An underbite is a jaw abnormality where the lower jaw is positioned abnormally forward of the upper jaw. [1]
What are the complications of an underbite?
The complications of an underbite include problems such as:
- Disorders in chewing and digesting food
- Speech disorders
- Abnormal wear of teeth
- Jaw and temporomandibular joint (TMJ) pain [19]
- Respiratory problems such as snoring and sleep apnea [2, 26]
- Decreased self-confidence and psychological problems
- Increased risk of tooth decay and gum disease. [2]
Confirmed by the dental specialists at Dr. Bonyanian’s clinic
The content of this article is solely for your information. Before taking any action, consult with the dentists at Dr. Bonyanian’s clinic for treatment.
Having a well-proportioned jaw is important not only for facial aesthetics but also for the proper function of the teeth and overall oral health. An underbite is one of the common jaw abnormalities that can cause physical discomfort and even reduce a person’s self-confidence.
This problem may arise from hereditary reasons or bad oral habits, but fortunately, various methods are available for its treatment. [1, 2] In this article, we will examine this abnormality in detail, its causes, and methods for its correction.
What is an underbite?
An underbite, or Class III malocclusion, is considered a type of jaw disorder. [3] In this disorder, the lower front teeth are positioned in front of the upper front teeth, and the person’s facial appearance changes in a way that it seems the lower jaw is placed on top of the upper jaw, just like in the image below.
The severity of an underbite can range from mild to severe. In a mild underbite, the change in appearance may not be very noticeable. [1] But when this abnormality is severe, the person’s jaw and facial structure deviate from the normal state and take on an unattractive shape.
Many dental specialists believe that an underbite is the most dangerous type of jaw abnormality. This is because, in addition to aesthetic problems, it also creates severe problems for the health of the teeth, jaw, and even digestion.
An underbite is a type of bite disharmony where the lower teeth are positioned in front of the upper teeth. An underbite is also known as a protruding lower jaw or Class III malocclusion. In moderate to severe cases of protrusion, the face may have a bulldog-like appearance due to the protrusion of the lower jawbone.
Types of Underbite
Orthodontists and maxillofacial surgeons classify underbite abnormalities based on the extent and severity of the disorder into three categories: mild, moderate, and severe:
- Mild Underbite: In this type of underbite, the lower front teeth are only slightly ahead of the upper front teeth. The person may not have any symptoms, and the problem may only be identified during a dental examination. [12] This degree of underbite is usually treated with the help of orthodontics.
- Moderate Underbite: In this type of underbite, the lower front teeth are positioned significantly ahead of the upper front teeth. A person with a moderate underbite faces problems with chewing, speaking, and aesthetic issues. This degree of underbite is also often treated with orthodontics.
- Severe Underbite: In a severe underbite, the lower jaw is considerably forward of the upper jaw, and the person’s appearance is completely different from normal. The person will definitely face multiple problems such as difficulty speaking, chewing food, and even breathing. This level of underbite can only be treated with jaw surgery.
What are the causes of an underbite?
An underbite can be caused by various reasons. These reasons usually fall into one of two categories: skeletal problems (like genetics) or behavioral problems (like bad childhood habits). [2] However, the possibility of developing an underbite due to a combination of both genetic and behavioral factors also exists.
1. Heredity or Genetics
As you know, many physical abnormalities in people have their roots in their genetics. This is also true for the development of an underbite. In fact, one of the most effective factors in the way the jawbones are shaped and formed and the way the teeth are positioned on top of each other (underbite or Class III malocclusion) is a person’s genetics. [6] By genetic history, we mean that if one of the family members of the patient has this abnormality, the probability of that person also developing an underbite will increase.
2. Lack of Proportion and Order Between the Jaw and Teeth
By lack of proportion and order between the jaw and teeth, we mean issues such as the lower jaw being smaller, shorter, longer, or having a skeletal deviation with the teeth. The mentioned cases can occur for various reasons, including trauma and injury from accidents, falling from high places, and other similar incidents.
3. Problems Related to the Jawbone
Problems related to the jawbone are another effective factor in the creation of an underbite. These problems include the growth of a tumor in the lower jaw, abnormal growth of bones in the jaw area, protrusion of the lower jaw, and also receding of the upper jaw, fractures, and the creation of skeletal deviation.
