J. Collyer

Stereotactic navigation in oral and maxillofacial surgery.

Navigation is an adjunct to existing surgical procedures. It is potentially useful in any procedure where it is possible to make a three-dimensional surgical plan from computed tomography (CT) or magnetic resonance imaging (MRI) data, but is not easy to translate this plan into surgical reality because of absolute limitations of access or lack of anatomical landmarks. For navigational surgery to be successful it is essential to have a sound understanding of its limitations in terms of intraoperative changes in tissue position, and how the registration process works, to achieve optimum surgical accuracy with minimal impact on time. In maxillofacial surgery one of the best examples of the benefit of navigation is in the field of secondary orbital reconstruction. As with many areas of surgery careful attention to planning will yield good results.

Use of an image-guided navigation system for insertion of a Lester-Jones tube in a patient with disturbed orbito-nasal anatomy

Image-guided navigation systems are increasingly used in orbito-facial surgery where advanced pre-operative image manipulation and intra-operative localisation have proved invaluable. We describe the novel use of one such system for Lester-Jones tube placement to the contralateral nasal space in a 54-year-old man with left nasolacrimal duct obstruction following left rhinectomy, hemi-maxillextomy, radiotherapy and reconstruction for a left sinonasal squamous cell carcinoma. Reconstruction included a vascularised iliac crest graft, titanium mesh implant and polyaryletheretherketone (PEEK) maxillo-orbital implant. Pre-operative image analysis was used to determine the required tube length to extend to the right nasal space. Passive optical tracking facilitated intra-operative localisation of suitable entry and exit sites for the tube to avoid the orbital implants and achieve drainage into the contralateral nasal cavity. Free drainage and good positioning of the tube was confirmed by nasal endoscopy. This case supports a role for image-guided navigation in complex lacrimal surgery, particularly in cases with distorted anatomy.

Screw and washer fixation for onlay rib grafts to the mandible

fractured edentulous mandible can be a challenging injury o treat, particularly so in a patient with a severely atrophic andible the vertical height of which is less than 10 mm.1 ne technique for fixation of such a fracture that was previusly described from our unit is the use of autologous rib as nlay fixation grafts.2 We have found that this is a reliable ay of achieving bony union in a severely atrophic mandible. One of the difficulties with the technique is how to secure he rib. Newman has described the use of circummandibular ires to secure the rib in place.2 This can be effective, but he fixation is often not rigid and the fragments can move uring the postoperative period. To improve the rigidity we ave tried using screws from our 2.0 miniplate fixation set. hese screws pass through the buccal rib graft, both cortices f the mandible, and then the lingual rib graft. The rib graft s soft bone compared with the mandible. The screws effecively slide through the outer graft and compress the graft on he buccal aspect of the mandible. Unfortunately the conical hape of the head of a 2.0 screw is designed to fit in a counersunk hole in a miniplate. When used to secure rib grafts he conical head acts as a wedge, and causes the soft bone of he rib to split as the screw is tightened. The solution is to use a washer, which spreads the load of he screw as it is tightened, and prevents the onlayed rib from plitting. The use of biconcave washers has recently been escribed in the fixation of mandibular fractures with lag crews.3 Biconcave washers will work well; however, they ere not available when we treated the patient described. he photographs show single holes cut from a 2.0 miniplate hat were used as substitute washers. This is an alternative

Quality of life and communication in orthognathic treatment

Objective The primary aim was to determine what, if any, relationships exist between communication and quality of life in patients receiving orthognathic treatment since this has not been explored. A secondary aim was to compare the Quality of Life (QoL) of a pre-treatment sample with those at 2 years post-surgery. Design A cross-sectional questionnaire method was used. Setting Outpatient clinics providing orthognathic treatment at four UK hospital sites. Participants Two separate samples of pre-treatment (n = 73) and 2-year post-surgery (n = 78) patients participated in the study. Methods At clinic appointments, all eligible patients were invited to complete the Orthognathic Quality of Life Questionnaire (OQLQ), a previously validated condition-specific quality of life measure. At the same time, participants at the 2-year post-surgery stage also completed a second short questionnaire, the Communication Assessment Tool-Team (CAT-T), where they rated the quality of communication they had received during treatment. Results One hundred and fifty-one complete responses were received. The average age was 24.5 years (S.D. 9.77) and the majority (67%) were female in both groups. Statistically significant associations were found between QoL and quality of communication in the treated sample. Findings also showed a comparatively poorer QoL for the pre-treatment participants. This reduced QoL was more pronounced in females than males for all aspects except dentofacial appearance. Conclusions There was an improvement in QoL for patients at 2 years post-surgery compared to pre-treatment. There is an association between QoL and quality of communication as reported by participants at 2 years post-surgery. These novel findings are similar to outcomes in other patient settings such as oncology, but further investigation is required to establish the direction of cause and effect.

Dentigerous Cyst and Ameloblastoma of the Jaws: Correlating the Histopathological and Clinicoradiological Features Avoids a Diagnostic Pitfall.

Aim. To determine how many ameloblastomas were misdiagnosed as dentigerous cysts (DCs) by correlating the radiological and histopathological features of a series of both entities. Methods and results. Histopathology reports and radiological imaging of 135 DCs and 43 ameloblastomas were reviewed. Any clinical or radiological feature that suggested that the diagnosis of DC was wrong—for example, absence of an unerupted tooth—prompted review of the original histology. A total of 34 cases coded as DC at diagnosis were excluded; in the remaining 101 patients, the clinicoradiological and histopathological features were consistent with DC in 96 (95.0%). Review of the histology revealed that 4 patients had actually had odontogenic keratocysts (OKCs) and one a luminal/simple unicystic ameloblastoma (UA). One other OKC and 3 other ameloblastomas (1 luminal UA, 2 solid/multicystic) had originally been diagnosed as DC; these had been identified prior to the study. Of the 9 misdiagnosed patients, 6 were ≤20 years old. Clinically, DC had been the only, or one of the differential, diagnoses in 7 patients; in the other 2, the clinical diagnosis was radicular cyst. In none of the 4 misdiagnosed ameloblastomas was the radiology compatible with a diagnosis of DC. Incorrect terminology had been used on the histopathology request form in 5 of the 34 excluded cases where the clinical diagnosis was DC, despite the cyst being periapical to an erupted carious or root-filled tooth. Conclusions. The entire clinical team must ensure that a histopathological diagnosis of DC is consistent with the clinicoradiological scenario, particularly in younger patients.