1 myogenic
1) unilateral chewing
Long-term unilateral mastication leads to strong unilateral masticatory muscles, increased myofilament proliferation, and relative atrophy of non-masticatory muscles, which will make one side bigger and the other side smaller, especially hypertrophy at the mandibular angle at the attachment point of masseter muscle;
2) Hyperfunction of one abdominal muscle.
A type of temporomandibular joint disorder (TMD s), which is mainly caused by excessive lateral muscle activity, pulling one side of the mandible to shift to the healthy side, leading to the inclination of the lower part of the face (chin) to the healthy side, often accompanied by the snapping of the mouth-opening joint;
3) Masticatory muscle spasm
A kind of TMDs, when one side of masticatory muscle spasms, the condyle of the affected side can not slide forward normally, which leads to the mandibular inclination to the side of masticatory muscle spasms, and the mandibular inclination to the affected side when the mouth is limited;
4) A joint capsule or (and) ligament is slack.
A type of TMDs, when a joint capsule or (and) ligament is loose, a condyle slides forward or sideways too much (too much), the mouth is normal or too big, and the chin leans to the healthy side when opening and closing.
2. Articular
The main reason is that the articular disc can't be contracted forward or not, which leads to abnormal mandibular movement trajectory, which is characterized by the chin tilting to the affected side when opening and closing, often accompanied by joint pain, joint locking, limited mouth opening and so on.
3 Abnormal bone structure
1) The condyle is badly worn.
When arthritis causes serious wear of a condyle, one condyle will be raised relative to the healthy side, which will lead to the face tilting to the side where the condyle is raised relatively;
2) Mandibular fracture
Some patients with occult mandibular fractures are often not found at that time, and then the fracture malunion leads to facial deviation.
3) Abnormal development of condyle
Clinically, there are some abnormal condyle development, which are mostly manifested as the small or hypertrophy of one condyle, which leads to the movement of the mandible to the smaller side, or directly as the face on one side is big and the face on the other side is small, which looks crooked.
4 odontogenic
If many basin friends have irregular dentition, one side of the teeth is open, and one side of the posterior molars can bite, but the other side cannot. At this time, the face on the open jaw side is bigger and looks crooked.
Spine-derived
When torticollis or scoliosis occurs, the mechanical balance between the left and right sides of the human body is broken, and the face shows that one face will tilt to the other.
6 neurogenic
Mainly facial paralysis (facial paralysis) or facial nerve injury caused by trauma, leading to facial deviation.
7 origin of blood vessels
It is mainly caused by sequelae of central nervous system injury caused by cerebral hemorrhage or cerebral infarction.