4. Wrong Childhood and Adulthood Habits
One of the effective causes in the development of an underbite malocclusion is related to wrong and incorrect habits in childhood and even adulthood. These wrong habits include:
- Excessive thumb sucking and sucking on other fingers
- Excessive pacifier use
- Thrusting the tongue against the lower teeth
- Improper eating and consequently stomach reflux
5. Injury and Trauma to the Jaw
According to Dr. Nazi Bonyanian, another cause of underbite is injury and trauma to the jaw. A severe injury that can disrupt the natural structure of the jawbones. When a severe injury, such as a fracture or crack in the lower jaw occurs, its natural growth may be affected, and as a result, the lower jaw may be positioned further forward than the upper jaw. This issue is more important during childhood and adolescence when the facial bones are still growing. This is because any damage or disharmony in the bone healing process can lead to a permanent change in the position of the jaw.
6. Tumors
Tumors can also be one of the factors creating an underbite, especially when they grow in the jawbones or surrounding tissues. Abnormal masses that develop in the lower jaw may cause an increase in bone volume or a change in its growth direction, and as a result, push the lower jaw forward. Abnormal growth that can gradually disrupt the balance between the upper and lower jaw and lead to an underbite. Some tumors or jaw cysts may also destroy healthy tissues and disrupt the normal function of the jaw. In severe cases, such changes may require surgical interventions to not only remove the tumor but also restore the symmetry and coordination of the jaws.
Underbite Diagnosis
An underbite is usually a clear disorder, and its diagnosis (especially in moderate and severe cases) is easily made. [12] However, an orthodontist is the best person to diagnose the extent, cause, and severity of an underbite in individuals. An orthodontist will examine your or your child’s problem by assessing the condition of the teeth, the severity of the jaw protrusion, the shape and form of the face, and other factors.
Methods for Preventing an Underbite
Although an underbite is often caused by genetic factors and is not preventable, some measures can prevent its intensification or its occurrence due to non-genetic reasons. Prevention methods include the following:
- Correcting bad oral habits: Avoiding thumb sucking, prolonged use of a pacifier or baby bottle in children, which can affect jaw growth. [2]
- Early examination and treatment of dental problems in childhood: Early referral to an orthodontist to diagnose jaw abnormalities and take timely action to correct them.
- Protecting the jaw from physical injuries: Using a mouthguard during high-risk sports or activities that may lead to jaw injuries.
- Prompt treatment of respiratory and nasal problems: Addressing issues like mouth breathing that can affect jaw and tooth development. [17]
- Maintaining oral hygiene: Preventing tooth decay and the early loss of baby teeth, which can cause the improper placement of permanent teeth.
- Monitoring jaw and tooth development in children: Regular visits to the dentist to ensure the normal growth of the jaws and prevent potential problems.
What problems does an underbite cause?
An underbite can create multiple problems for an individual, which are important both functionally and aesthetically. Some of the most significant problems caused by an underbite include:
- Problems with chewing and digestion: Due to the misalignment of the jaws, the teeth do not fit together properly, which can make chewing food difficult and, consequently, disrupt the digestion process. [19]
- Speech impairment: Some people with an underbite may have trouble pronouncing certain letters and words correctly because the movement of the tongue and lips is affected by the jaw abnormality.
- Increased risk of tooth wear and tear: The improper position of the jaw and teeth can cause increased pressure on some teeth, and as a result, they may wear down faster and be damaged. [19]
- Jaw pain and temporomandibular joint (TMJ) disorders: The misalignment of the jaws can put extra pressure on the jaw joint, leading to chronic jaw pain, clicking sounds, and even locking of the jaw. [2]
- Respiratory and sleep problems: In some cases, an underbite can lead to respiratory problems, especially during sleep, which may cause snoring or sleep apnea (cessation of breathing during sleep). [18]
- Decreased self-confidence and psychological problems: Since an underbite can have a significant impact on facial appearance, some people may become concerned about their appearance, and their self-confidence may decrease, especially in social interactions.
What are the signs and complications of an underbite?
This abnormality is accompanied by signs and complications that cause many problems in the jaw and face. The most serious signs of an underbite are the following:
1. Alteration in Appearance
In this abnormality, the teeth are irregular, and the shape of the jaw and face changes. This causes a loss of facial beauty and a decrease in the person’s self-confidence. People with an underbite have difficulty speaking. They cannot laugh easily and, in some cases, are even ashamed of their appearance.
2. Problems with Swallowing and Chewing Food
A person who has an underbite will face problems with chewing, biting, and even swallowing food. These problems are more felt in the back teeth, and over time, they lead to the wearing down of the teeth at the end of the jaw.
3. Increased Vulnerability of Teeth
Protruding and irregular teeth cause more damage to the teeth, bad breath, and increased sensitivity. In such situations, if a sudden event such as a blow to the face, falling, or colliding with another person occurs, the front teeth are quickly damaged.
