IADR Abstract Archives
Overjet and vertical skeletal pattern in modifying perioral soft tissue
Objectives: This pilot study aimed to investigate the effect of overjet and vertical pattern on perioral soft tissue area.
Methods: Sixty pre-treatment lateral cephalograms of skeletal Class II patients were equally allocated into six groups of ten according to overjet (OJ) (normal OJ (NOJ=1-3mm) and increased OJ (IOJ=4-6mm)) and skeletal divergence (hypodivergence (Hypo), normodivergence (Normo), and hyperdivergence (Hyper)): NOJHypo, IOJHypo, NOJNormo, IOJNormo, NOJHyper, and IOJHyper, then measured randomly using Dolphin Imaging program and ImageJ. One-way ANOVA and Tukey’s HSD were used to compare parameters among groups (p<0.05).
Results: Upper incisors (UI-NA(deg)) in NOJHyper (mean±SD= 21.50±7.33°) were significantly more retroclined than IOJHypo (30.30±4.86°) and IOJHyper (32.00±4.67°)(p=0.033 and p=0.006, respectively). NOJHypo (23.62±7.19°) was also significantly more retroclined than IOJHyper (p=0.049). Protrusion of UI (UI-NA(mm)) was significantly greater in IOJHypo (8.99±1.87mm) and IOJHyper (8.37±1.98mm) when compared with NOJHypo (5.27±2.90mm) and NOJHyper (5.00±3.04mm) (p=0.016 and p=0.037, respectively). Meanwhile, NOJNormo and IOJNormo were similar regarding UI inclination and position. Lower vermilion lip thickness (LVLT) was significantly greater in IOJ groups between NOJHypo/IOJHypo (12.40±1.71mm/15.90±3.28mm), NOJNormo/IOJNormo (11.60±2.50mm/15.40±2.80mm), and NOJNormo/IOJHyper (p=0.021, p=0.009, and p=0.044, respectively). A significantly more backward position of the soft tissue pogonion (Pg-SnTVP) increased with hyperdivergence and OJ (NOJHypo(-4.80±2.82mm)/NOJHyper (-9.40±2.80mm), NOJHypo/IOJHyper(-11.00±4.06mm), IOJHypo (-6.40±3.57mm)/IOJHyper, and NOJNormo(-6.00±2.21mm)/IOJHyper (p=0.024, p=0.001, p=0.024, and p=0.011, respectively). A deeper mentolabial sulcus depth (MSD) was found between NOJNormo(-4.30±0.95mm) and IOJNormo(-6.48±1.06mm)(p=0.005).
Conclusions: OJ affected LVLT in Hypo and Normo group, however Hyper group was not affected which might have to do with mandibular and lower lip position. Having IOJ together with hypodivergence exhibited a more forward position of lower lip and chin. MSD could be influenced by UI. NOJ of varying divergence did not show any significant difference except for a more backward chin position caused by a smaller SNB angle and hyperdivergence.
Methods: Sixty pre-treatment lateral cephalograms of skeletal Class II patients were equally allocated into six groups of ten according to overjet (OJ) (normal OJ (NOJ=1-3mm) and increased OJ (IOJ=4-6mm)) and skeletal divergence (hypodivergence (Hypo), normodivergence (Normo), and hyperdivergence (Hyper)): NOJHypo, IOJHypo, NOJNormo, IOJNormo, NOJHyper, and IOJHyper, then measured randomly using Dolphin Imaging program and ImageJ. One-way ANOVA and Tukey’s HSD were used to compare parameters among groups (p<0.05).
Results: Upper incisors (UI-NA(deg)) in NOJHyper (mean±SD= 21.50±7.33°) were significantly more retroclined than IOJHypo (30.30±4.86°) and IOJHyper (32.00±4.67°)(p=0.033 and p=0.006, respectively). NOJHypo (23.62±7.19°) was also significantly more retroclined than IOJHyper (p=0.049). Protrusion of UI (UI-NA(mm)) was significantly greater in IOJHypo (8.99±1.87mm) and IOJHyper (8.37±1.98mm) when compared with NOJHypo (5.27±2.90mm) and NOJHyper (5.00±3.04mm) (p=0.016 and p=0.037, respectively). Meanwhile, NOJNormo and IOJNormo were similar regarding UI inclination and position. Lower vermilion lip thickness (LVLT) was significantly greater in IOJ groups between NOJHypo/IOJHypo (12.40±1.71mm/15.90±3.28mm), NOJNormo/IOJNormo (11.60±2.50mm/15.40±2.80mm), and NOJNormo/IOJHyper (p=0.021, p=0.009, and p=0.044, respectively). A significantly more backward position of the soft tissue pogonion (Pg-SnTVP) increased with hyperdivergence and OJ (NOJHypo(-4.80±2.82mm)/NOJHyper (-9.40±2.80mm), NOJHypo/IOJHyper(-11.00±4.06mm), IOJHypo (-6.40±3.57mm)/IOJHyper, and NOJNormo(-6.00±2.21mm)/IOJHyper (p=0.024, p=0.001, p=0.024, and p=0.011, respectively). A deeper mentolabial sulcus depth (MSD) was found between NOJNormo(-4.30±0.95mm) and IOJNormo(-6.48±1.06mm)(p=0.005).
Conclusions: OJ affected LVLT in Hypo and Normo group, however Hyper group was not affected which might have to do with mandibular and lower lip position. Having IOJ together with hypodivergence exhibited a more forward position of lower lip and chin. MSD could be influenced by UI. NOJ of varying divergence did not show any significant difference except for a more backward chin position caused by a smaller SNB angle and hyperdivergence.