A new classification for mandibular defects after oncological resection.

No universally accepted classification system exists for mandibular defects after oncological resection. Here, we discuss the scientific literature on classifications for mandibular defects that are sufficiently presented either pictorially or descriptively, and propose a new classification system based on these findings. Of 167 studies included in the data analysis, 49 of these reports sufficiently described the defect for analysis. These reports were analysed for classification, reconstruction, size of defect, number of osteotomies needed, and complications. On the basis of these findings, a new classification is proposed based on the four corners of the mandible (two angles and two canines): class I (lateral), class II (hemimandibulectomy), class III (anterior), and class IV (extensive). Further classes (Ic, IIc, and IVc) include condylectomy. The increasing defect class relates to the size of the defect, osteotomy rate, and functional and aesthetic outcome, and could guide the method of reconstruction.

Accuracy of preoperative clinical examination and imaging for mandibular resection in oral cancer: a systematic review of diagnostic test accuracy studies.

The aim of this systematic review is not only to analyse the accuracy of clinical examination and radiological preoperative assessment of mandibular invasion reported in isolation, but to highlight those reports that have combined them. A total of 1636 titles and abstracts published between 1995 - 2000 were screened following a literature search in PubMed. Keywords were "mandible" and "squamous cell carcinoma". A total of 90 full manuscripts were reviewed with 24 meeting defined inclusion/exclusion criteria and yielding the data reported. The most sensitive test was single photon emission tomography with eight out of the 10 studies reporting sensitivity higher than 95%. Magnetic resonance imaging (MRI) demonstrated superior sensitivity but was less specific than computed tomography (CT). A single report attempted to report the combined CT and MRI scans with a separate expert reporting but did not result in more reliable detection. Periosteal stripping was not reported, and there was insufficient data to establish the value of new technologies. This review confirms that, to our knowledge, there are no reliable data on the results of combining imaging techniques with or without clinical examination. It emphasises the lack of data for the combination of preoperative techniques to enhance safe oncological resection of the mandible. Based on the evidence gathered in this review an algorithm of assessment of possible mandibular invasion is proposed. With new technologies available and 3-dimensional models to help plan the mandibular resection and reconstruction, the potential of combining preoperative investigations should be fully realised through prospective research.

Reconstruction of the maxilla and midface: introducing a new classification.

Most patients requiring midface reconstruction have had ablative surgery for malignant disease, and most require postoperative radiotherapy. This type of facial reconstruction attracts controversy, not only because of the many reconstructive options, but also because dental and facial prostheses can be very successful in selected cases. This Personal View is based on a new classification of the midface defect, which emphasises the increasing complexity of the problem. Low defects not involving the orbital adnexae can often be successfully treated with dental obturators. For the more extensive maxillary defects, there is consensus that a free flap is required. Composite flaps of bone and muscle harvested from the iliac crest with internal oblique or the scapula tip with latissimus dorsi can more reliably support the orbit and cheek than soft-tissue free flaps and non-vascularised grafts, and also enable an implant-borne dental or orbital prosthesis. Nasomaxillary defects usually require bone to augment the loss of the nasal bones, but orbitomaxillary cases can be managed more simply with local or soft-tissue free flaps. We review the current options and our own experience over the past 15 years in an attempt to rationalise the management of these defects.

An audit of routine practice: a prospective study on the use of mouth props in oral surgery.

Introduction Mouth props are routinely used for patients treated under general but not local anaesthesia (LA). Patient discomfort and excess operator time is an often cited argument against the routine use of mouth props.Aim and methods We surveyed patients, surgeons and assistants following the use of mouth props during minor oral surgical procedures under LA in order to assess their acceptability and utility in clinical practice.Results Forty-seven patients were included, with 24 patients treated using mouth props and 23 without. Thirty-three patients had dental extractions, three had intraoral biopsies and one underwent a tube removal following cyst marsupialisation.Discussion Patients reported less difficulty in mouth opening where a mouth prop was used. Patients reported similarly low levels of discomfort with or without a mouth prop. Ninety-five percent of patients who used a mouth prop reported they would recommend their use. The surgeon and assistant reported mouth opening as less problematic and assisting as easier where a mouth prop was used.Conclusion The results of this study demonstrate the benefits and broad acceptability of mouth prop use in the awake patient. We question current practice in that mouth props are not routinely offered to patients during oral surgical and dental procedures.

The effect of exercise on nasal uptake of ozone in healthy human adults.

