What opening pattern helps differentiate DDwoR from DDwR during opening?

What opening pattern helps differentiate DDwoR from DDwR during opening?

• A. Normal opening with joint click.
• B. Deflection toward affected side on opening with normal opening.
• C. Limited opening with deflection toward the affected side.
• D. Normal opening with no noises.

Answer: (C)

Opening pattern is the key clue to tell disc displacement without reduction from with reduction. When the disc is displaced and does not reduce during opening, the mandible’s movement on the affected side becomes limited, so the mouth cannot open to a normal extent. This restriction causes the jaw to deviate toward the side with the displaced disc as that side’s condyle cannot translate properly. So, the combination of a limited maximal opening and deflection toward the affected side during opening is the hallmark of disc displacement without reduction. In contrast, disc displacement with reduction typically allows a normal or near-normal opening because the disc recaptures during movement, often accompanied by a click when it reduces. A pattern of normal opening with no noises suggests there isn’t a troublesome disc displacement.

Opening pattern is the key clue to tell disc displacement without reduction from with reduction. When the disc is displaced and does not reduce during opening, the mandible’s movement on the affected side becomes limited, so the mouth cannot open to a normal extent. This restriction causes the jaw to deviate toward the side with the displaced disc as that side’s condyle cannot translate properly. So, the combination of a limited maximal opening and deflection toward the affected side during opening is the hallmark of disc displacement without reduction.

In contrast, disc displacement with reduction typically allows a normal or near-normal opening because the disc recaptures during movement, often accompanied by a click when it reduces. A pattern of normal opening with no noises suggests there isn’t a troublesome disc displacement.