Cephalometric Assessment of Lips in Skeletal Class II Patients by Steiner’s Line

Introduction: Steiner’s (S) Line has been used as reference line to assess antero-posterior position of lips cephalometrically and has been an effective diagnostic aid in this era of soft tissue paradigm. Norms for S-line has been established for different populations and it has been used widely to assess treatment outcomes in Skeletal Class II malocclusion, however antero-poste-rior position of lips and determinants of lip position in Skeletal Class II has not been explored. Study Design: This Prospective study was aimed to find out the antero-posterior position of lips on cepha-lograph using S-line in patients with retrognathic pro-file and to establish correlation between determinants of lip prominence. Data was collected using non-pro-bability convenience sampling technique following the selection criteria. Materials and Methods: The study was conducted on 65 subjects, with retrognathic profile as judged by orthodontists in consensus and confirmed by lateral cephalogram (ANB 4). S-Line was drawn on lateral cephalograph to assess the prominence of upper Lip and lower lip. SPSS 17.0 was used for statistical evalu-ation. Results: Antero-posterior position of upper and lower lip in patients with retrognathic profile with reference to S-line was 1.96  2.6 mm and 3.09  3.16 mm res-pectively. Moreover it was found that statistically sig-nificant correlation existed between lower lip promi-nence as assessed by S-line and upper lip prominence using the same reference line (r = 0.411), Lower inci-sor inclination (r = 0.535) and Skeletal Class II as as-sessed by ANB angle (r = 0.27). Upper lip prominence as assessed S-line was found to be statistically signi-ficantly correlated with lower incisor inclination and lower lip prominence. Discussion: Results were compliant with the previous studies. Conclusion: In the present study both upper and low-er lips were more prominent in Skeletal Class II patie-nts as compared to Steiner’s norms for skeletal class I.