Peri-orbital bone dimensional analysis using computed tomography for placement of osseointegrated implants

ABSTRACT

Craniofacial osseointegrated implants enabled producing implant-retained facial prosthesis, namelythe orbital prosthesis. Aim: To evaluate the length and width of the bone structure of the peri-orbitalregion and to present the method validation. Methods: Computed tomography scans of 30 dryhuman skulls were obtained in order to register linear length and width measurements of the periorbitalregion. Two examiners made the measurements twice with intervals of at least 7 daysbetween them. Data were analyzed by descriptive statistics and the paired Student’s t-test wasused as inferential technique (SAS, α=0.05). Results: In most cases, the intra- and inter-examinervariations were not significant (p>0.05). Therefore, the method proposed was considered asprecise and valid for the measurement of the peri-orbital region. The measured points correspondto the hours of a clock. The major lengths were observed at 1 h (18.32 mm) for the left peri-orbitalbone and at 11h (19.28 mm) for the right peri-orbital bone, followed by the points situated at 2h(13.05 mm) and 12h (11.37 mm) for the left side and at 10 h (12.34 mm) and 12 h (11.56 mm) forthe right side. It was verified that the three points with lowest values followed the same anatomicalsequence in the supraorbital rim for the right and left orbits, showing compatibility with the insertionof the intraoral osseointegrated implants. The medial wall of both orbits did not present sufficientlength to allow the insertion of intraoral or craniofacial implants. Conclusions: The largest widthpoints were observed in the supraorbital rim and in the infralateral region of both orbits and thoseof smallest width were found in the supralateral region of both orbits.