Morphology and Identification - T. tenax is the smallest species in the genus Trichomonas, measuring 5-14µm long and 6-9µm wide. - It can be identified by its long axostyles and tails, 4 anterior flagella, and undulating membrane. - The undulating membrane may appear like small legs. - It may be confused with Trichomonas vaginalis due to similar morphology. - Confirmation of an oral or vaginal parasite is necessary in such cases.

Life Cycle and Transmission - T. tenax trophozoites survive in the oral cavity, feeding on microorganisms between the teeth and gums. - They multiply by longitudinal binary fission. - Trophozoites cannot survive the digestive process. - There are no cysts, and transmission occurs through direct contact of mucous membranes. - The parasite can be transmitted through saliva, droplet spray, kissing, or contaminated dishes/drinking water.

Clinical Manifestations - T. tenax is a commensal found in the oral cavity, particularly in individuals with poor oral hygiene and advanced periodontal disease. - It is not known to cause any symptoms on its own. - It may worsen preexisting periodontal disease. - In rare cases, it has been reported to cause bronchopulmonary infections in patients with underlying lung diseases or cancers. - The parasite can be found among dental calculus and tonsillar crypts in infected hosts.

Diagnosis - Mouth scrapings are the specimen of choice for diagnosing T. tenax trophozoites. - Microscopic examination of tonsillar crypts and pyorrheal pockets can yield typical trophozoites. - Tartar between the teeth and the gingival margin may also harbor the organism. - T. tenax can be cultured on appropriate media. - Phase-contrast microscopy using the patient's saliva as the medium is an effective method of detection.

Research Studies - Trichomonas tenax culture in vitro (Published in 1997, Journal: Journal of Fujian Medical College) - Neutralizing salivary pH by mouthwashes after an acidic challenge (Published in May 2017, Journal: Journal of Investigative and Clinical Dentistry) - Molecular identification of Trichomonas tenax in the oral environment of domesticated animals in Poland (Published in September 2018, Journal: Annals of Agricultural and Environmental Medicine) - Zoonotic Trichomonas tenax and a new trichomonad species, Trichomonas brixi n. sp., from the oral cavities of dogs and cats (Published in April 2017, Journal: International Journal for Parasitology) - First report of Trichomonas tenax infections in the Philippines (Published in April 2014, Journal: Parasitology International)