Young Dental Manufacturing Co., Inc. v. Q3 Special Products, Inc.

Young (plaintiff) patented an improved dental polishing instrument (a disposable prophy angle), disclosing its gear structure and specifying two plastics for its parts. After a competitor, Kraenzle, designed a similar device and formed Q3 (defendant) to sell it, Young sued for infringement, and Q3 counterclaimed that Young's patent was invalid for failing to disclose the specific gear ratio and plastic grades the inventor believed produced the best results, violating the best-mode requirement. A jury found for Q3.

Whether, under the best-mode requirement, an inventor must disclose information about the best mode that would have been apparent to a person skilled in the art.