Anterior Cross Bite

These involve a mismatch in the position of the upper and lower jaws. For example, the upper jaw is relatively far back compared to the forwardly placed lower jaw. This is referred to as Class III jaw pattern. Within this group, there is large variation in severity and jaw patterns which influences the type of treatment required. Some mild Class III with favourable facial pattern and sufficient overbite will benefit from early treatment with reverse pull head gear/face mask from 7 – 9 years of age. Hence, it is important that these cross-bite cases are seen by an orthodontist for an early assessment. In contrast, an adult who presents with a severe Class III would be offered a combination of orthodontics and jaw surgery to create the ideal bite with harmonious facial features.

Frequently, when an upper incisor tooth is positioned back, it interferes with a lower tooth during jaw closing. The lower jaw is then postured forwards to enable the back teeth to meet and chew. This initial contact and posture can be harmful to the teeth involved. Teeth can loosen, be worn down or become displaced from the arch, resulting in gum recession i.e. traumatic bite. The forward posture can also exacerbate the forward growth of the lower jaw which is undesirable in a Class III pattern. When there are signs of traumatic occlusion and posture, it is beneficial that the child be assessed early (7 – 8 years) and have the cross-bite corrected