[1] Univ Groningen, Univ Med Ctr Groningen, Dept Pulm Dis, AA11,Hanzepl 1,POB 30-001, NL-9700 RB Groningen, Netherlands
[2] Univ Groningen, Univ Med Ctr Groningen, Groningen Res Inst Asthma & COPD, Groningen, Netherlands
[3] Univ Groningen, Univ Med Ctr Groningen, Dept Oral & Maxillofacial Surg, Groningen, Netherlands
[4] Univ Amsterdam, Acad Ctr Dent Amsterdam, MOVE Res Inst Amsterdam, Dept Oral Kinesiol, Amsterdam, Netherlands
[5] Vrije Univ Amsterdam, Amsterdam, Netherlands
[6] Acad Med Ctr, Dept Oral & Maxillofacial Surg, Amsterdam, Netherlands
[7] Tjongerschans Hosp, Dept Oral & Maxillofacial Surg, Heerenveen, Netherlands
[8] Martini Hosp, Dept Ear Nose & Throat Surg, Groningen, Netherlands
[9] Univ Groningen, Univ Med Ctr Groningen, Ctr Home Mech Ventilat, Groningen, Netherlands