Ciao, prova così:
codice HTML:
<!DOCTYPE HTML>
<html>
  <head>
    <title>Esempio</title>
    <meta charset="utf-8">
    <style type="text/css">
      button{
        padding:0;
        width:150px;
        height:50px;
        vertical-align:middle;
      }
    </style>
  </head>
  <body>
    <button type="button">Lorem ipsum</button> dolor sit amet.
    Ut enim ad minim veniam, <button type="button">quis nostrud exercitation ullamco</button> laboris nisi ut aliquip ex ea commodo consequat.
  </body>
</html>