Chapman v. Proctor & Gamble Distribution, LLC

Marianne Chapman (plaintiff) used Fixodent denture adhesive for eight years and was later diagnosed with myelopathy, a neurological disease. Chapman brought a products-liability suit against Proctor & Gamble Distribution, LLC (P&G) (defendant), the manufacturer of Fixodent. Chapman claimed that her symptoms were caused by copper-deficiency myelopathy (CDM) triggered by the zinc contained in Fixodent. Chapman produced three expert witnesses who testified that Fixodent can generally cause CDM. Chapman also produced a fourth expert, Dr. Greenberg, who ultimately diagnosed Chapman with CDM after Chapman filed suit. Greenberg testified that Chapman’s use of the Fixodent product specifically caused Chapman’s CDM. Greenberg’s methodology for determining specific causation was differential diagnosis. Differential diagnosis is a process under which all possible causes of a condition are eliminated until only one cause remains. However, Greenberg failed to consider whether Chapman’s CDM resulted from idiopathic, hereditary, or multiple causes. Greenberg also testified that an additional diagnostic test was performed on Chapman’s spinal cord after the diagnosis of CDM had been made. P&G presented evidence that Chapman had suffered from neurological issues since childhood. The district court found Chapman’s proffered expert testimony inadmissible. The court held that the testimony did not meet the standard under Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993), because the testimony was unreliable to prove both general and specific causation. The district court then granted P&G’s motion for summary judgment. Chapman appealed.