Patrick K. Sullivan

Cranio-orbital reconstruction: Safety and image quality of metallic implants on CT and MRI scanning

A study was undertaken to evaluate the safety of magnetic resonance imaging (MRI) of metallic implants used in cranio-orbital reconstruction (stainless steel wire and titanium and Vitallium plates) and also to compare the degree of artifact created on computed tomographic (CT) scanning and MRI by each material. Samples of each material were tested for deflection (movement) in a 1.5-T MRI field and for temperature change under conditions simulating a clinical MRI scan. None of the materials exhibited any deflection, and none exhibited any significant temperature change compared with water. Standardized bars of each material and commonly used, commercially available titanium and Vitallium implants (plates, mesh) were evaluated for artifact. On blinded evaluation by three radiologists and on quantitative computer analysis of the CT images, the stainless steel produced the most artifact on both CT scan and MRI, followed by the Vitallium, with the least artifact caused by titanium. All the titanium images were felt to be acceptable to detect orbital pathology, while only the images with the thinnest Vitallium (micromesh) implant were acceptable. (Plast. Reconstr. Surg. 94: 589, 1994.)

A morphometric study of the external ear: age- and sex-related differences.

The human ear is a defining feature of the face. Its subtle structures convey signs of age and sex that are unmistakable yet not easily defined. With analysis of normative cross-sectional data, this study explored anatomic and aesthetic differences in the ear between men and women, as well as changes in ear morphology with age. A total of 123 volunteers were randomly selected for this study. The cohort consisted of 89 women ages 19 to 65 years (median age, 42 years) and 34 men ages 18 to 61 years (median age, 35 years). The average total ear height across the entire cohort for both left and right ears was 6.30 cm, average lobular height was 1.88 cm, and average lobular width was 1.96 cm. As expected based on head size, significant sex-related differences were noted in the distance from the lateral palpebral commissure to both the helical root and insertion of the lobule. Measured distances in both vectors were approximately 4.6 percent longer in men than in women. Similarly, the height of the pinna was significantly larger in men than in women by approximately 6.5 percent. The average height and width of the lobule, however, were nearly identical in men and women. Analysis of age-related data showed a significant difference in the total ear height between the subpopulations; however, this difference was not significant after the lobular height was subtracted from total ear height, suggesting that the lobule was the only ear structure that changed significantly with age. In addition, lobular width decreased significantly with age. This study establishes normative data for ear morphology and clearly demonstrates the changes in earlobe morphology that occur with advancing age.

Bone-graft reconstruction of the monkey orbital floor with iliac grafts and titanium mesh plates: A histometric study

Bone-graft reconstruction of large orbital defects has been difficult because of a lack of marginal support of the grafts and unpredictable reserption. A titanium mesh orbital plate has been developed to provide this marginal support for bone grafts. However, the problem of unpredictable bone-graft resorption remains. To determine if this plate has any effect on graft resorption, this study was designed to quantitate the dimensions and composition of bone autografts (1) with and without titanium plate support and (2) in the anterior and posterior orbit. Bilateral full-thickness large orbital floor defects were surgically created in five monkeys, and a titanium orbital floor plate was fixed with screws into the right orbit. Two iliac crest grafts were measured and placed transversely and without fixation in each orbit, one anterior and the other posterior to the axis of the globe. The orbits were retrieved 28 weeks after surgery and were analyzed histologically and histometrically. Comparison of the supported and nonsupported grafts revealed no differences in their histologic appearance. There were three significant histometric findings: (1) resorption of bone was similar for those grafts which spanned an orbital floor defect and those which were supported by a titanium plate; (2) resorption of grafts in the posterior orbit did not differ from that of grafts in the anterior orbit; and (3) resorption of approximately one-third of bone-graft thickness and width had taken place during the 28-week study interval. We conclude that the benefits of bone-graft support by a titanium mesh orbital floor plate are not offset by any alteration in bone-graft resorption.

