An overjet is a dental condition where the top front teeth protrude horizontally over the lower teeth. Various safe and effective orthodontic treatments are available for correcting excessive overjet, including dental braces, tooth extraction, and orthognathic surgery.
What is Overjet?
An overjet describes a condition in which the top front teeth protrude outwards, past the bottom teeth in the direction of the lips. Commonly referred to as “buck teeth” or a “protrusion,” overjet usually results from the underdevelopment of either the upper jaw or lower jaw, leading to a disproportionate facial structure.
As it is widely considered unattractive, this condition often causes those affected to feel very self-conscious, leading to social anxiety, social isolation, depression, and a lower quality of life. An overjet can make it challenging to bite, chew, speak, drink, and perform other common oral functions. It can also cause the teeth to rub together unnaturally, causing jaw or tooth pain in some people.
This article describes what an overjet is, how it compares to overbite and underbite, the key causes of an overjet, and some of the treatment options available to improve it.
The Specifics
Differences Between Overjet and Overbite
Overjet and overbite are not the same, although both conditions involve the upper teeth extending past the vertical plane of the bottom teeth. According to MedlinePlus, “Overbite is defined as the vertical, or top-to-bottom, overlap of the front teeth while biting. Overjet is the horizontal, or front-to-back overlap of the front teeth while biting.”
The difference between an overjet and an overbite lies in the angle of the upper teeth. An overjet causes the upper teeth to stick out past the bottom teeth at an angle, jutting out diagonally across the plane of the bottom teeth. With an overbite, the upper teeth are pointing straight downwards.
Differences Between Overjet and Underbite
Overjet, which is a horizontal protrusion of the front upper teeth, differs from an underbite, where the bottom teeth stick out farther than the top teeth. An underbite can be caused by:
- Undevelopment of the upper jaw (maxillary)
- Overgrowth of the lower jaw (mandible)
- Flared upper incisors
- Missing lower teeth
- A combination of any or all of the above
Causes of Overjet
Overjet is caused by the lower jawbone (mandible) failing to keep up with the forward growth of the upper jawbone (maxillary). This results in the bottom jawbone and the teeth in it being situated behind their optimal positions for an ideal smile. Common causes include:
- Genetic factors
- Childhood habits such as thumb or finger sucking
- Extended use of pacifiers or bottles
- Tongue thrusting
- Underdeveloped lower jaw
Signs and Symptoms of Overjet
Overjet is a type of dental malocclusion, which is defined as the imperfect positioning of the teeth when the mouth is closed. Common symptoms of overjet include:
- Frequently biting the tongue or inner cheeks
- Developing a lisp or other speech problems
- Discomfort when biting and chewing
- Unbalanced facial appearance
- Habitual mouth breathing
- Improper teeth alignment
- Inability to seal lips
If you or your child exhibit any of these signs or symptoms, schedule a visit with your dentist or orthodontist to determine the best course of action.
Grades of Malocclusion
Malocclusion refers to the misalignment of the teeth. An overjet is one of the various types of malocclusions. When an orthodontist diagnoses a malocclusion, they categorize it based on its severity and type. The three primary classifications of malocclusion are:
- Class I Malocclusion: The upper teeth slightly overlap the bottom teeth. The bite is still considered normal with this most common type of malocclusion.
- Class II Malocclusion: Also called retrognathism, this is diagnosed when the patient has a severe overbite. Most overjets fall into this category. An estimated 25% of the global population has a Class II bite.
- Class III Malocclusion: Diagnosed when the patient has a significant underbite, causing the lower jawbone to protrude forward and making the lower teeth stick out farther than the upper teeth.
Normal vs. Needing Treatment
Normal treatment of a malocclusion means that there is no medical emergency or severe limitation of oral function. Options include orthodontic treatments like dental braces, selective tooth extractions, and other dental restorations like veneers, bonding, and implants.
Needs-based treatment refers to cases where the patient cannot function normally or is at medical risk due to excessive overjet. Children with an overjet greater than 3 millimeters are about twice as likely to suffer traumatic dental injuries to their front teeth compared to those with an overjet of fewer than 3 millimeters.
Treatment Options for Overjet
Dentists diagnose malocclusions routinely, and most cases require no treatment. Slight malocclusions are very common. However, when a malocclusion is severe, the dentist will likely refer the patient to an orthodontist for further examination and treatment. The orthodontist might recommend any of the following treatment options:
- Removal of certain teeth
- Dental braces to straighten teeth
- Dental bonding, caps, or implants
- Orthognathic surgery to reform the jawbone
- Metal wires or plates to stabilize the jawbone
Each patient receives a customized treatment plan based on age, orthodontic needs, and various other personal factors.
Traditional Metal Braces
Traditional braces use metal brackets and archwires, hooks, and elastic bands called ligatures to gradually reposition the teeth and jawbones. Most patients wear these for 1-3 years to achieve the desired corrections. This system requires routine readjustments by an orthodontist.
New heat-activated archwires use body heat to help teeth move more quickly and with less pain than in the past. These are the least expensive, but still the most noticeable type of dental braces available today.
Damon Braces
Damon braces are a newer orthodontic treatment that uses a self-ligating system with specialized brackets and wires. This system requires fewer adjustments and is generally more comfortable than traditional braces. Damon braces can move teeth more quickly and with less pain, often without the need for palatal expanders or extractions.
Lingual Braces
Lingual braces are placed on the backside of the teeth instead of the front side like other types of braces. They also use brackets, archwires, hooks, ligatures, and other devices, but they are positioned in front of the tongue and cannot be seen without close inspection. They are preferred by adults who do not want their braces to be seen.
Clear Aligners
Clear aligners are manufactured with strong, transparent plastic that is customized to fit the patient’s mouth. They are worn up to 20 hours daily, only being removed when brushing, flossing, and eating.
Clear aligners like Invisalign® blend in very well with the natural color of the patient’s teeth. They are effective for correcting various types of malocclusion in adolescents and adults. However, they are not well-suited for cases of severe overjet, overbite, or underbite caused by jawbone irregularities.
Teeth Extraction
Selective tooth extraction is often part of the plan for correcting an overjet or other dental malocclusions. A common option for correcting an excessive overjet is to remove the maxillary first premolars and then to retract the anterior teeth to shorten the maxillary arch. This is especially useful when a patient has a short mandible.
Orthognathic Surgery
In some cases, orthodontic treatment alone is not enough to correct excessive overjet, and orthognathic surgery is recommended. This is especially common in patients with overjet caused by deficient mandibular (lower jaw) development. This may also involve repositioning the maxillary (upper jaw) teeth.
The Takeaway
Conclusion
In children and adults, orthodontic treatment for overjet and other dental malocclusions generally enhances oral function and improves facial aesthetics. Detecting malocclusions in early childhood significantly increases the chances of successful treatment. Early diagnosis and action typically shorten the duration of treatment necessary.
Adults with overjet can also achieve good results from treatment, although it may take more time than if the treatment had been initiated earlier. Longer treatment plans also increase total costs significantly.
Be aware that treating excessive overjet can result in some complications, including discomfort, pain, mouth irritation, tooth decay, and decreased oral function. If you or your child exhibit signs or symptoms of overjet or another malocclusion, schedule a checkup with your dentist and discuss your treatment options.
