Can antegonial notch angular measurements on lateral cephalometry be used to monitor children following TMJ ankylosis treatment?

OBJECTIVE

This research aims to introduce using antegonial notch angular measurements on lateral cephalometry as a simple low-dose radiographic approach for monitoring mandibular growth in children after TMJA treatment.

METHODS

This retrospective cohort study used dental records to identify eligible patients: healthy children with true unilateral TMJA who underwent conservative gap arthroplasty followed by post-operative physiotherapy. The primary outcome was changes in antegonial notch angular measurements over time. Secondary outcomes included correlations between antegonial notch angular measurements and two growth-related conventional cephalometric angles (SNB and ANB). We also explored the relationship between changes in antegonial notch angle over time and study covariates.

RESULTS

Eleven patients aged 4 to 9.5 years with unilateral bony TMJA for periods ranging from 9 to 20 months who had undergone conservative gap arthroplasty followed by physiotherapy were included. Significant increases were observed in antegonial notch angles on both the affected and non-affected sides after treatment (p < .05), indicating resumed mandibular growth. Although the affected side remained significantly smaller than the non-affected side at both timepoints (p= 0.033 and 0.005), asymmetry did not change significantly over time (p= 0.273), suggesting parallel bilateral growth. Positive correlations were found between antegonial notch changes and SNB (p= 0.039-0.047). Multivariate regression indicated that TMJA duration significantly influenced changes in the affected-side notch angle (p= 0.004).

CONCLUSION

Based on these preliminary data, antegonial notch angular measurements on lateral cephalometric radiographs may offer a simple, reliable, and low-radiation alternative for monitoring mandibular growth in children after TMJA treatment. Further studies with larger sample sizes are required to support our findings.