General DentistryWhat Causes An Overbite

Within this blog we will be covering all the key points to know about what causes an overbite. This includes what an overbite is, the causes of an overbite, and how to treat an overbite:

What An Overbite Is

Overbite is the vertical overlap of the upper incisors over the lower incisors and could be measured as a proportion (%), a normal overlap could be approximately 30% of the lower incisors being covered by the upper incisors or 2-4mm in measurement. On the other hand, an overlap over this amount will be referred to as ‘deep’ and is an issue. If the lower teeth are completely covered by the upper teeth, and potentially goes into the lower gums then the overbite is referred to as ‘severe’. While you can still live with this issue, it is advisable to have dental visits and check the situation regularly.

Overbite Causes

There are several potential reasons for an overbite, and some of the key reasons for it have been detailed below.

  • Genetic Factors: An individual can actually inherit a certain type of jaw, and in turn if this jaw is not even with regards to the upper and lower parts, then you may be predisposed to overbite that caused by skeletal condition.
  • Existing Teeth Issues: If you already have existing issues with your teeth such as loss of teeth, impacted teeth, or supernumerary teeth then it can alter your teeth alignment. For example, missing teeth can make teeth shift over time, while crowded teeth will leave no space for future teeth and mean that teeth will be moved out of position.
  • Sucking the Thumb: If you excessively suck on your thumb then it can cause pressure of teeth and lead to them forming at an abnormal angle.
  • Thrusting of the Tongue: If the tongue is pressed too far within the mouth, then it can lead to overbite or an open bite. The issue is common in children, but adults can also suffer from it due to stress during sleep or swollen glands.
  • Using Pacifiers: If a pacifier is used significantly when young and teeth are forming then it can have similar effects to thumb sucking.
  • Cysts or tumours in jaw/mouth: A cyst or tumour within the jaw/mouth area can alter the shape of the area, as well as impact your teeth alignment. This will occur when there is any significant growth/swelling within your jaw/upper mouth area and can lead to teeth shifting forward. Other issues caused by this includes tenderness, lumps and discomfort.

Treating Overbite

It is essential to first know that as long as your overbite is not of a certain length (2-4mm) then it does not actually necessitate treatment. It is only deep or severe overbites which will likely need to be corrected, and your specific scenario will dictate the proper course of treatment. Some possible treatment options have been outlined below.

Removable Retainer

It is possible that a removable retainer can help fix some overbite cases. This works similarly to braces and moves the teeth slowly into the desired position. A dentist will evaluate your scenario and decide if this is a suitable course of treatment for you, and even you undertake other treatment a retainer may still be used in the long run to keep the teeth in the new position.


This is perhaps the most common form of treatment for overbites, and as long as retainer is used afterwards then the results can be for life. Treatment time will depend on severity of the malocclusion. This option can however result in some short-term discomfort at points, especially when braces are tightened, but the final results should motivate you through it.


In more serious cases surgery may be required, particularly when the overbite is caused due to skeletal issues such as underdeveloped lower jaws. Surgery will allow for the jaw shape and overall facial appearance to be significantly improved. This surgery is usually free for kids on the NHS when deemed essential, although adults will require to pay for treatment.


An increasingly popular option, this form of braces is transparent and meant to act as invisible form of treatment. They can be used for certain types of overbites, and through pressure over time will move teeth into the correct position. A new set of Invisalign aligners will be given to you every 2 weeks, and the progress will be noticeable very quickly. This form of treatment can avoid potential differential treatment that those with metal braces can experience and will allow you to be more confident. You will also be able to better clean your teeth and you will have full access to teeth, unlike with metal braces.