

Routinely using seat belts and car seats can reduce the risk of trauma as a result of car accidents.


At home, you can clean injured skin surfaces with mild soapy water and a soft, clean cloth. To clean cuts inside the mouth, rinse with salt water or a hydrogen peroxide solution (one part hydrogen peroxide and one part water). Be sure not to swallow this peroxide rinse. However, do not be concerned if it foams. This is what the rinse normally does when it contacts mouth tissue.

If your lip is swollen or bruised, apply a cold compress. If there is bleeding, apply pressure with a clean cloth for at least five minutes. Using ice can help limit swelling, bleeding and discomfort. Wrap crushed ice in clean gauze or a clean piece of cloth and hold it on the area affected.

Certain injuries will require treatment by an oral surgeon or plastic surgeon. It is particularly important to have an experienced surgeon stitch cuts that cross the vermilion border. This is the line that forms the junction between the skin and the fleshy part of the lip. Experience is required to make sure this boundary heals correctly. Even a small irregularity will remain noticeable.

The doctor will first thoroughly clean the wound with lots of saline or a hydrogen peroxide rinse. Cleaning removes bacteria as well as foreign matter such as dirt that might have entered the wound. A betadine solution will then be applied to the area to disinfect it. Puncture wounds to the lip will then be closed from the inside out. Stitching all layers reduces the chance of scarring..

Small puncture wounds in the tongue usually heal without any treatment other than cleansing with antiseptic or hydrogen peroxide rinses. Large cuts may require stitches.

The mouth contains many bacteria. For this reason, an antibiotic often is prescribed after a cut to the lip or tongue to prevent infection.

When To Call a Professional

Seek medical care if:

  • Bleeding cannot be controlled with pressure and a cold compress
  • You have a deep cut
  • A cut crosses the border between the lip and facial skin
  • The lip is punctured
  • An infection develops after an injury — Signs of any infection usually will be evident about four days after the injury. Signs include:
    • Redness
    • Tenderness
    • Fever
    • Drainage of pus
    • Swelling

If a tooth is loose or broken, visit your dentist.


The outlook is excellent. The rich blood supply in the mouth promotes rapid healing, often with little scarring.

5 year old bit through lip (pic included – not for faint hearted!)

12 hours ago my 5 year old fell face first off a bed. He was sitting on his knees, slipped and has managed to bite through his lip.
First picture was taken an hour after it happened, after he had held a tissue on it for an hour.
I took that picture while we were in the doctors – nurse cleaned it up and put a steristrip on it.
Second picture was when he was in bed 4 hours after it had happened.
I won’t be sending him to school today because I’ve just checked him and accidentally woke him up. He says it still hurts (understandable!). I’ve given him nurofen which is what the nurse suggested for the pain and swelling.
He was sick after it happened, and felt tired – down to shock. So I got him straight down doctors. He was so brave and let the nurse look.
He’s grazed the inside of his lip with his bottom teeth, and we can only assume it’s his top teeth that have caused the wound on the outside. Luckily his teeth aren’t damaged, he just has all baby teeth still and they haven’t got wobbly either!
BUT where his lips have swelled up, he’s dribbling. So the steristrips aren’t staying on! It doesn’t matter how much I try to dry it, the dribble still seems to gravitate there! Cleaned it before bed with the sterile saline water the nurse gave me.
I’m wondering if I should try get him back down the docs today. We only live 5 minute walk away so it’s not that bad.
This morning, it’s looking a bit gunky and yellowy. After some thorough googling – I think that’s where the tissue is trying to fix itself. But can often be confused with an infection.
I can take a picture of it when he’s awake (don’t want to accidentally wake him again!).
How do I know if it’s infected or if it’s healing! Nurse said to keep the strips on, but they just won’t stay on because of the dribble!

Patient Education

Lip or Mouth Laceration

A laceration is a cut through the skin. When the cut is on the outside of the lip, it may be closed with stitches. Cuts inside the mouth may be stitched or left open, depending on the size. When stitches are used in the mouth, they are usually the kind that dissolve on their own.

