# Sagittal changes in the dens significantly slowed after 12 years of age

## TL;DR

This study shows that the shape of the odontoid process in children's necks changes rapidly until age 12, after which the changes slow down significantly.

## Contribution

The study provides new insights into the developmental trends of the odontoid process inclination in children using CT data.

## Key findings

- The angles PEOA and PDAA decrease sharply until age 12 and then slightly until 18.
- AEOA and ORA decline gradually from birth to adulthood.
- SIA remains largely unchanged with age, while PB-C2 line increases until age 12 and then decreases.

## Abstract

The odontoid process is an important component of the upper cervical, and the process of ossification for odontoid does not cease completely until skeletal maturity.

The aim of the study was to obtain the inclination parameters of the dens in many healthy children and to analyze the trends and variations in the inclination of the dens.

All the CT data obtained from our hospital was reviewed for next measurement. Posterior edge of odontoid angle (PEOA), anterior edge of odontoid angle (AEOA), odontoid retroflection angle (ORA), posterior dens angulation angle (PDAA), screw insertion angle (SIA), and pB-C2 line were measured and analyzed.

A total of 219 patients were divided into 6 groups based on age at an interval of 3 years. The mean values of PEOA and PDAA dropped dramatically with age up to the ten to twelve-year group and then decreased slightly until 18 years old. Moreover, the AEOA and ORA declined gradually from birth to adulthood. These parameters were statistical significance within different age groups. However, the SIA was largely unchanged from birth to 18 years old and appeared to be independent of age. In contrast, the PB-C2 line has a distinguish distribution, with an increase up to the nine to twelve-year age group and then gradually decreased until 18 years old.

The inclination of dens was constantly changing during pediatric growth, but the trends were different. These developmental changes slow down significantly after the age of 12 years.

•The dens is essential in the upper cervical region and is connected to the C2 vertebra via dentocentral synchondrosis.•We undertook a more extensive investigation of the inclination of the dens to analyze its trends and variations during growth.•The inclination of the dens constantly changed during pediatric growth, while these changes slow significantly after age 12.

The dens is essential in the upper cervical region and is connected to the C2 vertebra via dentocentral synchondrosis.

We undertook a more extensive investigation of the inclination of the dens to analyze its trends and variations during growth.

The inclination of the dens constantly changed during pediatric growth, while these changes slow significantly after age 12.