According to Hoyme et al classification of hemihyperplasia, Hemifacial hyperplasia involves:

Hoyme et al (1998) provided an anatomic classification of hemihyperplasia:  Complex hemihyperplasia is the involvement of half of the body (at least one arm and one leg); affected parts may be contralateral or ipsilateral. Simple hemihyperplasia is the involvement of a single limb. Hemifacial hyperplasia is the involvement of one side of the face. Ref: Shafer's textbook of oral pathology 7th edition page 14