In a support proceeding in which petitioner wife brought an application for relief because of alleged violation by the husband of a prior support order of the Family Court, Westchester County, the parties cross-appeal from an order of said court, dated July 2, 1971, which, inter alia, directed the husband to make payment on account of orthodonture for the parties’ child and for the wife’s counsel fees and denied the application as to certain claims. Order modified, on the law, by striking so much of the second ordering paragraph as directs the husband to pay $150 in connection with the testimony of Dr. Arthur Ash. As so modified, order affirmed, without costs. We note in passing that the evidentiary problem encountered as to the necessity for and reasonable value of most of the medical and dental expenses for which claim was made might have been avoided by the use of CPLR 4533-a, which became available in all civil actions as of September 1, 1970. The notice to admit sought the husband’s admission of the necessity for and reasonableness of the dental treatment furnished by Dr. Ash. These issues were matters of expert opinion, not of fact, and were at the heart of the dispute between the parties. Accordingly, they were not a proper part of a request for admissions under CPLR 3123. Hopkins, Acting P. J., Shapiro, Gulotta, Christ and Brennan, JJ., concur.