Ameloblastoma is an odontogenic tumour — it arises from tooth-forming tissue — and in its usual presentation it is a locally aggressive but manageable disease of the jaw. It grows slowly, recurs if inadequately excised, but is accessible, plannable, and well within the scope of contemporary maxillofacial surgery. The case that arrives at a skull base with intracranial extension is a different proposition. When an ameloblastoma has expanded out of the jaw, through the skull base, and into the frontotemporoparietal region — eroding the zygoma, the zygomatic arch, and the frontal, parietal, and squamous temporal bones on its way — it has become a neurosurgical problem as much as a maxillofacial one. Resecting it with adequate margins without injuring the adjacent neural and vascular structures, and then reconstructing the resulting defect, cannot be accomplished without precise pre-operative planning.
The patient presented with a massive acanthomatous ameloblastoma that had extended well beyond any conventional jaw boundary. Imaging confirmed extensive bony erosion: the tumour had invaded the temporoparietal region, destroyed the zygoma and zygomatic arch, and crossed the skull base into an extra-axial position in the frontotemporoparietal region. The intracranial component was displacing the adjacent neuroparenchyma and producing a mass effect with midline shift. Vision was affected. The surgical team — working across maxillofacial and neurosurgical disciplines — engaged Osteo3d for the planning and fabrication work.
The first step was digital mapping. Using the patient's CT data, the tumour volume and its three-dimensional relationship to the surrounding bony and soft-tissue anatomy were reconstructed in detail. A virtual resection was performed in the digital environment, the resulting defect was characterised, and the contralateral unaffected side was used as the anatomical reference for the planned reconstruction. This allowed the surgical team to agree on resection boundaries before the procedure — establishing the margins and the reconstruction target in a shared visual space rather than working it out under time pressure in the operating room.
From the virtual plan, Osteo3d fabricated a patient-specific resection template encoding the agreed margins: 1.5 cm in most regions, and 1 cm in the petrous temporal bone where the proximity of critical structures — cranial nerves, the petrous carotid, the sigmoid sinus — demanded the tightest boundary achievable. The template guided the surgical cuts to the planned lines and removed the need for margin estimation at a location where a millimetre of error carries disproportionate consequences.
Reconstruction of the defect presented its own challenge. The missing bone — spanning the zygomatic arch, portions of the temporal, frontal, and parietal bones, and the skull base itself — needed to be replaced accurately and durably. A series of custom 3D molds were produced by Osteo3d from the digital reconstruction, designed to replicate the contralateral anatomy. Polymethyl methacrylate bone cement was adapted into these molds intraoperatively, producing anatomically accurate reconstruction elements that matched the planned contour without manual shaping under anaesthetic.
The post-operative outcome was clinically remarkable given the extent of disease. Hearing, balance, and facial movements were unaffected. The most significant recovery was of vision — compromised preoperatively by the mass effect of the intracranial component and restored following tumour removal and decompression. The surgical team had prepared for a more complicated neurological picture.
This case sits at the outer limit of what pre-operative 3D planning can be asked to address: a tumour whose own-side anatomy had been entirely replaced by disease, resection margins defined at the skull base within millimetres of critical neurovascular structures, and a reconstruction that had to be accurate before the first incision was made. The outcome reflects both the quality of the surgical team's execution and the precision of a plan that left nothing to intraoperative estimation.
Osteo3d Team
Clinical Affairs