Dentsply International, Inc. (Dentsply) (defendant), was the leading manufacturer of artificial teeth. Dentsply sold artificial teeth to dental dealers, who would then sell the teeth to dental laboratories for use in dentures. Dentsply enjoyed a share of 75 to 80 percent in the market for artificial teeth. This market only consisted of 12 or 13 manufacturers. In 1993, Dentsply began a policy of terminating relationships with dealers who stocked artificial teeth sold by Dentsply’s competitors. Although many dealers would have preferred to stock artificial teeth from several manufacturers, no dealer could afford to lose Dentsply as a supplier. Subsequently, all of the major dealers began to exclusively purchase artificial teeth from Dentsply. The United States (plaintiff) brought an action against Dentsply, seeking an injunction. The government contended that Dentsply had engaged in unlawful conduct aimed at maintaining a monopoly in a violation of § 2 of the Sherman Act. The district court held that Dentsply’s excusive-dealing policy did not foreclose competition in the relevant market. The government appealed the decision.