A cadaveric study of a combined trans-mandibular and trans-zygomatic approach to the infratemporal fossa.

The infratemporal fossa (ITF) is a deep retromaxillary space corresponding to the inferior aspect of the middle cranial fossa. There are numerous surgical approaches, indicating the difficulty of access, accentuated by the communications with the neighboring regions. The aim of this anatomical study was the optimization and photographic demonstration of the pre-auricular infra-temporal trans-zygomatic approach combined with a trans-mandibular approach allowing access to the different regions of the ITF. Six human heads preserved in formalin were dissected under the operating microscope (magnification between x6 and x4). Intra-arterial injection of colored silicone had been done in advance. A plastinated hemi-head was conserved as a teaching and training specimen using the S10 silicone technique. After a pre-auricular temporo-cervical incision, skin flaps, the superficial temporalis fascia and the temporal fascia were elevated. The facial nerve and its branches were preserved and the temporal and zygomatic branches were protected by the superficial temporalis fascia. The division of the temporal muscle and osteotomy of the zygomatic arch opened the superior part of the ITF. Osteotomy of the mandibular ramus preserving the division of the mandibular nerve opened the inferior part of the ITF. This was thus perfectly exposed and access was not impeded by the trunk of the facial nerve and its branches. The place of this complex approach is discussed among the principal exocranial surgical approaches to the ITF.