Dose optimization in dental radiography: A comparative and adaptive protocol based on PR and LCR retrospective...

Panoramic radiography (PR) and lateral cephalometric radiography (LCR) are commonly used in dental and maxillofacial diagnostics but differ substantially in radiation exposure and image quality. Optimizing protocols according to patient characteristics and clinical indication is essential to minimize dose while maintaining diagnostic performance.

This retrospective study included 20 patients (mean age: 32 ± 12 years) who underwent both PR and LCR under standardized acquisition protocols. Dose-area product (DAP), a proprietary image quality (IQ) index, and contrast-to-noise ratio (CNR) were recorded for each modality. Three experts evaluated diagnostic quality using a 5-point Likert scale. Correlation analyses between objective metrics and expert ratings were performed, and a two-tier adaptive imaging protocol was developed based on clinical indication, age group, and image quality thresholds.

PR images demonstrated a mean DAP of 100.0 ± 2.8 mGy cm² (95 % CI: 98.7-101.3), IQ index of 533 ± 22.5, and CNR of 1.47 ± 0.12. LCR images yielded significantly lower DAP (10.2 mGy cm²), IQ index of 515 ± 10.0, and CNR of 2.18 ± 0.15. Expert Likert scores were higher for LCR (4.13 ± 0.25) than PR (3.37 ± 0.60). Strong correlations were observed between CNR and expert scores (r = 0.64, 95 % CI: 0.38-0.81, p < 0.001). The adaptive protocol simulation suggested a potential 15 % (95 % CI: 12-18 %) reduction in cumulative dose without loss of diagnostic quality.

Compared with PR, LCR provides superior diagnostic image quality at a markedly reduced radiation dose, consistent with international diagnostic reference levels (DRLs). The integration of CNR and IQ indices as objective predictors of diagnostic quality supports the development of adaptive, patient-specific imaging strategies.

This study highlights the feasibility of implementing evidence-based, dose-efficient protocols in dental radiography. By aligning with international guidelines (ICRP, IAEA, EC), the proposed adaptive protocol offers practical recommendations for reducing radiation exposure while preserving diagnostic accuracy.