You can use Simple SEO Improvements WordPress plugin, which is integrated with OG.

Or you can use og_array a filter to add (or modify) OpenGraph tags.

add_filter( 'og_array', 'add_og_facebook_data' );
function add_og_facebook_data( $og ) {
    $og['fb'] = array(
        'app_id' => 'my-app-id',
        'pages' => 'foo, bar',
    );
    return $og;
}