Comparison of Hockey-Stick and Conventional Linear Ultrasound Transducers for Detection of Non-Displaced Dentoalveolar Fractures: An Ex Vivo Paired Comparative Study

Objectives: To compare fracture detection rates and observer confidence between a high-frequency hockey-stick transducer and a conventional linear transducer for detecting non-displaced dentoalveolar fractures in a paired ex vivo model. Materials and Methods: This paired ex vivo study included 88 experimentally created non-displaced dentoalveolar fracture sites in fresh ovine specimens. Two oral and maxillofacial radiologists independently evaluated all sites with both a 12L3 conventional linear transducer (10–15 MHz) and an 18H5 hockey-stick transducer (10–18 MHz), with transducer order randomized. Cone-beam computed tomography (CBCT) confirmed fracture status. Within-observer paired fracture-detection outcomes were compared using the exact McNemar test, and a cluster-adjusted generalized estimating equation (GEE) analysis accounted for repeated assessments and clustering within ovine heads. Observer confidence was compared using the Wilcoxon signed-rank test. Results: Observer 1 detected 76/88 fracture sites (86.4%) with the hockey-stick transducer and 64/88 (72.7%) with the conventional linear transducer (p = 0.004). Observer 2 detected 74/88 sites (84.1%) and 62/88 (70.5%), respectively (p < 0.001). In the cluster-adjusted GEE analysis, the hockey-stick transducer was associated with higher odds of fracture detection (OR, 2.29; 95% CI, 1.84–2.86; p < 0.001). For both observers, confidence scores were higher with the hockey-stick transducer (median [IQR], 4 [3–4] vs. 3 [2–3]; both p < 0.001), with Cohen’s dz values of 0.849 and 0.791, respectively. In a separate pre-study calibration set, interobserver agreement was 95% (κ = 0.828; 95% CI, 0.503–1.000). Conclusions: In this ex vivo model, the hockey-stick transducer achieved consistently higher fracture-detection rates across both observers and greater observer confidence than the conventional linear transducer. The observed differences may reflect the combined technical and ergonomic characteristics of the two transducers rather than probe geometry alone. Prospective clinical studies including both fractured and non-fractured sites are required before conclusions regarding diagnostic accuracy or clinical superiority can be established.