ABSTRACT Introduction It is believed that direct odontoid screw fixation preserves the physiological cervical range of motion following surgery. However, there are no clinical studies confirming the motion sparing value of this technique. Objective. (1) to assess active cervical range of motion following type II and type III odontoid fracture, successfully treated with anterior odontoid screw fixation, (2) to examine the relationship between the range of motion of the head and: (i) duration of collar usage, (ii) neck pain, (iii) quality of life, and (iv) patients’ age. Material and method. The study involved 41 patients subjected to a procedure of direct osteosynthesis of the dens with lag screw. Following the operation all the patients had to wear a cervical collar to protect the osteosynthesis. The control group consisted of 41 individuals with no clinical diagnosis of any cervical spine disorders. Spinal motion was assessed using Multi-Cervical Unit, taking into account bending/extension, left and right lateral flexion, as well as left and right axial rotation. The ranges of motion in the study group were compared to the corresponding control data. Results. Compared to the controls, the study group presented significantly lower ranges of cervical movement (p<0.001). In the study group spine mobility correlated with the duration of hard collar usage following the operation, with a longer duration corresponding to poorer spine mobility at the end of the treatment. Statistically significant correlation was observed in the case of extension (p<0.021) and axial rotation (p<0.007). In the study group there was a negative correlation between the range of motion and the patients’ age, i.e. the older the patient the poorer his/her spinal mobility (p<0.001). The strongest correlation between age and range of motion was identified in the case of lateral flexion and axial rotation (p<0.001). The findings also showed a correlation between intensity of neck pain and range of motion (most significantly in lateral flexion p<0.005) where lower range of motion corresponded to greater neck pain. Conclusions. Active cervical range of motion in patients following direct osteosynthesis of the dens, augmented with hard collar, was significantly lower than in the control population and it correlated negatively with the duration of collar usage, the patients’ age and intensity of spinal pain.