Final answer:
The mixed lesion described in the question is most likely an odontoma, which is a common odontogenic tumor composed of dental tissues. Odontomas can cause impaction and malpositioning of teeth.
Step-by-step explanation:
The mixed lesion described in the question, with a radiolucent rim and corticated border causing impaction of a permanent tooth, is most likely an odontoma. Odontomas are the most common odontogenic tumors and are composed of a mixture of dental tissues such as enamel, dentin, and cementum. They can cause impaction and malpositioning of teeth.
For example, if the lesional tissue hampers the eruption of a permanent tooth, it can lead to its impaction, which means the tooth cannot emerge properly from the gum. This can cause complications and may require surgical intervention to remove the odontoma and allow the affected tooth to align correctly.