Excess space is the result of disproportion of the jaw and tooth size in favour of the jaw. Gaps in the upper jaw's frontal area are particularly conspicuous (diastema mediale), whereby a differentiation between a "true" and "false" diastema is possible. True diastema is often congenital; false diastema may be related to the non-existence of lateral incisors, a mesiodens (excess tooth) or short labial frenum.