The correction of microtia with autogenous cartilage grafts: II. Atypical and complex deformities

Microtia encompasses a diverse variety of derformities whose correction must be considered individually. In part I, the classic form of microtia is described. In this article, an overview of complex microtic problems is presented and various techniques to facilitate their management are proposed.     

The role of the zygomatic arch in the statics of the skull and its adaptive shape

The zygomatic arch of mammals is usually considered a phylogenetic relic of the fenestrations of the skull roof which may be observed in morphological sequences of primitive vertebrate skulls. If this concept is correct, the element is comparable (though not homologous) to the jugal arches of diapsid reptiles. Two major questions then remain unanswered: why different elements are maintained in reptiles and mammals during evolution, and why the arches are maintained as relics of ancestral forms. It is tempting to respond to the latter question with a very simple answer, namely that the elements function in order to sustain mechanical stresses. In this paper, we raise the questions which quality of stresses occurs in a primate skull within the zygomatic arches and what relationship these stresses hold to the morphology of these bony elements. An answer has been sought by means of finite element stress analysis. We found that the zygomatic arch in primate skulls represents a structure which carries, under all biologically relevant conditions, either compressive or tensile stresses. In a very simple model of the human skull under bite forces, a strip of stresses occurs lateral to the orbits, which seems roughly comparable to the zygomatic arch. Once such a structure exists and is used as an insertion of adductor muscles, it will be exposed to bending stress in side view and in frontal view. Morphological details of the zygomatic arch (curvature, profile, suture) are well suited to sustain the evoked stresses by a minimum of material.     

In vivo strain in cranial sutures: the zygomatic arch.

Although cranial sutures presumably play a role in absorbing and/or transmitting loads applied to the skull, loading patterns on facial sutures are poorly understood. The zygomatic arch provides a comparatively isolated mechanical part of the skull containing a single suture, the zygomatico-squamosal. In pigs the zygomatico-squamosal suture has a short vertical segment located within the postorbital process and a longer horizontal segment which extends posteriorly. In anesthetized pigs single-element high-elongation strain gages were bonded over both segments of the suture. Strain was recorded during stimulation of the masseter muscles and while the lightly anesthetized animals masticated food pellets. The predominant strain patterns differed in the two segments of the suture. During mastication compressive strains predominated in the vertical segment, but tensile strains predominated in the horizontal segment. The same patterns were also produced by stimulation of the ipsilateral masseter muscle. Contraction of the contralateral masseter reversed the strain pattern, but strain levels were low and during mastication such reversals occurred only transiently. The two segments of the suture have contrasting morphologies. The vertical segment has broad, interdigitating contacts with fibers arranged in a compression-resisting orientation. The horizontal segment has a simple tongue and groove structure with fibers arranged to resist tension. Thus, the structure of the suture reflects the predominant strain pattern.     

The use of alloderm for the correction of nasal contour deformities

What rhinoplasty surgeon has not been frustrated by unmet expectations from unreliable graft materials? The quest for an ideal graft continues. Septal cartilage is not always adequate in amount or substance. Ear cartilage may cause unsightly irregularities over time. Cranial bone or rib harvest sites add to the complexity of the procedure and can be intimidating for many operators. This article describes the authors' successful experience with AlloDerm onlay grafts for the correction of nasal contour deformities in 58 primary and secondary rhinoplasty cases by means of the open and endonasal approaches. Forty-two patients received an open-approach procedure; the remaining 16 received grafting through an endonasal or closed approach. Thirty-seven of the patients were secondary rhinoplasty patients, and some underwent multiple nasal corrections. The indications, intraoperative surgical technique of graft placement, and representative results will be discussed. Long-term follow-up showed good results, though partial graft resorption occurred in some patients. Overall, this experience with AlloDerm for nasal augmentation was encouraging.     

Surgical correction of burn deformities of the nose.

We present a method for reconstruction of the everted nostrils of the burned nose. Through a "ram's horn" incision, the everted vestibular lining and lower lateral cartilages are mobilized and repositioned, and the resultant defect is covered with a full-thickness skin graft. The linear scar is created as part of a circle, so that the postoperative contracture will improve the alar contour.     

Analysis and results of treatment of established posttraumatic facial deformities.

