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There is a lack of consistency among published reports in the definition of what constitutes close resection margins (1-5mm) in the surgical treatment of oral and oropharyngeal squamous cell carcinoma (SCC). Our aim was to define what would constitute close resection margins in predicting local recurrence and disease-specific survival. The study comprised 192 previously untreated patients with oral and oropharyngeal SCC who were recruited at the Southern General Hospital, Glasgow, from 2001 to 2007 with a minimum follow-up of 2 years. Resection was the primary treatment and the surgical margins were recorded for all patients. Statistical analyses were aided by the Statistical Package for the Social Sciences, version 15.0, and MedCalc software. The status of the surgical margins was evaluated using a receiver operating characteristic (ROC) curve to define the cut-off point. Cox's proportional hazard model was used to establish predictive factors for local recurrence and disease-specific survival. Of 192 patients, 23 (12%) had involved margins (1.0mm), 107 (56%) had close margins (1.0-2.0mm (16.1%); 2.1-3.0mm (12%); 3.1-4.0mm (10.4%); 4.1-5.0mm (17.2%), and 62 (32.3%) had clear margins (5mm). No predictive cut-off point was found that related close surgical margins to local recurrence. However, there was a significant adverse association between surgical margins ≤1.6mm and disease-specific survival. In recommending postoperative adjuvant treatment for oral and oropharyngeal SCC, we suggest that surgical margins within 2mm should be considered as the cut-off. However, other clinical and pathological prognostic factors should also be taken into consideration when recommending further treatment.

A systematic study was carried out using plastic model skulls to quantify the accuracy of the transfer of face bow registration to the articulator. A standard Dentatus semi-adjustable articulator system was compared to a purpose built orthognathic articulator system by measuring the maxillary occlusal plane angles of plastic model skulls and of dental casts mounted on the two different types of articulators. There was a statistically significant difference between the two systems; the orthognathic system showed small random errors, but the standard system showed systematic errors of up to 28°.

The errors produced by occlusal wafers constructed on casts of the teeth mounted on a standard articulator and an improved orthognathic articulator were investigated by carrying out simulated orthognathic surgery on plastic skulls. The wafers were used to relocate the position of the maxillae of the skulls. The vertical and horizontal displacements of the maxillae were determined from measurements of the positions of markers on the skull and teeth. Comparison of the magnitudes of the actual and intended movements showed that wafers constructed on the standard articulator had systematic prediction errors of up to 5 mm, but the improved orthognathic articulator showed much smaller random errors. There was a statistically significant improvement in overall accuracy in predicting maxillary Le Fort I position with the use of the improved orthognathic articulator which the authors recommend for clinical use.

We present a new method for replicating the skull and occlusal surface with an accurate physical model that could be used for planning orthognathic surgery. The investigation was made on 6 human skulls, and a polyvinyl splint was fabricated on the dental cast of the maxillary dentition in each case. A cone beam computed tomogram (CBCT) was taken of each skull and a three-dimensional replica produced. The distorted dentition (as a result of magnification errors and streak artefacts) was removed from the three-dimensional model and replaced by new plaster dentition that was fabricated using the polyvinyl splint and a transfer jig replication technique. To verify the accuracy of the method the human skulls and the three dimensional replica model, with the new plaster dentition in situ, were scanned using a laser scanner. The three-dimensional images produced were superimposed to identify the errors associated with the replacement of the distorted occlusal surface with the new plaster dentition. The overall mean error was 0.72 and SD was (0.26) mm. The accuracy of the method encouraged us to use it clinically in a case of pronounced facial asymmetry.

The results of orthognathic surgery may differ significantly from the planned outcome using dental models. The orientation of dental models mounted on articulators using conventional face bows does not accurately replicate the orientation of the patients' teeth and jaws, but introduces a systematic error. A mathematical analysis showed that the misalignment of the maxillary model introduces errors in the perioperative wafers, which may lead to the incorrect surgical positioning of the maxilla reported in the literature. The results of the mathematical analysis were validated by image analysis of photographs of mounted maxillary models, used to simulate five orthognathic procedures. No significant difference between the experimental results and the theoretical predictions from the mathematical equations was noted. Planning for maxillary forward and upward movement produced more advancement and only 50% of maxillary impaction. Planning for maxillary forward and downward movement produced less advancement and more inferior displacement in relation to horizontal and vertical reference planes.

