The uncertainty of the surgical margin in the treatment of head and neck cancer.

We discuss our surgical philosophy concerning the subtle interplay between the size of the surgical margin taken and the resultant morbidity from ablative oncological procedures, which is ever more evident in the treatment of head and neck malignancy. The extent of tissue resection is determined by the "trade off" between cancer control and the perioperative, functional and aesthetic morbidity and mortality of the surgery. We also discuss our dilemmas concerning recent minimally invasive endoscopic microsurgical techniques for the trans-oral laser removal or co-ablation of aero-digestive tract tumours, which result in a minimal surgical margin of oncological clearance. By a process of inductive argument as to the nature of the surgical margin, we consider whether the risks of taking a lesser margin with adjuvant therapy is justified by the attendant gain in reduced surgical morbidity and the possible costs in tumour control.

Permanent sensory nerve impairment following third molar surgery: a prospective study.

OBJECTIVE: This prospective study reports the proportion of permanent sensory impairment of the inferior alveolar and lingual nerves and the factors influencing such prevalence after the removal of mandibular third molars under local anesthesia. STUDY DESIGN: There were 1,087 patients with 1,087 mandibular third molars removed under local anesthesia from 1998 to 2003. Standardized data collection included the patient's name, age, gender, radiographic position of extracted tooth, grade of surgeon, proximity of the inferior alveolar nerve, and the prevalence of lingual and/or inferior alveolar nerve paresthesia. RESULTS: Inferior alveolar nerve injury was 4.1% 1 week after surgery and decreased to 0.7% after 2 years of follow-up, and alteration in tongue sensation occurred in 6.5% of patients 1 week after surgery and decreased to 1.0% after 2 years of follow-up. CONCLUSION: The experience of the operator was found to be a significant factor in determining both permanent lingual nerve (P=.022) and permanent inferior alveolar nerve paresthesia (P=.026).

Photodynamic therapy down-regulates the invasion promoting factors in human oral cancer.

Squamous cell carcinomas of the head and neck are characterized by their high tendency for invasion and metastasis. Several studies have identified the roles of matrix metalloproteinases (MMPs), vascular endothelial growth factors (VEGF) and urokinase plasminogen activators (uPA) in this process. Photodynamic Therapy (PDT) is an emerging treatment currently in clinical practice for the treatment of early cancer. Here we evaluate, in vitro, the influence of PDT on the expression of these molecules. A series of human keratinocyte cell lines derived from human oral squamous cell carcinomas (OSCC) were used as the PDT 'targets' in this study. Each cell line was subjected to sublethal dose of PDT. Activity of MMP-2, MMP-9, MMP-13, uPA and VEGF were evaluated at protein levels using zymography and ELISA on culture medium. For uPA, a chromogenic assay was performed. Gelatin zymography results revealed that, in control medium, MMP-9 and MMP-2 were secreted in proform. MMP-2 was highly expressed by H376 cells while VB6 and UP cells relatively show similar MMP-2 with comparatively low expression. For MMP-9, the latent type was highly expressed by VB6 cells and only slightly by H376, while active-MMP-9 was expressed by VB6 cell line only. Following PDT, both active and latent MMP-2 and MMP-9 were down regulated by UP and VB6 cells (p<0.001), while H376 showed an increase in active-MMP-2. These observations were supported by ELISA. This study has demonstrated that, PDT causes the suppression of factors responsible for tumour invasion which may be of therapeutic value.

Fluorescence spectroscopy combined with 5-aminolevulinic acid-induced protoporphyrin IX fluorescence in detecting oral premalignancy.

BACKGROUND: Early detection of premalignant/malignant lesions in the oral cavity can certainly improve the patient's prognosis. This study presents fluorescence imaging with the topical application of 5-aminolevulinic as a way to improve detection of various oral tissue pathologies. This procedure depends mainly on comparing the intensity of red and green fluorescence emitted from tissues during examination. MATERIALS AND METHODS: Seventy-one patients who presented with clinically suspicious oral leukoplakia were recruited for this study. Each of the patients was required to have 5-aminolevulinic acid in the form of mouth rinse prior to fluorescence imaging. Following this a surgical biopsy was acquired from the exact examination site. The results of the fluorescence spectroscopy have been compared with histopathology. RESULTS: A Student's t-test was applied to test the viability of the ratio between red and green fluorescence. The red-to-green ratio was found to increase significantly when the lesion was identified as dysplastic or carcinoma in situ. By applying a threshold line to discriminate between normal and dysplastic lesions; a sensitivity of 83-90% and specificity of 79-89% were obtained. CONCLUSION: Fluorescence spectroscopy combined with 5-aminolevulinic acid-induced protoporphyrin IX was found as a valuable tool in the diagnosis of oral premalignancy. This technique offers the potential to be advantageous over other non-optical techniques in terms of providing real-time diagnosis, in situ monitoring, cost effectiveness and more tolerated by patient compared to surgical biopsy.

Maxillofacial Injury Severity Score: proposal of a new scoring system.

