Mouse was suffering from an underjet (correctly referred to as prognathism). This is a rare condition caused by misalignment of the upper and lower jaw (present from birth) where the lower incisors protrude in front of the upper incisors, causing uneven wear and over eruption of both selected incisors and cheek teeth. Feeding and chewing is affected as the overlong teeth restrict movement of the jaw. This condition can also cause discomfort with the bit.
Work was done to both the incisors and cheek teeth, reducing dominant areas and allowing greater freedom of movement and comfort for mouse. Regular appointments are necessary every 6 months to manage her condition.