The purpose of this study was to evaluate the accuracy of model surgery prediction after orthognathic surgery and to identify possible errors associated with the prediction process. The study included 46 patients who had undergone orthognathic surgical procedures; 22 in Group A who had had a Le Fort I osteotomy; and 24 in Group B who had had a Le Fort I osteotomy and mandibular setback surgery. The immediate postoperative and preoperative lateral cephalograms were analysed to calculate surgical changes; these were compared with those obtained from model surgery prediction and a statistical analysis was undertaken. The maxilla was more under-advanced and over-impacted anteriorly than predicted by model surgery. The amount of mandibular setback was more than that predicted by model surgery. None of the differences between prediction planning and actual surgical changes was statistically significant at p

Patients who require orthognathic surgery may have asymmetry of the position of the temporomandibular joints relative to the maxilla, which is impossible to reproduce on the current semiadjustable articulators used for surgical planning. We describe a highly-adjustable spirit level orthognathic face bow that allows records to be made of patients with asymmetrical maxillae. The orthognathic articulator also allows the position of the condylar components of the articulator to be adjusted in three dimensions. The use of the new face bow and articulator made it possible to mount the dental casts of asymmetrical faces to reproduce their clinical appearance. The devices were evaluated by comparing the measurements of anatomical variables obtained from cephalometric radiographs with equivalent values obtained from the orthognathic articulator and casts mounted on the articulator. Although the measurements showed significant intersubject variability, the angle between the horizontal and maxillary occlusal plane, occlusal cant angle, and intercondylar widths, were not significantly different.

Orthognathic surgery that involves movement of the maxilla relative to the skull is usually planned using casts mounted on an articulator. Accurate positioning of the maxilla relative to the skull is essential for reliable planning, but current methods of mounting casts on articulators are inaccurate and unreliable. We propose that the casts should be mounted using the relation between the horizontal plane and the resting head position to define the position of the skull. A photographic study of 10 subjects confirmed the reproducibility of the head position and its relation to the horizontal plane. A face bow incorporating a circular spirit level was used to transfer the relation between the horizontal and the maxillary dentition to a semiadjustable articulator. The angle between the horizontal and maxillary occlusal planes was measured from six lateral cephalograms and compared with those of casts mounted on a semiadjustable articulator using a face bow with either an orbital pointer or a spirit level. The face bow with a spirit level produced considerably more accurate results.

The aim of this study was to investigate the feasibility of reconstructing critical size continuity osteoperiosteal defects of the mandible using a composite of recombinant BMP-7 contained in a bovine type-1 collagen carrier wrapped in a pedicled sterno-occipitalis muscle flap. At 3 months following surgery, bridging of the surgical defect was noted in three subjects (60%). Histologically, the induced bone regenerate showed maturation from woven to lamellar bone. Islands of cartilage were distributed throughout the defect. Replacement ossification of the degenerated muscle was a common feature in all specimens. Microradiography showed a gradual increase in the calcification of mineralized tissue from the margin to the centre of the newly generated bone. This research represents a proof of the concept that bone can be satisfactorily formed within a muscular scaffolding at the site of the created defect in a one-stage procedure.

This investigation aimed to compare and contrast practical difficulties experienced by 54 children from three different centres (Mexico City, New York, Paris) treated with either extra-oral or intra-oral distraction devices. The possible effect of distraction osteogenesis on pain/sleeping difficulty, speech and eating problems and disturbance of recreational activities and alteration in sensation were investigated. It was expected that intra-oral devices would reduce the difficulties associated with the distraction process and their psychological effect on the child. Some benefits resulting from the use of intra-oral devices were identified, these included fewer sleeping problems (P = 0.006) and less disturbance of recreational activities (P = 0.002). However, eating and maintaining oral hygiene were more problematic with intra-oral devices the differences between the intra-oral and extra-oral groups was approaching significance at P = 0.07. A major disadvantage of the extra oral device was scarring. In both groups the alteration of lip sensation was temporary, pain was limited to the time of activation of the distraction device. A high level of patients' cooperation was mandatory for successful completion of the treatment.