Lateral nasal osteotomies: Implications of bony thickness on fracture patterns

Precise lateral nasal osteotomies combined with digital greenstick infracture can be a key feature in determining the success of a rhinoplasty procedure. This procedure may be difficult to perform consistently because the surgeon relies on tactile cues transmitted through intact soft tissue. In 17 cadavers with known demographics, bone fracture patterns after lateral osteotomy and digital greenstick infracture were studied and compared with measured lateral bone pyramid thicknesses. One side of each nose served to measure lateral wall thicknesses by drilling holes in a grid pattern and taking depth gauge measurements. Contralaterally, lateral osteotomy with digital greenstick infractures were performed. Consistent patterns of bone thickness were found. Bone was thinner near the pyriform aperture with a high fragmentation rate after osteotomy. Cephalocaudal thinning of the lateral bony pyramid near the medial canthus corresponded to the zone of greenstick fracture in 14 of 14 noses. Two major fracture pattern groups were noted. When lateral osteotomy was taken to the level of the medial canthus vertically, the greenstick fracture was consistent and predictable based on the transition in bone thickness from the radix area down across the lateral bony vault in untraumatized white cadavers.

Submandibular gland I: an anatomic evaluation and surgical approach to submandibular gland resection for facial rejuvenation.

Submandibular gland resection for aesthetic reasons has been hotly debated. Detractors maintain that the procedure is dangerous because it puts too many important structures at risk, notably motor nerves. The present study was undertaken to elucidate the neurovascular and soft-tissue anatomy of the digastric triangle via cadaver dissections so that a surgical approach to achieve safe aesthetic submandibular resection could be performed. Fifteen digastric triangles dissections were performed in fixed and fresh cadaver specimens. The dissection focus was to understand the submandibular neurovascular relationships, capsule as well as fascial layers, and measurements to known structures. The marginal mandibular nerve is located external to the submandibular capsule, approximately 3.7 cm cephalad to the inferior margin of the gland. The hypoglossal nerve is posterior to the digastric sling in a position that is protected deep within the visceral layer of the neck. The lingual nerve is located underneath the mandibular border, crossing anterior to the submandibular duct. The vascular supply is variant, but with an average of one and a half vessels entering medially to the superficial lobe of the gland, one intermediate vessel entering medially to supply the superficial and deep lobes, and one deep perforator that runs from the central portion of the deep lobe to the superficial lobe. Appreciation of this anatomy is critical in the submental approach for partial resection. Although it can be technically challenging, the anatomy is straightforward and partial submandibular gland resection can be executed via a consistent, safe approach to optimize facial rejuvenation in certain patients.

The importance of the retaining ligamentous attachments of the forehead for selective eyebrow reshaping and forehead rejuvenation

Background: Forehead rejuvenation procedures can lead to excessive elevation of the medial brow, resulting in the “surprised look.” Differential treatment of the medial and lateral brow allows more precise positioning. The purpose of this study was to determine whether retaining structures exist in the forehead that would permit this differential elevation. Methods: Anatomical dissections were performed in the foreheads of 12 cadavers. Multiplanar dissections at the subperiosteal, subgaleal, and subcutaneous levels were performed on eight hemiforeheads. Clinical correlation for these findings was obtained during endoscopic and open brow-lift surgery. Results: Four retaining structures of the brow were identified: three medial and one lateral. The superomedial attachment begins 13 mm from the midline and 10.8 mm above the supraorbital rim. The superolateral attachment begins 23 mm from the midline and 10.3 mm above the supraorbital rim. The inferomedial attachment begins 12.6 mm from the midline at the level of the supraorbital rim, just medial to the supraorbital nerve. These three structures were found to control the position of the medial brow. Laterally, brow position was controlled by a broad ligamentous attachment extending across the lateral aspect of the supraorbital rim. Conclusions: Medial retaining structures have been found to extend from the cranium into the forehead musculature. Release of the lateral broad ligamentous attachment was performed, followed by selective preservation of medial retaining structures. With this approach, we were able to gain control of the position of the medial brow and prevent overelevation and lateral spreading.

Maxillofacial fractures in the elderly: a comparative study.

Previous maxillofacial trauma research has dealt primarily with facial bone fractures in the general population. Very few studies have specifically addressed maxillofacial fractures in the elderly. We compared 45 elderly (65 years of age or older) and 201 younger adult (16 to 64 years of age) patients admitted to our hospital with maxillofacial fractures. The percentage of patients admitted with nasal bone fractures was much greater in the elderly population, while mandibular fractures were more common in the adult group. Motor vehicle accidents accounted for over half the injuries in both groups, while falls were more prevalent in the elderly. Management of the elderly patient may be complicated by their associated injuries or underlying medical problems, perhaps partially accounting for their longer median length of hospital stay. The elderly are a unique subpopulation of maxillofacial fracture patients and deserve further study regarding their injuries and optimal methods for treatment.

