Hereditary trembling chin is an autosomal dominant condition character
ized by recurrent bouts of tremor involving the chin. These episodes a
re precipitated by emotional upset. There has been considerable debate
about the gravity of this condition. This may be a benign movement di
sorder; however, the rhythmic trembling of mentalis at rest or during
times of stress in these patients is often misinterpreted as betraying
an incipient emotional upset. For this reason, some patients with thi
s condition may find it socially disabling. We have recently successfu
lly treated one such family with regular botulinum toxin injections to
the mentalis muscle.