Rhonda F. Jacob

Optimal Excitation Wavelengths for In Vivo Detection of Oral Neoplasia Using Fluorescence Spectroscopy

Abstract There is no satisfactory mechanism to detect premalignant lesions in the upper aero-digestive tract. Fluorescence spectroscopy has potential to bridge the gap between clinical examination and invasive biopsy; however, optimal excitation wavelengths have not yet been determined. The goals of this study were to determine optimal excitation–emission wavelength combinations to discriminate normal and precancerous/cancerous tissue, and estimate the performance of algorithms based on fluorescence. Fluorescence excitation–emission matrices (EEM) were measured in vivo from 62 sites in nine normal volunteers and 11 patients with a known or suspected premalignant or malignant oral cavity lesion. Using these data as a training set, algorithms were developed based on combinations of emission spectra at various excitation wavelengths to determine which excitation wavelengths contained the most diagnostic information. A second validation set of fluorescence EEM was measured in vivo from 281 sites in 56 normal volunteers and three patients with a known or suspected premalignant or malignant oral cavity lesion. Algorithms developed in the training set were applied without change to data from the validation set to obtain an unbiased estimate of algorithm performance. Optimal excitation wavelengths for detection of oral neoplasia were 350, 380 and 400 nm. Using only a single emission wavelength of 472 nm, and 350 and 400 nm excitation, algorithm performance in the training set was 90% sensitivity and 88% specificity and in the validation set was 100% sensitivity, 98% specificity. These results suggest that fluorescence spectroscopy can provide a simple, objective tool to improve in vivo identification of oral cavity neoplasia.

Vision enhancement system for detection of oral cavity neoplasia based on autofluorescence.

Early detection of squamous cell carcinoma (SCC) in the oral cavity can improve survival. It is often difficult to distinguish neoplastic and benign lesions with standard white light illumination. We evaluated whether a technique that capitalizes on an alternative source of contrast, tissue autofluorescence, improves visual examination.

Fluorescence Excitation Emission Matrices of Human Tissue: A System for in Vivo Measurement and Method of Data Analysis

We describe a system capable of measuring spatially resolved reflectance spectra from 380 to 950 nm and fluorescence excitation emission matrices from 330 to 500 nm excitation and 380 to 700 nm emission in vivo. System performance was compared to that of a standard scanning spectrofluorimeter. This “FastEEM” system was used to interrogate human normal and neoplastic oral cavity mucosa in vivo. Measurements were made through a fiber-optic probe and require 4 min total measurement time. We present a method based on autocorrelation vectors to identify excitation and emission wavelengths where the spectra of normal and pathologic tissues differ most. The FastEEM system provides a tool with which to study the relative diagnostic ability of changes in absorption, scattering, and fluorescence properties of tissue.

Functional results of dental restoration with osseointegrated implants after mandible reconstruction.

&NA; We reviewed the cases of 20 cancer patients (mean age 47.4 years) in whom osseointegrated implants were used for dental restoration after mandibular reconstruction between January of 1988 and December of 1994. Seventyone implants were placed into bone flaps (n = 60) or native mandible (n = 11), an average of 3.55 per patient (range, 2 to 5). Successful integration occurred in 91.5 percent (65 of 71); there were five early failures and one late failure, with no significant difference between the number lost in microvascular flaps (5 of 60) and native mandible (1 of 11) (as determined by Fishers exact test). Functional evaluation included assessments of diet, speech, and cosmesis. Based on our review, we concluded that (1) implants enhance dental restoration in selected patients, and (2) microvascular bone flaps, including the fibula and iliac crest, are well suited for dental implant restoration.

Fluorescence spectroscopy: A technique with potential to improve the early detection of aerodigestive tract neoplasia

Any innovation which facilitates the early detection of neoplastic changes in upper aerodigestive tract mucosa has potential to greatly improve survival and quality of life in persons prone to develop malignancies in this area. One technology that has shown great promise during initial investigations is fluorescence spectroscopy. Fluorescence spectroscopy evaluates the physical and chemical properties of tissue by analyzing the intensity and character of light emitted in the form of fluorescence. This technology has been investigated for the noninvasive detection of malignancy in various sites including the gastrointestinal tract, lung, breast, and cervix.

