Abstract: Objective To explore morphological classification of the Caldwell view of frontal sinuses in computer radiography(CR) for forensic identification and to construct a forensic identification system with digital X-ray films with assistance of identification indexes coding.Methods Four hundred CR films of the Caldwell view of frontal sinus were selected from Sichuan Han ethnic Chinese.The frontal sinuses were classified according to the relationship between the tangential line above the upper edge of the bilateral orbits and the location of the frontal sinus.Then to code the identification indexes for the frontal sinus.Results The Caldwell view of frontal sinuses were classified into 6 categories.Eight identification indexes for the frontal sinus were identified,including degree of asymmetry,superiority of side,ratio of the left frontal sinus area and orbit area(ALFS/ALOR),ratio of the right frontal sinus area and orbit area(ARFS/AROR),outline of the left upper border,outline of the right upper border,occurrence of partial septa and location of frontal median margin.Conclusion Initial identification by the Caldwell view classification of frontal sinuses followed with coding the frontal sinuses with 8 indexes is likely a novel approach for forensic identification of the frontal sinuses in CR.

Key words: forensic medicine, radiography, frontal sinus, identical authentication