For example GDF6 gene plays an important role in bone development and joint formation. The mutation in these genes can result in Klippel-Feil syndrome. As a result of having congenital Klippel-Feil syndrome, the spinal anatomy of the individual will present abnormal fusion of any two of the seven cervical bones in the neck. This is considered to be an anomaly of cervical bones. It affects the functioning of cervical spinal nerves (C1 - C8) because of compression on the spinal cord. Spinal stenosis also adds damage to the spinal cord resulting in symptoms that are caused by cervicocranial syndrome. Trauma
Traumatic injuries are caused when external forces damage the cervical spine, giving rise to various symptoms. In a motor vehicle accident, the vehicle jerks the neck forward and backward resulting in cervical spine damage. This is called whiplash. The neurological and biological symptoms resulting from neck trauma emerge as a culmination of clinically isolated or combined symptoms caused by cervicocranial syndrome. Pathophysiology
The body is innervated by spinal nerves that branch off from the spinal cord. This innervation enables the brain to receive sensory inputs and send motor outputs. There are 8 cervical spinal nerves of the peripheral nervous system. Cervical spinal nerves C1, C2 and C3 help control the movements of the head and neck. Cervical spinal nerve C4 helps control upward shoulder movements. Cervical spinal nerve C3, C4 and C5 help power the diaphragm and aid in breathing. Cervical spinal nerve C6 helps in wrist extension and some functioning of biceps.
The atrophic epithelium in OSF has been attributed to the senescence of basal stem cell layer and the development of hyperplastic epithelium through senescence escape. Diagnosis
Classification
Oral submucous fibrosis is clinically divided into three stages:
Stage 1: Stomatitis
Stage 2: Fibrosis
a- Early lesions, blanching of the oral mucosa
b- Older lesions, vertical and circular palpable fibrous bands in and around the mouth or lips, resulting in a mottled, marble-like appearance of the buccal mucosa
Stage 3: Sequelae of oral submucous fibrosis
a- Leukoplakia
b- Speech and hearing deficitsKhanna and Andrade in 1995 developed a group classification system for the surgical management of trismus:
Group I:  Earliest stage without mouth opening limitations with an interincisal distance of greater than 35 mm. Group II:  Patients with an interincisal distance of 26–35 mm. Group III:  Moderately advanced cases with an interincisal distance of 15–26 mm. Fibrotic bands are visible at the soft palate, and pterygomandibular raphe and anterior pillars of fauces are present. Group IVA:  Trismus is severe, with an interincisal distance of less than 15 mm and extensive fibrosis of all the oral mucosa. Group IVB:  Disease is most advanced, with premalignant and malignant changes throughout the mucosa.tumor necrosis factor alpha and keratin 17 areinterdependent regulators, they could be used as diagnostic makers and a prognostic mirror of oral
submucous fibrosis cases

Treatment
Biopsy screening although necessary is not mandatory most dentist can visually examine the area and proceed with the proper course of treatment.