The nose may help protect the lower respiratory tract from the effects of ambient ozone by scrubbing ozone from inspired air. Reductions in both nasal resistance and nitric oxide production with exercise may influence the efficiency of ozone uptake in the nose. Nasal ozone uptake was measured in 10 healthy volunteers before and after 15 min of moderate bicycle exercise. Ozone (0.2 parts/million) was pulled through both nostrils and out of the mouth at a constant flow while the subjects closed their epiglottises. Nasal uptake of ozone was determined by comparing the ozone concentration entering the nostrils to that exiting the mouth. Average preexercise uptake of ozone was 56 +/- 7.8 and 37 +/- 4.9% at 10 and 20 l/min, respectively. These averages did not significantly differ from those immediately postexercise (55 and 37%). Nasal ozone uptake increased significantly (P < 0.001) with decreasing flow rate, but intersubject variability in uptake could not be predicted by nasal volume or cross-sectional areas (as measured by acoustic rhinometry) or endogenous nitric oxide production. However, the percent change in ozone uptake after exercise, within an individual, was correlated with both 1) percent change in nasal volume (r = 0.70 at 10 l/min) and 2) percent change in the rate of volumetric expansion between the nasal valve and turbinates (r = 0.82 at 10 l/min). These results may be useful for assessing human risk associated with ozone exposure during exercise.

A comparison of the long-term morbidity following deep circumflex iliac and fibula free flaps for reconstruction following head and neck cancer.

Composite free tissue transfer has an established role in head and neck oncology for the reconstruction of the bony defect following tumor ablation, and while donor-site morbidity is variably reported, there is little consensus on the most favorable donor site. The fibula and deep circumflex iliac artery have distinct advantages in terms of the volume and length of bone in mandibular reconstruction. Few studies have compared their donor-site morbidity. The aim of this study was to compare the fibula and deep circumflex iliac artery flaps using a review of the case notes and cross-sectional review of patients attending a research clinic for validated orthopedic examination and completion of health-related quality-of-life questionnaires. Between February of 1993 and May of 2001, 44 fibula free flaps and 73 deep circumflex iliac artery free flaps were performed. Ninety-nine case notes and 36 patients were available for review of donor-site morbidity. Sixteen patients with fibula flaps and 20 patients with deep circumflex iliac artery flaps took part in the clinical examination component of the study, which was composed of a clinical examination by an orthopedic surgeon using the American Orthopedic Foot and Ankle Society ankle scoring system and the Harris hip scoring system, and two patient-completed questionnaires, the University of Washington Questionnaire and the Hospital Anxiety and Depression Scale. Subjective and objective markers of morbidity related to both flaps were similar in most parameters. However, fibula flaps were associated with more problems with donor-site healing, reduced power, and sensation. Poor orthopedic scores for both flaps were associated with notably poor scores on the University of Washington Questionnaire and the Hospital Anxiety and Depression Scale. The study would suggest that both deep circumflex iliac artery and fibula donor sites result in an acceptable and comparable morbidity for most patients, but in cases in which significant donor-site morbidity is encountered, health-related quality of life is significantly compromised.

Management of the neck and regional recurrence in squamous cell carcinoma of the maxillary alveolus and hard palate compared with other sites in the oral cavity.

BACKGROUND: The aim of this article was to assess the management of the neck and regional recurrence for squamous cell carcinoma of the maxillary alveolus and hard palate (n = 43) and compare that to the rest of the oral cancer sites (n = 465). METHODS: This is a retrospective report through database and case note review. RESULTS: The incidence of nodal metastases (pathologic node-positive necks added to regional recurrence for clinical N0 and pathologic N0) was 37% (16/43) for maxillary alveolus and hard palate compared with 40% (187/465) for the oral cavity in general. Regional recurrence occurred in 26% (11/43) in the maxillary alveolus and hard palate compared with 7% (31/465) in the remaining oral cavity sites (p = .001). CONCLUSIONS: Squamous cell carcinoma arising in the maxillary alveolus and hard palate has a similar risk of regional metastasis as the rest of the oral cavity, and a lower propensity for selective neck dissection is resulting in higher regional recurrence and lower survival rates.

De-escalation of surgery for early oral cancer--is it oncologically safe?

