Preventive Dentistry

Fluorescence Visualization Devices in General Dentistry: Seeing the Big Picture

David C. Morgan, PhD, Chief Science Officer, LED Dental Inc.

ental professionals have been might not be apparent to the na- basement membrane. traditionally limited to the ked eye, and to help specialists Duse of incandescent light for determine appropriate surgical • Increase in tissue blood con- the visual inspection of the oral margins. tent, either from inflammation cavity. Direct visualization of re- or angiogenesis (hemoglobin flected white light from mucosal The VELscope induces natural strongly absorbs fluorescence surfaces can enable the detection tissue fluorescence by illuminat- excitation [blue] and emission of gross tissue abnormalities, but ing the oral cavity with a bright light [green]). may fail to identify some early blue light. The resulting tissue disease processes (such as dys- fluorescence is significantly dim- • Presence of pigments (e.g. mel- plasia) that have not yet caused mer than the blue excitation light anin or amalgam particles) changes easily observed using in- reflected from the tissue, but can which absorb light. candescent light. be directly visualized by looking through the device’s handpiece, Fluorescence visualization de- The limitations of white light which blocks reflected light and vices are particularly sensitive have stimulated the search for al- optimizes contrast with filters to dysplasia and cancer, disease ternative modalities, and in 2006, situated along the viewing path. processes which often involve the after extensive research, the first three of the mechanisms VELscope system was approved Mucosal abnormalities often bulleted above. Inflammation, on in Canada and cleared by the present with abnormal fluores- the other hand, is a common oc- FDA in the United States. Like cence patterns that can aid the currence in the oral cavity and subsequent entries in its category, user in detecting unhealthy tis- also presents as a strong loss of such as the Identifi 3000, and the sue. Decreased tissue fluores- fluorescence, as will certain nor- Sapphire Plus Lesion Detection, cence resulting in abnormal fluo- mal tissues, usually because of the VELscope is a non-invasive, rescence patterns arises from a their high vascularity or associ- handheld device that allows the variety of causes1, including: ated blood content. Clinicians uti- direct visualization of oral-cavity lizing fluorescence devices should fluorescence. There are currently • Increases in metabolic activity familiarize themselves with the two approved indications for the in the epithelium. normal appearance and patterns use of oral fluorescence visualiza- of oral cavity fluorescence. This tion devices: to help clinicians • Breakdown of the fluorescent will better equip them to rec- detect cancerous and precancer- collagen cross-links in the con- ognize abnormal patterns when ous lesions and other lesions that nective tissue layer beneath the they present. 6|oralhealth December 2011 www.oralhealthgroup.com Preventive Dentistry

By definition, the use of an of applications and methodolo- of VELscope to routine clinical adjunctive device is subordinate gies; in particular, there has been examinations resulted in the de- to a larger diagnostic picture and excellent research devoted to sur- tection of a number of mucosal should not be thought of as a gical applications. Some of the re- abnormalities not detected by the diagnostic test with a definitive search directed towards general conventional exam. These abnor- “yes/no” or “positive/negative” an- use by dentists, however, adopts malities included a number of swer. To properly understand the a narrow vision of the utility of dysplasias, as well as lichen pla- significance of the fluorescence the technology, and often fails nus and other inflammatory le- examination, it must be consid- to evaluate the device accord- sions. The study highlights an as- ered together with the head and ing to its stated indications for pect of fluorescence visualization neck visual and tactile exam — use. In particular, many authors that is often overshadowed by its which itself is embedded within compare the use of fluorescence role in the detection of oral dys- a larger diagnostic process that visualization to a head and neck plasia and cancer. Devices such includes health history, patient exam as a standalone diagnostic as the VELscope provide general interview, and biopsy when re- procedure for oral cancer, instead practitioners with a powerful tool quired. A particular fluorescence of evaluating the added value of to aid in the discovery of most pattern or loss of fluorescence can using fluorescence visualization types of oral lesions, such as viral, mean different things in differ- in combination with the head and fungal and bacterial infections; ent clinical contexts. Fluorescence neck exam for the detection of inflammation from a variety of visualization never replaces the oral disease. This confusion is causes (including lichen planus clinical judgment of the clinician puzzling, as fluorescence visual- and other lichenoid reactions); nor overrules areas of concern ization is intended to be, and is squamous papillomas, salivary discovered by means of the tradi- approved as, an adjunctive meth- gland tumours, etc. tional examination. The value of odology for the detection of all fluorescence visualization lies in oral mucosal abnormalities. CLINICAL EXAMPLES the fact that it is based on a dif- The following clinical examples ferent type of interaction with tis- There have been some notable have been chosen to illustrate the sue than conventional reflectance exceptions; Huff et al9 conducted above concepts. of white light, and can therefore an interesting retrospective anal- show the clinician areas of con- ysis comparing consecutive years Figure 1 illustrates an im- cern that may have been missed in a private dental practice. During portant point — automatically during the white light exam. This the second year a VELscope ex- associating a loss of fluorescence can lead to the early discovery amination was added to the head with pathology is misguided. of lesions, with consequent ben- and neck exam and ten dysplastic Note that the left tonsillar pil- efits: enhanced quality of care lesions were detected in the pa- lars, palatine tonsil and orophar- provision for the clinician; more tient population as compared to ynx are predominantly dark (i.e., effective, less invasive therapeu- none in the previous year. Most show a “loss of fluorescence”) tic intervention for the patient; recently, a 620-patient study at because of absorption of light by potential improvement of the pa- the University of Washington18 the associated presence of vascu- tient’s quality of life. demonstrated that the addition larity and lymphoid tissue. Not

