Biomedical subjects
Publications and source records attributed to H K Kawamoto.
Two cases of late infection following aesthetic malar augmentation with Proplast implants are described. The etiology appears to be contamination because of erosion of the implants through the thin wall of the anterior maxilla. This problem might be avoided by confining placement of the implant over the thick portion of the zygoma.
A simple technique that relies on a fine wire to maintain vertical relationships of the maxilla during Le Fort I osteotomy is described. The advantages are (1) the hands of the assistant are free to help adapt plates, (2) it decreases the assistant's need to maintain a pose, and (3) the time of the operation decreases.
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Twenty-nine fractures of the mandible were studied by standard radiographs and axial computed tomographic scans (hard copy). Independent reviewers analyzed each study in a blinded, non-paired fashion. When radiographic diagnostic sensitivities were compared on the basis of known surgical findings, the plain films were found to have a higher diagnostic sensitivity (89%) than the hard copy computed tomograms (64%). This difference occurred primarily with images of nondisplaced fractures in posterior portions of the mandible, and is likely the result of tomographic orientation and volume averaging. Though computed tomography has emerged as the standard diagnostic test in evaluating intracranial and maxillofacial trauma, this study demonstrates that computed tomographic scanning alone is inadequate in excluding nondisplaced fractures of the posterior mandible.
Two cases of late infections of malar implants are reported following dental work. Inadvertent inoculation of the implants by mouth organisms during injections for local dental anesthesia is implicated as the causative factor. Patients should warn their dentists that a malar alloplast has been inserted. Alternative techniques of maxillary dental anesthesia should be entertained, and antibiotic prophylaxis should be considered.
The purpose of this survey was to evaluate the current trends in the care of facial trauma. Data were obtained through the responses of a survey mailed to all those members and candidates listed in the 1989 American Society of Plastic and Reconstructive Surgeons Directory. A total of 2777 questionnaires were sent, with 1113 (40 percent) returned by means of a self-addressed envelope. Demographic results show that over 70 percent of the treating plastic surgeons fall within the age range 30 to 50 years. Although significant advances have occurred, treatment goals have remained unchanged. These center around the principles of accurate reduction and precise stabilization of fracture segments. The results of this survey reveal that a number of acceptable techniques were employed in the surgical repair of mandibular and zygomatic complex fractures. In the care of Le Fort III fractures, 59 percent of the respondents preferred the use of miniplates and screws for stabilization. Only 26.8 percent believed that facial fracture repair should be performed within the initial 24 hours. With frontal sinus fractures, the vast majority of plastic surgeons (82.1 percent) obtained a neurosurgical consultation. When the posterior wall was involved, 45.6 percent favored removal of the sinus mucosa, 29.7 percent obliterated the frontal sinus with a variety of autogenous materials, while 20.5 percent preferred cranialization. In summary, this survey shows a wide variation in the practice of facial fracture management within the plastic surgical community.
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.
Myomucosal flaps employing the palatoglossi were used to correct posttonsillectomy velopharyngeal insufficiency because the palatopharyngeus were resected with the posterior tonsillar pillar. This new sphincter pharyngoplasty may have a role as a secondary option for treatment of velopharyngeal insufficiency. It should be remembered that this operation has only been performed in a single patient without cleft palate, and, therefore, its application in the cleft population and its potential complication rate are unknown.
Holoprosencephaly encompasses a series of midline defects of the brain and face. Most cases are associated with severe malformations of the brain which are incompatible with life. At the other end of the spectrum, however, are patients with midline facial defects and normal or near-normal brain development. Although some are mentally retarded, others have the potential for achieving near-normal mentality and a full life expectancy. The latter patients do not fit clearly into the previously defined classification system. Proposed is a new classification focusing on those patients with normal or lobar brain morphology but with a wide range of facial anomalies. The classification aids in planning treatment. Coupled with CT scan findings of the brain and a period of observation, patients unlikely to thrive can be distinguished from those who will benefit from surgical intervention. Repair of the false median cleft lip and palate may suffice in patients with moderate mental retardation. Patients exhibiting normal or near-normal mentality with hypotelorbitism and nasomaxillary hypoplasia can be treated with a simultaneous midface advancement, facial bipartition expansion, and nasal reconstruction.
Congenital clefts of the nose are rare and highly variable. Because there are few examples, standard methods for treatment do not exist. Therefore each patient must be evaluated and managed individually with respect to anatomic elements, timing, and sequence of reconstruction.
A previously unreported complication of pseudomeningocele following monoblock frontofacial advancement is described. The defect was repaired by means of an extracranial approach with a satisfactory outcome.
