Does vertical pattern affect lip strain in open-bite patients?: A cephalometric study

Aim: To examine effect of skeletal pattern on lip strain in open-bite, in individuals with normal and increased vertical pattern. Materials and Methods: 56 open bite patients with Normovergent (NG) and Hyperdivergent (HG) vertical patterns (Mean age: 16.57 years) underwent cephalometric analysis. Soft tissue labial, hard tissue, and dental inclinations were measured. Statistical analyses were performed using Kolmogorov Smirnov, Mann Whitney-U, and independent sample t-tests; Pearson and Spearman correlation analyses; and Linear regression analysis. Results: In HG, each degree of SN-UOP increase caused 0.371 mm increase in lower lip strain. While in NG, upper lip strain was associated with IMPA and SNB (each degree caused 0.14 mm increase and 0.207 mm decrease respectively). Conclusion: IMPA, SN-UOP and SNB were found to be the determinants of lip strain. Dental, vertical, and sagittal variables showed association with lower face.