A series of factors influence the normal development of the occlusion, interfering in correct alignment of the teeth and harmonic relationship with the adjacent and antagonistic elements. Developmental disturbances of the teeth may manifest by variations in number, position, size, shape, eruption, structure. Such disturbances may occur in association with some more generalised disorder or may occur independently. The present study is undertaken to review the etiopathogenesis of various developmental disturbances during apposition of dental hard tissues.