Oral lichenoid lesions of the upper lip and gingiva: What we know so far.

The clinical presentation of oral lichen planus and oral lichenoid lesions is diverse. A special category of patients presents with lichenoid lesions affecting only the mucosa of their upper lip and the anterior upper gingiva. This is a concise review summarizing the specific characteristics of these patients.

Management of dental patients taking direct oral anticoagulants: Dabigatran.

Direct oral anticoagulants (DOACs) are increasingly used as alternatives to warfarin because of the superior pharmacokinetic properties. Clinical guidelines on the influences of DOACs for dental procedures have emerged, but all of necessity based on low-quality available evidence. Herein, we share our experience with a case series, and propose a protocol regarding the management of dental patients taking DOACs.

Preferential lectin binding to specific layers of rat oral epithelium and modification by enzyme pretreatment.

Three fluorescein-labeled lectins were shown to bind differentially to cell surfaces in different epithelial layers of rat oral mucosa regardless of the age or the site of origin of the tissue. Griffonia simplicifolia (GS-1-B4), specific for alpha-D-galactosyl end groups, labeled basal cells only; Ulex europeus (Ulex 1) specific for alpha-L-fucosyl groups labeled spinous cells; and Bandeiraea simplicifolia (BSII), specific for N-acetyl-D-glucosamine, labeled cornified cells. Pretreatment of sections with alpha-galactosidase completely abolished the staining of basal cells by GS-1-B4, but had no effect on the staining of spinous cells by Ulex 1. In contrast, alpha-fucosidase abolished the staining of spinous cells by Ulex 1 and caused staining of both basal and spinous cells by GS-1-B4. Neuraminidase and chondroitinase ABC produced results similar to one another, with staining of basal cells by GS-1-B4 and labeling of both basal and spinous cells with Ulex 1. beta-galactosidase, beta-glucuronidase, and testicular hyaluronidase did not affect the staining pattern of GS-1-B4 or Ulex 1, whereas chymotrypsin completely abolished any staining with either lectin. The results demonstrate a complex arrangement of cell surface carbohydrates in the epithelium of rat oral mucosa. The findings indicate a possible simplification in the spatial arrangements of cell surface carbohydrates during the differentiation of basal to spinous cells.

Metaplastic bone formation in an unusual neural tumour of the oral cavity.

This case report describes an unusual variant of a nerve sheath tumour arising in the oral cavity which was partly surrounded by and contained bone. The differential diagnosis is discussed and the formation of bone within neural tumours reviewed.

Oral epithelial atypia and acantholytic dyskeratosis in rats painted with 4-nitroquinoline N-oxide.

Oral epithelial atypia and foci of acantholytic dyskeratosis (FAD) were investigated in 54 rats treated with the carcinogen 0.5% (w/v) 4-nitroquinoline-N-oxide in propylene glycol and in 18 rats treated with propylene glycol only. The palate of each animal was painted 3 times weekly for up to 9 months and rats were killed at monthly intervals. A gradual significant increase in the epithelial atypia indices of the palatal and lingual tissues (anterior and posterior of the intermolar tubercle) was observed with a maximum value of 17-22 of a possible 75 at 28-32 weeks. No significant differences were noted between the atypia indices of the palatal and lingual tissues. FAD were not evident in the palate or lingual tissues before 12 weeks and 16-24 weeks, respectively, and although the palate consistently showed more FAD compared with the lingual tissues the differences were not significant. Features of epithelial atypia and FAD were absent in the 18 control rats treated with propylene glycol only and in 8 untreated control animals. At 28 weeks of 4NQO treatment 2 of 5 rats, at 32 weeks 3 of 4 rats and at 36 weeks 3 of 3 rats had developed infiltrating squamous cell carcinomas in either/both the palate or tongue. The results suggest that epithelial dysplasia and acantholytic dyskeratosis may be late morphological features of a more fundamental change occurring earlier in the process of tumour development.

The use of the lectin Ulex europeus to study epithelial cell differentiation in neoplastic and non-neoplastic oral white lesions.

Ulex europeus (Ulex 1) has been used to study the expression of cell surface alpha-L-fucose on oral epithelial cells of normal human mucosa, white lesions and carcinomas. In normal tissue and in 11 of 12 specimens of non-specific keratoses (leukoplakia), Ulex 1 stained epithelial spinous cells only. In 16 specimens of oral lichen planus, Ulex 1 labelled spinous epithelial cells, and in 12 there was also staining of the basal epithelial cells. Two specimens of white sponge naevus showed a total absence of epithelial staining with Ulex 1. Squamous carcinomas showed a loss of staining in the invading epithelial islands in six of eight specimens, but normal labelling of the surfaces of spinous cells at sites distant from the areas of epithelial invasion. When the severity of epithelial dysplasia, as assessed by the index of epithelial atypia, was compared with the pattern of staining of Ulex 1 in normal mucosa and white lesions there was no correlation. The results show that failure of Ulex 1 to stain cell surface carbohydrates may not be attributable to malignant transformation. The staining of cells not normally stained may be related to hitherto masked residues revealed by cell damage or altered differentiation.

Sources and patterns of referrals of oral cancer: role of general practitioners.

Referrals of patients with oral squamous cell carcinomas to an oral medicine clinic were assessed with regard to the sources, delays, and pattern of referrals from general medical practitioners and general dental practitioners. Slightly more patients were referred by dental practitioners than by medical practitioners, but general medical practitioners were far more likely to see advanced tumours and to request an urgent second opinion or suggest a diagnosis of malignant disease. The greatest delay overall was caused by the patients in seeking advice from their practitioner, particularly those who attended a general medical practitioner. Both groups of practitioners requested a hospital opinion within roughly a month--a reasonable interval. Subsequent delays were minimal. Delays occur mainly because the patients are slow in seeking professional advice and, in general, do not appear to have been reduced over the decade since a previous British study on referral patterns was carried out. This study emphasises the importance of educating patients about oral cancer since it is they who appear to be mainly responsible for the delays in diagnosis. The results also help to dispel the myth that general medical practitioners might be less competent at diagnosis and referral of patients with oral cancer than are dental practitioners, though we are aware of misdiagnoses from both groups.