Reactivation of varicella-zoster virus in delayed facial palsy after dental treatment and oro-facial surgery.

In rare cases, acute peripheral facial palsy occurs several days after dental treatment and oro-facial surgery. Surgical procedures have been known to trigger reactivation of varicella-zoster virus (VZV) and herpes simplex virus type 1 (HSV-1). The present study examined eight patients who exhibited delayed facial palsy after dental treatment or oro-facial surgery. Ramsay Hunt syndrome was diagnosed in three patients and varicella-zoster virus (VZV) reactivation without zoster lesions (zoster sine herpete) was diagnosed in three patients either by PCR or serological assay. Therefore, VZV reactivation was detected in 75% (6 of 8) of patients who exhibited delayed facial palsy after dental or oro-facial treatment. The results suggest that VZV reactivation is a major cause of delayed facial palsy after dental treatment or oro-facial surgery.