title: Mandibular dysfunction as a reflection of bulbar involvement in SMA type 2 and 3.
abstract: OBJECTIVE
  In a cross-sectional study, we aimed to determine (1) the effect of spinal muscular atrophy (SMA) type 2 and 3 on mandibular function reflected as masticatory performance, mandibular range of motion, and bite force and (2) the predictors of mandibular dysfunction.
  
  
  METHODS
  Sixty patients with SMA type 2 and 3 (mean age 32.3 years, SD 17.4 years) and 60 age-matched controls filled out questionnaires about impairments of mandibular function. All participants underwent detailed clinical examination to document the mandibular range of motion including maximal mouth opening, bite force, and masticatory function.
  
  
  RESULTS
  All mandibular movements, including mouth opening, lateral range of motion, and protrusion of the mandible, were reduced in patients with SMA type 2 and 3 compared to healthy controls (p < 0.001). Maximal bite force was 19% lower in patients than controls, and more in patients with SMA type 2 than type 3. The strongest predictive factor was SMA type for impairment of mandibular range of motion (R(2) = 0.82) and weakness of neck muscles for bite force (R(2) = 0.47).
  
  
  CONCLUSIONS
  Reduced mandibular mobility and bite force are common complications in SMA. SMA type and neck muscle strength are important correlates of these complications. We provide further evidence for clinically relevant bulbar involvement in patients with SMA.
authors.affiliation: From the Departments of Oral Function and Prosthetic Dentistry (H.W.v.B., N.C., S.I.K.) and Preventive and Restorative Dentistry (E.M.B.), College of Dental Science, Radboud University Medical Center, Nijmegen; and Department of Oral-Maxillofacial Surgery, Prosthodontics and Special Dental Care (H.W.v.B., M.H.S.), and Department of Neurology and Neurosurgery and Spieren voor Spieren Kindercentrum, Brain Center Rudolf Magnus (R.I.W., M.L., W.L.v.d.P.), University Medical Center Utrecht, the Netherlands. Willemijn.vanBruggen@radboudumc.nl.
authors.forename: H Willemijn
authors.initials: HW
authors.lastname: van Bruggen
authors.affiliation: From the Departments of Oral Function and Prosthetic Dentistry (H.W.v.B., N.C., S.I.K.) and Preventive and Restorative Dentistry (E.M.B.), College of Dental Science, Radboud University Medical Center, Nijmegen; and Department of Oral-Maxillofacial Surgery, Prosthodontics and Special Dental Care (H.W.v.B., M.H.S.), and Department of Neurology and Neurosurgery and Spieren voor Spieren Kindercentrum, Brain Center Rudolf Magnus (R.I.W., M.L., W.L.v.d.P.), University Medical Center Utrecht, the Netherlands.
authors.forename: Renske I
authors.initials: RI
authors.lastname: Wadman
authors.affiliation: From the Departments of Oral Function and Prosthetic Dentistry (H.W.v.B., N.C., S.I.K.) and Preventive and Restorative Dentistry (E.M.B.), College of Dental Science, Radboud University Medical Center, Nijmegen; and Department of Oral-Maxillofacial Surgery, Prosthodontics and Special Dental Care (H.W.v.B., M.H.S.), and Department of Neurology and Neurosurgery and Spieren voor Spieren Kindercentrum, Brain Center Rudolf Magnus (R.I.W., M.L., W.L.v.d.P.), University Medical Center Utrecht, the Netherlands.
authors.forename: Ewald M
authors.initials: EM
authors.lastname: Bronkhorst
authors.affiliation: From the Departments of Oral Function and Prosthetic Dentistry (H.W.v.B., N.C., S.I.K.) and Preventive and Restorative Dentistry (E.M.B.), College of Dental Science, Radboud University Medical Center, Nijmegen; and Department of Oral-Maxillofacial Surgery, Prosthodontics and Special Dental Care (H.W.v.B., M.H.S.), and Department of Neurology and Neurosurgery and Spieren voor Spieren Kindercentrum, Brain Center Rudolf Magnus (R.I.W., M.L., W.L.v.d.P.), University Medical Center Utrecht, the Netherlands.
authors.forename: Maureen
authors.initials: M
authors.lastname: Leeuw
authors.affiliation: From the Departments of Oral Function and Prosthetic Dentistry (H.W.v.B., N.C., S.I.K.) and Preventive and Restorative Dentistry (E.M.B.), College of Dental Science, Radboud University Medical Center, Nijmegen; and Department of Oral-Maxillofacial Surgery, Prosthodontics and Special Dental Care (H.W.v.B., M.H.S.), and Department of Neurology and Neurosurgery and Spieren voor Spieren Kindercentrum, Brain Center Rudolf Magnus (R.I.W., M.L., W.L.v.d.P.), University Medical Center Utrecht, the Netherlands.
authors.forename: Nico
authors.initials: N
authors.lastname: Creugers
authors.affiliation: From the Departments of Oral Function and Prosthetic Dentistry (H.W.v.B., N.C., S.I.K.) and Preventive and Restorative Dentistry (E.M.B.), College of Dental Science, Radboud University Medical Center, Nijmegen; and Department of Oral-Maxillofacial Surgery, Prosthodontics and Special Dental Care (H.W.v.B., M.H.S.), and Department of Neurology and Neurosurgery and Spieren voor Spieren Kindercentrum, Brain Center Rudolf Magnus (R.I.W., M.L., W.L.v.d.P.), University Medical Center Utrecht, the Netherlands.
authors.forename: Stanimira I
authors.initials: SI
authors.lastname: Kalaykova
authors.affiliation: From the Departments of Oral Function and Prosthetic Dentistry (H.W.v.B., N.C., S.I.K.) and Preventive and Restorative Dentistry (E.M.B.), College of Dental Science, Radboud University Medical Center, Nijmegen; and Department of Oral-Maxillofacial Surgery, Prosthodontics and Special Dental Care (H.W.v.B., M.H.S.), and Department of Neurology and Neurosurgery and Spieren voor Spieren Kindercentrum, Brain Center Rudolf Magnus (R.I.W., M.L., W.L.v.d.P.), University Medical Center Utrecht, the Netherlands.
authors.forename: W Ludo
authors.initials: WL
authors.lastname: van der Pol
authors.affiliation: From the Departments of Oral Function and Prosthetic Dentistry (H.W.v.B., N.C., S.I.K.) and Preventive and Restorative Dentistry (E.M.B.), College of Dental Science, Radboud University Medical Center, Nijmegen; and Department of Oral-Maxillofacial Surgery, Prosthodontics and Special Dental Care (H.W.v.B., M.H.S.), and Department of Neurology and Neurosurgery and Spieren voor Spieren Kindercentrum, Brain Center Rudolf Magnus (R.I.W., M.L., W.L.v.d.P.), University Medical Center Utrecht, the Netherlands.
authors.forename: Michel H
authors.initials: MH
authors.lastname: Steenks
mesh_terms: D000328:Adult; D001732:Bite Force; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement; D016059:Range of Motion, Articular / Q000502:physiology; D014897:Spinal Muscular Atrophies of Childhood / Q000175:diagnosis / Q000503:physiopathology*; D013704:Temporomandibular Joint / Q000503:physiopathology*