- Body:
    - not ossified at birth
    - center (occassionally 2 centers) appears during 1st year after birth;
           - anterior ring of atlas remains unossified in infants (younger than 1 year) but progressively ossifies and enlarges through age 6-9 years;
    - body may fail to develop, & forward extension of neural arches may take place;

- Neural Arches:
    - appear bilaterally at approximately the 7 th fetal week;
    - most of the anterior portion of the superior articulating surface is usually formed by the body;
    - posterior arch closes by age 3 years;
    - body of C1 fuses with the neural arches through the neurocentral synchondrosis by age 7 years;

- Synchondrosis of the Spinous Process
    - unites by the 3 rd year;
    - union may rarely be preceded by appearance of secondary center within synchondrosis;

- Neurocentral Synchondrosis:
    - fuses at approximately the 7 th year;
    - ligament surrounding the superior vertebral notch;
    - may ossify, especially later in life