In this study a new injury severity score system, the Maxillofacial Injury Severity Score (MFISS), was developed to evaluate the characteristics of injury from maxillofacial trauma. Nine hundred and two cases of maxillofacial trauma were included in this study to evaluate injury severity using the MFISS, which was designed on the basis of Abbreviated Injury Scale, 1990 revision (AIS-90), and defined as the product of the sum of the three highest maxillofacial AIS scores and the sum of the injury severity scores for three maxillofacial functional parameters, malocclusion (MO), limited mouth opening (LMO), and facial deformity (FD). The correlation analysis was undertaken with the dependent factor of cost and number of days of stay in hospital. The results demonstrated a significant difference (P < 0.01) between bone and soft-tissue injuries and among various regional fractures. There was correlation (P < 0.01) between the MFISS and the cost of treatment and days of stay in hospital. The newly established MFISS thus characterizes maxillofacial injury severity while reflecting the management costs and treatment complexity.

Assessment of oral premalignancy using elastic scattering spectroscopy.

Optical spectroscopy systems have been involved in various clinical fields; however the main interest is still in the diagnosis of premalignant/malignant lesions. The aim of this study was to compare findings of Elastic Scattering Spectroscopy (ESS) with histopathology of oral tissues to see if this technique could be used as an adjunct or alternative to histopathology in identifying dysplasia. The technique involves the use of Mie scattering and is a simple non-invasive method of tissue interrogation. Twenty-five oral sites from 25 patients who presented with oral leukoplakia were examined by ESS using a pulsed xenon-arc lamp. Surgical biopsies were acquired from each of the examination sites. The results of the acquired spectra were then compared with histopathology. Two sets of spectra were obtained, and by using a linear discriminant analysis, a sensitivity of 72% and a specificity of 75% were obtained. These results are promising and could suggest that ESS may be able to identify dysplasia in oral tissues. To prove the usefulness of the ESS in dysplasia detection in oral tissues conclusively, a larger body of data is needed. We aim to continue this study to obtain more data in an attempt to increase the accuracy of the technique. Large, multi-centre trails are needed for each anatomical site, in order to gather more information about the differences between normal and dysplastic tissue.

Optical techniques in diagnosis of head and neck malignancy.

The "gold standard" of assessing pathological changes in tissue is currently histopathology. However, the processing of biopsy material and the interpretation of the results inevitably leads to diagnostic delay and the added possibility of taking an unrepresentative sample. Recently, there has been increasing interest in the use of optical spectroscopy systems to be able to provide tissue diagnosis in real-time, non-invasively and in situ. These systems rely on the fact that the optical spectrum derived from any tissue will contain information about the histological and biochemical make up of that tissue. The technique has not only been shown to have a role in the detection of dysplasia and malignancy but also in performing guided biopsies, monitoring of haemoglobin tissue perfusion in free-flaps and therapeutic drug levels during chemo- and photodynamic therapy. The assessment of surgical margins and a role in sentinel node biopsy are also interesting developments. The obvious advantages of being able to accurately diagnose pathology without the need to remove a tissue sample diminish patient trauma as well as having financial implications.

Inferior alveolar nerve injury and surgical difficulty prediction in third molar surgery: the role of dental panoramic tomography.

OBJECTIVE: The purpose of this study was to evaluate the relationship between preoperative panoramic radiological findings and postoperative inferior alveolar nerve paresthesia following third molar surgery, and to assess the surgical difficulty. METHODOLOGY: This retrospective study involved two groups of patients who were randomly selected. The first group presented with inferior alveolar nerve (IAN) paresthesia following surgery, and the second group presented with no complications, including IAN paresthesia. Radiological findings were collected from the panoramic radiographs of those patients and compared to postoperative paresthesia. The degree of surgical difficulty was also assessed radiographically. RESULTS: The application of Chi-square testing on the numbness group and the control group, as well as the numbness group (two years postoperatively) and the control group, showed that parameters like type of impaction (fully impacted), depth of impaction (depth C), ramus/space (class 3), spatial relationship (distoangular and horizontal), number of roots (multiple and incomplete), shape of root (thick and incomplete), shape of the tip of root (curved and incomplete), and relation to IAN (touching, superimposed, or non-specific) are highly significant (p < 0.001) in predicting the incidence of temporary and permanent paresthesia. Logistic regression showed that a patient whose lower third molar is > or = 1 mm from IAC has a 98% probability of no numbness, while if the tooth is touching the IAC the probability of numbness between one week and < two years is 60%. Numbness probability of darkening of the root is 48% for > two years, deflection of the root has a 42% probability of > two years numbness, narrowing of the root has 87% of numbness between > one month and < two years, a dark and bifid root has a 97% of numbness between > six months and < two years, interruption of the IAC has a 54% chance of numbness between > one month and < two years, diversion of the canal has a 60% probability of > six months to > two years numbness, while narrowing of the canal has a probability of 100% of > six months to > two years numbness. By using logistic regression, cases that were recorded as "very difficult," according to the Pederson Difficulty Index, were more likely to develop permanent paresthesia (95%). The application of logistic regression on the radiological findings showed that we can use them in predicting nerve paresthesia following third molar surgery. A classification tree has been developed and found to be very accurate in predicting permanent numbness (95%) and no numbness (100%) in third molar surgery depending on the radiological findings. CONCLUSION: Surgical difficulty of impacted third molars may be assessed radiographically through seven factors, including spatial relationship, depth of impaction, ramus relationship/space available, type of impaction, number and shape of roots, shape of the tip of the root, and relation of the root to the inferior alveolar nerve. The application of logistic regression on the radiological findings showed that we could use them in predicting nerve paresthesia following third molar surgery. By developing a classification tree, it is easier to predict the possibility of temporary or permanent paresthesia. A full collaboration between clinicians and radiologists may help to uncover more parameters that can lead to a more accurate prediction of temporary and permanent paresthesia.

