The effect of local injection of botulinum toxin A on the immunoreactivity of nNOS in the rat submandibular gland: an immunohistochemical study

Histological and immunohistochemical findings of the action of botulinum toxin in salivary gland: systematic review

The treatment of sialorrhea is necessary for the constant risks posed by hypersalivation. A new therapeutic option comes up with the application of botulinum toxin in salivary glands. However, little is known about its mechanism of action in glandular tissue. Based on the above, this work had the objective to systematically review the literature about the action of botulinum toxin on submandibular and parotid salivary glands tissues. Electronic search was performed in databases of great relevance for this study (PubMed, SciELO, HighWire, Crossref, Scopus, Science Direct, MEDLINE, OLDMEDLINE, Serials Database, NLM Catalog, LILACS and IBECS). Inclusion and exclusion criteria for articles were established, and a total number of 14 articles were selected and used. There are few publications that clarify how the salivary gland acini behave with application of botulinum toxin. Although, the immunohistochemical findings were consistent among authors, showing weak immunoreactivity in glands treated with botulinum toxin. Histometric data are divergent, requiring more detailed studies to answer the questions about the efficacy and safety of botulinum toxin in salivary glands.

Histopathologic Effects of Onabotulinum Toxin A Treatment in Pediatric Submandibular Glands

Onabotulinum toxin A (OBTXA) is an effective treatment for drooling. Our objective was to determine if there are histologic changes in the submandibular glands (SMGs) after repetitive OBTXA injections. The study included blinded histologic analysis and comparison of SMGs with ≥4 OBTXA injections versus controls who never received OBTXA. The number of acinar cells were counted, and the morphology of the cells was evaluated within each histologic sample of the SMGs. Thirty-one glands were analyzed (14 control, 17 cases). No physical differences were observed between the 2 acinar cell groups. There was no significant difference in the number acinar cells per surface area in the control group as compared with the OBTXA group (1.29 ± 0.13 vs 1.17 ± 0.11 cells/μm², respectively). To conclude, no significant histologic findings were established in this first human study on SMGs post-OBTXA treatment.