Fourteen patients or their immediate family were interviewed about their experiences of having either unilateral or bilateral external distraction osteogenesis of the mandible. The patients showed a high level of co-operation with treatment. Six of the 14 patients required repeat distractions, and had been informed and accepted that this was a possibility before the initial distraction. However, patients or their parents expressed some reservations about the extraoral distractors, which prevented them from practising their favourite sport and made them vulnerable to bullying by their friends and colleagues. Patients had moderate pain when the appliances were removed. They all expressed their satisfaction with the results and would recommend this treatment to others. Problems, including speech, eating, pain, and sleeping difficulties, were encountered by patients at all stages of treatment. Of considerable concern was the disruption of education when the child was treated during the school term.

Infection of soft tissues surrounding extra-oral craniofacial endosseous implants is a common clinical problem. The aim of this study was to analyse the microflora associated with such implants, in both health and disease. Eighteen patients with a total of 49 implants were studied. Each patient was seen on two occasions for both a clinical examination and for collection of microbiological samples, using swabs and paper points, from the peri-abutment soft tissues. Specimens were cultured on blood agar and on agars selective for staphylococci and yeasts. Isolates were identified and selective antibiotic susceptibility testing undertaken. No single organism emerged as a predominant cause of peri-abutment skin infection but Staphylococcus aureus, Gram-negative bacilli and yeasts were all present as potential pathogens in this context. Culture and sensitivity results should therefore guide the treatment of these infections.

Objectives: Correction of craniofacial microsomia (CFM) presents several challenges concerning the modality of surgical intervention. The aim of this study was to assess early and late surgical outcome, by undertaking Euclidean distance matrix analysis (EDMA) of CFM patients exhibiting an unilateral mandibular deformity that was surgically corrected by an inverted L osteotomy and autogenous bone graft. Design: Longitudinal study. Preoperative, ≈1-year postoperative and ≈3-year postoperative assessments of 14 consecutive children (mean age 9 years) with CFM. Posteroanterior cephalographs were scanned and five homologous mandibular landmarks were digitized in triplicate (< 1% digitization error). Average mandibular geometries, scaled to an equivalent size, were generated using a generalized rotational fit program (Procrustes superimposition) and subjected to EDMA. Results: The mean pre- and both postoperative mandibular configurations differed statistically (p < .01). Early postoperative improvemen...

We compared the use of one miniplate (n = 36) with that of two miniplates (n = 26) for the treatment of the mandibular angle in a randomised trial. There were no significant differences between the groups in total morbidity (22/36 compared with 14/26) or for individual complications. We conclude that two miniplates seem to confer no extra benefit to patients, but a much larger trial would be required to show this conclusively.

We describe a vision-based three-dimensional facial data capture system designed for the planning of maxillofacial operations. We describe the system requirements and outline the methods used to develop a complete three-dimensional facial capture system. Our approach is based upon imaging the face using two stereo-pair sets of cameras. Scale-space-based stereo-matching is then used to recover correspondences between each of the captured stereo-pairs. Photogrammetric routines based on adjustment of bundles are used off-line to calibrate the system by imaging a single object that references all cameras to the same co-ordinate frame. This calibration scheme allows us to convert stereo correspondences to world points for each pair of cameras without the need for any subsequent fusion of data. Initial results show that we are able to capture key facial landmarks to within 0.5 mm.

Sensory disturbance following orbitozygomatic complex fractures was studied in 65 patients from 4 treatment groups which represented potentially varying degrees of sensory disturbance. The fracture-type-dependent treatments were: no surgical intervention ( n =20), closed reduction with or without wire fixation ( n =17), open reduction with miniplate fixation ( n =15) and/or reconstruction of the orbital floor ( n =13). In order to assess the sensory function of different classes of afferent fibres, several methods of sensory testing were applied. On average 6.3 months after treatment, the patient's report was obtained, and tests regarding touch, two methods of two-point discrimination, and cold were applied on the cheek and upper lip. The degree of sensory disturbance was method-dependent. In patients who underwent closed reduction, pronounced levels of positive correlation occurred between results from different tests or from both test sites. The levels of these correlations were, in general, low for all other treatments. These findings suggest that afferent fibres of both large and small diameter tended to be permanently damaged in the patient group with closed reduction. In contrast, the types of sensory afferent fibres that were involved in the trauma and/or their recovery were highly variable within patients and sites for all other treatment groups.