Broad nasal bone reduction: an algorithm for osteotomies.

Background: A persistent problem with nasal bone osteotomies is inadequate reduction of the width of the nasal dorsum. In addition, an algorithm as to which osteotomy to use has not been fully explored. Methods: Nine cadavers received a medial oblique osteotomy (15 to 30 degrees off midline) following a humpectomy in six. On one side, the osteotomy was performed on the medial side of the apex of the open roof. On the contralateral side, it was performed on the lateral side of the apex. The osteotome was then pried posteriorly. The resultant hemidorsal widths were compared. Clinically, 53 patients were classified into the following: type I, broad nasal base (lateral osteotomy only); type II, broad nasal base and broad dorsum (lateral and medial oblique osteotomy); and type III, broad dorsum only (medial oblique osteotomy only). Results: The reduction in hemidorsal width was greatest when the osteotome was placed on the lateral side of the apex (t test, p < 0.008). The improved width reduction was attributable to the slippage of the lateral nasal bone under the dorsal hood of the nasal bone. A lateral osteotomy did not have to be performed to reduce the dorsal width alone. After 15 to 32 months, nasal bone width was satisfactory in all but three cases, one of which required a revision. Conclusions: Reduction of the nasal dorsal width is facilitated by a medial oblique osteotomy alone if it is placed at the lateral aspect of the apex of the open roof. A classification of broad nasal bones is given that emphasizes the distinction between dorsal width and nasal base width and suggests which osteotomy to use.

Optimizing Bone-Graft Nasal Reconstruction: A Study of Nasal Bone Shape and Thickness

&NA; Nasal reconstruction may best be carried out with bone grafting in certain cases of loss of structural support. In order to optimize both the aesthetic and functional results of bone‐graft nasal reconstruction, we studied the shape and thickness of the normal human nasal bone. Sixty Caucasian skull nasal bones were measured by width throughout their length at three planes of depth. Seventeen Caucasian cadaver nasal bones were examined to determine the thickness of the bone throughout its length at three sagittal planes. The results showed that the nasal bone was widest at the nasofrontal suture (14 mm), narrowest at the nasofrontal angle (10 mm), and then widened again to a maximum width of 12 mm about 9 to 12 mm inferior to the nasofrontal angle. The nasal bone was thickest superiorly at the nasofrontal angle (average 6 mm) and progressively thinned toward the tip. It was 3 to 4 mm thick in the critical area where screws are most commonly placed for fixation (5 to 10 mm inferior to the nasofrontal angle). From these data, three‐dimensional models of the normal nasal bone shape were formulated and used in clinical bone‐graft cases. (Plast. Reconstr. Surg. 97: 327, 1996.)

Relevance of the lesser occipital nerve in facial rejuvenation surgery

Nerve injuries are possible during facial rejuvenation surgery. The great auricular nerve has been studied; however, little is known about the lesser occipital nerve and its relevance in facial rejuvenation surgery. To understand the importance of the lesser occipital nerve in a face lift procedure, the specific anatomy of the nerve was studied in the laboratory in 19 hemifaces, with additional nerve observations in the operating room. The course of the lesser occipital nerve, its branches, and the relationship with the surrounding structures were evaluated and recorded. The great auricular nerve was also dissected to compare the two nerve territories. In the majority of the dissections, the lesser occipital nerve supplied the superior ear and the mastoid area, whereas the great auricular nerve innervated the inferior ear and a portion of the preauricular area. The nerves, however, were variable in size and distribution. Five lesser occipital nerves provided the dominant supply to the ear, compensating for a small great auricular nerve contribution. Therefore, injury to the lesser occipital nerve can result in a major sensory deficit of the ear. We also found the lesser occipital nerve to have a subcutaneous course at a proximal and variable level. These nerve branches can be superficial, and therefore postauricular flap dissection can injure the nerve if the flap is dissected at the fascial level. We therefore suggest that the dissection be at a more superficial level to avoid nerve injury. And finally, if SMAS/platysma suspension sutures are placed, we suggest these be done in a vertical-oblique direction along the course of the lesser occipital nerve, because this should minimize the possibility of trapping terminal branches.