Oksana Grigorieva has been handed a legal setback in her ongoing custody dispute with Mel Gibson, Breaking Celebrity News has exclusively learned.

Oksana's mega lawyers, Sorrell Trope and Anne Kiley petitioned to have a new pediatrician appointed for baby Lucia, and Judge Scott Gordon denied that request.

It is the first setback for Oksana's new legal team since formally taking the case.

Sources familiar with the situation tell us