Optical coherence tomography imaging of oral mucosa bullous diseases: a preliminary study

State of the Art in the Diagnosis and Assessment of Oral Malignant and Potentially Malignant Disorders: Present Insights and Future Outlook-An Overview

Oral Potentially Malignant Disorder (OPMD) is a significant concern for clinicians due to the risk of malignant transformation. Oral Squamous Cell Carcinoma (OSCC) is a common type of cancer with a low survival rate, causing over 200,000 new cases globally each year. Despite advancements in diagnosis and treatment, the five-year survival rate for OSCC patients remains under 50%. Early diagnosis can greatly improve the chances of survival. Therefore, understanding the development and transformation of OSCC and developing new diagnostic methods is crucial. The field of oral medicine has been advanced by technological and molecular innovations, leading to the integration of new medical technologies into dental practice. This study aims to outline the potential role of non-invasive imaging techniques and molecular signatures for the early detection of Oral Malignant and Potentially Malignant Disorders.

Optical coherence tomography: Promising imaging technique for the diagnosis of oral mucosal diseases

OBJECTIVE

This review aims to summarize the latest application of optical coherence tomography (OCT) in oral mucosal diseases, promoting an accurate and earlier diagnosis of such disorders, which are difficult to be differentiated.

SUBJECTIVE AND METHODS

References on the application of OCT in oral mucosal diseases were mainly obtained from PubMed, Embase, Web of Science and Scopus databases, using the keywords: "optical coherence tomography and 'oral mucosa/oral cancers/oral potentially malignant diseases/oral lichen planus/oral leukoplakia/oral erythroplakia/discoid lupus erythematosus/oral autoimmune bullous diseases/oral ulcers/erythema multiforme/oral mucositis'".

RESULTS

It is found that OCT is showing a promising application potential in the early detection, diagnosis, differential diagnosis, monitoring of oral cancer and oral dysplastic lesions, as well as the delineation of tumor margins. OCT is also playing an increasingly important role in the diagnosis of oral potentially malignant disorders, oral mucosal bullous diseases, oral ulcerative diseases, erythema multiforme, and the early detection of oral mucositis.

CONCLUSION

Optical coherence tomography, as a novel optical technique featured by real-time, noninvasive, dynamic and high-resolution imaging, is of great use to serve as an adjunct tool for the diagnosis, differential diagnosis, monitoring and therapy evaluation of oral mucosal diseases.

U-shaped fusion convolutional transformer based workflow for fast optical coherence tomography angiography generation in lips

Oral disorders, including oral cancer, pose substantial diagnostic challenges due to late-stage diagnosis, invasive biopsy procedures, and the limitations of existing non-invasive imaging techniques. Optical coherence tomography angiography (OCTA) shows potential in delivering non-invasive, real-time, high-resolution vasculature images. However, the quality of OCTA images are often compromised due to motion artifacts and noise, necessitating more robust and reliable image reconstruction approaches. To address these issues, we propose a novel model, a U-shaped fusion convolutional transformer (UFCT), for the reconstruction of high-quality, low-noise OCTA images from two-repeated OCT scans. UFCT integrates the strengths of convolutional neural networks (CNNs) and transformers, proficiently capturing both local and global image features. According to the qualitative and quantitative analysis in normal and pathological conditions, the performance of the proposed pipeline outperforms that of the traditional OCTA generation methods when only two repeated B-scans are performed. We further provide a comparative study with various CNN and transformer models and conduct ablation studies to validate the effectiveness of our proposed strategies. Based on the results, the UFCT model holds the potential to significantly enhance clinical workflow in oral medicine by facilitating early detection, reducing the need for invasive procedures, and improving overall patient outcomes.

Potential use of optical coherence tomography in oral potentially malignant disorders: in-vivo case series study

BACKGROUND

Evidence confirms that the use of Optical Coherence Tomography (OCT) in oral medicine can be a reliable aid for the diagnosis and management of Oral Potentially Malignant Disorders (OPMDs). Several authors described the ability of this system to detect the structural changes of the epithelia involved by the OPMDs. The purpose of this case series is to provide a suggestion for interpretation of OCT images from different OPMDs, compared to OCT images of healthy tissues.

