Brown IV

This defect involves the vertical aspects of the maxilla including the orbital rim, floor and soft tissue content including the globe. The horizontal component can include a portion of the dental arch, Brown IVa-b, the entire arch (bilateral infrastructure maxillectomies), Brown IIIc. This defect can also include the nasal septum and turbinates and always results in an oral-antral/oro-nasal fistulae.

This defect typically results from a maxillary sinus neoplasm invading through the orbital periosteum and involving the orbital adnexa and/or globe.