Anatomical evaluation of oral microcirculation: capillary characteristics associated with sex or age group

Automated Stabilization, Enhancement and Capillaries Segmentation in Videocapillaroscopy

Oral capillaroscopy is a critical and non-invasive technique used to evaluate microcirculation. Its ability to observe small vessels in vivo has generated significant interest in the field. Capillaroscopy serves as an essential tool for diagnosing and prognosing various pathologies, with anatomic-pathological lesions playing a crucial role in their progression. Despite its importance, the utilization of videocapillaroscopy in the oral cavity encounters limitations due to the acquisition setup, encompassing spatial and temporal resolutions of the video camera, objective magnification, and physical probe dimensions. Moreover, the operator's influence during the acquisition process, particularly how the probe is maneuvered, further affects its effectiveness. This study aims to address these challenges and improve data reliability by developing a computerized support system for microcirculation analysis. The designed system performs stabilization, enhancement and automatic segmentation of capillaries in oral mucosal video sequences. The stabilization phase was performed by means of a method based on the coupling of seed points in a classification process. The enhancement process implemented was based on the temporal analysis of the capillaroscopic frames. Finally, an automatic segmentation phase of the capillaries was implemented with the additional objective of quantitatively assessing the signal improvement achieved through the developed techniques. Specifically, transfer learning of the renowned U-net deep network was implemented for this purpose. The proposed method underwent testing on a database with ground truth obtained from expert manual segmentation. The obtained results demonstrate an achieved Jaccard index of 90.1% and an accuracy of 96.2%, highlighting the effectiveness of the developed techniques in oral capillaroscopy. In conclusion, these promising outcomes encourage the utilization of this method to assist in the diagnosis and monitoring of conditions that impact microcirculation, such as rheumatologic or cardiovascular disorders.

Morphologic Mapping of the Sublingual Microcirculation in Healthy Volunteers

PURPOSE

Monitoring the sublingual and oral microcirculation (SM-OM) using hand-held vital microscopes (HVMs) has provided valuable insight into the (patho)physiology of diseases. However, the microvascular anatomy in a healthy population has not been adequately described yet.

METHODS

Incident dark field-based HVM imaging was used to visualize the SM-OM. First, the SM was divided into four different fields; Field-a (between incisors-lingua), Field-b (between the canine-first premolar-lingua), Field-c (between the first-second premolar-lingua), Field-d (between the second molar-wisdom teeth-lingua). Second, we investigated the buccal area, lower and upper lip. Total/functional vessel density (TVD/FCD), focus depth (FD), small vessel mean diameters (SVMDs), and capillary tortuosity score (CTS) were compared between the areas.

RESULTS

Fifteen volunteers with a mean age of 29 ± 6 years were enrolled. No statistical difference was found between the sublingual fields in terms of TVD (p = 0.30), FCD (p = 0.38), and FD (p = 0.09). SVMD was similar in Field-a, Field-b, and Field-c (p = 0.20-0.30), and larger in Field-d (p < 0.01, p = 0.015). The CTS of the buccal area was higher than in the lips.

CONCLUSION

The sublingual area has a homogenous distribution in TVD, FCD, FD, and SVMD. This study can be a description of the normal microvascular anatomy for future researches regarding microcirculatory assessment.

Potential Utility of Oral Mucosal Capillaroscopy as an Indicator of Microvascular Damage in Behçet Disease: A Preliminary Study

Introduction

Behçet disease (BD) is an auto-inflammatory condition characterized by multisystemic vasculitis. Oral mucosal capillaroscopy is an easy-to-use, repeatable, non-invasive method for evaluating mucosal microvasculature, contributing to the differential diagnosis and prognosis of various acute and chronic inflammatory diseases.

Objectives

This study aims to characterize and describe the oral labial mucosal capillary findings in patients with BD using handheld dermatoscopy and to investigate the relationship between the capillary findings and the severity of the disease.

Methods

This cross-sectional study included patients with BD and healthy subjects. Capillaroscopic examination of the oral labial mucosa in each subject was performed by a handheld dermatoscope using polarized light. The clinical severity of BD was evaluated using Krause's Clinical Severity Scoring for BD.

Results

Sixty patients with BD and 60 healthy subjects were enrolled in the study. The frequencies of irregular capillaries, microhemorrhages, glomerular vessels, megacapillaries, and tortuous vessels were statistically significantly higher in the patient group when compared to the healthy individuals. In addition, a correlation was detected between the oral mucosal capillaroscopic findings and disease duration, severity, and vascular complications.

Conclusions

Our study is the first to explore the potential role of oral mucosal capillaroscopic examination in patients with BD. Data obtained from this study indicated that oral mucosal capillaroscopy may be a useful tool to demonstrate microvascular damage in patients with BD.

In-vivo imaging of the microvasculature of the soft tissue margins of osteonecrotic jaw lesions

