Add a link in management menu for specific role
Shame on me ! The solution relied of course in a single line of my code, shared below in case it could help somebody. 

I aimed to block many admin pages access, from which the admin path, in  a radical manner :

function vts_dashboard_menu_alter(&amp;$items) {
   $items['admin']['access callback'] = 'vts_dashboard_admin_access_only';
  //more items ...  
}
function vts_dashboard_admin_access_only() {
  global $user;
  if( !in_array('administrator', $user-&gt;roles)){
    return false;
  }
  return true;
}


But $items['admin']['access callback'] blocks also descendant menus items... commented out and all's fine again !

Be what it is, if any enlightened Drupal guru can tell me how to restrict access to foo path but no foo/bar, he'll receive all my consideration !