**2.5 Aetiology of asymmetric tooth formation and eruption**

Eerens et al. compared 54 children with cleft, 63 children in the sibling group without cleft as well as 250 normal children in the non-sibling control group and found that the cleft group and sibling group showed a significantly higher frequency of asymmetric tooth formation compared to the control group, hence suggesting some common genetic factors for delayed tooth formation and clefting [41].

Another possible reason for asymmetric tooth formation and delayed eruption in CLP patients has also been proposed. The effects of surgical cleft repair could result in damage to the tooth bud, or fibrosis and reduced blood supply to the cleft area [18]. Other etiological factors include lack of space in the cleft area [39] and growth attenuation due to improper nutrition as a result of feeding problems [18].
