Medically reviewed by Dr. Amin P. Samadian, DDS, MBA, Diplomate of the American Board of Dental Sleep Medicine and Fellow of the American Academy of Craniofacial Pain. Last reviewed November 7, 2026.
In a crossbite some of the upper teeth close inside the lower teeth instead of outside them. It can involve one tooth or a whole side, and it can come from the position of the teeth or from an upper jaw that is too narrow. Which of those it is decides the treatment. Dr. Amin Samadian treats crossbites in children and adults at our San Francisco office. Call 415-570-2841 to book an evaluation.
Types of crossbite
Posterior crossbite
The upper back teeth sit inside the lower back teeth, on one side or both. Most often the upper jaw is narrow. This is the type most closely tied to mouth breathing and a low tongue position during childhood.
Anterior crossbite
One or more upper front teeth sit behind the lower front teeth. Sometimes a single tooth came in at the wrong angle. Sometimes the whole upper jaw is set back relative to the lower jaw.
Dental or skeletal
A dental crossbite is a tooth problem and can be fixed by moving teeth. A skeletal crossbite is a jaw-width or jaw-position problem. Moving teeth alone in a skeletal crossbite tends to tip them and the bite drifts back, so the jaw has to be addressed.
Signs we look for
- Upper teeth that close inside the lower teeth when you bite
- The lower jaw sliding to one side as the teeth come together
- Uneven wear, chipping or receding gums on certain teeth
- A face or chin that looks slightly off to one side
- Jaw clicking or soreness on one side
- In children: mouth breathing, snoring, and a narrow, high palate
Why it is worth correcting
When a crossbite makes the lower jaw shift to one side every time the teeth meet, the jaw joints and chewing muscles work unevenly thousands of times a day. That is one reason we check the bite closely in TMJ patients. In a child the shift can also guide the jaw to grow unevenly, which is why we prefer to correct a skeletal crossbite while the child is still growing.
How we treat crossbites
Children: expansion while they are growing
In children the seam in the middle of the palate is still open, so a palatal expander or an ALF appliance can widen the upper jaw gently. This often corrects a posterior crossbite and makes room for crowded teeth at the same time.
Adults: MARPE for a narrow upper jaw
In adults the seam has matured. MARPE, including the MSE appliance, anchors the expander to small miniscrews in the palate so the jaw itself widens rather than the teeth tipping. For many adults this avoids jaw surgery.
Dental crossbites: aligners or braces
When the jaw width is fine and only the teeth are out of place, clear aligners or clear braces move them into the right position.
Your first visit
- Bite and jaw exam. We watch how the jaw closes and whether it shifts.
- 3D CBCT scan. Taken in the office, it shows whether the crossbite is dental or skeletal, the width of the jaws, and the airway.
- A plan you understand. We explain which type you have, the options that fit it, and how long each takes, before anything starts.
Book crossbite treatment in San Francisco
We are at 260 Stockton St, 4th Floor, San Francisco, CA 94108. Call 415-570-2841 or request an appointment online.