This study is a review of practice for patients with T1 or T2 squamous cell carcinoma (SCC) of the anterior tongue and floor of the mouth who presented to the regional maxillofacial unit in Liverpool between 1992 and 2007. We examined trends in management and analysed their effects on resection margins, recurrence, and survival. The Liverpool head and neck oncology database was used to identify patients, and to retrieve their clinical, surgical, and pathological data. When data were missing the case notes and pathology records were reviewed. Follow up was taken to January 2011. A total of 382 patients were included. Despite more conservative treatment with closer resection margins (27% in 1992-1995 and 60% in 2004-2007), fewer free flaps (79% in 1992-1995 and 38% in 2004-2007), and less adjuvant radiotherapy (37% in 1992-1995 and 22% in 2004-2007), there has been no significant increase in local recurrence (14% in 1992-1996 and 8% in 2004-2007), and overall survival has not been adversely affected. This is most striking when T1 tumours are considered in isolation with a consistent trend towards fewer clear margins (95% in 1992-1995 and 28% in 2004-2007) and fewer free flaps (53% in 1992-1995 and 11% in 2004-2007). The case mix was similar over the study period. These data support a more conservative approach to the management of early oral cancer.

Accuracy of MRI in prediction of tumour thickness and nodal stage in oral squamous cell carcinoma.

We aim to compare radiological with histological tumour thickness (RTT with HTT) for oral squamous cell carcinoma (OSCC), and the ability of both to predict cervical metastasis. The MRI images and histopathology reports of 102 consecutive OSCC cases were compared and the relationship between RTT and HTT, calculated as a "shrinkage factor" by the gradient of the best fitting regression line. Most (69%) tumours appeared thicker on MRI than was revealed by histopathology. Shrinkage factor was 0.70 (interquartile range 0.63-0.77, correlation co-efficient 0.63) for all cases, 0.87 (IQR 0.80-0.95, CC 0.88) for tongue and 0.65 (IQR 0.49-0.82, CC 0.45) for floor of mouth sub-sites. RTT did not correlate well with the presence of nodal metastases in any sub-site, i.e. there was no clinically applicable cut-off value of RTT to determine the prescription of elective neck dissection. Although RTT has some predictable relationship with HTT, this varies between sub-sites with tongue the most accurately predicted shrinkage using axial MRI. It is not possible from either the MRI staging of neck or tumour thickness to safely determine the need for neck dissection in OSCC. It is necessary to re-evaluate the benefit of MRI as a staging investigation (particularly for early stage OSCC) and further explore the contribution of molecular biomarkers and ultrasound.

Preoperative Doppler assessment of perforator anatomy in the anterolateral thigh flap.

Despite its many evident merits as a donor site, the principal disadvantage of the anterolateral thigh flap is the variability in its vascular anatomy. Preoperative assessment by Doppler of the vascular perforators has been advocated as routine. We report the accuracy of this method, and describe the strategy for rescue where adequate perforators are not evident. Eighty-six consecutive patients were marked preoperatively using hand-held Doppler and the pattern was compared with intraoperative findings. Assessment by Doppler predicted a median of 3 (range 0-8) perforator signals, and a median of 2 (range 0-5) was found intraoperatively. This overall trend towards false positives was exaggerated in thin thighs, but in the obese there were more false negative results. In 79% of cases explored medially it would have been possible to raise an apparently viable anteromedial thigh flap. As this can be done without extending the incision, it is the option of choice for rescue, although use of more proximal perforators may often be possible.

Particle inhalability at low wind speeds.

Accurate quantification of the dose delivered by aerosol exposures is essential for estimating the risk of potential adverse health effects. The fraction of airborne particles that can enter the nose or mouth during inhalation is referred to as the inspirable particulate mass fraction. This inhalable fraction is equivalent to delivered dose for particles greater than approximately 25 microm (aerodynamic particle diameter, d(ae)), which deposit completely and almost exclusively in the extrathoracic airways. Particle inhalability at high wind speeds (1-9 m/s) has been well characterized. However, there is a paucity of data describing the inhalability of particles at low wind speeds (< or =0.3 m/s), which are typical of indoor environments. High-wind-speed criteria poorly describe inhalability at low wind speeds. Based on the aspiration efficiencies of blunt and sharp-edged inlets, a function was developed for oral inhalability, P(I(O)), of particles at low wind speeds. This function predicts a slow decline in P(I(O)) from 0.95 at d(ae)= 8 microm, to 0.5 at d(ae) = 74 microm, and 0.1 at d(ae)= 175 microm. Data available from the literature for inhalability at relatively low wind speeds during oral breathing are well described by this logistic function (r(2)= 0.69).

Oral rehabilitation after treatment for head and neck malignancy.

