Massimo Robiony

Condylar positioning devices for orthognathic surgery: a literature review

In the past few years, many devices have been proposed for preserving the preoperative position of the mandibular condyle during bilateral sagittal split osteotomy. Accurate mandibular condyle repositioning is considered important to obtain a stable skeletal and occlusal result, and to prevent the onset of temporomandibular disorders (TMD). Condylar positioning devices (CPDs) have led to longer operating times, the need to keep intermaxillary fixation as stable as possible during their application, and the need for precision in the construction of the splint or intraoperative wax bite. This study reviews the literature concerning the use of CPDs in orthognathic surgery since 1990 and their application to prevent skeletal instability and contain TMD since 1995. From the studies reviewed, we can conclude that there is no scientific evidence to support the routine use of CPDs in orthognathic surgery.

Review of segmental and marginal resection of the mandible in patients with oral cancer.

This paper reviews the medical literature of the last decade to ascertain the criteria used to assess mandibular invasion by cancer of the oral cavity and to suggest how best to evaluate the mandible with a view to surgical management. It is generally agreed that patients with mandibular invasion should be treated surgically, but the extent of mandibular resection required remains a controversial matter and the accurate preoperative determination of neoplastic invasion of the mandible remains a challenge for head and neck surgeons. The relative reliability of preoperative orthopantomography, (OPG) bone scanning, computed tomography (CT) and magnetic resonance imaging (MRI), and of peroperative periosteal stripping and direct inspection in clinical assessment for mandibular surgery, is discussed. The histological patterns of tumor invasion and the most common routes of tumor entry in the mandible are described and the influence of variables such as prior radiotherapy and an edentulous vs a dentate state in relation to perineural invasion are also discussed. Finally, a comparison is drawn between the reported outcome of marginal vs segmental resection procedures and a decision-making algorithm is proposed. In selected cases, marginal mandibulectomy can ensure satisfactory tumor control, with a favorable effect on the morbidity associated with mandibular surgery.This paper reviews the medical literature of the last decade to ascertain the criteria used to assess mandibular invasion by cancer of the oral cavity and to suggest how best to evaluate the mandible with a view to surgical management. It is generally agreed that patients with mandibular invasion should be treated surgically, but the extent of mandibular resection required remains a controversial matter and the accurate preoperative determination of neoplastic invasion of the mandible remains a challenge for head and neck surgeons. The relative reliability of preoperative orthopantomography, (OPG) bone scanning, computed tomography (CT) and magnetic resonance imaging (MRI), and of peroperative periosteal stripping and direct inspection in clinical assessment for mandibular surgery, is discussed. The histological patterns of tumor invasion and the most common routes of tumor entry in the mandible are described and the influence of variables such as prior radiotherapy and an edentulous vs a dentate state in relation to perineural invasion are also discussed. Finally, a comparison is drawn between the reported outcome of marginal vs segmental resection procedures and a decision-making algorithm is proposed. In selected cases, marginal mandibulectomy can ensure satisfactory tumor control, with a favorable effect on the morbidity associated with mandibular surgery.

Is Extended Selective Supraomohyoid Neck Dissection Indicated for Treatment of Oral Cancer with Clinically Negative Neck

Oral cavity tumors may develop occult metastases to the cervical lymph nodes. Current imaging techniques and routine histopathologic methods may fail to detect lymph node micrometastases, but the surgeon has to electively dissect a neck at risk of developing clinical disease. Supraomohyoid neck dissection has been the elective surgery for treating a clinically negative neck in patients with oral cavity primaries. A literature review revealed that level IV nodes can be significantly affected by occult disease with and without metastases in level I-III lymph nodes. This means that level IV nodes have to be included in the supraomohyoid neck dissection, resulting in a more extensive surgical procedure to ensure a margin of oncological safety.

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.

