Nicoletta Zerman

Accuracy of virtual reality and stereolithographic models in maxillo-facial surgical planning.

Computed tomography is a medical instrument that can be useful not only for diagnostic purposes, but also for surgical planning, thanks to the fact that it offers volumetric information which can be translated in three dimensional models. These models can be visualized, but also exported to Rapid Prototyping (RP) systems, that can produce these structures thanks to the rapidity and versatility of the technologies involved. The literature reports various cases of stereolithographic models used in orthopedic, neurological, and maxillo-facial surgery. In these contexts, the availability of a copy of the real anatomy allows not only planning, but also the practical execution of surgical operations, within the limitations of the materials. Nevertheless, the Rapid Prototyping model also presents some disadvantages that can be reduced if practical simulation is accompanied by virtual simulation, performed on a digital model. The purpose of this work is to examine and present the use of Virtual Reality (VR) and Rapid Prototyping for surgical planning in Maxillo-Facial surgery.

Feasibility of preoperative planning using anatomical facsimile models for mandibular reconstruction

BackgroundFunctional and aesthetic mandibular reconstruction after ablative tumor surgery continues to be a challenge even after the introduction of microvascular bone transfer. Complex microvascular reconstruction of the resection site requires accurate preoperative planning. In the recent past, bone graft and fixation plates had to be reshaped during the operation by trial and error, often a time-consuming procedure. This paper outlines the possibilities and advantages of the clinical application of anatomical facsimile models in the preoperative planning of complex mandibular reconstructions after tumor resections.MethodsFrom 2003 to 2005, in the Department of Maxillofacial Surgery of the University of Udine, a protocol was applied with the preoperative realization of stereolithographic models for all the patients who underwent mandibular reconstruction with microvascular flaps. 24 stereolithographic models were realized prior to surgery before emimandibulectomy or segmental mandibulectomy. The titanium plates to be used for fixation were chosen and bent on the model preoperatively. The geometrical information of the virtual mandibular resections and of the stereolithographic models were used to choose the ideal flap and to contour the flap into an ideal neomandible when it was still pedicled before harvesting.ResultsGood functional and aesthetic results were achieved. The surgical time was decreased on average by about 1.5 hours compared to the same surgical kind of procedures performed, in the same institution by the same surgical team, without the aforesaid protocol of planning.ConclusionProducing virtual and stereolithographic models, and using them for preoperative planning substantially reduces operative time and difficulty of the operation during microvascular reconstruction of the mandible.

Endoscopically assisted enucleation and curettage of large mandibular odontogenic keratocyst

This article reports a case of a mandibular multilocular keratocyst treated with endoscopically assisted enucleation and curettage. An ectopic third molar displaced in the coronoid process area was also removed.Odontogenic keratocysts (OKCs) are known for their propensity to recur. The incomplete removal of the cyst is one of the mechanisms for which it is thought that the keratocyst recurs. The endoscopic assistance allowed us to explore accurately the operative field and the areas of difficult access, improving the complete removal of the cystic lesion. Moreover, it allowed us to monitor closely the separation of the cyst lining from the inferior alveolar nerve and limit the extension of the surgical approach. At 3-year follow-up no evidence of recurrence was evidenced by radiological and clinical controls.

Unilateral Swelling of the Cheek

A 34-year-old man was referred to our department due to 4-month history of a left cheek growth. He reported a radual increase of the lesion. He denied fever, dysphagia, dynophagia, difficulty breathing, and pain since 1 week rior to visiting the department. During the last 5 days he xperienced pain, increased swelling, and reduced mouth pening. There was no history of trauma; no other skin esion was present. His medical history was significant for ericoronitis of the left lower third molar 1 year before and revious endodontic treatment of the second left upper olar 1 month before. Upon initial examination, the face appeared asymmetrical ith a mass in the left cheek (Fig 1). The patient was febrile. A reduced mandibular opening of 2 cm was resent. The skin over the left facial region was normal. ropharyngeal examination showed normal findings and ood oral hygiene. No evidence of inflammation was noted n the previous site of the left lower third molar extraction nd in the region of the second left upper molar. The oral oft tissues were normal. Bimanual palpation showed a iffuse, painful, mobile lesion in the left masseter muscle. eurologic deficits were absent. Salivary flow was normal rom the left Stenson’s duct. All hematologic parameters ere within normal limits. There were no masses or adeopathy on neck examination. The rest of the examination as unremarkable. Serologic tests were unremarkable except for a neutrohilia with 15,000 WBC/mL.