Mucosal condition of the oral cavity and sites of origin of squamous cell carcinoma

940 nm diode laser induced differentiation of human adipose derived stem cells to temporomandibular joint disc cells

Background

Temporomandibular disorder (TMD) refers to a group of disorders that affect temporomandibular joint (TMJ) and its associated muscles with very limited treatment options. Stem cell research is emerging as one of the promising fields in the treatment of degenerative diseases. The ability of human adipose derived stem cells to differentiate into many cell types is driving special interest in several disease management strategies. Photobiomodulation has enhanced the role of these stem cells through their ability to promote cell proliferation and differentiation. Hence, this study examined the differentiation potential of human adipose derived stem cells (ADSCs) into fibroblasts and chondrocytes using a 940 nm diode laser for possible TMD therapy.

Materials and methods

ADSCs were cultured at different seeding densities and for different time intervals. After irradiation at 24, 48, 72 h, 1, 2 and 3 weeks, ADSC viability and morphological changes were assessed in groups with and without basic fibroblast growth factor. Additionally, the level of adenosine triphosphate (ATP) in the cells was also recorded. The differentiated fibroblasts and chondrocytes were characterized with flow cytometry and immunofluorescence techniques, at 1- and 2-weeks post-irradiation.

Results

Increased ATP proliferation and cell viability above 90% were observed in all post-irradiation experimental groups. Post irradiation results from flow cytometry and immunofluorescence at 1- and 2‐weeks confirmed the expression of chondrogenic and fibroblastic cell surface markers.

Conclusion

This study describes stimulatory techniques utilized to differentiate ADSCs into fibroblastic and chondrogenic phenotypes using diode lasers at 940 nm. The study proposes a new treatment model for patients with degenerative disc diseases of the TMJ. The study will offer new possibilities in tissue engineering and TMJ disc management through photobiomodulation of ADSCs using a 940 nm diode laser.

Effects of flavonoids on tongue squamous cell carcinoma

Squamous cell carcinoma (SCC) of the tongue is associated with tobacco use, alcohol abuse, and human papillomavirus (HPV) infections. While clinical outcomes have recently improved for HPV-positive patients in general, 50% of patients suffering from tongue cancer die within 5 years of being diagnosed. Flavonoids are secondary plant metabolites with a wide range of biological activities including antioxidant, anti-inflammatory, and anticancer activities. Flavonoids have generated high interest as therapeutic agents owing to their low toxicity and their effects on a large variety of cancer cell types. In this literature review, we evaluate the actions of flavonoids on SCC of the tongue demonstrated in both in vivo and in vitro models.

A preliminary study of the use of bioimpedance in the screening of squamous tongue cancer

Oral cancers are the 11th most common malignancy reported worldwide, accounting for 3% of all newly diagnosed cancer cases, and one with high mortality ratios among all malignancies. The objective of this study was to study the electrical properties of cancerous tongue tissue (CTT) and normal tongue tissue (NTT). Five tongue cancer patients participated in this study. A disposable probe incorporating four silver electrodes was used to measure the electrical properties of CTT and the surrounding NTT of patients. Measurements were performed at six frequencies: 20 Hz; 50 kHz; 1.3 MHz; 2.5 MHz; 3.7 MHz; and 5 MHz, with the amplitude of the applied voltage limited to 200mV. Four measurement parameters of impedance (Z), phase angle (θ), real part of impedance (R), and imaginary part of impedance (X) of tongue tissue were assessed to see if there was any significant difference in the values obtained in CTT and surrounding NTT. The intraclass correlation coefficient showed that all measurements were reliable. A significant difference (P < 0.05 for the four measurement parameters) was found at 50kHz between CTT and surrounding NTT. It was also found that Z and R of CTT were generally smaller than that of surrounding NTT. In conclusion, bioimpedance at a particular frequency is a potentially promising technique for tongue cancer screening.

The use of bioimpedance in the detection/screening of tongue cancer

Oral cancers are the 11th most common malignancy reported worldwide, accounting for 3% of all newly diagnosed cancer cases, and one with high mortality ratios among all malignancies. The objectives of this study were therefore to study the electrical properties of cancerous tongue tissue and normal tongue tissue, as well as to investigate a new approach for low-cost, noninvasive, and real-time screening of oral cancer. Twelve tongue cancer patients and twelve healthy subjects participated in this study. A disposable probe with four silver electrodes was used to measure the electrical properties of patient's and healthy subject's tongue tissues at six different frequencies, which were 20Hz, 50kHz, 1.3MHz, 2.5MHz, 3.7MHz and 5MHz. The amplitude of the applied voltage was limited to 200mV. Four measurement parameters of impedance, phase angle, real part of impedance, and imaginary part of impedance of tongue were assessed to see if significant difference in values obtained in patient's and healthy subject's tongue tissues existed. Intraclass correlation coefficient showed that all measurements had good reliability and validity (ICC>0.95 for all measurements). Significant differences were found at 20Hz (p<0.05-0.001 for the four measurement parameters) and 50kHz (p<0.001 for the four measurement parameters) between patient's and healthy subject's tongue tissues. In conclusion, bioimpedance at a particular frequency is a potentially promising technique for tongue cancer screening.

Recommendation of modified classification for odontogenic carcinomas

Primary squamous cell carcinoma (SCC) derived from odontogenic epithelium is diagnosed as primary intraosseous carcinoma (PIOC). The term "intraosseous" means the bone marrow spaces. Odontogenic cells, however, exist not only in the bone marrow space but also in the periodontal space and the subepithelial soft tissue space. In our survey for 36 SCC lesions of odontogenic origin, many lesions involved two or all of the three spaces. There was only one lesion which involved the bone marrow space alone. In some cases, the extent of the early lesions was restricted around the tooth or at a part of the alveolar crest. The possibility of a SCC of odontogenic origin arising in the periodontal and the subepithelial soft tissue spaces was suggested. We proposed the term "Odontogenic SCC" to replace "PIOC".

Possible routes of spread of carcinoma of the maxillary sinus to the oral cavity

Carcinomas arising in the maxillary sinus, occasionally present clinically in the oral cavity along the occlusal ridge of the upper alveolus. The mechanism of this spread has not been investigated but it may resemble invasion of the mandible by oral carcinomas, which tend to invade the soft tissues rather than eroding through bone. In Britain, such patients are usually edentulous. This project examines deficiencies in the bony walls of the maxillary sinus to determine possible routes of spread. Maxillae were obtained from one side of 17 dissecting room cadavers, aged 71-95 years; 15 were edentulous. The roof of the maxillary sinus was removed in all specimens. Five maxillae were each cut into six slices, 0.5 cm thick, in a vertical bucco-lingual plane. In all, soft tissues were removed by treatment in dilute bleach. Histological sections, cut in the horizontal plane, were prepared of a further three maxillae. Several possible routes were identified by which tumors could spread from the sinus to the oral cavity: 1) directly through foramina in its floor; 2) through numerous foramina in its floor to the marrow cavity of the alveolar process, which mostly contained fat amongst narrow bony trabeculae. (The marrow cavity, in turn, had numerous communications with the occlusal surface); 3) through foramina which carried branches of the superior alveolar nerves and vessels; 4) through deficiencies in the bony walls of the sinus at the neurovascular grooves and elsewhere.