METHODS

A sample of 11 OPMDs patients was recruited and analyzed with OCT. The images obtained were then compared with an OCT repertoire image. In this work the reflectance degree was considered, together with the analysis of the increased/decreased thicknesses of the various layers. Keratin Layer (KL), Epithelial Layer (EP), Lamina Propria (LP), Basal Membrane (BM) assessment, for each lesion, was performed.

RESULTS

OCT measurements of KL, EP and LP layers, together with BM assessing, should aid the physicians to recognize and describe different oral lesions, relating them to the corresponding oral pathology.

CONCLUSION

More studies like this, on larger samples, are needed to validate the results and provide, in the future, a kind of manual that could guide clinicians to correctly interpret the OCT images in relation to the causing pathologies.

TRIAL REGISTRATION

The present trial has been registered with ISRCTN (#17,893,224).

Site-Coded Oral Squamous Cell Carcinoma Evaluation by Optical Coherence Tomography (OCT): A Descriptive Pilot Study

Optical Coherence Tomography (OCT) is an emerging non-invasive method for oral diagnostics, proving to be a practicable device for epithelial and subepithelial evaluation. The potential validity of OCT in oral cancer assessment has been explored but, to date, there are very few investigations conducted with a systematic comparison between clinical/histological and OCT parameters, especially in strict reference to the anatomical site-codification of the oral mucosa. In this regard, our study performed a two-steps evaluation (in vivo OCT and histological investigations) of suspected OSCCs, progressively recruited, using as references the OCT images of the same site-coded healthy mucosa, to provide as much as possible site-specific determinants. Thirty histologically confirmed OSCCs were recruited. Specific OCT mucosal features (SEL-Stratified Epithelial Layer; BM-Basement Membrane; LP-Lamina Propria) were registered and processed using the SRQR (Standards for Reporting Qualitative Research) statement. The systematic dual descriptive OCT analysis revealed that OSCC scans present a complete alteration of epithelial (KL, SEL) and subepithelial (BM, LP) layers with a site-specificity characteristic; moreover, peculiar OCT configurations such as "icicle-like" structures could be strongly suggestive of neoplastic infiltration. This study supports the OCT use for the development of more specific optical structural models applied to oral carcinogenesis.

In vivo evaluation of traumatic and malignant oral ulcers with optical coherence tomography: A comparison between histopathological and ultrastructural findings

Ulcers in the oral mucosa is a relatively common, although challenging, entity in oral medicine, as it can arise due to a wide range of traumatic, infective, autoimmune, and neoplastic disorders. Although histopathology of lesional and peri‑lesional tissues remains the gold standard for persistent oral breaching, optical coherence tomography (OCT) has been recently suggested as a potential ally to enhance the early or non-invasive diagnosis of likely causation. The aim of the present study was to provide an in-vivo OCT analysis and description from a sample of 70 patients affected by traumatic or neoplastic-related ulcers, located on the buccal mucosa, tongue or gingiva, and compare the OCT data with those of 20 patients with healthy oral mucosa. OCT dynamic scans revealed clear distinction of epithelial layer (EP), lamina propria (LP) of healthy buccal mucosa, gingiva, and tongue as well as allowing observation of the keratin layer in gingiva, and the subepithelial vascularization of each site. Traumatic lesions had an EP of reduced in thickness, with an irregular, if not disrupted surface. Interestingly, LP seemed to preserve its reflectiveness and vascularization only in the traumatic lesions. Among neoplastic lesions, regardless their site of onset, both EP integrity/homogeneity, and LP reflectiveness/vascularization were lost and unrecognizable when compared to their healthy counterparts. OCT scanning allowed some differentiation between traumatic and malignant ulcers and thus may a useful and non-invasive means of determining the need and/or urgency of histopathological examination of oral lesions.

Quantitative Ultrasound Analysis of Oral Mucosa: An Observational Cross-Sectional Study

