Technical Report: Creation of a Cartesian coordinate system within the mandibular ramus for precise analysis of its morphology.

The purpose was to create a Cartesian coordinate system (CCS) within the mandibular ramus relating to specific anatomical landmarks, which can then be used to analyse the mandibular ramus further. Therefore, STL files of mandibular rami were imported into the specifically created program CTinA. Anatomical landmarks, such as the Loukota line and the posterior edge of the mandibular ramus, were marked by hand. Afterwards, a CCS was created, which is related to the marked structures. This means, a reproducible CCS for the mandibular ramus and condyle was established referencing anatomical landmarks. In conclusion, the introduction of the CCS enables standardised clinically interpretable analysis of morphology and may support implant design, such as osteosynthesis plates made from magnesium alloys. Compared to the best-fit alignment, it relies on anatomical landmarks and may be more robust in cases of morphological variation and remodelling.