Toy (plaintiff) swallowed a tooth during a dental procedure conducted by Mackintosh (defendant). Toy alleged Mackintosh's negligence caused this mishap. Toy also argued the swallowed tooth caused Toy to suffer internal injuries. Toy sued the dentist. At trial, Toy testified his symptoms improved after he coughed up the tooth weeks later. Toy produced no other evidence proving negligence or a link between the swallowed tooth and his injuries. Mackintosh, a skilled dentist, and four medical experts testified Mackintosh followed proper procedures. Their testimony indicated Toy's injuries resulted from unrelated medical conditions, which they described. The jury issued a verdict for Toy. On appeal to the Supreme Judicial Court of Massachusetts, Mackintosh argued no evidence supported Toy's allegations and therefore the judge should have directed the jury's verdict for Mackintosh.