(1) Background: Ultrasonography is gaining popularity as a diagnostic tool in the study of the oral mucosa. The precision of ultrasound has made it possible to identify the various layers, based on their echogenicity. The aim of this study was to perform a quantitative analysis of healthy oral mucosa based on the analysis of greyscale, echo levels (dB), and attenuation values (dB/cm). (2) Methods: Thirty-three patients (17 females and 16 males; 58.42 ± 13.29 y.o) were recruited for this study. The images were acquired with the GE Logiq-e R7 with a linear probe at 18 MHz frequency (harmonic). For each tissue (epithelium, rete ridges, connective tissue, muscle, and bone), regions of interest were traced for the analysis of echo levels, grey levels, and attenuation values. One-way ANOVA and pairwise comparison were performed. (3) Results: Three-hundred and thirty images were analyzed. Analysis of echo levels and grey levels showed a significant difference between epithelium and rete ridges (p = 0.001), and between rete ridges and connective tissue (p = 0.001), but not between epithelium and connective tissue (p = 0.831) or connective and muscle layers (p = 0.383). The attenuation values appeared to be specific for each tissue layer (p = 0.001). (4) Conclusions: Quantitative analysis applied to ultrasound imaging of the oral mucosa allows the definition of specific tissue areas.

Oral Cancer Screening by Artificial Intelligence-Oriented Interpretation of Optical Coherence Tomography Images

Early diagnosis of oral cancer is critical to improve the survival rate of patients. The current strategies for screening of patients for oral premalignant and malignant lesions unfortunately miss a significant number of involved patients. Optical coherence tomography (OCT) is an optical imaging modality that has been widely investigated in the field of oncology for identification of cancerous entities. Since the interpretation of OCT images requires professional training and OCT images contain information that cannot be inferred visually, artificial intelligence (AI) with trained algorithms has the ability to quantify visually undetectable variations, thus overcoming the barriers that have postponed the involvement of OCT in the process of screening of oral neoplastic lesions. This literature review aimed to highlight the features of precancerous and cancerous oral lesions on OCT images and specify how AI can assist in screening and diagnosis of such pathologies.

A handheld fiber-optic probe to enable optical coherence tomography of oral soft tissue

This study presents a highly miniaturized, handheld probe developed for rapid assessment of soft tissue using optical coherence tomography (OCT). OCT is a non-invasive optical technology capable of visualizing the sub-surface structural changes that occur in soft tissue disease such as oral lichen planus. However, usage of OCT in the oral cavity has been limited, as the requirements for high-quality optical scanning have often resulted in probes that are heavy, unwieldy and clinically impractical. In this paper, we present a novel probe that combines an all-fiber optical design with a light-weight magnetic scanning mechanism to provide easy access to the oral cavity. The resulting probe is approximately the size of a pen (10 mm 140 mm) and weighs only 10 grams. To demonstrate the feasibility and high image quality achieved with the probe, imaging is performed on the buccal mucosa and alveolar mucosa during routine clinical assessment of six patients diagnosed with oral lichen planus. Results show the loss of normal tissue structure within the lesion, and contrast this with the clear delineation of tissue layers in adjacent inconspicuous regions. The results also demonstrate the ability of the probe to acquire a three-dimensional data volume by manually sweeping across the surface of the mucosa. The findings of this study show the feasibility of using a small, lightweight probe to identify pathological features in oral soft tissue.

Diagnostic Concordance between Optical Coherence Tomography and Histological Investigations for Immune-Mediated Desquamative Gingivitis: Observational Study

Desquamative gingivitis (DG) denotes a heterogeneous immune-mediated disease for which early diagnosis represents a great challenge. The main aim of this study is to validate diagnostic concordance between specific Optical Coherence Tomography (OTC) patterns for DG related to oral Lichen Planus (OLP), Pemphigus Vulgaris (PV), and Mucous Membrane Pemphigoid (MMP) and definitive histological diagnosis. Forty-three patients with suspected immune-mediated DGs, were progressively recruited. Before biopsy, an OCT preliminary evaluation was performed using specific pre-determined OCT diagnostic patterns (i.e., morphology and localization of blisters, status of the basal membrane, epithelial thickness, presence/absence of acantholytic cells into blister and/or inflammatory infiltrate) related to OLP, PV and MMP. After histological confirmation, OCT and histological diagnoses were compared. Using pre-determined patterns, OCT diagnoses of DGs were: 22 (51%) OLP, of which 11 (26%) were with the bullous variant, 4 (9%) PV and 6 (14%) MMP. The same diagnoses were found by histological investigations (with the main OCT discriminatory potential for the bullous variant of OLP). The concordance between the two diagnostic methods was confirmed by the Fisher exact test (p-value < 0.01). These specific OCT patterns show a diagnostic reliability in 100% of the cases investigated, suggesting their accuracy to support the complex diagnosis and management of immune-mediated DGs.

