[1] Univ Med Ctr Groningen, Dept Oral & Maxillofacial Surg, POB 30-001, NL-9700 RB Groningen, Netherlands
[2] Univ Groningen, POB 30-001, NL-9700 RB Groningen, Netherlands
[3] Univ Utrecht, Univ Med Ctr Utrecht, Dept Oral Maxillofacial Surg Prosthodont & Specia, Utrecht, Netherlands
[4] Univ Groningen, Dept Implant Dent, Groningen, Netherlands
[5] Univ Med Ctr Groningen, Groningen, Netherlands