Osteopenic consequences of botulinum toxin injections in the masticatory muscles: a pilot study.
Patients with temporomandibular muscle and joint disorder (TMJD) increasingly seek and receive treatment for their pain with botulinum toxin (BoNTA; botulinum toxin A). Used intramuscularly in therapeutic doses, it produces localised paresis. Such paresis creates risk of reduced bone mineral density, or 'disuse osteopenia'. Animal studies have frequently used BoNTA as a model of paralysis to induce bone changes within short periods. Osteopenic effects can be enduring in animals but have yet to be studied in humans. This is the first study in humans to examine bone-related consequences of BoNTA injections in the masticatory muscles, comparing oral and maxillofacial radiologists' ratings of trabecular bone patterns in the condyles of patients with TMJD exposed to multiple masticatory muscle injection sessions with BoNTA to a sample of patients with TMJD unexposed to masticatory muscle injections with BoNTA. Cone-beam computed tomography (CBCT)-derived images of bilateral condyles were evaluated in seven patients with TMJD receiving 2+ recent BoNTA treatment sessions for facial pain and nine demographically matched patients with TMJD not receiving BoNTA treatment. Two oral and maxillofacial radiologists evaluated CBCT images for evidence of trabecular changes consistent with osteopenia. Both evaluators noted decreased density in all participants exposed to BoNTA and in none of the unexposed participants (P < 0.001). No other abnormalities associated with reduced loading were detected. These findings need replication in a larger sample and over a longer time period, to ensure safety of patients with TMJD receiving multiple BoNTA injections for their pain.
Department of Oral & Maxillofacial Pathology, Radiology, and Medicine, New York University College of Dentistry, New York, NY, USA.
K G
KG
Raphael
A
A
Tadinada
J M
JM
Bradshaw
M N
MN
Janal
D A
DA
Sirois
K C
KC
Chan
A G
AG
Lurie
D000328:Adult; D015519:Bone Density / Q000187:drug effects*; D001851:Bone Diseases, Metabolic / Q000139:chemically induced* / Q000000981:diagnostic imaging*; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage / Q000009:adverse effects*; D054893:Cone-Beam Computed Tomography; D005157:Facial Pain / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008335:Mandibular Condyle / Q000000981:diagnostic imaging / Q000187:drug effects; D008410:Masticatory Muscles / Q000503:physiopathology; D009465:Neuromuscular Agents / Q000008:administration & dosage / Q000009:adverse effects*; D017060:Patient Satisfaction; D010865:Pilot Projects; D011788:Quality of Life; D013706:Temporomandibular Joint Dysfunction Syndrome / Q000188:drug therapy*; D016896:Treatment Outcome
D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A
bone density; bone remodelling; botulinum toxin; osteopenia; temporo-mandibular joint; temporomandibular disorders