WISDOM TEETH
AND WHAT TO DO ABOUT THEM
Wisdom teeth (also called "third molars") usually do not push through the gums until people are in their late teens, twenties or even older. Wisdom teeth are usually the last teeth to come through the gums.
Most people have four wisdom teeth. Some people have no wisdom teeth. In many people, not enough space is at the rear of the jaws for wisdom teeth to come easily through the gums. If the jaw does not have enough space for the wisdom tooth to come through, the tooth will become wedged in or "impacted".
Some impacted wisdom teeth remain in place and cause no trouble. However, other impacted wisdom teeth cause severe problems.
Often one or more wisdom teeth will cause problems and must be removed. If one (or more) of your wisdom teeth causes problems, your dentist may recommend that it be removed. Removal of a wisdom tooth is a very common procedure. Removal of troublesome wisdom teeth should be usually be done as soon as possible before the problems get worse.
If your wisdom teeth are likely to be very difficult or complicated to remove, your dentist may refer you to an oral and maxillofacial surgeon. Due to the shape and position of some wisdom teeth and the shape of the jaws, it may be preferable in some cases for an oral and maxillofacial surgeon to remove the teeth.
THE DECISION TO REMOVE TEETH
After inspecting your mouth, jaws and X-ray films, your dentist can discuss the diagnosis with you.
Your dentist may recommend removal of one or more wisdom teeth or other options.
If the area around the tooth has been infected, your dentist may decide to delay surgery while infection is treated.
Even though a wisdom tooth has caused problems, it may "settle down" after it pushes through the gum. Tour dentist may delay surgery to see if the tooth stops causing problems.
While implacted wisdom teeth may cause problems, some never cause trouble and may not need to be removed.
The decision to have wisdom teeth removed is always yours.
EARLY REMOVAL OF WISDOM TEETH
Your dentist may recommend early removal of one or more wisdom teeth due to the following reasons:
There is not enough room for the tooth to push through.
You need orthodontic work, and the remaining teeth must not be crowded by wisdom teeth.
The tooth has started to cause trouble. It should be removed soon so that pain, infection or other problems do not get worse.
It is best to have troublesome wisdom teeth removed while the patient is young. In young people, a tooth's roots have not formed totally, and the bone surrounding the tooth is softer. This allows for easier removal of the tooth and less risk of damage to nerves, bone or other teeth.
PROBLEMS CAUSED BY IMPACTED WISDOM TEETH
INFECTION
When an impacted wisdom tooth starts to push through the gum, an infection can start around the top of the tooth. Infection and inflammation (swollen, red gums) can cause pain, swelling, and jaw stiffness. The infection can cause bad breath and an unpleasant taste.
Swallowing may be painful. The person may feel generally unwell.
CROWDING
A wisdom tooth may push nearby teeth out of their correct position.
PAIN
Pressure from the wisdom tooth may cause pain in the tooth next to it. Pain can also be caused by infection around the wisdom tooth.
CYST
If a wisdom tooth is not removed, a sac of fluid called a cyst can form around the tooth and may displace the tooth. The cyst can destroy bone and damage other teeth and the gums. Cyst formation around unerupted teeth is fairly common.
ULCER
An upper wisdom tooth may push sideways out of the gum. It may cause an ulcer where it rubs against inside of the cheek.
A FOOD TRAP
Food becomes trapped between the wisdom tooth and the molar next to it. This can cause cavities in both teeth.
RESORPTION CAVITY
An impacted wisdom tooth may keep pushing against the molar next to it. This can cause a resorption cavity where the wisdom tooth hits the other molar. This often leads to serious damage to both teeth.
The molars may become infected or abscessed. Removal of both molars is often needed. Resorption cavities are uncommon.
TREATMENT OF INFECTION
Your dentist may gently clean the infected area around the tooth. You may be advised to rinse your mouth often with a warm saltwater mouthwash. Use one teaspoon of salt in a glass of warm water. The water should be as warm as possible, but not too hot.
Your dentist may also suggest a disinfectant mouthwash and a pain killer. Your dentist may prescribe antibiotics.
If a lower wisdom tooth is infected, it can be made worse by the upper wisdom tooth biting down on to the gums. The patient can be helped by removal of the upper wisdom tooth.
DENTAL & MEDICAL HISTORY
Tell your dentist your complete dental and medical history. This helps your dentist plan the best possible treatment.
