Childhood Cancer Treatment and Long-Term Dental Growth: Findings from a Multicentre Study

Advances in paediatric cancer care have significantly improved survival rates. For children diagnosed with rhabdomyosarcoma—the most common soft tissue sarcoma (a cancer of connective tissues) in children—survival rates now reach approximately 80 percent. Because about 40 percent of these tumours occur in the head and neck region, healthcare researchers are increasingly focused on understanding and managing the late complications that treatments can cause as young patients grow into adulthood.

A transatlantic multicentre study examined the long-term impact of head and neck rhabdomyosarcoma treatments on dental development. The results highlight the frequency and types of dental complications that can arise years after cancer therapy.

What the Study Examined

The researchers systematically investigated late dental adverse effects in a group of 103 childhood cancer survivors treated between 1990 and 2014. Among these survivors, the median age at diagnosis was 5.4 years, and 42.7 percent were female.

To evaluate dental health, the research team analysed orthopantomograms—specialised panoramic dental X-rays that provide a broad view of the entire mouth, including the jaws, upper and lower teeth, and tooth roots. The X-rays were scored using a validated tool called the DENTALE system. This tool assesses seven specific dental characteristics: skeletal deformations, tooth presence, tooth wear, crown shape, tooth eruption (the natural movement of a tooth as it emerges through the gum into its normal position), root shape, and the crown-to-root ratio (the proportion between the visible part of the tooth and the root anchored in the jawbone).

What the Researchers Found

The analysis showed that late dental complications were widespread among the survivors:

• Overall frequency: 92.2 percent of the 103 survivors exhibited at least one dental adverse effect.
• Root abnormalities: Changes in root shape or structure were the most common issue, identified in 72.8 percent of survivors.
• Crown-to-root ratio problems: 56.3 percent had abnormalities in the proportions between their tooth crowns and roots.
• Missing molars and eruption disturbances: Missing molars were observed in 45.6 percent of survivors, and another 45.6 percent experienced disturbances in how their teeth erupted into the mouth.

The findings also revealed a clear relationship between the child’s age during treatment and the severity of subsequent dental issues. Age at diagnosis was inversely correlated with the total adverse effect score. Survivors diagnosed before the age of 6 had significantly higher total dental complication scores compared to those diagnosed at older ages. Specifically, children treated before age 6 showed significantly more adverse effects involving tooth crowns, crown-to-root ratios, root formation, and tooth eruption.

Study Strengths and Limitations

This study provides detailed, structured data from a multicentre cohort spanning more than two decades of treatment. However, it also has specific boundaries. The study was retrospective, relying on historical radiographic records from 103 patients who had head and neck rhabdomyosarcoma specifically. The findings describe dental developmental patterns seen on panoramic X-rays and do not evaluate other forms of cancer or non-head-and-neck treatments.

What This Means for Patients

For families and individuals who have undergone treatment for paediatric head and neck tumours, these findings underline the importance of long-term dental surveillance. Because cancer therapies delivered during early childhood can alter how developing teeth and roots form, routine dental follow-up should be a standard component of survivorship care. Ongoing monitoring allows dentists and orthodontists to identify missing teeth, root abnormalities, or eruption delays early and provide specialised dental or orthodontic management whenever clinically necessary.