Reply To: [Waiting for user confirmation] Detect child and hide div

<?php
	$children = get_posts ('meta_key' => '_wpcf_belongs_review_id', 'meta_value' => $post->ID, 'post_type' => 'review');
        if( count( $children ) > 0 ) {?>
            <style type="text/css">#review{display:none;}</style>           
            <?php }
        else { }
?>