What is a protruding upper or lower jaw?
A protruding jaw describes two opposite situations: a protruding upper jaw, in which the upper jaw and upper teeth sit forward of the lower ones, and a protruding lower jaw (mandibular prognathism), in which the lower jaw sits forward. The consequences go beyond appearance and affect everyday functions such as chewing, speaking and breathing. An examination by a dentist, and when needed by an orthodontist and an oral and maxillofacial surgeon, identifies the type of problem and leads to a personal treatment plan.
The right solution depends on the severity, your age and the factors that caused the problem. In mild cases, orthodontic treatment may be enough; in more complex cases, orthodontics combined with orthognathic (jaw) surgery may be necessary. Treatment sometimes combines orthodontics, oral and maxillofacial surgery, restorative dentistry and cosmetic dentistry.
The normal relationship between the upper and lower jaw
In a normal bite, the upper jaw sits slightly forward of the lower jaw, and the upper front teeth slightly overlap the lower ones.
A significant deviation from this relationship is described as a protruding jaw and warrants an orthodontic examination. It affects not only appearance but also how the chewing system and the jaw joints work.
The relationship between the jaws is influenced by ethnic, hereditary and sex-related factors. Unbalanced growth of one jaw can be hereditary, and can also come from habits such as tongue thrusting or prolonged thumb sucking in childhood. At the diagnostic visit, cephalometric X-rays and precise measurements show how far the jaws deviate from the ideal relationship and guide the treatment plan.
Types of protruding jaw and how they affect you
Bites are classified into three main groups (Angle's Class I, II and III). In Class II, the upper teeth sit forward of the lower ones, sometimes because of a protruding upper jaw and often because of a small or receding lower jaw; in everyday English this is often called an "overbite" (the forward distance is the overjet). In Class III, the lower jaw or lower teeth sit too far forward, which gives an underbite. These conditions go beyond appearance and can affect self-confidence, function and health. Many patients describe lower self-esteem and self-consciousness because of an unbalanced profile.
| Criterion | Class II (protruding upper jaw or teeth) | Class III (protruding lower jaw) |
|---|---|---|
| Situation | The upper teeth or upper jaw sit forward of the lower ones | The lower jaw sits forward |
| Effects | Difficulty closing the lips at rest, chewing problems, sometimes a gummy smile | Prominent chin, reverse bite (underbite), excessive wear of the front teeth |
| Orthodontic appliances during growth | Twin Block or Herbst | Face mask or reverse-pull headgear |
In some cases, mainly when the lower jaw is small and set back, there is also a link with breathing problems during sleep.
How is a protruding jaw diagnosed?
An accurate diagnosis combines a thorough clinical examination with imaging, including a panoramic dental X-ray, cephalometric X-rays and sometimes a 3D scan. The examination looks at the relationship between the jaws, the face, the bite and the jaw joints, to understand the problem, its severity and its effect on chewing and the face.
A functional assessment is part of the diagnosis: how the jaw position affects chewing, speech and breathing. Your concerns and expectations are also taken into account, so that the plan addresses the root causes, not only the symptoms.
In children and teenagers, early diagnosis matters, because treatment during growth may improve the jaw relationship. According to a Cochrane review, face mask treatment in children with a protruding lower jaw improved the bite in the short term, but the benefit decreased in the years after treatment.
The American Association of Orthodontists (AAO) recommends a first orthodontic check-up no later than age 7, when the first signs of a jaw growth problem can be identified and early treatment started if needed.
Examination, treatment plan and price quote
detailed and personalized
During the consultation, Dr Haim Aseriel examines your teeth, explains all the options and gives you a transparent price quote, with no obligation. The clinic is at 12 HaTnufa Street, Jerusalem.
What causes a protruding upper jaw?
A protruding upper jaw (maxillary protrusion) means the upper jaw sits forward relative to the lower jaw, which affects the bite and the face. It is one form of Class II bite and usually results from a combination of genetic and environmental factors.
Genetics and childhood habits
Genetic factors play a significant role: growth patterns of the face and jaws are largely inherited, and a protruding upper jaw runs in some families. Childhood habits also matter, such as prolonged thumb sucking, using a pacifier or bottle for too long, or chronic tongue thrusting, which change the forces on the jaws during growth.
Breathing problems
In some patients, breathing problems such as chronic mouth breathing because of nasal blockage or enlarged adenoids contribute to a protruding upper jaw, by changing the position of the tongue and lips during growth. Problems in how the bite develops, such as early loss of baby teeth or abnormal eruption of permanent teeth, can make it worse. Early diagnosis allows these factors to be treated during growth.
Treating a protruding upper jaw: orthodontics and orthognathic surgery
Treatment combines orthodontic and surgical approaches according to severity and age:
Children or adults: what changes in treatment?
