The mean expansion obtained between cusp tips and between cervical-palatal points was , respectively : for inter-canine width , 4.80 mm and 4.35 mm with the Haas appliance and 5.91 mm and 5.91 mm with the Hyrax appliance ; as for first deciduous molars or first deciduous premolars , the values obtained were 6.46 mm and 5.90 mm in the Haas group , and 7.11 mm and 6.65 mm in the Hyrax group ; with regard to first molars , values were 6.11 mm and 5.24 mm in the Haas group , and 7.55 mm and 6.31 mm in the Hyrax group .