Characterization of muscle alteration in oral submucous fibrosis-seeking new evidence

Abstract

BackgroundThe aim of the study was to assess the progression of Oral Submucous Fibrosis (OSF) by investigating the correlation between clinical mouth opening and muscle-epithelial distance in tissue sections. Characterization of changes involving muscle was ascertained.Material and Methods50 cases and 10 controls were included in this case-control study. Inter-incisal mouth opening was measured and classified according to Lai et al. as Group A (more than 35mm), Group B (30 to 35mm), Group C (20 to 30mm), Group D (less than 20mm). Histopathological sections were graded as very early, early, moderately advanced, advanced OSF. Muscle-epithelial distance was calculated using image analysis software. The four most common degenerative changes observed in muscles, namely fragmentation, highly eosinophilic areas with loss of striations, nucleus internalization and multiple pyknotic nuclei were also assessed.ResultsComparisons of muscle-epithelial distance were made between the clinical and histopathological groups to those of controls. The mean muscle-epithelial distance was: Group A-626.8±309.36 µm, B-827.5±549.72 µm, C-673.2±321.93 µm, D-439.9±173.84µm, Controls-1222.19 ±441.7µm. Post-hoc Bonferroni Test revealed a statistically significant reduction in the muscle-epithelial distance in Group C (p-value = 0.001) and D (p-value = 0.001) as compared to controls. The mean muscle-epithelial distance in very early, early, moderately advanced and advanced OSF was 732.73±232.81µm, 726.54±361.63 µm, 548.36±273.13 and 172.40±58.41 µm respectively. Highly significant difference in muscle-epithelial distance was seen between controls as compared to early (p-value =0.002), moderately advanced (p-value = 0.001) and advanced OSF (p-value = 0.001. Fragmentation and highly eosinophilic areas were invariably noticed in advanced OSF. Multiple pyknotic nuclei were variable with no specificity.ConclusionsReduction in muscle-epithelial distance may prove to be a significant predictor of OSF progression. Degenerative changes must be noted while observing OSF cases, irrespective of the histopathological grade. Key words:Oral submucous fibrosis, muscle changes, muscle-epithelial distance.

Limited mouth opening in oral submucous fibrosis: reasons, ramifications, and remedies

“…Histological studies have shown that the muscle fibers undergoing necrosis are frequently delimited by edematous fluid and extravasated RBCs . An explanation for edema surrounding muscle fibers and subsequent MF in OSF was stumbled upon during the literature search (Fig. , violet box).…”

Assessment of Maximum Bite Force in Pre-Treatment and Post Treatment Patients of Oral Submucous Fibrosis: A Prospective Clinical Study

“…Previous histopathological and electron microscopical studies confirmed muscle degeneration in OSMF patients 4,9) . Khanna and Andrade observed dense collagen fibres interspersed with muscle fibres in OSMF patients with mouth opening of 15-25 mm, along with this, severe muscle degeneration in advanced cases with mouth opening of less than 15 mm was also observed 7) .…”

“…Masticatory muscle involvement and replacement with fibrous tissue is noted in individuals with OSMF 9) . In previous studies, OSMF subjects revealed significant amount of muscular atrophy, degeneration and necrosis of muscle fibers.…”

“…EI -Labban and Canniff noted that that the tissues from patients with restricted mouth opening revealed severe degenerative changes in a high proportion of muscle fibres 18) . Chawla et al, observed degenerative muscular changes in OSMF patients in the form of fragmentation, nucleus internalization, highly eosinophilic areas with loss of striations and multiple pyknotic nuclei 19) .…”

Network‑based identification of signature genes KLF6 and SPOCK1 associated with oral submucous fibrosis

“…Restricted mouth open ing in OSF cases relies solely not only on subepithelial fibrosis but also on the degree of muscle destruction. There is a progressive decline observed in the muscle fibers from the epithelial surface as the advancement of OSF occurs (53). Also, features suggestive of muscle atrophy and necrosis have been demonstrated in moderate and advanced OSF cases (54).…”