Plaintiff appeals the trial court’s granting of a directed verdict in favor of defendant in this dental malpractice action. We affirm.

Causation of nerve damage which results in the loss of sense of taste is a complicated medical question that must be resolved by expert medical testimony. Cleland v. Wilcox, 273 Or 883, 887, 543 P2d 1032 (1975). The only medical testimony offered by plaintiff was that of Dr. Henkin and Dr. Hodson. Dr. Hodson made no conclusion as to causation in this case. Although Dr. Henkin stated unequivocally that the injection of a local anesthetic administered by defendant’s dental hygienist caused plaintiffs loss of taste, he was unable to state with any degree of certainty whether the injury was the result of a chemical reaction (a rare but known side effect of the drug) or the negligent administration of the injection by defendant’s dental hygienist.

Although there was some evidence the injection was improperly administered, there was no evidence on which the jury could do more than speculate that such negligence caused plaintiffs injury.

Affirmed.