Which of the following diseases of the skin is the most
likely to be associated with partial anodontia?
Ectodermal dysplasia is characterized by congenital dysplasia of ectodermaL structures, manifested as hypohidrosis (partial or complete absence of sweat glands) hypotrichosis and hypodontia or partial anodontia.
Two types

Hypohidrotic (Christ-Siemens-Touraine syndrome) most common type and includes dental manifestations.
Hidrotic (Clouston syndrome)- no specific dental defects are seen.
erythema multiformae
hereditary ectodermal dysplasia
keratosis follicularits
lichen Onus