Other complications of this abnormality include:
- Improper alignment of teeth on top of each other
- Covering of the upper teeth by the lower teeth
- Disruption of facial balance
- Problems with speaking and pronouncing words
- Protrusion and disarray of the lower jaw teeth
Why is underbite treatment necessary?
Treating a protruding lower jaw is not just for aesthetic reasons. This problem can also cause much more serious and irreparable damage to your health. People with this abnormality experience problems such as chronic headaches or indigestion. These complications are dangerous to the health of any individual and endanger their quality of life.
How is an underbite treated?
Underbite treatment is performed using one of the orthodontic and surgical methods, depending on the severity of the abnormality and the person’s age. Below, we will provide more explanations about each of these two methods.
Using an Expander for Underbite Treatment
An expander, or palate widener, is an orthodontic device used to widen the upper jaw and create more space in the mouth. This device usually consists of a central screw and two wings that are attached to the upper molars, and by gradually adjusting the screw, it causes the palate to widen gradually.
In underbite treatment, an expander can be particularly useful in cases where the upper jaw is narrower than normal. By widening the upper jaw, this device helps the upper teeth to be positioned more correctly relative to the lower teeth and prevents the lower jaw from protruding too much. This method is more effective in children and adolescents who are still in their growth phase, as their jawbones are more flexible and easily adapt to orthodontic treatment. [9] The expander is usually adjusted by an orthodontist, and the patient must visit the doctor regularly to monitor the treatment process.
Underbite Treatment with Orthodontics
One of the effective treatment methods for improving mild to moderate underbite abnormalities is the use of orthodontic methods (removable or fixed orthodontics). This method is effective for both adults and children. An orthodontist treats an underbite and protruding jaw, and misaligned and crowded teeth by applying continuous and relatively severe pressure with the help of orthodontic tools and equipment to guide them to their correct position. This work, in addition to straightening and improving the condition of the teeth, also causes the lower jaw to move back and the underbite to be completely treated. But do not forget that orthodontics is only used for cases where the underbite is at a mild and sometimes moderate level; not in all situations and cases.
Underbite Treatment with Surgery
Jaw surgery is the last resort for treating Class 3 malocclusion. [9] This method is used in cases where the underbite is not treatable with the help of orthodontics. Jaw surgery is considered an invasive procedure, and only a specialist in maxillofacial surgery is capable of performing it. In this method, the jaw surgeon, by changing the position (and even cutting a part of the jawbone), guides the lower jaw to its correct position and then fixes it in place using special equipment such as screws and plates. Although many people are frightened by the name of surgery, underbite treatment with surgery has many benefits. For example:
- The pressure that is applied to the teeth, jaw, and facial muscles during orthodontic treatment is eliminated.
- The possibility of tooth decay and gum disease is reduced.
- Brushing and cleaning the teeth will become easier.
- You will be treated faster.
- The possibility of developing temporomandibular joint disorder is reduced. [26]
Using a Chin Cup
One of the methods for treating an underbite in mild cases is the use of a chin cup, which is used as an external orthodontic device to guide the growth of the lower jaw to the correct position. This device includes a special band that is placed around the chin and, by applying a gentle but continuous force, controls the growth of the jaw and prevents it from protruding too much. A chin cup is usually most effective in childhood and adolescence when the jawbones are still growing and can help to gradually correct the abnormality. [7]
Underbite Treatment Using a Reverse-Pull Headgear
A reverse-pull headgear is another orthodontic appliance for treating underbite that moves the upper jaw forward by applying a pulling force and helps to correct the abnormality. This device, which is mostly used in children and adolescents, includes a metal frame that is placed on the forehead and chin and is connected to brackets installed on the upper teeth with the help of elastic bands. [7, 13] You should use the reverse-pull headgear for several hours a day, especially during sleep, to gradually stimulate the growth of the upper jaw and guide it to its correct position. The success of this method depends on the patient’s cooperation and regular use of the device according to the orthodontist’s recommendation.
What is the best method for underbite treatment?
Choosing the best method for underbite treatment depends on various factors such as the severity of the abnormality, the cause of the underbite, the patient’s age, and their general health. An experienced and skilled orthodontist is the best person to make a decision in this regard. They can introduce the best treatment method to you after examining your condition.
Underbite Treatment at Dr. Bonyanian’s Dental Clinic
If you have decided to treat your or your child’s underbite disorder, you can trust the skill, experience, and expertise of the dentists at Dr. Bonyanian’s dental clinic for your treatment. Our specialists provide you with complete services for underbite treatment. These services include the following:
- Accurate examination and diagnosis
- Developing a treatment plan
- Orthodontics, jaw surgery, or combined treatment
You can benefit from advantages such as the presence of top orthodontists and jaw surgeons in Tehran, a personalized treatment plan, high-quality services, a very suitable and relaxing clinic environment (with the best accessibility in the city), and paying the cost in installments by having your underbite abnormality treated at Dr. Bonyanian’s dental clinic.
