While orthodontic treatment ensures proper tooth alignment, dentofacial orthopedics helps guide the growth and development of the face. Dentofacial orthopedics is implemented before or in conjunction with traditional orthodontic treatment.
Because the upper and lower jaw bones connect to the sinuses and cheekbones, the way they grow affects facial appearance. To support an ideal face structure and proper tooth development, the position of the upper jaw should be more forward position and wider than the lower jaw.
However, the upper and lower jaws sometimes grow at different rates or to irregular proportions, creating bite malocclusions. Often, orthodontists cannot fix these misalignments through braces alone and must use specialized equipment or procedures.
Detecting Abnormal Jaw Growth
Between the ages 7 and 9 (when a mix of baby and adult teeth are present) is the ideal time to detect abnormal jaw growth in children. Early detection allows the orthodontist to assess whether a child needs intervention or close monitoring as the mouth and jaws grow. She can determine this by taking impressions and three-dimensional scans of the mouth.
Jaw growth typically stops between ages 14 and 16 in females and between 17 and 21 in males. As jaw growth ceases, the bones harden, making gradual correction difficult or impossible. The earlier jaw abnormalities are detected, the better.
Orthodontists can use dentofacial orthopedic appliances on children to regulate the size of the growing jaws and glide them into the desired positions. Adults can also benefit from dentofacial orthopedic treatment, but they will require surgery in most cases.
Dentofacial Orthopedic Treatment: Appliances
A palatal expander is a dentofacial device that widens a child’s upper jaw when it’s too small. The upper jaw develops in two halves that don’t fuse until the teenage years. A palatal expander can gradually separate and stabilize these bones before they fuse. This type of dentofacial orthopedic appliance is custom-made for each individual and fits over several top teeth in the back of the mouth. The expander can be worn with or without concurrent treatment with braces.
A screw connects the appliance’s two halves in the middle. To activate the device, the patient turns the screw with a key a small amount daily, which creates tension at the junction of the two palatal bones, causing them to move apart gradually. When the mouth achieves the desired expansion, the appliance will stay in place for a few months to allow new bone to form in the gap.
Palatal expanders can also work on the lower jaw, but since that bone cannot stretch, the expander gradually moves the teeth apart to make room.
If your child’s jaws are not growing in proportion to one another, the orthodontist may recommend a bionator device to achieve dentofacial orthopedic correction. The Bionator I is a removable appliance used to treat patients with an overbite or deep bite. It uses screws to lengthen and widen the upper and lower jaw while opening the bite. At the same time, it expands the dental arches.
The Bionator II treats patients with an open bite. This appliance fully covers the posterior teeth while leaving the anterior teeth uncovered, which helps to close the bite while repositioning the lower jaw.
A twin block is similar to a bionator but has separate upper and lower components that interlock and posture the lower jaw forward. Though it is a removable appliance, a twin block is worn almost all the time–both day and night. It activates each time the patient bites, chews, swallows or talks by exerting gentle pressure on the teeth and dental arches while stabilizing the jaw joints.
Headgear is most commonly used to correct overjets, where the upper and lower jaws cause the front teeth to protrude. It also can reserve space for new teeth or correct an overbite. The headgear attaches to metal hooks called a facebow and straps around the back of the head or neck. The headgear is removable but must be worn for at least 14 hours per day. For most patients, this means after school each day and through the night.
Herbst & Forsus Appliances
A Herbst appliance is a metal tube and rod that attaches to the top molars and bottom teeth. It is very effective in correcting large overbites by enhancing the growth of the lower jaw in a forward direction while applying pressure to the upper jaw in a backward direction.
The Forsus appliance also attaches to the upper and lower teeth to treat overbites. However, a Forsus uses spring coil rods instead of solid ones. This is a fixed appliance, so the patient does not need to worry about remembering to wear it. It typically is placed about six months into the orthodontic treatment period.
Dentofacial Orthopedic Treatment: Jaw Surgery
Jaw problems that don’t get corrected in childhood often cause speech difficulties, uneven wear, damage to teeth, and TMJ pain. While an adult who wants to correct her bite will not have the same range of options as children, surgical interventions can produce similar results. Surgical intervention can occur independently or in conjunction with traditional orthodontic treatment.
Corrective jaw surgery, or orthognathic surgery, typically corrects jawbone irregularities by realigning these bones to affect how they work. A bonus is that jaw surgery results may also include an improved facial appearance. Surgery is often a good option when irregularities are too pronounced for braces alone to correct.
Surgery may be performed on the upper jaw, lower jaw, or both. During upper jaw surgery, the surgeon will cut the bone above the teeth so that the entire roof of the mouth and upper teeth can move as one unit. She will adjust the position until it fits with the lower teeth properly. After the bones are set, further orthodontic treatment can correct the positioning of the individual teeth.
Lower jaw surgery, also known as mandibular osteotomy, is primarily performed to correct a lower jaw that either juts out or caves in. During this procedure, the surgeon cuts behind the molars and lengthwise down the jawbone to move the jaw either forward or backward. Small plates and screws hold the bone together as it heals.
Sometimes, the surgeon may need to add extra bone to the jaw. The patient’s own bone can be transferred from areas such as the hip or leg. In other cases, the surgeon will reshape the existing bone to provide a better fit.
Are you ready to take the next step toward improving your overall health and smile? Start by contacting us today to schedule a consultation with one of our board-certified orthodontists.