BACKGROUND: Advances in the management of oral malignancy have resulted in significant improvements in survival and functional outcome. Ablation of oral tissues and radiotherapy render many patients unable to wear conventional prostheses, and these patients are, thus, candidates for oral rehabilitation with osseointegrated implants. We aim to present outcomes and complications of such treatment over a 14-year period in a single unit. METHODS: Data were collected for 81 consecutive patients, most of whom had received microvascular free flap reconstruction after surgical ablation of oral squamous cell carcinoma. Three hundred eighty-six implants were placed after a delay of 12 months after surgery. Sixty-five percent of implants were placed in the anterior mandible. Radiotherapy was used in 47% of the patients, and hyperbaric oxygen treatment was routinely used in irradiated subjects during the latter half of the series. Retrospective analysis of implants and prostheses was made by use of case notes, radiographs, and a computerized database. RESULTS: Data are presented for 364 of the 386 implants in 77 of the 81 patients after a median follow-up of 4 years. Two hundred sixty-five (73%) of the implants were in function supporting prostheses, 56 (15%) had been lost, and 43 (12%) were present but not loaded (ie, "sleepers"). Implant loss seemed patient specific and was also correlated with host bone type. Thirteen percent of patients in whom implants were placed in the mandible lost at least one implant, and the equivalent values for the maxilla was 40%. Thirty-six percent of patients in whom implants were placed in bone graft or flap lost at least one implant. The effects of implant manufacture, dimensions, radiotherapy, and hyperbaric oxygen did not reach statistical significance in this series. Cases of a second primary malignancy were noteworthy; however, the impact of recurrence was minimized by the delay between resection and rehabilitation. Of the 42 fixed and 29 removable prostheses fitted, 12 (17%) failed. CONCLUSIONS: Implants placed in mandible were reliable, but failure rates in vascularized bone graft and maxilla were higher. Radiotherapy did not seem to prejudice implant survival, and hyperbaric oxygen had no demonstrable benefit in this series. Despite some persistent soft tissue problems and implant loss, most patients reached a successful prosthetic and functional outcome.

Health-related quality of life after maxillectomy: a comparison between prosthetic obturation and free flap.

PURPOSE: The purpose of this cross sectional study was to evaluate the health-related quality of life of patients following maxillectomy and to compare obturation and free flap reconstruction. PATIENTS AND METHODS: At the Regional Maxillofacial Unit in Liverpool, United Kingdom, between 1992 to 1996, 39 patients underwent maxillectomy for malignant pathology. Of these patients, 28 (10 underwent obturation and 18 underwent free tissue reconstruction) completed a postoperative semi-structured interview. Eight questionnaires were used to test aspects of health-related quality of life and function. RESULTS: The main findings were the associations between the size of maxillectomy defect and the University of Washington activity (-0.53; P =.005) and recreation (-0.70; P <.001) domains, and with the physical functioning (-0.58; P =.001) and quality of life (-0.51; P =.007) domains of the European Organization for Research and Treatment of Cancer questionnaire. No statistically significant differences were seen between the obturator and free flap groups. Borderline trends were for obturator patients to be more concerned about their appearance, to have more pain and soreness in their mouths, to be more aware of their upper teeth, more self-conscious and less satisfied with their upper dentures, and less satisfied with function. CONCLUSION: Similar subjective outcomes were found for both groups, and a larger longitudinal study is needed to test these relationships more rigorously.

Patterns of invasion and routes of tumor entry into the mandible by oral squamous cell carcinoma.

BACKGROUND: An understanding of the patterns, spread, and routes of tumor invasion of the mandible is essential in deciding the appropriate level and extent of mandibular resection in oral squamous cell carcinoma. METHODS: A prospective study of histologic patterns of tumor invasion and routes of tumor entry into the mandible was performed in a consecutive series of 100 previously untreated patients. RESULTS: The pattern of tumor invasion of the mandible depended on the depth of invasion both in the hard (p =.001) and soft tissues (p =.001). There was evidence that the pattern of invasion was related to histologic prognostic indicators of the disease, such as extracapsular spread from invaded lymph nodes (p =.03). The route of tumor entry was at the point of abutment to the mandible (direct) in all 13 cases, invading the dentate part of the mandible. Fifty-five percent (23 of 42) of tumors invading the edentulous ridge entered through the occlusal (superior) surface. Direct entry to the mandible in the edentulous ridge was more likely for tumors arising in the tongue, floor of the mouth and the buccal mucosa compared with alveolar or retromolar sites (p =.003) CONCLUSIONS: Larger or more deeply invading tumors in the soft tissue are more likely to invade the mandible and show the more aggressive (invasive) form of tumor spread, reducing the options of a more conservative (rim) resection. Tumors tend to enter the mandible at the point of abutment, which in both the dentate and edentulous jaw is often at the junction of the reflected and attached mucosa. A point of tumor entry below the occlusal ridge or gingival crest should be assumed when planning rim or marginal resections of the mandible.

