A 30-year-old patient complains of a painless tumour-like formation in the region of the left mandibular alveolar process. Objectively: there is a pale pink 1x1,5 cm large tumour-like formation on the vestibular surface of the alveolar process at the 34 and 35 teeth. The formation has a broad base, it does not bleed. Crowns of the 34, 35 teeth are intact, the teeth are non-mobile. X-ray picture of the alveolar process shows no changes in bone structure. What is the most likely diagnosis?