Some health problems may interfere with surgery, anaesthesia and care after surgery. Your dentist may recommend blood tests or other health tests.
Medicines: Give your dentist a list of all medicines you are taking now or have been taking. This includes "Pill" and any over-the-counter medicines, such as aspirin or cough medicines. Tell your dentist if you have ever had any type of allergic or bad reaction to antibiotics or any other medicine.
Pregnancy: Tell your dentist if you are or may be pregnant. This could affect your treatemnets, including:
• anaesthesia
• pain treatment
• antibiotic and other medicines
• whether surgery should be delayed.
Dental X-ray films can be safely taken as the X-ray beam is not pointed at the uterus.
Bleeding or blood disorders: Tell your dentist if you:
• bleed a lot when you are injured or have surgery
• have any blood disorders, such as haemophilia
• are taking any blood thinners such as aspirin, warfarin or clopidogrel, among others.
Smoking: Stop smoking two weeks before the surgery. Smoking impairs healing and increases the risk of post-operative infection.
X-RAY EXAMINATION
Your dentist needs to take X-ray films of your jaw. The films will help your dentist plan the best way to remove troublesome wisdom teeth.
WHERE TO HAVE SURGERY
Your dentist will advise you whether your wisdom teeth should be removed in the surgery, in a hospital or in a day-surgery clinic.
ANAESTHESIA
After discussion with your dentist, a decision will be made whether the wisdom tooth will be removed under local or general anaesthesia. Discuss the options with your dentist.
Local anasthesia: If the surgery is fairly simple, your dentist may give you a local anaesthetic with a needle. The local anaesthetic will numb the gums and lower parts of the face.
The dentist can then extract the tooth. Your dentist may give you a tablet to help you relax during the surgery.
General anaesthesia: For some people, the dentist may recommend general anaesthesia, that is, putting them to sleep with an injection.
General anaesthesia is given by a specialist anaesthetist. General anaesthesia may be used in people who:
• have wisdom teeth that may be more difficult to remove
• do not want to remain awake during the surgery
• have other problems with their wisdom teeth, gums and jaws
• need multiple teeth to be removed.
NOTE: For six hours before surgery under a general anaesthetic, do not eat or drink anything. If your surgery will be done in the morning, do not eat or drink after midnight the night before.
Your dentist or anaesthetist will give you full instruction.
Modern anaesthesia is safe with few risks. However, a few people may have serious reactions to them. If you have ever had a reaction to an anaesthetic drug, tell your dentist.
REMOVAL OF WISDOM TEETH
Your dentist will have to make an incision to open your gums to remove the wisdom tooth. A small portion of the bone may have to be removed so your dentist can get to the tooth.
The tooth may have to be divided into segments so it can be removed easily and safely.
The incision in your gums may have to be closed with stitches.
Some stitches dissolve after a few days. Other stitches will be removed by your dentist.
AFTER THE SURGERY
After the tooth or teeth have been removed, you will have to rest for a while before you go home. Your dentist will check on you as you recover.
Do not drive after surgery. A family member or friend should take you home. Arrange this well in advance.
When your dentist is satisfied with your recovery, you can go home.
If you have been staying in hospital, you will return to your room when you recover from the anaesthetic.
TAKING CARE OF YOURSELF
• Rest at home after the surgery.
• Do not drive, engage in active exercise, or operate machinery
• Take several days off work, school or other duties.
• Do not drink alcoholic drinks while you are taking antibiotics or pain killers.
• Eat soft foods such as soups, blended (pureed) vegetables and meats, and gelatine for the first two days.
• Drink lots of water.
• Use ice packs to reduce swelling and pain.
PAIN RELIEF AFTER SURGERY
Pain may be minor in some people and greater in others. Your dentist will prescribe a pain reliever for you.
If you are uncertain about the best pain relief medicine for you, ask your dentist. Pain usually starts to decrease after the second day. However, some people may still need pain relief after one week.
If your pain does not decrease as the days go by, tell your dentist. Further pain management may be needed.
CONTROL OF BLEEDING
You can apply pressure over the area of bleeding by biting gently but firmly on a piece of cotton gauze.
The pressure helps stop bleeding, and a blood clot forms. It is important not to disturb the area or bleeding may start again. The gums may ooze blood slightly for a day after surgery.
