Modified ridge lap is the pontic of choice in:
In the mandibular posterior region where esthetics is not a major consideration, spheroidal pontic is  the design of choice because of its contour.
In the maxilla, modiﬁed ridge lap design satisﬁes both esthetics and hygiene so it is the pontic design  of choice in both anterior and posterior region.
Maxillary anteriors
Mandibular posteriors
Maxillary posteriors
Both 1 & 3