Over the past six years, considerable research has at- tempted to evaluate the use of fluorescence visualization (predominantly focused on the VELscope system) as an aid for the general dentist and special- ist.1-18 In addition, some re- view articles have attempted to evaluate the general ben- efits of oral cancer screening, and of adjunctive aids such as Figure 1—Normal factors such as vascularity and lymphoid tissue contribute to the VELscope.19-21 This work has spectrum of normal pattern variability under fluorescence visualization. encompassed a broad spectrum www.oralhealthgroup.com December 2011 oralhealth|7 Preventive Dentistry

Inflammatory changes from a wide variety of causes are rel- atively commonplace. Probably the most common occurrence is trauma-associated inflamma- tion, as seen in this example on the left buccal mucosa (Fig. 2). The subtle visual appear- ance under white light is trans- formed, under VELscope, into two dramatic areas of loss of Figure 2—Trauma-associated inflammation on the left buccal mucosa. (Images cour- fluorescence that are difficult tesy of the University of Washington Oral Medicine Program.) not to notice. Once seen, the fluorescence response together with the white light presenta- tion paints a consistent picture of the underlying cause. The two dark patches correspond to the two mildly erythema- tous areas visible under white light. The vessel damage on the upper part of the buccal surface presents predictably as a dark area under fluores- Figure 3—Loss of fluorescence under VELscope paired with observable inflammation cence due to blood absorption, under white light contributed to a diagnosis of oral candidiasis. (Images courtesy and is consistent with the pic- of Dr. Samson Ng.) ture of trauma from the teeth. Rather than being viewed as some sort of “false positive” or distraction, the fluorescence re- sponse should help focus the clinician on a legitimate (albeit non-life threatening) possibility of chronic trauma to the buc- cal mucosa, that may not have otherwise been noticed. This type of trauma can be caused Figure 4—Fluorescence and white light confirm the resolution of candidiasis (as pre- by parafunctional habits, sharp sented in Figure 3) after treatment. (Images courtesy of Dr. Samson Ng.) or jagged cusps or malposed teeth, and could be addressed all individuals, however, show ing of fluorescence and conven- through counseling, oral appli- this type of lymphoid aggregate tional white light photographs, ances or smoothing of rough tooth proliferation. With a little experi- even of normal appearing tissue, surfaces. ence, one becomes familiar with facilitates this process by estab- the spectrum of normal variation lishing a baseline against which This next case (Fig. 3) illus- present in a wide cross-section future clinical and fluorescence trates inflammation of a biologi- of individuals seen in a typical presentations can be compared. cal, as opposed to traumatic, ori- dental practice. Lymphoid ag- Photographic documentation is gin. The patient had a history gregates may become uniformly an important part of the fluores- of asymptomatic red patches on more prominent from inflamma- cence visualization protocol, and the hard palate for the previous tory response; the clinician, how- is made possible by LED Dental’s eighteen months. The loss of fluo- ever, should pay close attention newest device, the VELscope Vx, rescence and the erythematous, to unilateral or asymmetrical designed to accommodate an op- inflamed appearance under white changes as possibly suggestive tional, custom-built digital cam- light led the clinician to suspect of pathological change. The tak- era system. candidiasis. Subsequent anti-fun- 8|oralhealth December 2011 www.oralhealthgroup.com Preventive Dentistry