Any bleeding should stop by the second day. If bleeding does not stop, contact your dentist.
SWELLING
Swelling almost always occurs after surgery and can vary from a little to severe. Most swelling takes four to five days to go down completely.
Swelling can be reduced by applying ice packs on the cheeks.
FOLLOW-UP
A follow-up visit is important. Your dentist will want to check on healing. Stitches may be taken out.
POSSIBLE COMPLICATIONS OF WISDOM TOOTH SURGERY
All surgery carries some degree of risk. It is not usual for a dentist to dwell at length on every possible side effect or rare but serious complication of any dental procedure. However, it is important that you have enough information to weigh up the benefits and risks of wisdom tooth extraction.
Most people will not have complications, but if you have concerns about possible complications, discuss them with your dentist. Pain, swelling and limited jaw opening are normal conditions after wisdom tooth surgery.
The following possible complications are listed to inform you, not to alarm you. There may be other complications that are not listed.
NUMBNESS OR ALTERED SENSATION
An impacted wisdom tooth may be close to nerves, such as the inferior alveolar nerve or lingual nerve. Sometimes, the impacted wisdom tooth may be touching a major nerve. When the tooth is removed, the nerve may become bruised. This can cause numbness, tingling and loss of feeling in teeth, gums, cheeks, lips, chin, tongue and around the upper jaw and lower jaw.
If a nerve is injured, it usually will heal. As it heals, the numbness and tingling go away. Often this takes from four to eight weeks. In some people, complete healing of the nerve may take six months to 18 months. In rare cases, the nerve may not heal completely, and numbness or altered sensation may be permanent.
NERVE DAMAGE CAUSING PAIN
In rare cases, an injured nerve may heal poorly, and pain may persist or recur without diminishing. This can happen even though the dental surgery was successful and all care was taken to avoid injury to major nerves. It is not known why some nerves react this way. The pain in these cases can sometimes be difficult to treat.
DRY SOCKET
After the wisdom tooth is removed, a blood clot will form over the bone. This clot is important for proper healing and relief of pain.
If the blood clot is washed away or dissolves, the bone will be exposed. This is called a "dry socket". The result is a constant throbbing pain that may last for many days. If you have pain like this, contact your dentist. To help prevent a dry socket:
• You may rinse your mouth very gently with warm salt water to wash away the blood. Do not rinse vigorously or spit with force because you may loosen the blood clot and cause slow healing. Rinse every four hours or more often. This will help healing, reduce swelling and pain, and reduce the risk of infection.
• Do not smoke after surgery. Smoking interferes with healing.
• For the first day after surgery, do not brush your teeth around the area of surgery. After first day, brush gently
INFECTION
An infection in the gum or bone is usually treated with an antibiotic. Tell your dentist if you have ever had an allergic reaction to any antibiotic or other drug. Take the complete course.
DIFFICULTY IN OPENING THE MOUTH
Pain or discomfort when opening the mouth is common after removal of a wisdom tooth. This usually goes away in a few days as swelling goes down.
FEVER
Body temperature may be slightly higher after surgery. It should go back to normal after 12 to 24 hours.
A fever that lasts longer may be an indication of an infection or other problems. You should contact your dentist.
EXCESSIVE BLEEDING (HAEMORRHAGE)
Although rare, haemorrhage may occur. It may be caused by too much exertion or by vomiting. It can be stopped by putting gauze over the wound and applying pressure by biting gently on the gauze for 15 minutes. If severe bleeding does not stop, tell your dentist at once.
LIP SORES
While the tooth is being removed, pressure or stretching of the lip by the surgical instruments may cause bruises or small sores.
They usually heal without any problems. These lip sores are not common.
DAMAGE TO NEARBY TOOTH OR FILLINGS
When a wisdom tooth is removed, the tooth or filling next to it may be chipped or loosened. This is rare.
VOMITING
Some people may vomit when they are recovering from the effects of a general anaesthetic.
SINUS PROBLEMS
The roots of the upper wisdom teeth are close to the sinuses. In some cases, a sinus may be opened when a wisdom tooth is removed. The opening will usually heal quickly without infection.
However, if an infection sets in or other problems start, more treatment may be necessary.
WEAK JAW
Removal of a wisdom tooth can cause the jaw bone to become temporarily weaker. Rarely, it may fracture or break.
