Design and application of over-flexion–extension position mould based on computed tomography examination of nasal bone patients

Background: we aimed to develop a mould for the over-flexion and over-extension positions to solve the technical problem of patients who find it difficult to form the over-flexion and over-extension positions of the cervical spine by lowering their heads forwards and raising their heads backwards. materials and methods: we calculated the average physiological bending radian of normal people and measured the depth of the cervical physiological curve using borden's method. finally, we designed a mould that conformed to the characteristics of the human cervical spine to conduct nasal bone examinations in the over-flexion and over-extension positions in combination with the patient's examination position. results: when the neck is equipped with an over-flexion and over-extension mould when performing coronal nasal bone examinations, the nasal bone structure is more fully displayed than in routine examinations; furthermore, the clinical diagnosis efficiency greatly improves, and the rate of misdiagnosis significantly reduces. conclusion: this model increases the comfort of patients and solves the technical problem of patients who cannot maintain the over-flexion and over-extension positions for an extended period.