A skeletal malocclusion is not simply a dental problem. When the bones of the face develop disproportionately — the upper jaw too far back, the lower jaw too far forward, or vice versa — the consequences extend across function and form. Chewing becomes laboured. Speech may be affected. Breathing, particularly during sleep, can be compromised. And the way a person's face appears to the world — and to themselves — is altered in ways that accumulate over years into a significant psychological burden. Orthodontic treatment can address tooth position. It cannot move bone.
The patient was a young adult with a Class III skeletal pattern: the lower jaw was positioned forward relative to the upper, producing a reverse overjet, a posterior crossbite, and a chin that protruded visibly. The functional consequences were real — he chewed on the side, avoided certain foods, and described fatigue after meals. He had completed pre-surgical orthodontic treatment. The bones were now in the correct position relative to the teeth. Surgery to reposition the jaws themselves was the next step.
The procedure planned was a bimaxillary osteotomy: a Le Fort I osteotomy to advance and vertically position the upper jaw, combined with a bilateral sagittal split osteotomy to set the lower jaw back. Moving both jaws simultaneously is technically necessary when the discrepancy is large — but it adds complexity. Each movement changes the three-dimensional relationship between the jaws. The final occlusion depends on both bones ending in exactly the right position, simultaneously. The margin for error is narrow. Traditional planning — dental model surgery on a semi-adjustable articulator, guided by lateral cephalometric measurements — works, but it is a two-dimensional approximation of a three-dimensional surgical problem.
Virtual surgical planning was performed using a CT scan of the patient's craniofacial skeleton and a digital scan of the dental arch. The bones were segmented, and the upper and lower jaw were repositioned digitally to the planned target — advancement of the maxilla, clockwise rotation, impaction, and setback of the mandible, all precisely quantified. The result was a complete simulation of the post-surgical anatomy, confirmed with the surgeon and the treating orthodontist before a single cut was made. From the plan, Osteo3d produced a set of patient-specific surgical wafers — the intermediate splint, positioning the jaws after the first osteotomy cut, and the final splint, setting the occlusion once both osteotomies were complete.
The wafers were taken into the operating theatre. After the Le Fort I cut, the intermediate splint seated the upper jaw and guided its fixation. After the bilateral sagittal split, the final splint confirmed occlusion before the plates were applied. The surgical team did not need to estimate position intraoperatively — the targets had been established in the digital environment and encoded into the physical guides.
The patient's post-operative occlusion was correct on the table. Facial symmetry was improved. At follow-up, the patient reported that chewing had become effortless for the first time he could recall. The orthodontist completed the final finishing in six weeks — ahead of schedule, reflecting the precision of the intraoperative positioning.
Bimaxillary osteotomy is a procedure where pre-operative planning directly determines the intraoperative result. Virtual surgical planning does not make the surgery easier to perform — the technical demands remain the same. What it does is ensure that when the surgeon reaches the final step, the target is already known, already agreed upon, and already encoded in a physical object that can be held and followed. The guesswork is moved out of the operating room.
Osteo3d Team
Clinical Affairs