Wisdom teeth (also called "third molars") usually do not push through the gums until people are in their late teens, twenties or even older. Wisdom teeth are usually the last teeth to come through the gums.
Most people have four wisdom teeth. Some people have no wisdom teeth. In many people, not enough space is at the rear of the jaws for wisdom teeth to come easily through the gums. If the jaw does not have enough space for the wisdom tooth to come through, the tooth will become wedged in or "impacted".
Some impacted wisdom teeth remain in place and cause no trouble. However, other impacted wisdom teeth cause severe problems.
Often one or more wisdom teeth will cause problems and must be removed. If one (or more) of your wisdom teeth causes problems, your dentist may recommend that it be removed. Removal of a wisdom tooth is a very common procedure. Removal of troublesome wisdom teeth should be usually be done as soon as possible before the problems get worse.
If your wisdom teeth are likely to be very difficult or complicated to remove, your dentist may refer you to an oral and maxillofacial surgeon. Due to the shape and position of some wisdom teeth and the shape of the jaws, it may be preferable in some cases for an oral and maxillofacial surgeon to remove the teeth.
THE DECISION TO REMOVE TEETH
After inspecting your mouth, jaws and X-ray films, your dentist can discuss the diagnosis with you.
Your dentist may recommend removal of one or more wisdom teeth or other options.
If the area around the tooth has been infected, your dentist may decide to delay surgery while infection is treated.
Even though a wisdom tooth has caused problems, it may "settle down" after it pushes through the gum. Tour dentist may delay surgery to see if the tooth stops causing problems.
While implacted wisdom teeth may cause problems, some never cause trouble and may not need to be removed.
The decision to have wisdom teeth removed is always yours.
EARLY REMOVAL OF WISDOM TEETH
Your dentist may recommend early removal of one or more wisdom teeth due to the following reasons:
There is not enough room for the tooth to push through.
You need orthodontic work, and the remaining teeth must not be crowded by wisdom teeth.
The tooth has started to cause trouble. It should be removed soon so that pain, infection or other problems do not get worse.
It is best to have troublesome wisdom teeth removed while the patient is young. In young people, a tooth's roots have not formed totally, and the bone surrounding the tooth is softer. This allows for easier removal of the tooth and less risk of damage to nerves, bone or other teeth.
PROBLEMS CAUSED BY IMPACTED WISDOM TEETH
INFECTION
When an impacted wisdom tooth starts to push through the gum, an infection can start around the top of the tooth. Infection and inflammation (swollen, red gums) can cause pain, swelling, and jaw stiffness. The infection can cause bad breath and an unpleasant taste.
Swallowing may be painful. The person may feel generally unwell.
CROWDING
A wisdom tooth may push nearby teeth out of their correct position.
PAIN
Pressure from the wisdom tooth may cause pain in the tooth next to it. Pain can also be caused by infection around the wisdom tooth.
CYST
If a wisdom tooth is not removed, a sac of fluid called a cyst can form around the tooth and may displace the tooth. The cyst can destroy bone and damage other teeth and the gums. Cyst formation around unerupted teeth is fairly common.
ULCER
An upper wisdom tooth may push sideways out of the gum. It may cause an ulcer where it rubs against inside of the cheek.
A FOOD TRAP
Food becomes trapped between the wisdom tooth and the molar next to it. This can cause cavities in both teeth.
RESORPTION CAVITY
An impacted wisdom tooth may keep pushing against the molar next to it. This can cause a resorption cavity where the wisdom tooth hits the other molar. This often leads to serious damage to both teeth.
The molars may become infected or abscessed. Removal of both molars is often needed. Resorption cavities are uncommon.
TREATMENT OF INFECTION
Your dentist may gently clean the infected area around the tooth. You may be advised to rinse your mouth often with a warm saltwater mouthwash. Use one teaspoon of salt in a glass of warm water. The water should be as warm as possible, but not too hot.
Your dentist may also suggest a disinfectant mouthwash and a pain killer. Your dentist may prescribe antibiotics.
If a lower wisdom tooth is infected, it can be made worse by the upper wisdom tooth biting down on to the gums. The patient can be helped by removal of the upper wisdom tooth.
DENTAL & MEDICAL HISTORY
Tell your dentist your complete dental and medical history. This helps your dentist plan the best possible treatment.
