Type

Description

Characteristics

I

Normal web

Thumb web space not narrowed

IIA

Mildly narrowed web

Thumb web space mildly narrowed

IIB

Severely narrowed web

Thumb web space severely narrowed

III

Syndactylized web

Thumb and index rays syndactylized, web space obliterated

IV

Merged web

Index ray suppressed, thumb web space is merged with the cleft

V

Absent web

Thumb elements suppressed, ulnar rays remain, thumb web space no longer present