Subjective: Flat skin surface, with no ridge formation in the central region of the upper lip between the nasal base and upper vermilion border (Fig. 1)Comments:
There is a spectrum of this finding from total absence of the philtral ridges to a some prominence of the ridges. The central groove varies from absent to shallow. Normal values for the frequency of smooth philtrum are available [Queisser-Luft et al., ]. Grading of the smoothness of the philtrum, used in the assessment of Fetal Alcohol Syndrome [Astley and Clarren, ] (Fig. 2), has been developed. This finding is greatly influenced by the facial expression, and care should be taken to evaluate the philtrum when the face is in a neutral position. A smooth philtrum can be associated with a Long philtrum. However, the two findings should be coded separately.