gal therapy led to resolution in four weeks as shown below (Fig. 4).

The importance of always considering the results of the physical, visual and tactile ex- amination in the context of the larger clinical picture is high- lighted by consideration of the hard palates in these examples (Fig. 5). Figure 5a—These photos show an area of trauma caused by hard candy consump- tion. (Images courtesy of the Benjamin Dental Group.) Superficially, the cases in Figures 5a & 5b present simi- larly under both fluorescence and white light illumination, yet when evaluated together with patient history and risk fac- tors, the picture that emerges is significantly different. The first patient complained of a sore mouth and reported suck- ing on hard candies. The sec- Figure 5b—These photos show a dysplastic lesion that demonstrates loss of fluo- ond patient was asymptomatic, rescence due to dysplasia. (Images courtesy of the University of Washington Oral but had a number of risk fac- Medicine Program.) tors (such as tobacco use and age) for the development of oral squamous cell carcinoma. In addition, subsequent follow-up resulted in complete resolution for patient 1, but no change for patient 2, confirming the clini- cian’s intention to refer the sec- ond patient for biopsy, which de- tected the presence of dysplasia. Figure 6—The juxtaposition of the lesion to the gold crown suggests a possible al- lergic lichenoid reaction. (Images courtesy of Dr. Samson Ng.) The three cases shown in Figures 6, 7 and 8 are all related to lichenoid tissue changes, but each has its own story to tell about the role of fluorescence in the oral mucosal diagnostic process. The first case (Fig. 6) presented with a subtle appear- ance under white light but dem- onstrated a striking loss of fluo- Figure 7 rescence when viewed through —Erosive lichen planus under fluorescence and white light. (Images courtesy of the University of Washington Oral Medicine Program.) the VELscope. In addition to highlighting the presence of the lesion, fluorescence visualization sion to the gold crown suggests a The case in Figure 7 presented also indicates a much larger area possible allergic lichenoid reac- clinically as would classic erosive of mucosal involvement than sug- tion to the metal, but the final lichen planus; patch testing on gested by the white light appear- decision regarding causation re- the patient failed to reveal any ance. The juxtaposition of the le- quires patch testing. allergic reaction to typical den- www.oralhealthgroup.com December 2011 oralhealth|11 Preventive Dentistry

metal restoration on the rear molar, but less so in other re- gions of the lichenoid reaction. This is clinically significant since the cause of the lichenoid response has a direct bearing on the therapeutic interven- tion: palliative use of topical steroids to treat the inflamma- tion, as opposed to removing the Figure 8—Fluorescence visualization helped answer the question — is this classic cause of the allergic lichenoid reticular lichen planus or a lichenoid reaction? (Images courtesy of the University of reaction by replacing the metal Washington Oral Medicine Program.) restoration.

The distinct and localized loss of fluorescence observed on the hard palate of this patient (Fig. 9) is in striking contrast to the almost complete lack of colour or texture change as observed under white light. Although not evidenced by the white light photograph, there was a pal- Figure 9—This salivary gland tumour is difficult to visualize under white light but pable bump corresponding to stands out under fluorescence visualization. (Images courtesy of Dr. Samson Ng.) the area of loss of fluorescence. Biopsy confirmed the presence of a salivary gland tumour (low- grade mucoepidermoid carci- noma). This case demonstrates how loss of fluorescence can indicate serious abnormal pa- thology in the almost complete absence of other visual changes. (It also demonstrates the im- Figure 10—Fluorescence visualization helps bring this squamous papilloma to the portance of palpating all oral attention of the clinician. (Images courtesy of Dr. Samson Ng.) structures when conducting the intra-oral soft tissue examina- tion.) Note that fluorescence vi- sualization played two roles: as an aid to discovery and to help confirm that this is a suspicious area warranting follow-up.