The clinical records of 125 patients undergoing treatment for posttraumatic facial deformities (PTFD) from 1979 to 1990 were retrospectively reviewed. Patients with complex fractures had a combination of at least three of the major fracture categories [Le Fort I, II, III; naso-orbital-ethmoid (NOE); zygomatic; frontobasilar; and mandibular]. Twenty-five patients (20 percent) were found to have severe posttraumatic facial deformities resulting from a complex facial fracture pattern. Sixteen were males and nine were females, and their ages at the time of our first reconstructive procedure ranged from 22 to 64 years (mean 33 years). All patients presented to our clinic with severe posttraumatic facial deformities from 1 month to 26 years (mean 5 years) after original injury. The number of prior reconstructive attempts averaged two (range 0 to 9). Arbitrary severity scores assigned by us were mild in 4, moderate in 12, and severe in 9 patients. Once treatment was initiated in our clinic, the average number of operations was 3.76 until completion (range 1 to 15). Surgical treatment was aimed first at reestablishing proper skeletal, vertical, transverse, and sagittal proportions. Once skeletal foundations were reset, the more delicate naso-orbital-ethmoid and lateral canthal relations were addressed. Of the 25 patients, 13 (52 percent) suffered a complication at some point during their surgical management. In these 13 patients, 20 complications occurred in a total of 94 operations for an overall complication rate of 21 percent. Fifteen of the 20 complications were related to infection. Skeletal abnormalities in patients with posttraumatic facial deformities can generally be corrected with current craniomaxillofacial techniques. Ultimately, an excellent result in terms of skeletal reconstruction is compromised by the status of the surrounding soft tissue. More in-depth knowledge of the nature and magnitude of the initial and subsequent soft-tissue injury will contribute to our ability to treat these disfiguring posttraumatic sequelae.     

The alar contour graft: correction and prevention of alar rim deformities in rhinoplasty

One of the most common problems affecting both the primary and secondary rhinoplasty patient is deformity of the alar rim. Typically, this deformity is caused by congenital malpositioning, hypoplasia, or surgical weakening of the lateral crura, with the potential for both functional and aesthetic ramifications. Successful correction and prevention of alar rim deformities requires precise preoperative diagnosis and planning. Multiple techniques of varying complexity have been described to treat this common and challenging problem.Over the past 6 years (1994 through 2000), the authors have employed a simple technique in 123 patients for alar retraction that involves the nonanatomic insertion of an autogenous cartilage buttress into an alar-vestibular pocket. Among the 53 patients who underwent primary rhinoplasty in this study, 91 percent experienced correction or prevention of alar notching or collapse. However, correction was achieved for only 73 percent of the patients who underwent secondary rhinoplasty; many of whom had alar retraction secondary to scarring or lining loss. In patients with moderate or significant lining loss or scarring, a lateral crural strut graft is recommended. The alar contour graft provides the foundation in the patient undergoing primary or secondary rhinoplasty for the reestablishment of a normally functioning external nasal valve and an aesthetically pleasing alar contour. This article discusses the anatomic and aesthetic considerations of alar rim deformities and the indications and the surgical technique for the alar contour graft.     

Postquadrantectomy breast deformities: classification and techniques of surgical correction

The deformity which is encountered following quadrantectomy (or similar procedures such as segmentectomy or partial mastectomy) and radiation therapy is difficult to evaluate objectively, and subjective assessment of the cosmetic outcome is extremely variable. In a group of 54 patients who underwent the procedure between 1979 and 1983, the types of cosmetic changes were evaluated and classified according to morphologic criteria. Four types of deformities and their related etiopathologic factors were identified. Type I is characterized by malposition and distortion of the nipple-areola complex and is mainly due to postoperative fibrosis and scar contracture. In type II deformity, localized tissue insufficiency is observed, which may be due to skin deficiency (type IIa), subcutaneous tissue deficiency (type IIb), or both (type IIab). Type III deformity is characterized by breast retraction and shrinkage and is mainly due to the effects of radiotherapy on residual breast parenchyma. In type IV deformity, severe radiation-induced damage to the skin, nipple-areola complex, and subcutaneous and glandular tissues is present. Surgical correction of each type of deformity is discussed, and examples are reported.