During about the sixth month of fetal life, two centres make their appearance in the base of this process: they are placed laterally, and join before birth to form a conical bilobed mass deeply cleft above; the interval between the sides of the cleft and the summit of the process is formed by a wedge-shaped piece of cartilage. The base of the process is separated from the body by a cartilaginous disk, which gradually becomes ossified at its circumference, but remains cartilaginous in its center until advanced age. In this cartilage, rudiments of the lower epiphyseal lamella of the atlas and the upper epiphyseal lamella of the axis may sometimes be found. The apex of the odontoid process has a separate centre that appears in the second and joins about the twelfth year; this is the upper epiphyseal lamella of the atlas. In addition to these, there is a secondary centre for a thin epiphyseal plate on the undersurface of the body of the bone. Clinical significance
Fracture of dens
Fractures of the dens, not to be confused with Hangmans fractures, are classified into three categories according to the Anderson Alonso system:

Type I fracture - Extends through the tip of the dens. This type is usually stable. Type II fracture - Extends through the base of the dens. It is the most commonly encountered fracture for this region of the axis. This type is unstable and has a high rate of non-union. Type III fracture - Extends through the vertebral body of the axis.
This gene suffers mutations that cause the PABPN1 protein to have extra alanine (amino acids), this manifests itself physically in the symptoms of this MD.The expansion caused by the mutations on the PABPN1 gene ultimately interrupts the cellular mechanics of poly(A) RNA. In most cases oculopharyngeal muscular dystrophy is inherited via autosomal dominance.The alleles, which are a variant form of a gene involved in this form of MD are:  PABPN1, (GCG)n EXPANSION, (GCG)8-13, PABPN1, (GCG)n EXPANSION, (GCG)7 and PABPN1, GLY12ALA. Diagnosis
The diagnosis of oculopharyngeal muscular dystrophy can be done via two methods, a muscle biopsy or a blood draw with genetic testing for GCG trinucleotide expansions in the PABPN1 gene. The genetic blood testing is more common. Additionally, a distinction between OPMD and myasthenia gravis or mitochondrial myopathy must be made, in regards to the differential diagnosis of this condition. Treatment
Currently no cure or specific treatment exists to eliminate the symptoms or stop the disease progression. A consistent diet planned with the help of a dietitian along with exercises taught by a speech therapist can assist with mild symptoms of dysphagia. Surgical intervention can also help temporarily manage symptoms related to the ptosis and dysphagia. Cutting one of the throat muscles internally, an operation called cricopharyngeal myotomy, can be one way to ease symptoms in more severe cases. However, for a majority of people, the benefits from such treatments are only temporary. There is currently no treatment available to address the proximal limb weakness.