Aim of the study: to compare the effect of Hyrax appliance and the Haas appliance improving the transverse skeletal and dental dimensions in cleft lip and palate patients during mixed dentition.

•Steps in short Full records pre-treatment. Bands selection for upper first molars then construction of expansion appliances(Haas or Hyrax) . Delivery of appliances and instructions to the patients and their parents about their activation regimen 2 quarter turns in the morning and 2 in the evening.The posterior crossbite will be measured as the distance from the palatal cusp tips of upper first molars to central fossae of lower first molars then the needed time for expansion will be calculated .When the time calculated for correction ends, we will stop activation, we will take impressions for digital models to see if real expansion occurred or not and so testing the efficiency of the two appliances.

Afterthat, if correction was not yet achieved, activation of the appliances will continue till overcorrection at the molar region with the palatal cusp tip of the maxillary posterior teeth contacting the buccal cusp tip of the mandibular posterior teeth. We will then leave the appliance insitu for retention.

After 6 months from the first CBCT we will take a second CBCT to see any bony changes .

Inclusion Criteria:

• (1) Mixed dentition; (2) Both males and females; (3) Lip repair performed between 3 and 6 months of age and palate repair performed between 12 and 24 months of age; (4) Presence of maxillary constriction and posterior crossbite and need for maxillary expansion previous to the secondary bone graft; (5) Permanent first maxillary molars present; (6) Good periodontal health; (7) No previous orthodontic treatment;

Exclusion Criteria:

• (1) Presence of a syndrome in companion with the present cleft defect (2) Previous secondary alveolar bone grafting (3)Taking medications affecting growth