Labial and buccal minor salivary glands of the dog – location, three‐dimensional arrangement and histology

Abstract

Objective Transplantation of minor salivary glands (MSGs) to the conjunctiva is a treatment option for patients suffering from dry eye disease. As there is not enough information about labial and buccal MSGs in dogs, the aim of this study was to provide evidence of the presence of these glands and to investigate their spatial arrangement and excretory ducts. Methods The oral mucosa of the lower lip of 4 dogs and the whole lower jaw of 1 dog were used for histological and microCT analysis. Presence, number, volumes and the tissue depth of MSGs were assessed. Results Histological analysis showed that compact tubulo‐acinar glands were located in the submucosal connective tissue. MicroCT images revealed that 9 to 21 MSGs were arranged in a single row at the level of the dental alveolae. The volume of the MSGs increased from rostral to caudal and the total volume of glandular tissue per animal ranged from 35.01 mm3 to 549.43 mm3. The mean tissue depth of MSGs ranged from 0.57 mm to 1.37 mm (upper surface of glands) and between 1.43 mm and 3.09 mm (lower surface of the glands). Excretory ducts left the dorsal part of the glands and ran in dorso‐rostral direction. Conclusions The location, number and volume of the labial and buccal MSGs in the dog could be detected and described using microCT scans and histology. The present results can provide valuable information for future transplantation of labial MSGs as therapeutic measure against keratoconjunctivitis sicca.

Morphology and volume of Meibomian glands ex vivo pre and post partial tarsal plate excision, cryotherapy and laser therapy in the dog using microCT

“…In an insect anatomy study, glandular tissue was visualized by the authors 16 . Gabner et al 17 proved the existence of glandulae labiales and buccales ventrales of the dogs using microCT. Not only was it possible to visualize the small salivary glands in dogs, but it was also possible to calculate the volume as well as the length of the excretory ducts.…”

First report of primary tonsillar salivary gland adenocarcinoma in a dog

“…However, as in humans, dogs also have minor salivary glands that are not normally appreciable with advanced imaging unless severe diseases are present. 13,14 Minor salivary gland tissue is located in small clusters scattered throughout the submucosa of the oral cavity. Minor salivary gland tissue is reported to be more concentrated in the buccal, labial, lingual and palatine mucosa.…”

“…Minor salivary gland tissue is reported to be more concentrated in the buccal, labial, lingual and palatine mucosa. 13 In a retrospective study describing histopathological findings of 179 canine salivary gland biopsy submissions, the minor salivary glands represented approximately 24% of the samples submitted. Cases submitted included a combination of inflammatory, traumatic and neoplastic diseases, as well as normal salivary tissue and benign conditions.…”

“…The four major salivary glands in the dog consist of the parotid, zygomatic, mandibular and sublingual gland. However, as in humans, dogs also have minor salivary glands that are not normally appreciable with advanced imaging unless severe diseases are present 13,14 . Minor salivary gland tissue is located in small clusters scattered throughout the submucosa of the oral cavity.…”

An optimized workflow for microCT imaging of formalin‐fixed and paraffin‐embedded (FFPE) early equine embryos

“…Already in 2008, it was shown that different structures such as hair follicles and collagen bundles can be discriminated in punch biopsies of skin (Cnudde et al, 2008). More recently, microCT imaging of paraffin samples has been become more popular for imaging of tissue biopsies (Gabner et al, 2021; Walton et al, 2015) and pathology samples (Hutchinson et al, 2017; Jones et al, 2016; Katsamenis et al, 2019; Scott et al, 2015; Senter‐Zapata et al, 2016; Teplov et al, 2019) and has also been used for high‐resolution imaging of brain tissue (Deyhle et al, 2018; Eckermann et al, 2021; Töpperwien et al, 2018; Töpperwien et al, 2019). Moreover, it has been demonstrated that microCT can be used to image early mouse development (before E9.5) in unstained paraffin‐embedded samples (Ermakova et al, 2018).…”