Analysis of the changes in components of smile after maxillary arch distalization using infra-zygomatic crest (IZC) screws – A cephalometric and photographic study

Abstract

Objectives: The purpose of this study was to analyze the effects of infra-zygomatic crest (IZC) screws on smile components after maxillary arch distalization. Materials and Methods: The study was conducted on 20 subjects (11 boys and 9 girls) between 19 and 30 years. It was a time-bound study where screening of patients was done based on the inclusion and exclusion criteria for a year. Before placement of orthodontic bone screws (IZC), pre-treatment (T0) photographs, and cephalograms were taken where photographs were analyzed using Makhter’s software. After 6–8 months, post-distalization treatment (T1) photographs and cephalograms were taken and evaluated. Results: Descriptive statistics were used to obtain the mean and standard deviation for continuous data. Paired t-test was performed to analyze the changes in pre- and post-distalization. The categorical data were calculated using the McNemar test. Differences were considered significant if P < 0.05. Inner commissure right and left, smile arc, posterior maxillary dentition visible - left (PMDVL), upper incisal visibility, and gingival showed statistical significance. Conclusion: Maxillary arch distalization using IZC screws was associated with changes in horizontal smile components but mainly in vertical components, reducing the gummy smile, and making the smile esthetically pleasing.