Three dimensional reconstruction of late post traumatic orbital wall defects by customized implants using CAD-CAM, 3D stereolithographic models: A case report

Abstract

Aim: Purpose of this case report is to highlight the precision and accuracy obtained with patient specific implants for orbital reconstruction designed on the basis of volumetric analysis of orbital computed tomographic scan (CT) scans using virtual planning, computerised designing and manufacturing and stereolithographic models to correct late post-traumatic orbital deformities such as enophthalmos and diplopia.

Material and methods: This case report describes a patient who visited our outpatient clinic for correction of enophthalmos and persistent diplopia in upward gaze, seven months post trauma. Three dimensional (3D) virtual treatment planning was carried out by using the 3D CT data. The unaffected orbit of the contralateral side was superimposed on the deformed orbit to highlight the defect and a customized implant was designed in the desired size and shape on the virtual model using computer aided designing and manufacturing (CAD-CAM) and milled in titanium mesh for precise anatomic orbital reconstruction.

Results: There was a marked improvement in both the diplopia in upward gaze and enophthalmos post surgery when the customized patient specific orbital implant was used.

Conclusion: The concept of using customized implant with the help of 3D virtual treatment planning, 3D stereolithographic models and CAD-CAM greatly improves the correction of extremely difficult late post-traumatic orbital deformities.

Keywords: Customized implant; Diplopia; Enophthalmos; Orbital volume.

Fig. 1

Preoperative frontal view of a patient having 3 mm hypoglobus and facial asymmetry.

Fig. 2

Preoperative picture showing marked hypoglobus and scar mark present over his nose.

Fig. 3

Preoperative picture showing restriction of left eye movement in upward gaze.

Fig. 4

Preoperative picture showing depressed left malar and infraorbital region and also marked enophthalmos (5 mm) in his left eye.

Fig. 5

Preoperative CT face 3D reconstruction frontal view, section showing fracture of orbital floor left side, medial orbital, superior orbital wall, and inferior, medial and superior orbital rim.

Fig. 6

Preoperative CT coronal section, showing marked increase in orbital volume in left eye, fracture orbital floor, medial wall, superior wall and fronto zygomatic suture region.

Fig. 7

Preoperative CT axial section fracture at zygomatico-sphenoid suture region, and posterior positioning of left eye globe as compared with right eye.

Fig. 8

Computer Assisted Designing of implant for 3D reconstruction of fracture medial wall, orbital floor and superior orbital wall.

Fig. 9

3D computerized designing of implant with its antero-posterior dimension.

Fig. 10

Computerized designed complete implant extension.

Fig. 11

Stereolithographic model showing fracture of orbital floor, medial wall and superior walls for treatment planning.

Fig. 12

Intraoperative picture showing placement of 3D reconstructed customized implant.

Fig. 13

Postoperative frontal profile of the patient showing marked correction of hypoglobus and enophthalmos in his left eye and improvement in facial symmetry of the patient.

Fig. 14

Postoperative coronal section showing symmetrical orbital volume in both the orbit after reconstruction with customized implant.

Fig. 15

Postoperative 3D CT face section showing proper reconstruction of medial orbital wall, orbital floor, and superior orbital wall in left eye.