# Developing an Adaptive 3D Vertebrae Model of Scoliosis Patients for Customize Garment Design
## 3 Anatomical Description and Generic Model of Different Vertebrae Morphology  
Spine modeling requires a thorough analysis of the different functionalities of the vertebrae, which strongly influence the morphology of each of them. The goal is to understand why it is divided into three distinct groups (lumbar, dorsal, and cervical vertebrae), which generate three types of morphology [45; 46]. Given that some features could be expected, it is possible to find a basic generic model on which to graft the morphological specificities of each group. However, the C1 and C2 vertebrae have different morphologies and biomechanics [47]. It is also indicated that the axial trabecular architecture of the dens appears to be crucial for the physiological and biomechanical function of the C1-2 joint. One of the studies demonstrated the presence of a Y-shaped trabecular structure of the dens on the axial CT and described its anatomical and biomechanical implications [48]; it would have a generic model that could be derived in three morphological variants. The spine not only provides vertical stability in the trunk and neck, but it also has a protective role for sensitive organs such as the spinal cord, ventral and dorsal nerve roots, nerve roots of the spine, and vertebral arteries. The spine's modeling must consider all morphological constraints imposed by different functional, mobility, and stability criteria. Each verteb has an anterior and posterior arch. The posterior arch forms a hole called the foramen and the spinal cord passes through the foramen of each vertebra. The vertebral bodies defined by the anterior arches are connected among themselves by the intervertebral discs. The posterior arch is composed of the pedicles, laminae, and processes. The pedicles can be represented by two short cylinders of bone that extend from the vertebral body. Laminae are two plates of bones that form the walls of the posterior arch. The transverse processes extend out on either side of the laminae. The spinous process is very variable according to the function of the vertebra type. It can be felt through the skin in the body's back. The spinous process will allow for defining the exact position of the spine when inserted into the body. Figure 1 schematizes the relationship between the spinal cord and the nerve roots coming out on either side of the spine. This connection towards the whole nervous system acts on the morphology of the vertebrae by excavations. Similarly, each vertebra's stacking and adjustment (Figure 2a) on top of each other contributes strongly to their morphology by the prominences leading to the upper and lower facets representing the joint process contact zones. Other contact zones are located at the intervertebral disc level, whose role is to ensure the spinal column's damping against heavy loads and facilitate mobility or the 3D deformation of the spine. The spine's modeling must consider all these morphological constraints imposed by these different functional, mobility, and stability criteria. Other physical constraints are more specific to the group to which the verteba belongs. For example, the lumbar rachis has a protective role in the spinal cord but also one of support. It guarantees the posture of the trunk and standing support. For this, the lumbar vertebrae structure is robust to allow the trunk to twist, bend or stretch. On the other hand, the dorsal rachis is not very mobile and carries the thoracic cage. For this purpose, it is provided with a specific transverse process and costovetrebal joint to allow each rib's hanging and positioning. As far as the cervical rachis is concerned, it has excellent mobility like the lumbar rachis without having this important supporting role. Its particularity is that each cervical vertebra presents notable differences that will lead to different vertebrae models for this rachis. Although the vertebrae have slightly different appearances, they all have the same basic structures with the same names as shown in the previous analysis.