Indications for facial implants






The shape of the human face is composed of a skeletal bony framework that is covered by a soft tissue envelope. Overall, skeletal proportions are probably the most important component of facial attractiveness. Fritz E. Barton Jr., 2009


Since the skeletal infrastructure of the human face is fundamental to its appearance, its surgical change can be powerful. Conceptually, autogenous bone would be the best material to restore or augment the craniofacial skeleton because it has the potential to be vascularized and, then, incorporated into the facial skeleton. In time, it can be biologically indistinguishable from the adjacent native skeleton. Practically, the use of autogenous bone to augment facial skeletal contours is limited. Donor site morbidity as well as the time and operative costs associated with autogenous bone graft harvest can be significant. Furthermore, the inevitable resorption and the poor handling characteristics of autogenous bone grafts limit the quality and predictability of the aesthetic result. With the exception of interposition grafts used to reconstruct segmental load-bearing defects of the maxilla and mandible, the majority of craniofacial skeleton replacements and, particularly, facial skeleton augmentation is done with alloplastic implants. A diagrammatic survey of the alloplastic implants used for facial skeletal reconstruction and enhancement is presented in Fig. 1.1 . Subsequent chapters will address each anatomic area.




Fig. 1.1


A diagrammatic survey of the alloplastic implants used for facial skeletal reconstruction and enhancement.


Patients with normal, deficient, and surgically altered or traumatically deformed anatomy may all benefit from implant augmentation of their craniofacial skeleton.


Facial Balance and Definition


Most often, facial skeletal augmentation is done to enhance facial appearance in patients whose skeletal relationships are considered within the normal range. They want more definition and angularity to their appearance. Other patients desire to “balance” their facial dimensions. The woman in Fig. 1.2 underwent chin and mandible angle augmentation at the time of rhytidectomy to provide angularity and balance between her upper and narrower lower face.




Fig. 1.2


A 52-year-old woman underwent mandible augmentation, chin augmentation, and rhytidectomy. (A) Preoperative frontal and (B) preoperative lateral view. (C) Diagrammatic representation of implant augmentation. (D) Postoperative frontal and (E) postoperative lateral view.




Skeletal deficiency


Craniofacial deformities that are disfiguring and are of functional consequence to vision, breathing, and mastication usually require skeletal osteotomies and rearrangement as treatment. Less severe midface and mandibular hypoplasia are common facial skeletal variants. In patients with these morphologies, occlusion is normal or has been compensated by orthodontics. These patients have neither respiratory nor ocular compromise. In skeletally deficient patients whose occlusion is normal or has been previously normalized by orthodontics, skeletal repositioning would necessitate additional orthodontic tooth movement. Such a treatment plan is time-consuming, costly, and potentially morbid. It is, therefore, appealing to few patients. In these patients, the appearance of skeletal osteotomies and rearrangements can be simulated through the use of facial implants. Diagrammatic representations of how implant surgery can mimic the appearance of skeletal osteotomies are shown in Figs. 1.3 and 1.4 .




Fig. 1.3


Diagrams show how multiple implant augmentation of the midface skeleton can simulate the visual appearance of Le Fort III osteotomy and advancement without altering dental occlusion. (A) Illustration of midface concavity and class III malocclusion. Dotted line shows potential lines of osteotomy. Arrow shows anticipated advancement. (B) Osteotomy and advancement at the Le Fort III level provides midface projection and class I occlusion. Note change in soft tissue profile. (C) Illustration of corrected class I skeletal occlusion after orthodontic tooth movement. (D) Multiple implants augmented the midface skeleton whose occlusion was corrected by orthodontia as shown in (C). The implants project the soft tissue envelope to mimic the contour of the soft tissue envelope of Le Fort III skeletal osteotomy and advancement.



Fig. 1.4


Diagrams show how implant augmentation of the mandible can simulate the visual appearance of sagittal and horizontal osteotomy with advancement without altering dental occlusion. (A) Mandibular deficiency with class II occlusion. Dotted line shows potential lines of osteotomy. Arrows show anticipated advancement. (B) After sagittal split osteotomy with horizontal osteotomy advancement of the chin to increase chin projection. Note that the occlusion has been corrected from class II to class I. Note change in soft tissue profile. (C) Mandibular deficiency after corrected class I occlusion. (D) The skeletal deficiency of mandibular deficiency has been augmented with implants. Note that the class I occlusion is unchanged. Also note the change in soft tissue profile. Notice the absence of border regularities that are inherent with skeletal osteotomies.


Fig. 1.5 shows a patient with corrected occlusion who underwent multiple implant correction of her midface and mandibular deficiencies.


Feb 9, 2020 | Posted by in Craniofacial surgery | Comments Off on Indications for facial implants
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