## 4 Discussion  
In a recent review performed by [PERSON] et al., it was concluded that facial augmentation with alloplastic material is a well-established technique with a low incidence of complications for both Silicone and Medpor malar, chin, and mandibular implants [5]. The insertion technique of these implants is the same, regardless of the used materials. Although the fixation of silicone implants can be performed with several techniques, Medpor is exclusively fixed with screws. Similarly, silicone implants can benefit from screw fixation, although the rigid fixation could damage the smooth silicone implant. Consequently, the use of anchoring sutures to the periosteum or the percutaneous fixation of the implant has been described in the literature [10,11]. [PERSON], in 1992, first described a facial implant fixation technique, which he carried out by placing two percutaneous 18-gauge needles through the soft tissue, deeply into the implant, which then remained in place for 24-48 h [8]. In 1994, [PERSON] replied to [PERSON], suggesting a similar technique for temporary fixation of the silicone prosthesis [9]. The implant was placed onto the skin in the desired location; two symmetrical points were marked on the silicone (A'-B') and the corresponding point on the skin (A-B) that would then overlie the implant. A 4-0 nylon suture was passed through the full thickness of the soft tissue and from the pocket through the implant (interoposterior) at point A and made its way out through the silicone (posteroanterior) at point B'. It then ran through the soft tissue and the skin at cutaneous point B. The suture was taped onto the skin or tied over a piece of foam and remained in place for three to seven days [9]. In this paper, the used fixation technique was similar to the one reported by [PERSON] 26 years ago, although some useful variations were added. We found that inserting the needle into the implant while it was outside rather than inside the pocket to be of considerable help; once the needle was passed through the four points (two through the soft tissues and two through the implant), whilst accompanied by the lead surgeon, the assistant surgeon pulls the two sutures thus carefully placing the implant into the pocket. Finally, the suture will be tied over the skin. This variation allows having better  
Figure 8: Upper displacement of the sub-malar implant. control on the final position of the implant contrary to the \"blind\" fixation proposed by [PERSON], with an overall stricter relationship of the implant to the periosteum and the underlining bone. Moreover, anchoring the suture outside the pocket allows the pre-operative position planning to be respected, avoiding unwanted malpositioning during fixation maneuvers. The firm position of the implant provided by the suture fills any gaps between the implant and both the superficial and the deep plane where hematoma or seroma could accumulate, causing its dislocation. Some authors suggested that the use of porous implants could decrease the incidence of this complication although the occurrence rate is generally low and not statistically divergent between porous and non-porous materials (0.75-0.83%) [4]. Instructing the patients to avoid wide facial muscular movements for at least seven days is mandatory since the influence of muscular forces could promote the processes involved in this complication. Another difference with [PERSON]'s technique is the use of absorbable sutures that are left in place, with just the suture emerging from the skin being cut after four days. This is done in order to avoid implant displacement during suture removal. Polyglactin suture has great knot security, is biologically well-tolerated, and loses its tensile strength after about 14 days [12,13]. Therefore, during the first four postoperative days, the fixation of the implant is guaranteed while after the cut of the external threads, the inner parts will still hold some tension through the subcutaneous and periosteal healing tissue, until its full degradation.