The purpose of this study was the comparison of maxillary growth after treatment of cleft palate by a supraperiosteal or mucoperiosteal flap. The subjects selected for this study were the patients under Hellman's dental stage IIC or IIIA. The upper and lower plaster models were obtained from 53 cases of the children with cleft lip and palate who were treated by mucoperiosteal flap at one year and six months old in our clinic (13 cases of bilateral cleft lip and palate [BCLP], 20 cases of unilateral cleft lip and palate [UCLP], 20 cases of cleft palate [CP]) and 45 cases of the children with cleft lip and palate who were treated by supraperiosteal flap (12 cases of BCLP, 18 cases of UCLP, 15 cases of CP). For the control, 30 upper and lower plaster models were obtained from normal children. The following results were obtained.
1. Occlusal patterns: In dental stage IIC period, classified by the terminal plane, a ratio of the mesial step type was 75.0% of the mucoperiosteal flap groups, while it was 56.8% of the supraperiosteal flap groups. In dental stage IIIA period, classified by the Angle's classification, a ratio of Class III was 7.8% of the mucoperiosteal flap groups, and it was 6.0% of the supraperiosteal flap groups.
2. Arch length: Upper arch length of the supraperiosteal flap groups were near to those of the normal groups, and for the comparison, different arch lengths of the mucoperiosteal flap groups in UCLP cases and CP cases were smaller than those of the normal groups.
3. Arch width: Widths between the first molars of the supraperiosteal flap groups were near to those of the normal groups.
4. Tongue space capacity: Tongue space capacity of the supraperiosteal flap groups was bigger than that of the mucoperiosteal flap groups, but it was smaller than those of the normal groups.
Therefore, the obstacle to maxillary growth of the supraperiosteal flap groups is less than that of the mucoperiosteal flap groups. It was suggested that it was one of the final targets of consistent treatment to greatly contribute to the acquisition of the neutral articulation as far as possible.