Immune-Mediated Desquamative Gingivitis and Optical Coherence Tomography Diagnostic Patterns: Clinical Implication from a Systematic Review

Desquamative Gingivitis (DG) comprises heterogeneous clinical manifestations of numerous immune-mediated muco-cutaneous diseases. Optical Coherence Tomography (OCT) has been proposed as a valuable diagnostic support even if, to date, there are no standardized OCT-diagnostic patterns applicable to DGs. A systematic review was performed to detect existing data on in vivo OCT diagnostic patterns of the most common immune-mediated DGs (i.e., pemphigus vulgaris, mucous membrane pemphigoid and oral lichen planus). It has been found that OCT exhibits specific patterns that address the diagnosis of DG by pemphigus vulgaris (i.e., intraepithelial unilocular blister, reduced epithelial thickness, presence of acantholytic cells in the blister) and by mucous membrane pemphigoid (i.e., subepithelial multilocular blister, presence of inflammatory infiltrate), but not by oral lichen planus. These patterns could offer an attractive diagnostic OCT framework to support the clinical preliminary assessment and monitoring of these complex pathological conditions.

Noninvasive Imaging Methods to Improve the Diagnosis of Oral Carcinoma and Its Precursors: State of the Art and Proposal of a Three-Step Diagnostic Process

Simple Summary

Oral squamous cell carcinoma (OSCC) accounts for 90–95% of malignant tumors of the lip and oral cavity and is associated with high mortality in the advanced stages. Early diagnosis is a challenge for oral pathologists and dentists, due to the ambiguous appearance of early OSCC, which is often misdiagnosed, mistreated, and associated with diagnostic delay. The gold standards for OSCC diagnosis are biopsy and histopathological assessment, but these procedures are invasive and time-consuming. Adjunctive noninvasive techniques allow the definition of the malignant features of a suspicious lesion in real time and noninvasively, thus improving the diagnostic procedure. The present review aimed to focus on some of the main promising noninvasive imaging techniques, to highlight their perspective adoption in a three-step diagnosis, which is idealistically faster and better, as well as enables the patient’s compliance.

Abstract

Oral squamous cell carcinoma (OSCC) is the most prevalent form of cancer of lips and oral cavity, and its diagnostic delay, caused by misdiagnosis at the early stages, is responsible for high mortality ratios. Biopsy and histopathological assessment are the gold standards for OSCC diagnosis, but they are time-consuming, invasive, and do not always enable the patient’s compliance, mainly in cases of follow-up with the need for more biopsies. The use of adjunctive noninvasive imaging techniques improves the diagnostic approach, making it faster and better accepted by patients. The present review aims to focus on the most consolidated diagnostic techniques, such as vital staining and tissue autofluorescence, and to report the potential role of some of the most promising innovative techniques, such as narrow-band imaging, high-frequency ultrasounds, optical coherence tomography, and in vivo confocal microscopy. According to their contribution to OSCC diagnosis, an ideal three-step diagnostic procedure is proposed, to make the diagnostic path faster, better, and more accurate.

Line field confocal optical coherence tomography: An adjunctive tool in the diagnosis of autoimmune bullous diseases

Autoimmune bullous diseases (AIBDs) still represent a considerable a source of morbidity and mortality: early identification of a specific AIBD is often difficult due to overlapping clinical and/or laboratory features and time-consuming invasive laboratory tests. We aimed to investigate the potential role of a new imaging technology, line-field confocal optical coherence tomography (LC-OCT), in the non-invasive diagnosis of AIBDs. LC-OCT was performed at lesional, perilesional and contralateral healthy sites in 30 patients, before histology and direct immunofluorescence. LC-OCT examination was able to identify the level of split (subcorneal/suprabasal/subepidermal/sublamina densa), to provide detailed images of the bulla roof morphology and content (eg, erythrocytes/acantholytic cells/polymorphonucleates). Areas of intra/subepidermal detachment were also detected also at clinically normal perilesional skin sites. LC-OCT can support physicians, real time and at bed-site, in the differential diagnosis of various AIBDs and their mimickers. Moreover, it can be used for the identification of subclinical lesions and therapy tapering.

