"A study to assess the use of ultrasonography in detecting maxillofacial fractures"

Abstract

Background:-Maxillofacial fractures occur most frequently as an after effect of trauma. Initially during first century, diagnosis of fracture was carried out using conventional radiographs but it has certain shortcomings which includes high radiation exposure, difficulty in detecting hair line & non dislocated fractures due to anatomical superimposition from the para-nasal air sinuses obscuring the visibility of underlying anatomical structures. At the time of this study the literature was focused more about isolated facial fracture and less about complete comprehensive evaluation of maxillofacial fractures using USG. A radiological confirmation is necessary because missed or incorrectly managed cases may encounter serious consequences. The most common causes of these fractures are road traffic accidents. The etiology and incidence of these fractures vary in different countries. The nasal bone being the most prominent bone is often prone to fracture (39% of maxillofacial fractures). The mandible and zygomatico-maxillary complex play an essential role in facial contour and mastication. A fracture in this area can affect facial appearance, function, and quality of life. To restore aesthetics, function, and quality of life, it is essential to completely diagnose these fractures for effective management. Thus we aim to add on more facts to the preexisting context which may further help to utilize ultrasonography as a first line diagnostic tool in detecting various maxillofacial fractures.

Materials & Methods:-Thirty four patients who presented with clinical signs & symptoms suggestive of maxillofacial fractures having computed tomography ( GE Revolution 16 slice, 1.25mm slices) & conventional radiographs( GENORAY PAPAYA Plus DP-1S )done as a standard protocol for management of maxillofacial fractures were included in this study. These patients were subjected to ultrasonographic ( VOLUSON 730 PRO )examination using 5-7 MHz frequency linear probe by an experienced sonologist who was blinded to the findings of computed tomography and conventional radiographs. Assessment was carried out in real time. The findings of conventional radiographs & ultrasonography were then correlated with findings on computed tomography. In this study computed tomography was taken as the gold standard & sample size estimation done with “two tailed test’ in EPI INFO SOFTWEAR

Results:-The data analysis was performed by diagnostic & sensitivity test. Inferentional statistics was performed using EPI INFO 1.1.1.14. In this study ultrasonography shows sensitivity 86.20%, specificity 100%, positive predictive value (PPV) 100%, negative predictive value (NPV) 20.00%, accuracy of 86.66% in detecting maxillofacial fractures. When correlating the fracture detected by computed tomography & ultrasonography the results were highly significant with P = 0.001893.

Conventional radiographs shows sensitivity 50.57%, specificity 66.66%, PPV 97.77%, NPV 4.44%, accuracy of 51.11% in detecting maxillofacial fractures. When correlating fractures detected by USG & CR the results are significant with P = 0.00467.

Conclusion:-In the present study ultrasonography has shown better accuracy than conventional radiographs in diagnosing maxillofacial fractures. Though CT scan is the gold standard, we had observed that USG is equal to CT scan in diagnosing most of the superficial fractures. Hence with the availability of well experienced sonologist and high resolution transducer USG can be considered as the first line diagnostic procedure in suspected maxillofacial fractures.