Willingness of dentists in Jordan to treat HIV-infected patients.

UNLABELLED: Reluctance of dentists to treat human immunodeficiency virus (HIV) positive patients represents a major concern. Many efforts have been extended towards the documentation of the extent of this reluctance and speculation of factors that influence it. OBJECTIVES: Assess the willingness of dentists in Jordan to treat HIV-infected patients. MATERIALS AND METHODS: Two hundred and forty-two general dental practices were surveyed for their willingness to provide treatment of toothache and routine dental care of an HIV-infected individual. RESULTS: Only 15% of the dental practices were willing to provide such care. Willingness to provide treatment did not seem to be influenced by financial factors or the local prevalence of HIV disease. CONCLUSION: Present data suggest that HIV-infected individuals will have difficulty in obtaining dental health care in Jordan.

Study on the organoleptic intensity scale for measuring oral malodor.

The 0-5 organoleptic scale is used widely in breath research and in trials to measure the efficacy of anti-odor agents. However, the precise relationship between odor scores and gas concentrations of target odorants is unknown. The purpose of this study was to relate mean organoleptic scores from odor judges (n = 7) for pure odorants (n = 8) representative of those found in oral malodor. Judges used a common 0-5 scale to report the odor intensity of sample sets in random order of concentration. Regression analysis of data showed that odor score was proportional to the log concentration of odorant, and comparison of slopes showed H(2)S to be the most significant in terms of odor power. Detection thresholds (mol.dm(-3)) were: Skatole (7.2 x 10(-13)) < methylmercaptan (1.0 x 10(-11)) < trimethylamine (1.8 x 10(-11)) < isovalerate (1.8 x 10(-11)) < butyrate (2.3 x 10(-10)) < hydrogen sulphide (6.4 x 10(-10)) < putrescine (9.1 x 10(-10)) < dimethyl disulphide (5.9 x 10(-8)). The study demonstrates the exponential nature of the olfactory response and shows that any single compound's contribution to malodor depends on odor power and threshold in addition to concentration.

Breath odor: etiopathogenesis, assessment and management.

Oral malodor is a significant social disability which usually has a local cause, particularly arising from the oral flora. Malodor may arise from the lingual or periodontal flora, gram-negative anaerobes being the main organisms capable of releasing sulphur compounds from the putrefaction of debris and other material. Volatile sulphur compounds, cadaverine and other substances appear responsible for much of the malodor. Systemic disease may underlie some cases of oral malodor. The objective assessment of malodor is still best performed by the human sense of smell (organoleptic method) but more quantifiable measures are being developed.

Cross-infection compliance of UK dental staff and students.

OBJECTIVES: The objectives of the study were to determine the compliance of a group of dental health care workers and students in aspects of cross-infection control. DESIGN: The dentists and dental students working in a dental clinic were observed by a 'hidden' ceiling-mounted video camera. Procedures were recorded onto videotape and the actions of the observed clinicians and students assessed by two suitably qualified assessors. SETTING: An emergency Oral Medicine clinic in a dental hospital. SUBJECTS: Seventy nine dentists and 35 dental undergraduates. METHODS: The action of staff and students were recorded on videotape and assessed retrospectively. MAIN OUTCOME MEASURES: Degree of compliance with recognised infection control policies. RESULTS: Compliance with recommended guidelines for control of cross-infection was poor. In only 56% of health care worker-patient contacts were protective gloves changed between patients. Facemasks and protective eyewear were only worn in 38% and 29% of such contacts respectively. CONCLUSIONS: Compliance with cross-infection control measures are poor in dentistry--even when clinicians are provided with appropriate facilities.

Willingness of Brazilian dentists to treat an HIV-infected patient.

A study of the willingness of 363 general dental practices in Brazil to accept a patient infected with human immunodeficiency virus for treatment of dental pain and the provision of routine dental care showed only 44% of dental practices to be willing to provide dental care. Willingness was influenced neither by financial factors nor the local prevalence of human immunodeficiency virus disease.

Willingness of Brazilian dentists to treat an HIV-infected patient / Prontidão de dentistas brasileiros para tratar pacientes HIV infectados

A study of the willingness of 363 general dental practices in Brazil to accept a patient infected with human immunodeficiency virus for treatment of dental pain and the provision of routine dental care showed only 44 percent dental practices to be willing to provide dental care. Willingness was influenced neither by financial factors nor the local prevalence of human immunodeficiency virus disease