A tetanus shot may be given if you are not current on this vaccine and the object that caused the cut may lead to tetanus.

Home care

  • If you were given an antibiotic to prevent infection, don’t stop taking this medicine until you have finished it all or the healthcare provider tells you to stop.

  • The healthcare provider may prescribe medicines for pain. Follow instructions for taking these medicines.

  • Follow the healthcare provider’s instructions on how to care for the cut.

  • Wash your hands with soap and warm water before and after caring for your cut. This helps prevent infection.

  • If the cut is inside your mouth, clean the wound by rinsing your mouth after each meal and at bedtime with a mixture of equal parts water and hydrogen peroxide. (Don’t swallow!) Or you can use a cotton swab to apply hydrogen peroxide directly onto the cut. You may also be prescribed chlorohexidine to swish and spit to keep the wound clean.

  • Mouth wounds can cause pain when chewing. Soft foods can help with this. If needed, use an over-the-counter numbing solution for pain relief, such as one for teething babies. Put this directly to the wound with a cotton-tip swab or your clean finger.

  • If the wound is bandaged, leave the original bandage in place for 24 hours. Replace it if it becomes wet or dirty. After 24 hours, change it once a day or as directed.

  • If the cut is on the outside of the lip and stitches were used, you may shower as usual after the first 24 hours, but don’t put your head under water or swim until the sutures are removed. After removing the bandage, wash the area with soap and water. Use a wet cotton swab to loosen and remove any blood or crust that forms. After cleaning, keep the wound clean and dry. Talk with your healthcare provider before applying any antibiotic ointment to the wound. You may apply an adhesive bandage or leave the wound open. Unless told otherwise, stitches on the inside of the mouth will likely dissolve on their own.

Follow-up care

Follow up with your healthcare provider, or as directed. If you have stitches that don’t dissolve on their own, return as directed to have them removed.

When to seek medical advice

Call your healthcare provider right away if any of these occur:

  • Wound bleeding not controlled by direct pressure

  • Signs of infection, including increasing pain in the wound, increasing wound redness or swelling, or pus or bad odor coming from the wound

  • Fever of 100.4°F (38.ºC) or higher, or as directed by your healthcare provider

  • Stitches come apart or fall out

  • Wound edges reopen

  • Wound changes colors

  • Numbness around the wound

Lip Laceration: Care Instructions

How can you care for yourself at home?

  • Put ice or a cold pack on the area for 10 to 20 minutes at a time. Put a thin cloth between the ice and your skin.
  • If the cut is inside your mouth:
    • Rinse your mouth with warm salt water right after meals. Saltwater rinses may help healing. To make a saltwater solution for rinsing the mouth, mix 1 tsp of salt in 1 cup of warm water.
    • Eat soft foods that are easy to chew. Avoid foods that might sting. These include salty or spicy foods, citrus fruits or juices, and tomatoes.
    • Try using a topical medicine, such as Orabase, to reduce mouth pain.
  • Do not use a straw until your lip is healed.
  • If your doctor told you how to care for your cut, follow your doctor’s instructions. If you did not get instructions, follow this general advice:
    • After the first 24 to 48 hours, wash around the cut with clean water 2 times a day. Don’t use hydrogen peroxide or alcohol, which can slow healing.
  • If you have strips of tape on the cut, leave the tape on for a week or until it falls off.
  • If your doctor prescribed antibiotics, take them as directed. Do not stop taking them just because you feel better. You need to take the full course of antibiotics.
  • Be safe with medicines. Read and follow all instructions on the label.
    • If the doctor gave you a prescription medicine for pain, take it as prescribed.
    • If you are not taking a prescription pain medicine, ask your doctor if you can take an over-the-counter medicine.
  • Avoid any activity that could cause the cut to reopen.
  • Do not remove the stitches on your own. Your doctor will tell you when to come back to have the stitches removed.

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