Another interesting facet of this case is that the lesion was not an epithelial-based cancer Figure 11—Classic example of an irregular area of loss of fluorescence associated but originated from the salivary with dysplasia. (Images courtesy of Dr. Samson Ng.) gland. It is postulated that the loss of fluorescence was caused tal restorative materials. Notice The case in Figure 8 initially by disruption of stromal col- how much better visualized the presented under white light as a lagen (breakdown of collagen full inflammatory response of classic case of reticular lichen pla- cross-linking) brought about by the tissue is under fluorescence, nus; fluorescence highlights the tumour growth in the connective as compared to conventional presence of an intense inflam- tissue layer. One might wonder illumination. matory response adjacent to the if “benign” growths such as an 12|oralhealth December 2011 www.oralhealthgroup.com Preventive Dentistry

This final example (Fig. 13) illustrates how the VELscope can bring the clinician’s atten- tion to an area that might oth- erwise be overlooked. At first sight, this appeared to be a case of denture trauma with inflam- mation in the vestibule, as well as hyperkeratotic areas appar- ent on the edentulous ridge. However, the striking loss of Figure 12—Even when lesions are clinically obvious under white light, fluorescence fluorescence corresponding to visualization helps in the confirmation process and provides additional information the hyperkeratosis on the ridge about the extent of the lesion. (Images courtesy of the University of Washington Oral (in the absence of any other Medicine Program.) clinical signs of inflammation) is highly suspicious, and alerted the clinician to biopsy the area. This resulted in a diagnosis of dysplasia.

When fluorescence visu- alization devices such as the VELscope are used in their proper clinical context, adjunc- tively and as part of the com- Figure 13—The loss of fluorescence exhibited in proximity to hyperkeratosis on plete diagnostic protocol, in- the edentulous ridge was biopsy-confirmed as dysplasia. (Images courtesy of the cluding patient history and the University of Washington Oral Medicine Program.) traditional head and neck exam using white light and palpation, adenoma cause a loss of fluores- This somewhat clinically obvi- general dentistry practices are cence. In fact, loss of fluorescence ous lesion in the floor of mouth provided with a new perspective is likely to be a feature of both (Fig. 11) is a classic example of on the health of oral mucosal tis- benign and malignant tumours, a large, irregular area of loss sues. Beyond the dramatic and since both disrupt stromal col- of fluorescence corresponding to profound benefits of early dys- lagen. An enlightened approach precancerous dysplasia. Note the plasia and cancer detection, ex- to the utility of fluorescence as a highly asymmetric nature of the amination including fluorescence diagnostic tool would not regard lesion when viewed through the visualization can assist dentists this as a limitation, but as a VELscope, as well as the irreg- and hygienists in bringing their useful feature; benign and ma- ular, well-defined border — an patients closer to a state of “total lignant tumours require biopsy abnormal fluorescence pattern oral health,” with its corollary for definitive diagnosis and both highly suggestive of precancerous systemic benefits. require therapeutic intervention. or cancerous changes. David Morgan is Chief Science Figure 10 illustrates another This example of a dysplastic Officer at LED Dental Inc. and example of how an unremark- lesion on the lateral border of has 15 years of R&D and product able appearance under white light the tongue (Fig. 12) highlights development experience in the use can correspond to an obvious ab- the added clinical value that the of fluorescence as an aid to disease normality with fluorescence. This VELscope can bring even when detection. particular lesion is a squamous the main part of the lesion is papilloma which must be biopsied clinically obvious. In this case the The author gratefully acknowl- for definitive diagnosis and then area of loss of fluorescence ex- edges the help of Jeff Keller in is typically excised. Note that ear- tended at least 10-15mm anterior the preparation of this manuscript lier discovery and diagnosis leads to the main, clinically apparent and would also like to thank Drs. to less invasive intervention for part of the lesion, and was also Edmond Truelove, Samson Ng the patient. biopsy-confirmed as dysplasia. and Scott Benjamin for providing 14|oralhealth December 2011 www.oralhealthgroup.com Preventive Dentistry

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