Sensory disturbance following orbitozygomatic complex fractures was studied in 65 patients in relation to type of fracture and method of treatment. The fracture-type-dependent treatments were: no surgical intervention (n=20), closed reduction with or without wire fixation (n=17), open reduction with miniplate fixation (n=15) and/or reconstruction of the orbital floor (n=13). Several methods were applied to assess sensory function, on average 6.3 months after treatment, i.e. the patient's report and tests regarding touch, two methods of two-point discrimination, and cold, all applied on the cheek and upper lip. The various examinations indicated that, on average, the long-term sensory disturbance was most pronounced and severe in patients who underwent closed reduction without miniplate fixation. As the sensory disturbance of patients with open reduction and miniplate fixation approached the base-line level of patients for whom surgical intervention was not indicated, open reduction with miniplate fixation can be recommended as treatment for frontozygomatic suture fractures. The degree of sensory disturbance of patients who underwent orbital floor reconstruction was intermediate compared to patients with closed and open reduction respectively.

Purpose: A retrospective review of silicone rubber (Silastic; Dow Corning, Midland, MI) implants placed in orbits was undertaken. These implants were used to reconstruct defects in the orbital floor and/or walls secondary to trauma, or those created during malar or orbital osteotomies. The purpose of the study was to determine the incidence of removal of these implants from the surgical site. Materials and Methods: The records of 311 patients treated over a 20-year period were reviewed. Of these, 302 had received silastic implants secondary to trauma. Results: Forty-one patients (13%) had their implant removed at a second operation. The reasons for removal included infection, migration of the implant, worsening eye signs such as diplopia, and others. Conclusion: Because there was a clinically significant rate of removal of this material, consideration should be given to the use of other available materials.

61 orthognathic surgery patients were studied (39% male, 61% female). It confirms that the group of patients we see in the West of Scotland are well adjusted psychologically and that the majority seek orthognathic surgery for aesthetic reasons. The degree of satisfaction is high (87%). Dissatisfaction is not related to sex, age or procedure. Patients who were dissatisfied tend to have higher neuroticism scores on the Eysenck Personality Inventory and those patients who had had unreal expectations of post surgical pain, numbness and swelling, were likely to express dissatisfaction with the outcome in the early stages. Several patients initially expressed some dissatisfaction with the outcome after 3 months then went on to increase their score and by 12 months became satisfied with the procedure. The authors outline the importance of adequate patient preparation prior to surgery and the use of printed literature is recommended.

During cone beam computed tomography (CBCT) scanning, intra-oral metallic objects may produce streak artefacts, which impair the occlusal surface of the teeth. This study aimed to determine the accuracy of replacement of the CBCT dentition with a more accurate dentition and to determine the clinical feasibility of the method. Impressions of the teeth of six cadaveric skulls with unrestored dentitions were taken and acrylic base plates constructed incorporating radiopaque registration markers. Each appliance was fitted to the skull and a CBCT performed. Impressions were taken of the dentition with the devices in situ and dental models were produced. These were CBCT-scanned and the images of the skulls and models imported into computer-aided design/computer-aided manufacturing (CAD/CAM) software and aligned on the registration markers. The occlusal surfaces of each dentition were then replaced with the occlusal image of the corresponding model. The absolute mean distance between the registration markers in the skulls and the dental models was 0.09 ± 0.02 mm, and for the dentition was 0.24 ± 0.09 mm. When the method was applied to patients, the distance between markers was 0.12 ± 0.04 mm for the maxilla and 0.16 ± 0.02 mm for the mandible. It is possible to replace the inaccurate dentition on a CBCT scan using this method and to create a composite skull which is clinically acceptable.

