Clinician variability in characterizing mandible fractures

Purpose: This study evaluated variability in the clinical parameters common ly used to characterize mandible fractures. Patients and Methods: Inter-rater reliability of 18 oral and maxillofacial surgeons was assessed using radiographs of 22 cases of mandible fractures. Raters were asked to evaluate each case based on several parameters includi ng number, location, and displacement of the individual fractures and sever ity of the composite injury. To evaluate intra-rater reliability, selected cases were reviewed at a second session by a subgroup of these surgeons. Te sts of concordance used to quantify measurement reliability included the in terclass correlation coefficient and multiple-rater kappa statistics. Results: Inter-rater agreement on the number of constituent fractures range d from excellent for simpler fractures to poor for complex gunshot injuries . Even within raters, the range of interclass correlation for complex injur ies was only 0.33 to 0.42 between the 2 assessments. Clinicians appeared to be better at delineating coronoid, condyle, ramus, and angle fractures; sy mphyseal and canine region fractures had lower inter and intrarater agreeme nt. Tests of concordance showed moderate to excellent reliability when frac ture displacements were expressed in millimeters, but only fair reliability when displacements were expressed as categories. Even when the clinicians concurred on displacement measurements, a large overlay, was observed in th eir categorization of these displacements. Despite the differences in the a ssessment of individual parameters, the high intrarater reliability coeffic ient (0.78) indicated that the individual clinicians had a high internal co nsistency in their assignment of summary severity scores. Multiple regressi on analysis revealed the number of constituent fractures, the type of fract ure, and amount of fracture displacement (millimeters) to be significant pr edictors of clinician ratings of injury severity. Conclusions: The clinician variability underscores the difficulties involve d in trauma description and scoring. The study identifies some sources of c linician variability and emphasizes the need to standardize the characteriz ation of mandible fractures by using explicit guidelines. (C) 2001 American Association of Oral and Maxillofacial Surgeons.