The aim of the study was to determine the etiology and incidence diastema median of the upper jaw, with tutins and rozajs high school. Biostatistical data collection, analysis and interpretation was conducted after specialist systematic review of 100 patients, of equal gender representation. Methodological defined parallel, divergent and convergent diastema median, measured in gingival and incisal part of the crown, using a digital vernier.In multicausal aetiology dominates heritage (37,05 %), ahead of the low attachment fibrous frenulum (14,28 %) and the discrepancies in the length of the dental arch and the size of the teeth (14,28 %). Diastema median is represented in 14 persons (14.0 %), of which at 5 females 5 (10,0 %) and 9 men (18,0 %). According to the most common form is represented parallel to the median diastema, in both sexes, more common in males (10.0 %) than females (6,0 %). The incidence of diastema median in the sample is higher than the representation of the majority of Europeans, but less than most African and Asian nations.