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.

AIM: To investigate the correlation of degree of myopia in adolescents with axial length, corneal curvature and axial ratio.METHODS: Cross-sectional study. A total of 246 adolescents(492 eyes)aged 8-18 years consecutively enrolled for orthokeratology lens fitting at the Fifth Affiliated Hospital of Zhengzhou University between 2021 and 2023 were included based on random sampling method, with 447 eyes finally included due to the elimination of 45 eyes that did not meet the inclusion criteria. Biometric measurements under scotopic conditions assessed axial length(AL), corneal radius of curvature(CR), and AL/CR ratio. Cycloplegic refraction determined spherical equivalent(SE), classifying eyes into mild(216 eyes)or moderate(231 eyes)myopia groups. Furthermore, the correlation of degree of myopia with AL, CR and AL/CR was analyzed by multiple linear regression analysis.RESULTS: A statistically significant difference in myopia severity was observed between the 8-12-year-old and 13-18-year-old age groups(all P<0.001). There were statistically significant differences between mild and moderate groups in SE, AL and AL/CR(all P<0.001). Linear regression analysis revealed significant negative correlations of SE with AL and AL/CR(r=-0.531, -0.598, all P<0.001). The areas under the ROC curve(AUC)for predicting moderate myopia were 0.812(95% CI: 0.773-0.852)for AL/CR combined with gender and age, 0.800(95% CI: 0.759-0.841)for AL/CR alone, 0.726(95% CI: 0.680-0.773)for AL alone, and 0.548(95% CI: 0.494-0.601)for CR alone. The optimal AL/CR cut-off value for predicting moderate myopia was 3.189(sensitivity: 0.632, specificity: 0.852), suggesting its potential as a clinical threshold.CONCLUSION: In adolescents with mild-to-moderate myopia, AL/CR, AL, and SE showed significant negative correlations. The combination of AL/CR with gender and age demonstrated the highest diagnostic accuracy for SE. AL/CR shows independent predictive value for myopia degree in adolescents, irrespective of refractive status.