Attempt to bring out those who are silent. What is said here stays here. Stretch for closure. Sometimes it helps to have a team clock watcher. Invite participant feedback.
Silence is a statement in and of itself.
Sometimes you need to affirm the position of those who are silent. Retire useless practices. Always seek to fully understand the subject. Mistakes due to misunderstandings or incomplete information can be tragic. Consensus testing is a behavior that periodically test whether the group has reached consensus or whether more discussion of the issue is required.