A straight class bite (straight bite, Orthogenetic) is a type of bite in which the upper and lower teeth are in close contact (touching each other). This bite is typical for people with rectangular faces, straight lips, prominent cheekbones and dimples (harmonious facial proportions). This jaw position is optimal for humans. A straight bite occurs in 70 percent of Europeans. It is less common among negroid species. It is characterized by convex facial contours and an asymmetrical line of the lower jaw.