Dentistry Expert’s Differential Cancer Diagnosis is Questioned Under Admissibility Criteria

    Court: United States District Court for the Middle District of Florida, Tampa Division
    Jurisdiction: Federal
    Case Name: Kirchman v. Novartis Pharm. Corp.
    Citation: 2014 U.S. Dist. LEXIS 71158


    This case deals with claims against a drug manufacturer by the deceased’s estate. The deceased had been diagnosed with multiple myeloma, a type of cancer. In order to delay the development of cancer and reduce the risk of skeletal associated injuries, his oncologist recommended some of the bisphosphonate medications developed by the defendant. At the time the drugs were administered, the doctor was unaware of the risk of osteonecrosis of the jaw—bone tissue death caused by a lack of blood supply—associated with those medications. As a result, the deceased developed necrosis and eventually died of cancer. His estate brought a diversity lawsuit against the defendant, arguing that the defendant’s drugs had caused the injuries. The defendant brought a Daubert motion to exclude the testimony of the plaintiff’s dentistry expert who had treated the deceased.

    Dentistry Expert Witness

    The dentistry expert was an oral and maxillofacial surgeon who had been consulted in a number of lawsuits about the specific drugs at issue to provide evidence of causation. The expert’s opinion was that the use of the drugs by the deceased induced him to develop osteonecrosis of the jaw. The deceased’s condition was called bisphosphonate-induced avascular osteonecrosis, a documented consequence of nitrogen-containing IV bisphosphonates, such as in the drugs in question. According to his expert report and his deposition, the dentistry expert checked the medical and dental history of the deceased but did not directly inspect the deceased nor review his X-rays.

    The defendant claimed that the expert’s testimony was inadmissible because he had not used a reliable approach to shape his opinion on the cause of the deceased’s cancer. The defendant further asserted that the expert had neglected to accurately rule out any other possible causes of osteonecrosis of the jaw. Specifically, the defendant argued that the expert’s assertion that the deceased’s jaw injury did not have infectious etiology was not confirmed by documented evidence. In response, the plaintiff argued that the expert had implemented a judicially and scientifically acceptable differential diagnosis methodology and eliminated other potential causes of the deceased’s osteonecrosis.


    The court acknowledged that, as observed in Dopson-Troutt v. Novartis Pharms. Corp., the defendant’s effort to remove the expert from testifying about causation related to these drugs was rejected. The court also cited this same rationale presented in Taylor v. Novartis Pharms. Corp. to refuse the Daubert motion of the defendant to exclude the expert. The court agreed with the rationale and conclusions laid out in Taylor, where the court decided that the expert’s differential diagnosis satisfied the admissibility criteria as he had considered other possible causes of osteonecrosis of the jaw and established that plaintiff’s use of the medications was the probable cause. The Taylor court had also held that inconsistency in the expert’s report and deposition affected weight and not admissibility.


    The motion to exclude the dentistry expert witness’s testimony was denied.