Final answer:
The anterior portion of a trimmed maxillary dental model is thicker due to the alveolar process, whereas the anterior portion of a mandibular model is thinner because of the flatter coronoid process.
Step-by-step explanation:
A trimmed maxillary model will be thicker at the anterior portion, and the mandibular model will be thinner at the anterior portion. When trimming dental models, it is essential to consider the unique anatomical features of each arch. The maxillary bone, which forms the upper jaw, includes the alveolar process of the maxilla that supports and anchors the upper teeth. On the other hand, the mandibular model, which corresponds to the lower jaw, features the alveolar process of the mandible containing the lower teeth and the prominent coronoid and condylar processes. Therefore, in a dental model, the maxilla will present a more voluminous anterior section due to the alveolar bone and tooth sockets, whereas the mandibular model will appear less bulky in the anterior section due to the flatter coronoid process and overall mandible contour.