Ordered that the order is affirmed insofar as appealed from, with costs.
The court’s paramount concern in any custody dispute is whether, under the totality of the circumstances, a determination of custody is in the best interests of the child (see Eschbach v Eschbach, 56 NY2d 167, 171 [1982]; Matter of Roldan v Nieves, 76 AD3d 634 [2010]; Matter of Lamarche v Jessie, 74 AD3d 1341 [2010]; Matter of Nikolic v Ingrassia, 47 AD3d 819, 820 [2008]). Where modification of an existing custody arrangement is at issue, there must be a showing of a change in circumstances such that modification of custody is necessary to ensure the continued best interests and welfare of the child (see Eschbach v Eschbach, 56 NY2d at 171; Matter of Lamarche v Jessie, 14 AD3d at 1341; Matter of Quinones v Ibarrondo, 67 AD3d 686 [2009]; Matter of Pignataro v Davis, 8 AD3d 487, 488 [2004]). “Custody determinations turn in large part on assessments of the credibility, character, temperament, and sincerity of the parties, and where a full evidentiary hearing has been held on the child’s best interests, the resultant findings will not be lightly set aside on appeal” (Matter of Roldan v Nieves, 76 AD3d at 635; see Petek v Petek, 239 AD2d 327 [1997]). The Family Court’s determination should not be disturbed unless it lacks a sound and substantial basis in the record (see Eschbach v Eschbach, 56 NY2d at 173-174; Salvatore v Salvatore, 68 AD3d 966 [2009]; Matter of Berkham v Vessia, 63 AD3d 1155 [2009]).
Here, contrary to the father’s contention, the Family Court’s finding that there was a change of circumstances such that the children’s continued best interests and welfare would be served by an award of sole custody to the mother has a sound and substantial basis in the record.
The father’s contention that the Family Court should have ordered a forensic examination is without merit (see Dana-Sitzer v Sitzer, 48 AD3d 354 [2008]; Matter of Salamone-Finchum v McDevitt, 28 AD3d 670, 671 [2006]; Matter of Diaz v Santiago, 8 AD3d 562, 563 [2004]). The father’s remaining contentions are without merit. Prudenti, P.J., Covello, Florio and Belen, JJ., concur.