Cross-sectional Study of the Factors that Influence Radiographic Magnification of Implant Diameter and Length

Purpose: To study the factors that influence radiographic magnification of implant diameter and length. Materials and Methods: The dental records and panoramic radiographs of 80 patients with 210 dental implants treated with implant-supported prostheses at Bundang Jesaeng Hospital in South Korea from January 2000 through February 2003 were reviewed. The panoramic radiographs were developed under standardized conditions. The patient's gender and the anatomic locations of implants were identified from the dental records. To prevent bias, a blinded investigator measured implant diameter and length on a panoramic radiograph. To evaluate intra-examiner variability, the intraclass correlation coefficient (RI) was calculated. The Mann-Whitney rank-sum test and the Kruskal- Wallis test were used to determine the statistical significance of the difference between actual length and radiographic length. Results: The intraclass correlation coefficients (RI) were 0.83 for diameter and 0.87 for length. There was no statistically significant difference in length in regard to gender (P = .08). Magnification of diameter did differ on the basis of gender (P = .03; 25% magnification in radiographs of women; 20% in men). No difference in diameter was found in regard to anatomic location (P = .51), however, while evidence of difference in length in regard to anatomic location was found (P = .01). Discussion: Radiographic magnification of implant dimensions in diameter and length can have different influencing factors. Conclusions: This study found that radiographic magnification of implant diameter was influenced by gender, whereas radiographic magnification of implant length was influenced by anatomic location. Each anatomic location had a different amount of radiographic magnification for implant length.