Objective:To study the effects of modified maxillary protraction therapy on the changes in facial soft tissue in patients with maxillary hypoplasia using cephalometric measurements.Methods:26 cases(16 males and 10 females)of Class Ⅲ skeletal malocclu-sion with maxillary hypoplasia during the later period of pubertal peak(CVM Ⅴ to Ⅵ)were included.Treatment was carried out using modified palatal anchorage with a combination of a modified bite-jumping appliance and bilateral maxillary anterior traction.Cephalo-metric measurements were taken before and after treatment using lateral cephalograms,the changes in facial soft tissue-related parame-ters were compared.Results:(1)After treatment,the measurements of soft tissue landmarks in the midfacial region showed a signifi-cant increase(P＜0.05),with the average anterior movement exceeding 3 mm for the nasal tip,subnasale,soft tissue A point and upper lip protrusion point.(2)The changes in the G-Sn-Pos,Ns-Prn-Pos,and S-Ns-Sn were highly significant(P＜0.01),with an average increase in the G-Sn-Pos of 3.23°±3.74°,a decrease in Ns-Prn-Pos of 2.56°±4.99°,and an average increase in S-Ns-Sn of 2.63° ±3.39°.(3)Changes in soft tissue tension and facial height proportion after treatment were not statistically significant(P＞0.05).Con-clusion:The use of a modified pad type intraoral appliance in conjunction with bilateral maxillary anterior traction can effectively pro-mote the improvement of mid facial soft tissue profile in patients with maxillary underdevelopment during the peak growth and develop-ment period,and coordinate the relationship between nasal,lip and chin soft tissue.

AIM: To study the degree of astigmatism, axial distribution and axial symmetry pattern of binocular astigmatism in primary and secondary school students aged 7-18 years with myopia.METHODS:A total of 239 cases(478 eyes)of primary and secondary school students aged 7-18 years who underwent keratoplasty for myopia correction at the Fifth Affiliated Hospital of Zhengzhou University from 2020 to 2022 were randomly selected, and optometry was performed under ciliary muscle paralysis and was statistically analyzed.RESULTS:Astigmatism degree: 0.25 to 1.00 D accounted for 78.5%, 1.25 to 2.00 D accounted for 17.1%, and >2.00 D accounted for 4.4%. The axial distribution of astigmatism: 86.6% was astigmatism with the rule, 5.9% was astigmatism against the rule, and 7.5% was oblique astigmatism; both genders and different astigmatism degrees were dominated by astigmatism with the rule, and there were differences with the other two axes(both P<0.05). Axial symmetry pattern of astigmatism: the median axial difference in astigmatism between the direct symmetry model and the mirror symmetry model was 7° and 10°, respectively, with no statistical significance in both models(P=0.158), and there was no difference between the two in gender, degree of astigmatism, and axial distribution of astigmatism, but in the age group of 7-12 years old, the difference between the axial astigmatism of the direct symmetry model and the mirror symmetry model was statistically significant(P=0.027).CONCLUSION:The axial distribution of binocular astigmatism in myopic primary and middle school students is mostly astigmatism with the rule; the degree of astigmatism is more common from 0.25 to 1.0 D; however, there is no tendency for axial symmetry pattern of astigmatism.