Dental OSCE (Objective Structured Clinical Examination) Practice Exam

If a radiograph shows scalloping radiolucency between posterior roots, which diagnosis is suggested?

1. Odontogenic keratocyst

2. Traumatic bone cyst

3. Primordial cyst

4. Radicular cyst

The correct answer is: Traumatic bone cyst

The presence of scalloping radiolucency between the roots of posterior teeth is indicative of a traumatic bone cyst. This type of cyst is characterized by a radiolucent area that appears scalloped or notched due to the anatomical contours of the teeth adjacent to it. The scalloping is a reflection of the cyst’s growth along the roots and outlines the periapical structures. Traumatic bone cysts, also known as simple bone cysts, often occur in the jaw and can be associated with a history of trauma. Unlike odontogenic keratocysts or radicular cysts, traumatic bone cysts do not typically cause expansion of the bone or have a well-defined border. This makes the radiographic appearance distinct, particularly in how it interacts with the roots of the teeth, presenting with scalloped outlines rather than a smooth or uniform boundary. The other conditions listed have different radiographic features. For example, odontogenic keratocysts may appear as well-defined unilocular or multilocular radiolucencies but do not typically show scalloping. Primordial cysts are often found in the place of an undeveloped tooth and do not present the scalloping characteristic. Radicular cysts, while they can appear as radioluc