Model of front part of adult skull illustrating overdevleopment of one side of mandible resulting in cross bite, on stand, prepared by D. Greer-Walker, 1950-1970

The model shown in the middle of the top row is of the front part of an adult skull. It was created by dentist and oral surgeon Dr Desmond Greer Walker (1911-1987). It illustrated a condition known as a cross bite. A cross bite is where the lower teeth do not ‘line up’ with the upper teeth. They appear to sit in front, behind or to the side of the upper teeth. An untreated cross bite can lead to limited jaw movement, popping and cracking in the jaw joint, and facial pain. Many cross bite cases can be corrected by braces fitted by an orthodontist. A cross bite results from overdevelopment of one side of the lower jaw.