Plastic and Craniofacial Surgery
In bilateral cleft lip, the two sides of the cleft may be of the same or very different severity. In general, the major difference between unilateral and bilateral clefts are the effects of the forward displacement of the bone under the middle portion of the lip (premaxilla). This portion of the upper gums contains the middle four front teeth. This center portion of the lip and gums gets pushed forward by the tongue over the course of the pregnancy as you can see in the photos below.