Background:The ethnic-based nasolabial reference values should be established for evaluations of the patients with dysmorphic faces and assessments of craniofacial surgeries

Objective: To establish 1) standard nasolabial values for Thai neonates and 4-month-old infants at Srinagarind Hospital, Khon Kaen University, and 2) to compare mean values between sexes.

Materials and Methods: Thirty neonates and thirty 4-months-old infants were enrolled in the study. Direct measurements of the nose and lip were taken by one examiner. Intra-observer variations had been tested. Means, standard deviations (SD) and range were reported. The independent t-test was used to compare all parameters between males and females.

Results: This study established standard values of nasolabial parameters among Thai neonates and 4 -month-old infants. In neonates, the mean values were 11.92±1.18 mm for upper lip height, inter-commissural distance 25.05±1.53 mm, right nostril width 5.55±0.80 mm, left nostril width 6.48±0.86 mm, right nostril height 3.23± 0.39 mm and left nostril height 3.25±0.38 mm. There were no statistically significant differences between sexes in this group. In 4-month-old infants, the mean values of the measurements were 14.25±1.06 mm for upper lip height, inter-commissural distance 31.52±2.68 mm, right nostril width 6.79±0.88 mm, left nostril width 6.73±0.87mm, right nostril height 4.79±0.73 mm and left nostril height 4.74±0.77 mm. In addition, there were no statistically significant differences between sexes except for left and right nostril width and inter-commissural distance.

Conclusion: Inthis study we established nasolabial norm values for Thai neonates and 4-month-old infants which could be used as a guideline to evaluate the efficacy of presurgical alveolar molding and cheiloplasty in cleft lip and palate infants.