An implant (100; 300; 400) for therapeutically separating bones of a joint, the implant comprising: - a first end plate extending between an anterior end and a posterior end, the first end plate having a bone engaging surface, and having a first pair of anterior ramped surfaces (118; 418) on a side opposite the bone engaging surface; - a second end plate extending between an anterior end and a posterior end, the second end plate having a bone engaging surface, and having a second pair of anterior ramped surfaces on a side opposite the bone engaging surface; - an anterior actuator (350; 450) positioned between the first and second end plates, the anterior actuator (350; 450) having a first pair of cylindrical protrusions (302; 412) extending from opposite ends of the anterior actuator (350; 450); - a posterior actuator (370; 470) positioned between the first and second end plates; characterized in that - a plurality of rotational pivot member assemblies (390, 392, 394), each one of the plurality of rotational pivot member assemblies pivotally connected to a corresponding one of the first pair of cylindrical protrusions (302; 412) and in sliding engagement with the first and second pairs of anterior ramped surfaces of the first and second end plates; and - an actuator assembly (410, 210, 220) extending between the posterior actuator (370; 470) and the anterior actuator (350; 450), the actuator assembly (410, 210, 220) configured to selectively move the posterior actuator (370; 470) and the anterior actuator (350; 450) simultaneously, move posterior actuator (370; 470) independently of the anterior actuator (350; 450), or move the anterior actuator (350; 450) independently of the posterior actuator (370; 470). - a first end plate extending between an anterior end and a posterior end, the first end plate having a bone engaging surface, and having a first pair of anterior ramped surfaces (118; 418) on a side opposite the bone engaging surface; - a second end plate extending between an anterior end and a posterior end, the second end plate having a bone engaging surface, and having a second pair of anterior ramped surfaces on a side opposite the bone engaging surface; - an anterior actuator (350; 450) positioned between the first and second end plates, the anterior actuator (350; 450) having a first pair of cylindrical protrusions (302; 412) extending from opposite ends of the anterior actuator (350; 450); - a posterior actuator (370; 470) positioned between the first and second end plates; characterized in that - a plurality of rotational pivot member assemblies (390, 392, 394), each one of the plurality of rotational pivot member assemblies pivotally connected to a corresponding one of the first pair of cylindrical protrusions (302; 412) and in sliding engagement with the first and second pairs of anterior ramped surfaces of the first and second end plates; and - an actuator assembly (410, 210, 220) extending between the posterior actuator (370; 470) and the anterior actuator (350; 450), the actuator assembly (410, 210, 220) configured to selectively move the posterior actuator (370; 470) and the anterior actuator (350; 450) simultaneously, move posterior actuator (370; 470) independently of the anterior actuator (350; 450), or move the anterior actuator (350; 450) independently of the posterior actuator (370; 470).