Comparative evaluation of nasal parameters in various vertical skeletal dimensions amongst Malay female orthodontic patients

Objectives: To establish cephalometric norms for various nasal parameters in skeletal normodivergent Malaysian Malay adult females, and to compare nasal parameter differences across normo-, hypo-, and hyperdivergent vertical skeletal dimensions.Materials and Methods: This retrospective study analysed 156 pre-orthodontic lateral cephalometric radiographs of skeletal Class I Malay females aged 18 to 30 years (mean age= 24.12 ± 3.38). Cephalograms were categorised into normodivergent (MMPA: 24.8° ± 6.7°), hypodivergent (31.5°). Sixteen nasal parameters were manually traced, comprising nine linear (nasal depth 1, nasal depth 2, nasal bone length, nasal length, columella convexity, nasal dorsum axis, nasal tip protrusion, nasal height, and hump) and seven angular (nasomental, nasofrontal, nasofacial, nasolabial, nasal tip, soft tissue facial convexity, and nasal bone angles) parameters. One-way ANOVA with Bonferroni post-hoc test (p < 0.05) was used to compare mean nasal parameters across the three vertical skeletal groups. Intra- and inter-examiner reproducibility was assessed using the Intraclass Correlation Coefficient (ICC) with remeasurements made after one week.Results: ICC analysis demonstrated excellent intra- and inter-examiner reliability (0.93 and 0.91, respectively). No significant differences were observed in linear nasal parameters across all groups except nasal depth 2 (p = 0.02) which was significantly greater in normodivergent than hyperdivergent group. No significant differences were found in angular nasal parameters.Conclusions: Nasal cephalometric norms in normodivergent Malaysian Malay female were established, providing an essential reference data for nasal assessment. Nasal depth 2 varied significantly across groups, suggesting that vertical skeletal pattern can influence this specific nasal variable, which is crucial for improving orthodontic and surgical treatment planning in the Malay population.