Some health problems may interfere with surgery, anaesthesia and care after surgery. Your dentist may recommend blood tests or other health tests.
Medicines: Give your dentist a list of all medicines you are taking now or have been taking. This includes "Pill" and any over-the-counter medicines, such as aspirin or cough medicines. Tell your dentist if you have ever had any type of allergic or bad reaction to antibiotics or any other medicine.
Pregnancy: Tell your dentist if you are or may be pregnant. This could affect your treatemnets, including:
• anaesthesia
• pain treatment
• antibiotic and other medicines
• whether surgery should be delayed.
Dental X-ray films can be safely taken as the X-ray beam is not pointed at the uterus.
Bleeding or blood disorders: Tell your dentist if you:
• bleed a lot when you are injured or have surgery
• have any blood disorders, such as haemophilia
• are taking any blood thinners such as aspirin, warfarin or clopidogrel, among others.
Smoking: Stop smoking two weeks before the surgery. Smoking impairs healing and increases the risk of post-operative infection.
X-RAY EXAMINATION
Your dentist needs to take X-ray films of your jaw. The films will help your dentist plan the best way to remove troublesome wisdom teeth.
WHERE TO HAVE SURGERY
Your dentist will advise you whether your wisdom teeth should be removed in the surgery, in a hospital or in a day-surgery clinic.
ANAESTHESIA
After discussion with your dentist, a decision will be made whether the wisdom tooth will be removed under local or general anaesthesia. Discuss the options with your dentist.
Local anasthesia: If the surgery is fairly simple, your dentist may give you a local anaesthetic with a needle. The local anaesthetic will numb the gums and lower parts of the face.
The dentist can then extract the tooth. Your dentist may give you a tablet to help you relax during the surgery.
General anaesthesia: For some people, the dentist may recommend general anaesthesia, that is, putting them to sleep with an injection.
General anaesthesia is given by a specialist anaesthetist. General anaesthesia may be used in people who:
• have wisdom teeth that may be more difficult to remove
• do not want to remain awake during the surgery
• have other problems with their wisdom teeth, gums and jaws
• need multiple teeth to be removed.
NOTE: For six hours before surgery under a general anaesthetic, do not eat or drink anything. If your surgery will be done in the morning, do not eat or drink after midnight the night before.
Your dentist or anaesthetist will give you full instruction.
Modern anaesthesia is safe with few risks. However, a few people may have serious reactions to them. If you have ever had a reaction to an anaesthetic drug, tell your dentist.
REMOVAL OF WISDOM TEETH
Your dentist will have to make an incision to open your gums to remove the wisdom tooth. A small portion of the bone may have to be removed so your dentist can get to the tooth.
The tooth may have to be divided into segments so it can be removed easily and safely.
The incision in your gums may have to be closed with stitches.
Some stitches dissolve after a few days. Other stitches will be removed by your dentist.
AFTER THE SURGERY
After the tooth or teeth have been removed, you will have to rest for a while before you go home. Your dentist will check on you as you recover.
Do not drive after surgery. A family member or friend should take you home. Arrange this well in advance.
When your dentist is satisfied with your recovery, you can go home.
If you have been staying in hospital, you will return to your room when you recover from the anaesthetic.
TAKING CARE OF YOURSELF
• Rest at home after the surgery.
• Do not drive, engage in active exercise, or operate machinery
• Take several days off work, school or other duties.
• Do not drink alcoholic drinks while you are taking antibiotics or pain killers.
• Eat soft foods such as soups, blended (pureed) vegetables and meats, and gelatine for the first two days.
• Drink lots of water.
• Use ice packs to reduce swelling and pain.
PAIN RELIEF AFTER SURGERY
Pain may be minor in some people and greater in others. Your dentist will prescribe a pain reliever for you.
If you are uncertain about the best pain relief medicine for you, ask your dentist. Pain usually starts to decrease after the second day. However, some people may still need pain relief after one week.
If your pain does not decrease as the days go by, tell your dentist. Further pain management may be needed.
CONTROL OF BLEEDING
You can apply pressure over the area of bleeding by biting gently but firmly on a piece of cotton gauze.
The pressure helps stop bleeding, and a blood clot forms. It is important not to disturb the area or bleeding may start again. The gums may ooze blood slightly for a day after surgery.
