Provided is an intraoral X-ray detector assembly that provides X-ray detection signals to an X-ray imaging apparatus main body, the assembly may comprises: an X-ray irradiation means disposed to emit X-rays toward a dentition to be imaged within an oral cavity of a patient a close-contact means that can bring the X-ray detection means capable of detecting the X-rays close to the patients face and can fix the X-ray detection means so as to face an X-ray emission direction of the X-ray irradiation means and a support means that supports a first shaft extending to the X-ray irradiation means and a second shaft extending to the close-contact means and is mechanically coupled to a connection means between the X-ray imaging apparatus main body.