We have used a two-part interlocking titanium plate for cranioplasty in two patients with large skull defects in which reconstruction with a titanium plate was required and extensive contouring of the plate was necessary.

Purpose To investigate whether there were any significant differences in the mode of presentation, treatment, and outcome of patients presenting with a primary diagnosis of ameloblastoma in Glasgow, Scotland and San Francisco, CA. Materials and Methods All cases of ameloblastoma seen in both institutions between January 1, 1980 and December 31, 1999 were included in this study. Mode of presentation, radiographic appearance, histologic appearance, treatment, and follow-up were recorded. Results There were no significant differences in the clinical features on presentation (swelling, followed by pain, and altered sensation), the radiographic appearance (unilocular approximately 30% and multilocular 70%), or management with either local treatment (enucleation and/or curettage in just over 50% of cases) or radical treatment (a form of resection in under 50%) in the 50 cases included in this study. Primary care by conservative treatment led to a recurrence in approximately 80% of cases and this included cases of unicystic ameloblastoma. Conclusion The mode of presentation, diagnosis, and management of the ameloblastoma was remarkably similar in Glasgow and San Francisco. The recurrence rate following local enucleation and curettage was unacceptably high, and this included the cases of unicystic ameloblastoma, which should be treated more aggressively than has been recommended in the past.

This study compared the morbidity associated with transconjunctival and transcutaneous approaches for orbital floor exploration with respect to the position of the lower eyelid following surgery. Two groups of 32 volunteers and 32 patients (12 transconjunctival and 20 transcutaneous) were recruited and three-dimensional (3D) imaging was carried out at 6 months following surgery. In the transcutaneous group, there were significant variations in the shape of the lower eyelid, with more medial displacement of the exocanthion. No significant differences were detected in the transconjunctival group compared to controls. The use of a 3D imaging system provided an objective method of assessing this aspect of morbidity associated with the use of lower eyelid incisions.

Records of patients undergoing the surgical removal of miniplates placed during the management of maxillofacial trauma (n=49) and orthognathic surgery (n=16) in a single unit, over a 2-year period have been analysed. Data concerning indications for plating, age and sex distribution, site of plating, time between insertion and removal, antibiotic prophylaxis, general medical factors and clinical indications for plate removal were evaluated for all patients. In addition, data for trauma patients included the site of fracture, and time delay between injury and plate insertion. Infection and/or wound dehiscence were the predominant causes for plate removal in both groups, in spite of the routine use of prophylactic antibiotics in a predominantly young, healthy cohort of patients. A removal rate of approximately 10% was found in the two groups of patients. This low rate would seem to imply that the routine removal of miniplates is not clinically indicated.

We report our experience of endosseous implants designed to retain various types of facial prostheses that were inserted by the West of Scotland Oral and Maxillofacial Surgery Service between January 1988 and September 1998. Forty-seven patients were given a total of 150 implants, most of which were auricular (n= 85) or orbital (n= 53). The functioning success rates were 100% and 75%, respectively. Soft tissue infection was the commonest complication, and could occur at any time after exposure of the implant, suggesting that life-long follow-up is required.

ObjectivesCorrection of craniofacial microsomia (CFM) presents several challenges concerning the modality of surgical intervention. The aim of this study was to assess early and late surgical outcome, by undertaking Euclidean distance matrix analysis (EDMA) of CFM patients exhibiting an unilateral mandibular deformity that was surgically corrected by an inverted L osteotomy and autogenous bone graft.DesignLongitudinal study. Preoperative, ≈1-year postoperative and ≈3-year postoperative assessments of 14 consecutive children (mean age 9 years) with CFM. Posteroanterior cephalographs were scanned and five homologous mandibular landmarks were digitized in triplicate (< 1% digitization error). Average mandibular geometries, scaled to an equivalent size, were generated using a generalized rotational fit program (Procrustes superimposition) and subjected to EDMA.ResultsThe mean pre- and both postoperative mandibular configurations differed statistically (p < .01). Early postoperative improvements in mandibular form were noted; increases in length arising in the treated mandibular body (≈ 19%) and ramus (≈ 13%). Comparing early and late postoperative configurations, a decrease of ≈ 22% in the late postoperative mandibular body length was evident, but the ramus maintained steady vertical growth (≈ 7%). Comparing the preoperative and late postoperative configurations, the decrease observed in the mandibular body on the treated side was reduced to ≈ 8% while the ramus maintained good growth (≈ 20%) on that side.ConclusionMandibular morphology is improved significantly in CFM patients surgically treated by an inverted L osteotomy, but relapse in the mandibular body is evident after ≈ 3 years. Nevertheless, ramus growth proceeds well after the surgical reconstruction.

