Botulinum toxin B increases mouth opening in patients with spastic trismus.
BACKGROUND
Severe generalized spastic movement disorders of various aetiologies often involve the jaw muscles and lead to a spastic trismus with masseter muscle hypertonia. We report a placebo-controlled randomized study on patients with spastic trismus.


METHODS
Eleven patients with masseter hypertonia because of stroke, hypoxic encephalopathy or traumatic brain injury were allocated to either botulinum toxin serotype B (BoNT/B) injections into the masseter muscles or placebo treatment. The dental gap, the amount of saliva, salivation scales, and a clinical goal attainment were evaluated.


RESULTS
Three weeks after injection the BoNT/B group showed a significantly increased mouth opening compared with placebo treatment (P < 0.05). In addition to the muscle paralysing effect, a goal attainment scale demonstrated a clinical benefit for the BoNT/B group (P < 0.01).


CONCLUSIONS
Botulinum toxin serotype B injections into the masseter muscles effectively reduce hypertonia and provide for better mouth opening, thereby contributing to a positive and desired clinical goal.
Fietzek
U M
UM
Neurologisches Krankenhaus München, Center for Parkinson's disease and Movement Disorders, Parzivalplatz 4, D-80804 Munich, Germany.
Kossmehl
P
P
Barthels
A
A
Ebersbach
G
G
Zynda
B
B
Wissel
J
J
D000328:Adult; D000369:Aged, 80 and over; D001905:Botulinum Toxins / Q000627:therapeutic use*; D019274:Botulinum Toxins, Type A; D004311:Double-Blind Method; D006801:Humans; D008406:Masseter Muscle / Q000187:drug effects; D008875:Middle Aged; D009128:Muscle Spasticity / Q000188:drug therapy; D014313:Trismus / Q000188:drug therapy*
C096323:rimabotulinumtoxinB; D001905:Botulinum Toxins; D019274:Botulinum Toxins, Type A