Any bleeding should stop by the second day. If bleeding does not stop, contact your dentist.
SWELLING
Swelling almost always occurs after surgery and can vary from a little to severe. Most swelling takes four to five days to go down completely.
Swelling can be reduced by applying ice packs on the cheeks.
FOLLOW-UP
A follow-up visit is important. Your dentist will want to check on healing. Stitches may be taken out.
POSSIBLE COMPLICATIONS OF WISDOM TOOTH SURGERY
All surgery carries some degree of risk. It is not usual for a dentist to dwell at length on every possible side effect or rare but serious complication of any dental procedure. However, it is important that you have enough information to weigh up the benefits and risks of wisdom tooth extraction.
Most people will not have complications, but if you have concerns about possible complications, discuss them with your dentist. Pain, swelling and limited jaw opening are normal conditions after wisdom tooth surgery.
The following possible complications are listed to inform you, not to alarm you. There may be other complications that are not listed.
NUMBNESS OR ALTERED SENSATION
An impacted wisdom tooth may be close to nerves, such as the inferior alveolar nerve or lingual nerve. Sometimes, the impacted wisdom tooth may be touching a major nerve. When the tooth is removed, the nerve may become bruised. This can cause numbness, tingling and loss of feeling in teeth, gums, cheeks, lips, chin, tongue and around the upper jaw and lower jaw.
If a nerve is injured, it usually will heal. As it heals, the numbness and tingling go away. Often this takes from four to eight weeks. In some people, complete healing of the nerve may take six months to 18 months. In rare cases, the nerve may not heal completely, and numbness or altered sensation may be permanent.
NERVE DAMAGE CAUSING PAIN
In rare cases, an injured nerve may heal poorly, and pain may persist or recur without diminishing. This can happen even though the dental surgery was successful and all care was taken to avoid injury to major nerves. It is not known why some nerves react this way. The pain in these cases can sometimes be difficult to treat.
DRY SOCKET
After the wisdom tooth is removed, a blood clot will form over the bone. This clot is important for proper healing and relief of pain.
If the blood clot is washed away or dissolves, the bone will be exposed. This is called a "dry socket". The result is a constant throbbing pain that may last for many days. If you have pain like this, contact your dentist. To help prevent a dry socket:
• You may rinse your mouth very gently with warm salt water to wash away the blood. Do not rinse vigorously or spit with force because you may loosen the blood clot and cause slow healing. Rinse every four hours or more often. This will help healing, reduce swelling and pain, and reduce the risk of infection.
• Do not smoke after surgery. Smoking interferes with healing.
• For the first day after surgery, do not brush your teeth around the area of surgery. After first day, brush gently
INFECTION
An infection in the gum or bone is usually treated with an antibiotic. Tell your dentist if you have ever had an allergic reaction to any antibiotic or other drug. Take the complete course.
DIFFICULTY IN OPENING THE MOUTH
Pain or discomfort when opening the mouth is common after removal of a wisdom tooth. This usually goes away in a few days as swelling goes down.
FEVER
Body temperature may be slightly higher after surgery. It should go back to normal after 12 to 24 hours.
A fever that lasts longer may be an indication of an infection or other problems. You should contact your dentist.
EXCESSIVE BLEEDING (HAEMORRHAGE)
Although rare, haemorrhage may occur. It may be caused by too much exertion or by vomiting. It can be stopped by putting gauze over the wound and applying pressure by biting gently on the gauze for 15 minutes. If severe bleeding does not stop, tell your dentist at once.
LIP SORES
While the tooth is being removed, pressure or stretching of the lip by the surgical instruments may cause bruises or small sores.
They usually heal without any problems. These lip sores are not common.
DAMAGE TO NEARBY TOOTH OR FILLINGS
When a wisdom tooth is removed, the tooth or filling next to it may be chipped or loosened. This is rare.
VOMITING
Some people may vomit when they are recovering from the effects of a general anaesthetic.
SINUS PROBLEMS
The roots of the upper wisdom teeth are close to the sinuses. In some cases, a sinus may be opened when a wisdom tooth is removed. The opening will usually heal quickly without infection.
However, if an infection sets in or other problems start, more treatment may be necessary.
WEAK JAW
Removal of a wisdom tooth can cause the jaw bone to become temporarily weaker. Rarely, it may fracture or break.