Electrotherapy and hyperbaric oxygen: Promising treatments for postradiation complications

Electrotherapy and hyperbaric oxygen therapy have been added to physical therapy to treat patients with postsurgery and radiation sequelae. Problems of reduced oral opening and range of head movement, soft tissue necrosis, osteoradionecrosis, and delayed wound healing were addressed in 37 patients over a 3-year period. Of this group, 16 irradiated maxillary resection patients were specifically followed up to determine the effectiveness of the new modalities on improving reduced oral opening. Although healing and the quality of the soft tissues showed marked improvement there was no significant improvement in oral opening.

Midfacial reconstruction using virtual planning, rapid prototype modeling, and stereotactic navigation

We present a method based on virtual planning and creation of rapid prototype models to accurately reestablish midfacial anatomy using vascularized bone flaps while saving time by streamlining the operative procedure, allowing prebending of titanium plates needed for fixation, and simplifying osteotomies. Accurate flap positioning through limited incisions is made possible using stereotactic navigation. Copyright

Classification of maxillectomy defects: A systematic review and criteria necessary for a universal description

STATEMENT OF PROBLEM Maxillectomy defects are complex and involve a number of anatomic structures. Several maxillectomy defect classifications have been proposed with no universal acceptance among surgeons and prosthodontists. Established criteria for describing the maxillectomy defect are lacking. PURPOSE This systematic review aimed to evaluate classification systems in the available literature, to provide a critical appraisal, and to identify the criteria necessary for a universal description of maxillectomy and midfacial defects. MATERIAL AND METHODS An electronic search of the English language literature between the periods of 1974 and June 2011 was performed by using PubMed, Scopus, and Cochrane databases with predetermined inclusion criteria. Key terms included in the search were maxillectomy classification, maxillary resection classification, maxillary removal classification, maxillary reconstruction classification, midfacial defect classification, and midfacial reconstruction classification. This was supplemented by a manual search of selected journals. After application of predetermined exclusion criteria, the final list of articles was reviewed in-depth to provide a critical appraisal and identify criteria for a universal description of a maxillectomy defect. RESULTS The electronic database search yielded 261 titles. Systematic application of inclusion and exclusion criteria resulted in identification of 14 maxillectomy and midfacial defect classification systems. From these articles, 6 different criteria were identified as necessary for a universal description of a maxillectomy defect. Multiple deficiencies were noted in each classification system. Though most articles described the superior-inferior extent of the defect, only a small number of articles described the anterior-posterior and medial-lateral extent of the defect. Few articles listed dental status and soft palate involvement when describing maxillectomy defects. CONCLUSIONS No classification system has accurately described the maxillectomy defect, based on criteria that satisfy both surgical and prosthodontic needs. The 6 criteria identified in this systematic review for a universal description of a maxillectomy defect are: 1) dental status; 2) oroantral/nasal communication status; 3) soft palate and other contiguous structure involvement; 4) superior-inferior extent; 5) anterior-posterior extent; and 6) medial-lateral extent of the defect. A criteria-based description appears more objective and amenable for universal use than a classification-based description.

Total midface reconstruction after radical tumor resection: A case report and overview of the problem

We report an unusual repair of a massive midface defect resulting from resection of a recurrent squamous cell carcinoma of the nasal vestibule. The defect included both maxillas, the hard palate, the upper lip, and all nasal and perinasal tissues. After treatment, reconstruction was accomplished using prostheses and autologous tissue transferred from local and distant sites. The osseous component of the transferred tissue permitted placement of osseointegrated implants for fixation of maxillary and nasal prostheses. The rationale for this reconstruction and the problems associated with midface reconstruction after radical tumor resection are discussed.

Physical therapy techniques in the treatment of the head and neck patient

Limited jaw openings, which may develop following surgery and radiation therapy is a significant clinical problem. Some patients develop restricted oral opening because of extensive fibrosis and scarring of the affected tissues. The aid of the physical therapist is invaluable in the treatment of these patients.