Longitudinal health-related quality of life after mandibular resection for oral cancer: a comparison between rim and segment.

BACKGROUND: Mandibular resection for oral cancer is often necessary to achieve an adequate margin of tumor clearance. Segmental mandibulectomy has been associated with a poor health-related quality of life (HRQOL), particularly before composite free tissue transfer to reconstruct the defect. Little is published in the literature contrasting the subjective deficit of segmental compared with rim resection. The aim of this study was to use a validated head and neck HRQOL questionnaire to compare rim and segmental mandibular resection in patients having primary surgery for oral cancer. METHOD: There were 224 consecutive patients between 1995 and 1999 who were treated by primary surgery for oral squamous cell carcinoma. One hundred twenty-tree had no mandibular resection, 44 had a rim resection, and 57 had a segmental resection. The University of Washington Quality of life questionnaire (UW-QOL) was administered before treatment, at 6 months, 12 months and after 18 months. RESULTS: Preoperatively, patients undergoing segmental resection reported significantly more pain, chewing problems, and a lower composite UW-QOL score. Postoperatively, the segment group tended to score worse at all time points, particularly in appearance, swallowing, recreation, and chewing; however, the difference between rim and segment was only seen in smaller resections without adjuvant radiotherapy. Little difference was seen between rim or segment for tumors < 4 cm with radiotherapy and between rim and segments for tumors > 4 cm. CONCLUSION: After segmental mandibulectomy and reconstruction using composite free tissue transfer, the UW-QOL scores were relatively good. The only 2 difference between rim and segments was noted in the small resections without radiotherapy, and some of this was reflected in differences at baseline.

The influence of the pattern of mandibular invasion on recurrence and survival in oral squamous cell carcinoma.

BACKGROUND: Controversy exists over the predictive value of the presence and pattern of tumor invasion of the mandible in oral squamous cell carcinoma (SCC). Many authors have questioned increasing the classification of small tumors to T4 on the basis of mandibular invasion alone. There are little data on the influence of the pattern of invasion on prognosis. METHODS: We prospectively reviewed 100 consecutive mandibular resections for previously untreated oral SCC. Clinical and pathologic data collected included details of soft and hard tissue histologic findings. Outcomes included recurrence (local, regional, and distant metastases), disease-specific survival, and death from other causes. The median follow-up for survivors was 65 months. RESULTS: Of 100 cases, 65 involved segmental and 35 involved marginal resections. Sixty-two percent of mandibles were invaded by tumor. Local recurrence occurred in 21% and was strongly correlated with tumor size, nodal involvement, and pattern of soft tissue invasion. The 5-year disease-specific survival was 68%, and the crude survival was 50%. Mandibular invasion predicted for recurrence and disease-specific survival, even after correcting for the effects of other variables. The pattern of mandibular invasion (erosive/infiltrative) was also predicted for recurrence and disease-specific survival. CONCLUSIONS: Even in the presence of mandibular invasion, soft tissue factors are the most important determinants of prognosis. Upstaging tumors on the basis of mandibular invasion is justified. An infiltrative pattern of bone invasion is a marker of aggressive tumor biology and should be included in the pTNM classification.

Comparison of miniplates and reconstruction plates in mandibular reconstruction.

BACKGROUND: The aim of this study is to compare complication rates of miniplates versus reconstruction plates in the fixation of vascularized grafts into segmental mandibular defects. METHODS: Retrospective analysis of 143 consecutive successful microvascular composite flaps performed between 1993 and 2001 was performed. Data were gathered from a computerized database, case notes and pathology reports. Complications were classified as dehiscence, infection, plate or bone removal. RESULTS: In the series, 49% of patients received miniplates, and 51% received plates. No significant differences in complication rates were found between those grafts fixed with miniplates (27%) and those with reconstruction plates (30%). Plate choice was primarily determined by consultant preference. No significant differences were found in patient, defect, treatment, or follow-up characteristics between the plate groups. Twenty-nine percent of patients had at least one late complication at the reconstructed site, and this was higher (39%) in those who had postoperative radiotherapy. CONCLUSIONS: No evidence was found in this study that the increased rigidity offered by reconstruction plates influences the rate of plate or bone removal, infection, or plate exposure. Thus, the decision to use reconstruction or miniplates is not dependent on the rate of plate complications.