# Choice of Screws for Fixation of Mandibular Condyle Fractures Guided by Anthropometric Data
## 4 Discussion
### Clinical Relevance of the Study  
In post-traumatic patients, the ability to obtain unambiguous measurements is often limited by a deformed anatomy. Taking into account that the fracture stability is influenced by both the plate length and the length of the fixation screws [8], an assessment of thestandard measurement values in a large study group will improve the quality of the surgical fixations of fractures by avoiding the use of screws that are too short.  
Measurements were performed in places typical for the stabilization of osteosynthesis plates in the fractures of the condylar processes, i.e., the base, the top, and the sigmoid notch [34] (Figure 5).  
Thus, in the area at the base of the condylar process, 8 mm screws should be chosen (due to the skewness of the distribution). In the area of the sigmoid notch, 1.5-2 mm screws should be chosen. Both of the above measurements were not gender dependent (\(p>0.05\)).  
Measurements in the region of the condylar neck top revealed statistically significant differences in the measurements between the sex of the patients, but the average difference was below 1 mm (\(p<0.05\)). In this area, an appropriate choice would be 10 mm screws.  
In mandibular head fractures, the use of long screws is extremely important due to their mechanism of action (strong compression and bicortical anchoring) [37]. [PERSON] et al. obtained statistically better results in the treatment of mandibular head fractures using long bicortical screws compared to osteosynthesis with the use of mini-plates and monocortical screws as well as compared to the removal of the fractured part of the mandibular head [38].  
The use of an appropriate screw to ensure proper stability is important because reoperation in the mandibular head area is associated with a higher risk of complications related to facial nerve palsy [10].  
Statistically significant differences were found in the measurement results between women and men. Taking into account the distribution of the features, it can be concluded that the standard length of the bicortical screws that should be used in men is 22 mm and 20 mm in women.  
It should also be mentioned that there is a statistically significant correlation between some measurements (Width_neck_basal, Thickness_sigmoid_notch, Width_head) and the age of the examined patients. Depending on the age of the patients, values of the measurements Width_neck_basal and Width_head increase as described by the fol  
Figure 5: Typical fixation of the mandibular head with the exemplary headless compression screw (**left**) and the location of the ACP plate for condylar fracture fixation (**right**).  
lowing two formulas, respectively: Width_neck_basal \(=\sqrt{9.74743+27.7643\times\text{In(Age)}}\) and Width_head \(=\sqrt{309.884+31.728\times\text{In(Age)}}\). It should therefore be assumed that the values of the measurements Width_neck_basal and Width_head are lower in the younger patient group, increasing with age in a logarithmic manner. A statistically significant relationship described by the formula Thickness_sigmoid_notch \(=1.83246+0.000104693\times\text{(Age)}^{2}\) was observed between the Thickness_sigmoid_notch measurement value and the age of the examined patients. Measurement values were observed to increase with age in an exponential manner.