Introduction Given the increasing incidence of medication-related jaw osteonecrosis, and recognition of the mucosal blood supply's importance, we have developed a non-invasive Real Time Optical Vascular Imaging (RTOVI) instrument. Imaging the red blood cells within the sub-mucosal capillary networks demonstrates the microcirculatory anatomy. We report a small trial, demonstrating the technique's viability, examining mucosal microcirculatory changes adjacent to osteonecrotic lesions.Aims Imaging the microvasculature of soft tissue margins of patients' exposed necrotic bone lesions in situ was intended to provide unique observational as well as quantitative data, using an image analysis routine, based on ImageJ software. Our interest was to evaluate whether this could offer valuable information for complex wound margin management.Methods Four osteoradionecrosis and four medication-related osteonecrosis patients (M:F 1:1 mean 68.25 years) were enrolled under the NRES Ethics 11/LON/0354 and KCL Research Ethics Committee (REC) BDM/14/15-14 approvals. Microvascular images from mucosal margins of exposed mandibular osteonecrosis lesions were compared with equivalent images from both uninvolved contralateral mucosa and similar mucosal sites in four healthy subjects.Results We demonstrated narrow hypo-vascularised oedematous lesion margins surrounded by a concentric inflammatory band and normal mucosa beyond. Parameters reporting individual capillary shape, via mean percentage of occupancy per capillary per field of view and capillary loop aspect ratio, differed significantly between groups (ANOVA, p = 0.0002 and p = 0.04 respectively). Values reporting capillary number and area showed expected changes but did not reach statistical significance.Conclusion This pilot study demonstrated the feasibility of mucosal microvascular imaging in assessing the microvascular changes found in the soft tissues at the margins of osteonecrotic lesions, with potential to inform therapeutic interventions and clinical decisions to continue or modify regime strategies at the earliest opportunity. Given the increasing incidence of medication-related jaw osteonecrosis, and the recognition of the importance of mucosal blood supply, we developed a non-invasive instrument demonstrating microcirculation anatomy by imaging transiting red blood cells.

Microvascular imaging and monitoring of human oral cavity lesions in vivo by swept-source OCT-based angiography

We report the development of optical coherence tomography- (OCT) based angiography (OCTA) to image blood flow within microcirculatory tissue beds in human oral cavity in vivo with a field of view at 10 mm × 10 mm. Three-dimensional (3D) structural and vascular images of labial mucosa tissue are obtained at a single 3D acquisition. Pathologic mucosal sites with mouth ulcers are examined using the OCT tomograms and angiograms, upon which to monitor the lesion healing process over a period of 2 weeks. Quantitative metrics of the capillary loop density within the lamina propria layer are evaluated, providing statistically significant difference between healthy and diseased conditions over time. Furthermore, tissue anatomy and vessel morphology of other susceptible sites to ulcer, such as tongue, alveolar mucosa, and labial frenulum, are also imaged to demonstrate the promise of the proposed method as a clinically useful tool for the diagnosis and monitoring of therapeutic treatment of oral tissue abnormalities.

From restoration to regeneration: periodontal aging and opportunities for therapeutic intervention

With the march of time our bodies start to wear out: eyesight fades, skin loses its elasticity, teeth and bones become more brittle and injuries heal more slowly. These universal features of aging can be traced back to our stem cells. Aging has a profound effect on stem cells: DNA mutations naturally accumulate over time and our bodies have evolved highly specialized mechanisms to remove these damaged cells. Whilst obviously beneficial, this repair mechanism also reduces the pool of available stem cells and this, in turn, has a dramatic effect on tissue homeostasis and on our rate of healing. Simply put: fewer stem cells means a decline in tissue function and slower healing. Despite this seemingly intractable situation, research over the past decade now demonstrates that some of the effects of aging are reversible. Nobel prize-winning research demonstrates that old cells can become young again, and lessons learned from these experiments-in-a-dish are now being translated into human therapies. Scientists and clinicians around the world are identifying and characterizing methods to activate stem cells to reinvigorate the body's natural regenerative process. If this research in dental regenerative medicine pans out, the end result will be tissue homeostasis and healing back to the levels we appreciated when we were young.

A non-parametric segmentation methodology for oral videocapillaroscopic images

We aim to describe a new non-parametric methodology to support the clinician during the diagnostic process of oral videocapillaroscopy to evaluate peripheral microcirculation. Our methodology, mainly based on wavelet analysis and mathematical morphology to preprocess the images, segments them by minimizing the within-class luminosity variance of both capillaries and background. Experiments were carried out on a set of real microphotographs to validate this approach versus handmade segmentations provided by physicians. By using a leave-one-patient-out approach, we pointed out that our methodology is robust, according to precision-recall criteria (average precision and recall are equal to 0.924 and 0.923, respectively) and it acts as a physician in terms of the Jaccard index (mean and standard deviation equal to 0.858 and 0.064, respectively).

Periodontal microcirculation in diabetics: an in vivo non-invasive analysis by means of videocapillaroscopy

Background

Diabetes mellitus is today considered a society-wide disease of a chronic/degenerative nature. Among the secondary effects of diabetes, the one that interests the dental surgeon most is diabetic parodontopathy. The aim of this study was to underline and objectify microcirculatory variations at a periodontal mucous level in type 2 diabetics.

Material/Methods

The study enrolled 80 subjects: 40 subjects with a diagnosis of diabetes mellitus type II (18 males and 22 females, between 44 and 85 years of age); and 40 healthy subjects (17 males and 23 females, between 44 and 78 years of age). All the subjects, both diabetic and healthy, were submitted to a videocapillaroscopic examination of the mucosa of the oral cavity.

Results

The measurements concerning the density (expressed in the number of loops/mm²) of the capillary loops presented differences between the healthy subjects and the diabetic subjects. The average periodontal capillary density (DC-P) was clearly superior in diabetic subjects (35.62±10.40 n°loop/mm²) compared to healthy subjects (17.55±3.88 n°loop/mm²). The statistical analysis was performed by means of the Mann Whitney test. The value of P (p=0.000000986), well below the level of significance, demonstrates the high significance of the results obtained.

Conclusions

The increase in capillary density could suggest the presence of active inflammatory phenomena or, more probably, a tendency to a greater susceptibility to inflammatory phenomena. Ultimately, this study shows that there is some peripheral damage to microcirculation at the masticatory mucous level in diabetic subjects and that such alterations can be instrumentally objectified and quantified through the videocapillaroscopic method.