Most people think of orthodontics as a dentistry field that focuses on straightening teeth to improve a smile. But orthodontists are also concerned with the position of the specific facial bones that affect the shape and appearance of the jaws and face. In particular, dentofacial orthopedics is the field of study that concentrates on improving the position and dimensions of the bones that house the teeth.
As a child grows, both the maxilla (upper jaw) and mandible (lower jaw) will grow in three dimensions. This growth will decide the final positioning of the mid and lower face, as these bones are also connected to the sinuses, bottom of the nose and cheekbones. According to Nemours, this growth stops for girls at around age 15, while boys can continue to grow into their early 20s.
Sometimes, the upper and lower jaws will grow at different rates and create alignment issues between the upper and lower teeth. Ideally, the upper jaw should have a more forward position and be a bit wider than the lower jaw. Underbites (where the mandible protrudes), overbites (where the maxilla protrudes) and other occlusion or bite problems may also be caused by factors such as breathing difficulties and thumb sucking.
Misaligned jaw growth can start to be identified as early as two years of age, when all of a child's primary teeth have erupted. A dentist will usually decide if treatment is required during the stage of mixed dentition, when some baby teeth are still present but the adult teeth have started to grow in. This usually happens by the time a child is around eight or nine. At that point, your dentist might refer your child to an orthodontist to take impressions and three-dimensional scans of their mouth to make a proper diagnosis and treatment plan.
If a child's bite problems require intervention, an orthodontist can use a variety of appliances to change the rate, direction or amount of jaw growth. Dentofacial orthopedic appliances can be fixed to the teeth or removable. Some of the more common appliances that dental professionals may recommend are:
- Palate expander: This fixed device slowly pushes the cartilage above the upper jaw apart to widen a maxilla that is too small to hold the teeth.
- Lower jaw expander: The bone of the lower jaw can't be stretched, so this expander gradually moves the teeth apart to make room.
- Activators: According to the British Orthodontic Society (BOS), these devices have been used since the 1930s to gradually move the upper or lower jaws forward while guiding erupting teeth.
- Block: A fixed bite block uses the bite force to gradually and comfortably move teeth and correct malocclusion.
- Orthodontic headgear: For bite problems that can't be corrected from inside the mouth, some orthodontists will recommend an appliance that straps around the face to apply forces to the jaw and head.
An adult who wants to correct their bite will not have the same range of options as a child who is still growing, but there are still solutions available for those who want to change their smile later in life. Jaw problems that don't get corrected in childhood may not be painful, but they can often cause speech difficulties or uneven wear or damage to teeth.
For adults with a severe underbite, for example, the BOS details how an orthodontist can use multiple stages of orthognathic (jaw-altering) surgery and braces to move the lower jaw back under the upper jaw. The process of straightening teeth, undergoing orthognathic surgery and finishing orthodontic treatment takes about three years.
Dentofacial orthopedics' focus on prediction means that it can occasionally have unexpected results. Changing an abnormal growth pattern in the upper jaw can be difficult, and some controversial research has shown that altering facial growth in a young child can sometimes lead to craniofacial deformities. According to Sleep Apnea Today, altered growth of the palate has been linked to breathing difficulties such as sleep apnea.
It is important to have your child evaluated by a dentist from an early age for any potential issues in the development and growth of their jaw. Even if you think their smile is perfect the way it is, early diagnosis and treatment can have a lasting improvement on the appearance and function of their teeth.
This article is intended to promote understanding of and knowledge about general oral health topics. It is not intended to be a substitute for professional advice, diagnosis or treatment. Always seek the advice of your dentist or other qualified healthcare provider with any questions you may have regarding a medical condition or treatment.