nber category 3 Drugs & Medical subcat 39 Miscellaneous-Drgs & Med

uspto classes
351 Optics: Eye Examining, Vision Testing and Correcting
433 Dentistry
623 Prosthesis (i.e., Artificial Body Members), Parts Thereof, or Aids and Accessories Therefor

Historic patent counts for subcat 39

uspto search in the 1790 to present database

ccl/351/$ OR ccl/433/$ OR ccl/623/$

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