National Dental Assisting Examining Board (NDAEB) Practice Exam

How should the anterior portion of a maxillary study model be trimmed?

1. At a right angle from the canine to the central incisor

2. At an angle from the canine to the middle of the central incisor

3. Straight across the middle of the model

4. At an angle from the central incisor to the first molar

The correct answer is: At an angle from the canine to the middle of the central incisor

Trimming the anterior portion of a maxillary study model involves creating a precise contour that reflects the natural architecture of the dental arch. The correct approach is to trim at an angle from the canine to the middle of the central incisor. This technique mimics the natural gum line and enhances the overall appearance of the model, providing a more accurate visual representation of the patient’s dental anatomy. The angled trim allows for a more aesthetic presentation and promotes better visibility of the anterior teeth, which is essential for evaluating occlusion and alignment during treatment planning. It also helps in creating a functional model that can be used effectively for further dental assessments or procedures. The options suggesting a trim at a right angle or a straight cut do not provide the same level of detail and may create an unnatural appearance that could obscure important anatomical landmarks. The suggestion to angle from the central incisor to the first molar is also not appropriate, as it does not focus on the anterior region where the important anatomical features that need to be observed are located. Thus, the choice to trim at an angle from the canine to the middle of the central incisor is justified, allowing for both functionality and aesthetics in the study model.