title: Denervation and beta2-adrenoceptor-agonist administration on craniofacial bone density.
abstract: OBJECTIVE
  Beta2-agonist medications are thought to have adverse effects on bone density. Surgical denervation and intramuscular beta2-agonist injections appear to have opposing effects on skeletal muscles. The present study has been designed to assess the effects of denervation of the masseter, intramuscular injection of a beta2-agonist and the combination of both procedures, on bone density in the craniofacial skeleton in rats.
  
  
  METHODS
  Sprague-Dawley rats were prepared as four groups: 1. surgical sham + saline injection into the masseter (sham); 2. surgical denervation of the masseter (den.); 3. surgical denervation of the masseter + intramuscular formoterol injection into the affected muscle (den.+form.); 4. intramuscular formoterol injection into the masseter (form.). All specimens were submitted for CT examination and volumetric calculations of the mineralised bone tissue were performed.
  
  
  RESULTS
  The sham and form. groups had a greater volume of mineralised bone in the zygoma on the experimental side compared with the control side. The maxilla on the experimental side had a higher volume of mineralised bone in the den.+form. and form. groups compared with the sham and den. groups. The control side of the maxilla had a higher volume of mineralised bone in the den.+form. and form. groups compared with the den. group only.
  
  
  CONCLUSIONS
  Intramuscular administration of formoterol appears to induce a bilateral increase in bone mineral density in the maxilla and the zygoma, likely explained as a secondary effect of the well-described increase in muscle mass and strength associated with beta2-agonist administration.
authors: Brendan
authors: B
authors: Fitzpatrick
authors: Michael
authors: M
authors: Woods
authors: Gordon
authors: G
authors: Lynch
authors: David
authors: D
authors: Manton
mesh_terms: D058666:Adrenergic beta-2 Receptor Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D015519:Bone Density / Q000187:drug effects / Q000502:physiology*; D002113:Calcification, Physiologic / Q000187:drug effects / Q000502:physiology; D004983:Ethanolamines / Q000008:administration & dosage / Q000494:pharmacology; D005147:Facial Bones / Q000187:drug effects / Q000502:physiology*; D000068759:Formoterol Fumarate; D007273:Injections, Intramuscular; D008297:Male; D008406:Masseter Muscle / Q000187:drug effects / Q000294:innervation*; D008437:Maxilla / Q000187:drug effects / Q000502:physiology; D009121:Muscle Denervation; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013701:Temporal Bone / Q000187:drug effects / Q000502:physiology; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D015050:Zygoma / Q000187:drug effects / Q000502:physiology
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D004983:Ethanolamines; D000068759:Formoterol Fumarate