For more information about underbite treatment at Dr. Bonyanian’s dental clinic, you can visit us at our address located at Unit 7, No. 22, West Sixth Street, Ahmad Qasir (Bokharest) Street, Arjantin Square, Tehran, or contact us by phone at +982188539720.
What is the best age for underbite treatment?
In all methods of treating dental and jaw abnormalities, the younger the person, the easier and faster the treatment will be. If you find out that your child has this abnormality, you should immediately go to a dentist and start the treatment. A change in some of the child’s behaviors and correcting their habits may completely eliminate this problem. However, if you could not get treatment for your child at an age younger than 7, you can seek treatment for an underbite at any age and in any condition by visiting an orthodontist. Do not forget that the older the person, the more difficult the treatment will be.
How is at-home underbite treatment?
An underbite is a serious disorder in the structure of the jaw, and there is no effective at-home treatment for its correction. Because this problem is either caused by genetic reasons or by asymmetric growth of the jaw or jaw injuries. Therefore, its treatment requires specialized orthodontic or surgical intervention. Although some jaw exercises or changing oral habits may help to slightly improve some symptoms, no at-home method is capable of completely correcting this abnormality.
Therefore, be careful that the best solution is to visit an orthodontist or a maxillofacial surgeon for a detailed examination of the condition and choosing the appropriate treatment method.
Underbite Treatment in Adults
It is never too late to treat an underbite (and other oral disorders and abnormalities). Because the complications of these problems are much harder and more painful than their treatment.
Difference between Underbite and Overbite
In a correct bite, when the teeth are placed on top of each other, the upper jaw teeth cover the lower jaw teeth by a very small amount. If the amount of this coverage is more than the normal limit, it is called an overbite. [10, 16] But as we have said so far, an underbite is the opposite, and the lower jaw teeth cover the upper jaw teeth. Both of these abnormalities can destroy a person’s aesthetic beauty and cause problems in speaking, chewing, swallowing, and so on. According to studies, underbite is common in 5 to 10 percent of people. [4] However, research around the world shows that the probability of this problem occurring is 5% in Americans and up to 15% in Chinese, which is due to genetic reasons. This difference can be due to genetics.
Benefits of Underbite Treatment
- Improved chewing and digestion
- Increased clarity of speech and reduced speech problems
- Reduced pressure and abnormal wear on teeth
- Prevention of jaw joint (TMJ) problems and related pain [19]
- Improved breathing and reduced problems such as snoring or sleep apnea [18]
- Creating balance and symmetry in the face for increased aesthetic beauty
- Increased self-confidence and improved quality of life
- Reduced risk of tooth decay and gum disease due to improved tooth alignment
- Reduced likelihood of needing more complex treatments in the future, such as jaw surgery
Cost of Underbite Treatment
The cost of treating mandibular prognathism is one of the concerns and worries of people with this abnormality. Many people imagine that the cost of this treatment is very high. For this reason, they do not take its treatment seriously. This very issue causes more serious, and severe problems and, consequently, an increase in the cost of treatment. The cost of underbite treatment depends on the cases that we will mention below:
- Treatment method
- Condition of the mouth and jaw
- Severity of the abnormality
- Insurance coverage or lack thereof
Given these factors, determining the exact cost is a bit difficult. However, you can get more complete explanations about the costs of this process by studying articles on the cost of orthodontic treatment and the price of surgery and tooth extraction.
Conclusion
An underbite is a type of tooth and jaw abnormality that, due to the protrusion of the lower jaw and the covering of the upper teeth by the lower teeth, creates serious and severe problems for the affected person. Take the treatment of Class 3 malocclusion seriously. Because any negligence in the treatment of this abnormality will lead to irreparable consequences and an increase in the cost of treatment in the future.
Dr. Nazi Bonyanian
Dental Surgeon (DDS) — Medical Council Number: 138662
Graduate of Isfahan University of Medical Sciences with over 15 years of experience in implants, laminates, and oral and dental surgery.
Address: No. 22, Unit 7, West Alley 6, Bokharest Street, Argentina Sq., Tehran, Iran
Phone: +98-21-88539720 | WhatsApp: +98-912-514-2202
Email: info@drbonyanian.com
Working Hours: Sat–Wed 09:00–20:00 | Thu 09:00–14:00 | Friday Closed
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