Eighteen patients with nonsyndromic craniosynostosis underwent fronto-orbital remodeling with an advancement-onlay technique. The mean age of the infants was 5 months (range = 2-11 months) when the procedure was performed for the following indications: unilateral coronal synostosis (n = 10); bilateral coronal synostosis (n = 3); metopic synostosis (n = 2); and multiple craniosynostoses (n = 3). The technique consists of (1) unilateral or bifrontal craniotomy, (2) superior orbital rim recontouring and advancement, and (3) frontal bone graft rotation and onlay. Posteriorly, the frontal bone graft is left "floating," while anteriorly, rigid fixation with microplates and screws has supplanted wire osteosynthesis. The use of rigid fixation prevents uncontrolled "float" of the forehead and eliminates the need for temporal struts. Follow-up time ranged from 6 to 60 months (mean = 2.6 years). There were no serious postoperative complications. Surgical results were good to excellent in 94% of cases and poor to fair in 6%. Only 1 patient with a Kleeblattschädel deformity required major revision, while another patient with trigonocephaly underwent a minor, extracranial recontouring procedure. Supraorbital rim and/or forehead recession suggestive of relapse or initial inadequacy of anterior projection occurred in 3 patients (17%). Residual, mild contour abnormalities of the forehead and/or temporal regions were found in 5 cases. To date, no gross disturbances in craniofacial growth related to our method of rigid fixation have been observed and no clinically detectable resynostosis has occurred.
From January of 1985 to January of 1990, 31 patients with repaired cleft lip and secondary vermilion defects underwent 45 revisional procedures. A free tongue graft was utilized seven times in six patients (19 percent). Indications for its use were a V-shaped vermilion deficit or a "whistling" deformity associated with a sagittal vermilion deficiency and normal or insufficient lateral vermilion bulk. Of the seven free tongue grafts, none was lost. Three patients have required revisions, including repeat free tongue graft in one. Proper positioning of the graft along the free vermilion border has made color and texture match satisfactory. The free tongue graft is a simple and reliable means of transferring both vermilion bulk and surface mucosa. Introduction of the free tongue graft has eliminated the need for more cumbersome procedures, such as the Abbé flap or the tongue flap, in properly selected patients.
Insertion and subsequent removal of alloplastic chin implants is not an innocuous procedure, as commonly believed. Ten women, aged 23 to 62 years of age (mean 45 years) are reported in whom severe soft-tissue deformities were observed 6 months to 6 years (mean 32 months) after removal of their implants. Resulting deformities consisted of chin ptosis and bizarre soft-tissue pogonial bunching and dimpling in repose or on animation in 9 of the 10 patients (90 percent). Asymmetrical motion of the lower lip was noted by 5 of the 10 patients. Two patients complained of pain and tenderness over the soft-tissue pogonion. The "bizarre" soft-tissue chin deformities, once established, are virtually uncorrectable. Presently, we recommend serious consideration be given to performing an immediate osseous genioplasty in patients requiring removal of alloplastic chin implants to prevent the evolution of such abnormalities.
Scleroderma is a generalized disorder characterized by abnormalities of the small arteries and vasculature resulting in thickening and prominent fibrosis of the affected tissues. Its etiology remains uncertain. All connective tissue and certain internal organs, notably the gastrointestinal tract, heart, lung, and kidneys, as well as skin, are typically involved. Mandibular movement can become severely restricted when the facial skin is affected, sometimes resulting in secondary changes to both the mandible itself and the temporomandibular joint. We present 2 cases in which we improved facial aesthetics and mandibular function by surgically correcting malocclusion with a Le Fort I osteotomy and maxillary intrusion in patients with manifestations of scleroderma in the face and neck.
As the use of rigid internal fixation of the facial skeleton has become routine in adults, many craniofacial surgeons have expanded its use to the pediatric population. The effects of miniplate and screw fixation on subsequent craniofacial growth, however, have not been examined. Using 6-week-old rabbits as an experimental model, miniplates were placed across the right coronal suture. Calvarial changes were measured by direct osteometry on dry skull preparations. Compared with the control group, a significant reduction in growth was noted across the plated suture and adjacent bones. Because secondary growth disturbances can be produced with the use of these fixation devices, their use in the pediatric population should be viewed cautiously.
The buccal fat pad is an anatomically complex structure that has great importance in facial contour. In properly selected individuals, judicious harvesting of buccal fat can produce dramatic changes in facial appearance by reducing the fullness of the cheek and highlighting the malar eminences. Using fresh cadaver dissection, the anatomy of the buccal fat pad is delineated and its relationship to the masticatory space, facial nerve, and parotid duct is defined. An intraoral approach for buccal fat harvesting is described based on these anatomic findings. Clinical experience manipulating the buccal fat pad for aesthetic modification of facial contour is illustrated.
Although much has been written regarding the treatment of facial bone fractures, at the present time there are no available investigations of human microscopic sections to verify the exact nature of the healing process. The consensus in the literature is that following fractures of the midface, the bone segments are united by fibrous union. Biopsies of the healed fracture sites were obtained in 10 consecutive patients who underwent secondary reconstructive procedures to correct residual deformities. Clinical assessment confirmed that the fractures were completely healed and stable. Histologic sections were obtained across the healed fracture sites, sent for H&E staining, and then examined by light microscopy. All specimens showed that the defects between the segments were obliterated by the formation of a mature compact bone. This bridging bone was characterized by concentric lamellae surrounded by a typical bony architecture. From this study it can be concluded that fractures of the midface heal by direct bony union.