The Mid-Palatal Suture is the junction between two bones on the roof of the mouth. It runs from between the upper two front teeth backwards towards the back of the throat (the length of the dotted line in the above illustration). In growing children (under age 18), the suture has not completely fused together. Therefore, if the palate needs to be widened, your orthodontist can use a palate expander which opens the Mid-Palatal Suture and widens the roof of the mouth. In adults, the Mid-Palatal Suture has completely fused, so SARPE surgery might be necessary to widen the upper jaw.