What finding would support a diagnosis of anterior disc displacement without reduction in a patient with jaw pain?

What finding would support a diagnosis of anterior disc displacement without reduction in a patient with jaw pain?

• A. Increased jaw depression greater than 30 mm
• B. Decreased jaw depression less than 30 mm
• C. Audible clicking during opening and closing
• D. Pain during lateral jaw movement

Answer: (B)

A finding of decreased jaw depression less than 30 mm would support the diagnosis of anterior disc displacement without reduction in a patient experiencing jaw pain. In cases of anterior disc displacement without reduction, the disc does not return to its normal position during mouth opening, which typically results in limited jaw mobility. As a result, the patient often experiences restricted jaw depression (the vertical opening of the jaw), and a measurement of less than 30 mm indicates significant limitation. In contrast, increased jaw depression would suggest some degree of functional opening, which is not consistent with this specific type of anterior disc displacement. Audible clicking during opening and closing is more characteristic of anterior disc displacement with reduction, as it implies that the disc is intermittently returning to its proper position. Similarly, pain during lateral jaw movement can occur in various jaw disorders and is not specific to anterior disc displacement without reduction. Therefore, the measurement of limited jaw depression serves as a key indicator in supporting the diagnosis of this condition.

A finding of decreased jaw depression less than 30 mm would support the diagnosis of anterior disc displacement without reduction in a patient experiencing jaw pain. In cases of anterior disc displacement without reduction, the disc does not return to its normal position during mouth opening, which typically results in limited jaw mobility. As a result, the patient often experiences restricted jaw depression (the vertical opening of the jaw), and a measurement of less than 30 mm indicates significant limitation.

In contrast, increased jaw depression would suggest some degree of functional opening, which is not consistent with this specific type of anterior disc displacement. Audible clicking during opening and closing is more characteristic of anterior disc displacement with reduction, as it implies that the disc is intermittently returning to its proper position. Similarly, pain during lateral jaw movement can occur in various jaw disorders and is not specific to anterior disc displacement without reduction. Therefore, the measurement of limited jaw depression serves as a key indicator in supporting the diagnosis of this condition.