Preliminary evaluation of the utility of optical coherence tomography in detecting structural changes during photobiomodulation treatment in patients with atrophic-erosive oral lichen planus

INTRODUCTION

Oral lichen planus (OLP) is a common oral inflammatory condition. Against symptomatic atrophic-erosive OLP, topical steroids, or photobiomodulation (PBM) are deployed. Optical coherence tomography (OCT) provides a real-time, non-invasive, tissue investigation. Aim of this study was to evaluate modifications of OCT pattern in patients with painful atrophic-erosive OLP, before and after treatment with PBM, comparing those results with patients treated with topical steroid.

METHODS

Two groups of 20 OLP patients were evaluated. Group A underwent two daily application of 0.05 % clobetasol propionate for 8 weeks; group B was treated with eight weekly PBM sessions using a 980/645 nm diode laser. OCT scans were performed before and after treatment, and six months after end of the proposed protocol. Changes of width of stratified epithelium (EP) and lamina propria (LP) were quantified.

RESULTS

After 8-weeks, both groups experienced a significant increase of EP width (p < 0.05), and a significant decrease of LP width (p < 0.05), with Δ-EP in Group A significantly higher than Group B (p = 0.0015); conversely, Δ-LP was not significantly different (p > 0.05). After six months, significant increase of EP width remained only in group B (p = 0.01), with no significant decrease of LP mean width in both groups (p > 0.05).

CONCLUSIONS

Increase of EP and decrease of LP might be explained as consequence of clobetasol and PBM ability to promote epithelial healing, and to reduce interface inflammation. When investigated with OCT, clobetasol appears to provide more significant short-term structural changes, whereas PBM might guarantee long-term alterations.

Ultra-high frequency ultrasound in the differential diagnosis of oral pemphigus and pemphigoid: An explorative study

OBJECTIVES

Intraoral ultra-high frequency ultrasound (UHFUS) is an emerging technique in oral medicine, due to its possibility to provide submillimeter resolution imaging of superficial mucosal structures. In this study, the potential role of UHFUS in the diagnosis of oral pemphigus vulgaris (PV) and mucous membrane pemphigoid (MMP) is assessed.

MATERIALS AND METHODS

Consecutive patients with suspected oral PV or MMP were enrolled. All patients underwent clinical examination, laboratory tests, intraoral UHFUS scan, and biopsy. Histology and direct immunofluorescence were set as benchmark for diagnosis confirmation. The sensitivity and specificity of UHFUS compared to histology were assessed. Mann-Whitney test was performed to evaluate the presence of differences in the echogenicity of PV and MMP. P-value was set at P < 0.05.

RESULTS

Twenty-five patients were included. Thirteen patients were diagnosed with PV, and twelve with MMP. The UHFUS features of PV and MMP lesions were described. Image analysis showed statistically significant differences between the echogenicity of PV and MMP lesions (P < 0.05). Good concordance between UHFUS and histology was found. UHFUS showed 75% sensitivity in the diagnosis of PV and 66.7% in the diagnosis of MMP.

CONCLUSIONS

UHFUS appears a valuable tool in the diagnosis of PV and MMP. Although histology and immunofluorescence remain the gold standard, UHFUS role in the diagnostic algorithm of PV and MMP seems promising as a chair-side tool consistently enhancing clinical evaluation of oral bullous lesions.

Optical coherence tomography for fast bedside imaging, assessment and monitoring of autoimmune inflammatory skin diseases?

Optical coherence tomography (OCT) is a non-invasive, high-resolution imaging technique with a growing impact in dermatology. The principle of OCT is comparable to that of sonography, except that it uses infrared laser light instead of ultrasound waves. It has been clinically demonstrated that OCT is suitable for discriminating between different types of non-melanoma skin cancer at an early stage of disease. Optical coherence tomography generates two- or three-dimensional images of up to 2 mm penetration depth, a field of view of 6 mm × 6 mm, and an acquisition time of seconds. The resolution capability of OCT is more than 3 to 100 times higher than that of ultrasound imaging. It is of particular interest that the additional information on vasculature provided by OCT angiography enables the assessment and monitoring of inflammatory skin diseases. The use of OCT to locate exact blister levels was demonstrated for diagnosing autoimmune bullous diseases. It is anticipated that detection of subclinical lesions could indicate a relapse of the disease. In the future, this could enable intervention and early treatment. Furthermore, the development of high-speed OCT could allow fast scanning and bedside imaging of large body sites.