Localized alveolar sandwich osteotomy for vertical augmentation of the anterior maxilla

Extensive resorption of the alveolar ridge in a vertical direction may make implant insertion impossible, and aesthetic prosthetic rehabilitation is therefore compromised. Restoration of the atrophic anterior maxilla in the vertical direction can be resolved in several ways. Surgical procedures that have been proposed have used an autogenous corticocancellous onlay or inlay bone graft with primary or delayed implant placement.‘” We describe new surgical method based on a sandwich osteotomy of the basal alveolar bone, using an interpositional bone graft harvested from the chin to increase the vertical dimension. Surgical Technique A horizontal incision is made approximately 5 mm above the mucogingival reflection in the labiobuccal gingiva of the edentulous area. A flap is raised without detaching the palatal mucoperiosteum to expose the anterior wall of the atrophic maxilla. Two vertical and 1 horizontal bone cut are then made 4 mm under nasal floor (Fig 1) at the basal bone level. Using a small chisel, the osteotomy is completed and the fragment is downfractured, pedicled to the palatal mucoperiosteum (Fig 2). The caudal fragment must not be less than 5 mm thick. A partial-thickness bone graft is harvested from the mandibular symphysis and placed as an interpositional graft, without fixation, between the residual basal bone and the caudal fragment with the cortex facing superiorly (Fig 3). The bone graft must not be more

Cranioplasty: Review of Materials.

AbstractCranioplasty remains a difficult procedure for all craniofacial surgeons, particularly when concerning the reconstruction of large lacunae in the skull. Considering the significant clinical and economic impact of the procedure, the search for materials and strategies to provide more comfortable and reliable surgical procedures is one of the most important challenges faced by modern craniofacial medicine.The purpose of this study was to compare the available data regarding the safety and clinical efficacy of materials and techniques currently used for the reconstruction of the skull. Accordingly, the scientific databases were searched for the following keywords autologous bone, biomaterials, cranial reconstruction, cranioplasty, hydroxyapatite, polyetheretherketone, polymethylmethacrylate, and titanium. This literature review emphasizes the benefits and weaknesses of each considered material commonly used for cranioplasty, especially in terms of infectious complications, fractures, and morphological outcomes.As regards the latter, this appears to be very similar among the different materials when custom three-dimensional modeling is used for implant development, suggesting that this criterion is strongly influenced by implant design. However, the overall infection rate can vary from 0% to 30%, apparently dependent on the type of material used, likely in virtue of the wide variation in their chemico-physical composition. Among the different materials used for cranioplasty implants, synthetics such as polyetheretherketone, polymethylmethacrylate, and titanium show a higher primary tear resistance, whereas hydroxyapatite and autologous bone display good biomimetic properties, although the latter has been ascribed a variable reabsorption rate of between 3% and 50%.In short, all cranioplasty procedures and materials have their advantages and disadvantages, and none of the currently available materials meet the criteria required for an ideal implant. Hence, the choice of cranioplasty materials is still essentially reliant on the surgeons preference.

Piezosurgery: a new method for osteotomies in rhinoplasty.

Two basic techniques for lateral osteotomy have been developed to date; the internal (endonasal) continuous technique and the external (percutaneous) perforating method. Numerous investigators have subjectively reported that the application of the two techniques results in less postoperative ecchymosis and edema compared to the use of other techniques, but an alternative and gentle method for performing lateral osteotomy or bony hump removal has not been proposed yet. The authors present a new soft technique to perform nasal osteotomy in rhinoplasty using piezoelectric ultrasonic vibrations, and emphasize the advantages of this method.

Simultaneous malaroplasty with porous polyethylene implants and orthognathic surgery for correction of malar deficiency

PURPOSE Patients with skeletal malrelationships caused by maxillary anteroposterior defect and midface hypoplasia may present with an alteration of cheekbone contour. High osteotomies, segmental osteotomies of the zygomatic complex, and malar expansion with alloplastic materials can be performed to improve facial aesthetics. This article describes the restoration of cheekbone-nasal base-lip contour by performing a malaroplasty using an alloplastic implant in addition to orthognathic surgery. PATIENTS AND METHODS From 1995 to 1996, 17 patients with maxillomandibular malrelationships and deficient cheekbone contour were tested by malar augmentation with porous high-density polyethylene in association with maxillary advancement and mandibular setback. The diagnosis of cheekbone contour alteration was made after observing the patient from a lateral, frontal, and oblique point of view. The position of the implant was determined by using Mladicks point, with lateral or medial extension in relation to the depressed area. RESULTS By the restoration of normal cheekbone-nasal base-upper lip contour produced excellent aesthetic results in all patients. CONCLUSIONS Malaroplasty in association with bimaxillary orthognathic surgery seems to be an effective procedure for treating midface skeletal deficiencies.

Arthroscopy with open surgery for treatment of synovial chondromatosis of the temporomandibular joint

We report a case of synovial chondromatosis of the temporomandibular joint in which both joint compartments were affected. Because of the important involvement of the medial aspect of the joint, arthrotomy was done with arthroscopic assistance.