- Children and teenagers, while the jaws are still growing: orthodontic treatment with functional appliances or a face mask, to take advantage of natural growth.
- Adults, once growth is complete: orthodontics alone in mild cases; when the gap between the jaws is large, orthodontics combined with jaw surgery.
Teeth straightening with functional appliances such as a Twin Block or Herbst is used to correct protruding upper teeth: according to a Cochrane review, this treatment in adolescence reduces the protrusion, while earlier treatment in childhood mainly reduces the risk of injury to the front teeth (see also protruding teeth).
For adults or complex cases, orthodontics combined with orthognathic surgery is often the right option. The surgery moves the jaw bones to a planned position and is performed by an oral and maxillofacial surgeon; the surgeon who operates at the clinic is Dr Yves Weinberg, head of the Department of Oral and Maxillofacial Surgery at Barzilai Medical Center. Orthodontic treatment beforehand aligns the teeth for the planned post-surgical bite, and 3D computer simulations may be used to plan the operation and show you the expected change.
7 years
age of the first orthodontic check-up, at the latest (AAO)
At this age, problems with jaw growth and the bite can be spotted early. In adults, the choice between orthodontics alone (braces or clear aligners) and orthodontics combined with jaw surgery, such as moving the upper jaw (Le Fort I osteotomy) or the lower jaw (bilateral sagittal split osteotomy), depends on severity.
Treating a protruding lower jaw: orthodontics and jaw surgery
01
Early orthodontic treatment
In mild to moderate cases, especially in children, early orthodontic treatment may improve the situation, sometimes with a face mask or reverse-pull headgear that encourages the upper jaw forward. According to a 2024 Cochrane review, these treatments improve the bite and the jaw relationship in the short term, but the benefit of the face mask decreased in the years after treatment.
02
Surgical treatment
When the problem is more severe, or in adults whose growth has finished, surgery is usually the solution. Orthognathic surgery to correct a protruding jaw includes techniques such as bilateral sagittal split osteotomy (BSSO) for the lower jaw or Le Fort I osteotomy for the upper jaw, sometimes both. The technique is chosen after a full diagnosis with X-rays, 3D imaging and planning.
03
Recovery after jaw surgery
Recovery is critical to the success of treatment. Initial recovery takes a few weeks, starting with a soft or liquid diet, careful oral hygiene and limited physical activity, as the surgeon instructs. In the first weeks, a series of visits with the surgeon and the orthodontist checks that healing is on track, sometimes with jaw exercises or physical therapy; further orthodontic treatment may then refine the bite.
Beyond appearance, correcting a protruding jaw aims to improve chewing, speech and breathing, sometimes to ease jaw joint (TMJ) problems, and to boost self-confidence. The cost depends on the complexity of the case, the techniques used and the extent of the work. A treatment plan and a detailed written quote are given only after a consultation and examination.
Protruding jaw: consultation in Jerusalem. At the dental clinic in Jerusalem, Dr Haim Aseriel, a US-trained dentist (DDS, NYU College of Dentistry), examines you with panoramic and cephalometric X-rays and, if needed, a 3D scan, then explains the plan in English. The clinic is at 12 HaTnufa Street in Talpiot, south Jerusalem.
Protruding jaw: frequently asked questions
In children and teenagers whose jaws are still growing, orthodontic treatment with functional appliances or a face mask may improve the relationship between the jaws. In adults with mild cases, orthodontics alone, with braces or clear aligners, can improve the bite; when the gap between the jaws is large, orthodontics combined with jaw surgery is usually needed.
Yes. Beyond appearance, a protruding jaw can affect chewing, speech and lip closure, and cause excessive wear of the front teeth. When the lower jaw is small and set back, there is sometimes also a link with breathing problems during sleep. Correction aims to improve function, not only appearance.
A protruding jaw often has a hereditary component linked to the way the jaws grow. Childhood habits, such as prolonged thumb or pacifier sucking and tongue thrusting, and chronic mouth breathing can contribute to protruding front teeth and unbalanced jaw growth.
The American Association of Orthodontists (AAO) recommends a first orthodontic check-up no later than age 7, when problems with jaw growth and the bite can already be identified. If parents notice a problem earlier, there is no need to wait until that age.
Jaw surgery (orthognathic surgery) is mainly for adults whose growth has finished and for severe cases where orthodontics alone is not enough. It is planned with an orthodontist and is usually combined with orthodontic treatment before and after; in the first weeks after surgery, a soft diet and follow-up visits are needed.
Sources
- Batista KB et al., Cochrane Database of Systematic Reviews, 2018 – View source
- Owens D et al., Cochrane Database of Systematic Reviews, 2024 – View source
- American Association of Orthodontists, When Should a Child First See an Orthodontist? – View source