Regional Maxillofacial Unit, Southern General Hospital, 1345 Govan Road, Glasgow G51 4TF, UK College of Medical, Veterinary and Life Sciences, Medical Faculty, Glasgow University School of Dentistry, BACS research group, 378 Sauchiehall treet, Glasgow G2 3JZ, UK School of Mathematics and Statistics, College of Science and Engineering, The University of Glasgow, Glasgow G12 8QQ, UK Centre for Ultrasonic Engineering, Department of Electrical and Electronic Engineering, University of Strathclyde, 204 George Street, Glasgow G1 XW, UK

This study examined skeletal stability and the remodelling process following advanced pedicled genioplasty. Twenty patients who had advancement genioplasty concomitant with other adjunctive orthognathic surgery were evaluated. A finite element analysis method was used to assess these changes. The stability of the advanced segment was excellent after 6 months. At 6 months bone remodelling was observed in the form of bone apposition at B point and Pogonion with bone resorption at the superior aspect of the advanced segment. The genial segment rotated about 12 degrees antero-superiorly which was thought to be due to the action of the mentalis muscle. Finite element analysis is a sensitive tool for assessing changes after genioplasty and was able to separate them from the effects of other adjunctive orthognathic surgery.

Amyloidosis may involve the tongue, causing macroglossia. Such a case is described which resulted in airway obstruction. The subsequent management was by permanent tracheostomy.

A ten-year review of 2,067 cases of zygomatico-orbital fractures is presented. The age and sex distribution, anatomical types of fractures, associated maxillofacial and nonmaxillofacial trauma, and causes of the injuries are described. The majority of fractures were sustained by males and resulted from trauma inflicted in altercations. The most common associated facial fractures were mandibular; the most common associated nonmaxillofacial trauma was extremity fractures. Motorcycle accidents caused the most significant amount of associated trauma, followed by motor vehicle accidents in which no seat restraint was used by the victim. Treatment, when indicated, consisted of elevation via a temporal approach followed by fixation where necessary. The fixation methods used are presented and discussed.

Objectives: Spreading odontogenic infections (SOI) are the commonest type of serious infections encountered in the orofacial region. A prospective multi-centre study was conducted in the West of Scotland to investigate the contributing role of social, systemic and microbial factors in the pathogenesis of SOI. Methods: Twenty-five patients with severe odontogenic infections were recruited over a period of six months. At admission, clinical assessment included temperature rise, haematological and biochemical investigations. Demographic data, social and past medical histories were obtained. Microbiology samples were collected to identify causative microorganisms and the clinical management of each infection was recorded. Results: Most infections were associated with teeth or roots. Eighty percent of the patients were tobacco smokers and 72% came from deprived areas. Five patients were intravenous drug users, four admitted chronic alcohol abuse, six had underlying systemic disorders and two were at high risk of malnutrition. A raised C-reactive protein at admission was a useful indicator of the severity of infection. Inappropriate prior antibiotic treatment in the absence of surgical drainage was common. Microbiology results showed a predominance of strict anaerobes, notably anaerobic streptococci, Prevotella and Fusobacterium species. Conclusion: SOIs remain surprisingly common and our present pilot study showed a particular association with social deprivation and tobacco smoking. Further elucidation of the role of malnutrition in SOI would be of interest. Molecular characterisation of the microflora associated with SOI may help to highlight whether bacterial factors play a role in converting a localised dentoalveolar abscess into a serious, spreading odontogenic infection.