Sagittal mandibular retrognathism (mandibular deficiency) as basic deviation may occur in combination with various maxillary deformities: + Sagittal maxillary prognathism (maxillary protrusion) Maxillary alveolar protrusion A deep overbite often occurs in childhood as it is genetically determined. The upper incisors extend too far down and cover the incisors in the lower jaw. As with a deep bite, the upper row of teeth also overlaps the lower row of teeth in an overbite.