The HPO is using the definitions and preferred terminology of the ELements of Morphology Project, which has definitions and prefered names for about 500 items in dysmorphology. The authors state:
Nasal Tip, Narrow
Nasal tip width is assessed at the anterior junction of the alae and the tip. This is easier in persons with a somewhat squared shape of the nasal tip. This may be best viewed from the inferior aspect of the nose. No objective measures are available.
Replaces: Nasal Tip, Pinched
The HPO is using the definitions and preferred terminology of the ELements of Morphology Project, which has definitions and prefered names for about 500 items in dysmorphology. The authors state:
Nasal Tip, Narrow
Nasal tip width is assessed at the anterior junction of the alae and the tip. This is easier in persons with a somewhat squared shape of the nasal tip. This may be best viewed from the inferior aspect of the nose. No objective measures are available.
Replaces: Nasal Tip, Pinched
http://elementsofmorphology.nih.gov/index.cgi?tid=a9769c3dacf3fc83
Therefore, the two terms should be regarded as synonyms. The HPO lists pinched nasal tip as a synonym for narrow nasal tip.