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Biomedical subjects

Chen Lee

Publications and source records attributed to Chen Lee.

9 recordsLinked to original sources
PubMed2006

Condylar fracture repair: use of the endoscope to advance traditional treatment philosophy.

Traditional treatment of subcondylar fractures with maxillomandibular fixation often results in a malreduction and significant functional and aesthetic sequelae, including facial asymmetry, decreased jaw opening, and potential for late derangements of the temporomandibular joint. When used selectively, based on preoperative CT scans, the endoscopic technique will reliably restore condylar anatomy in nearly 95% of patients, thus obviating the consequences of malunion. Furthermore, unlike traditional open techniques no significant facial scarring or permanent facial nerve palsies have resulted. Thus, the authors strongly advocate endoscopic repair of adult condylar neck and subcondylar fractures that demonstrate displacement or dislocation and have adequate proximal bone stock to accept miniplate fixation.

Endoscopy↗
PubMed2006

The rationale and technique of endoscopic approach to the zygomatic arch in facial trauma.

The reliable form and strategic position of the zygomatic arch make it a valuable landmark in midfacial trauma management. The benefits of arch repair have been used infrequently, mainly because traditional coronal access to this structure is fraught with undesirable sequelae. Endoscope-assisted zygomatic arch realignment and fixation allow anatomic repair without sustaining the drawbacks of extensive access incisions. The relative importance of this approach increases with trauma complexity, being most useful in Le Fort III and complex zygoma injuries.

Endoscopy↗
PubMed2005

Quantitative topographical evaluation of the orbitozygomatic complex.

BACKGROUND: The orbitozygomatic complex is a tetrapod-shaped bone of the upper midfacial skeleton of particular clinical significance. By defining the malar prominence, it provides a significant contribution to the overall facial form. Moreover, it is the second most frequently fractured bone on the craniofacial skeleton. A method for quantitative determination of the position of the orbitozygomatic complex has important applications in the fields of reconstructive and aesthetic plastic surgery. METHODS: Ten individuals were evaluated using craniofacial anthropometry techniques. The position of the orbitozygomatic complex in three planes, x, y, and z, was determined by measuring linear projective distances between complex landmarks: the maxillozygion (the most prominent landmark on the malar prominence), the orbitale (the lowest point on the inferior orbital rim), the zygion (the most lateral point on the zygomatic arch), and the cranial reference landmarks (the vertex, opisthocranion, and nasion). RESULTS AND CONCLUSIONS: Low variability between measurements within the same individual (<1.5 mm) underscores the reliability of the chosen landmarks and techniques in the determination of orbitozygomatic complex position. Second, the complex occupies a consistent position among individuals, as shown by the low intersubject variability. Third, there is no statistically significant difference in the position of the complex, in any plane of space, between the left and right sides of the face. Thus, the authors' method may be used to determine the degree of complex displacement in individuals with unilateral facial trauma or with unilateral residual postsurgical deformity, and to calculate the amount of realignment needed to produce a symmetrical facial appearance.

Adult↗
PubMed2005

Quantitative comparison of open reduction and internal fixation versus the Gillies method in the treatment of orbitozygomatic complex fractures.

BACKGROUND: Precise repair of orbitozygomatic complex fractures is essential for proper re-establishment of facial symmetry, ocular globe position, and infraorbital nerve function. Controversy regarding the optimal treatment method remains. METHODS: To compare uniform study groups, only patients without previous craniofacial injuries or operations who had sustained moderate-energy orbitozygomatic complex fractures, based on preoperative computed tomography scans, and who were treated using the Gillies repair or open reduction and internal fixation were selected. Quantifiable end-points, including orbitozygomatic complex position, ocular globe projection, and infraorbital nerve function, were measured to objectively compare the accuracy of repair produced by the Gillies procedure and open reduction and internal fixation. Negative sequelae resulting from cutaneous access were tabulated. RESULTS: Overall, 12 patients treated using the Gillies repair and 12 treated with open reduction and internal fixation were examined. The results demonstrated that the open reduction and internal fixation technique produces superior realignment of the orbitozygomatic complex, that is, a smaller difference in the position of the orbitozygomatic complex between the injured and noninjured sides of the face. The differences in orbitozygomatic complex projection, height, and lateral position were 1.4 mm, 1.4 mm, and 1.6 mm, respectively, in the open reduction and internal fixation group and 7.5 mm, 5.6 mm, and 4.1 mm in the Gillies group. The p values were 0.0003, 0.01, and 0.06, respectively. Visible cutaneous scarring was present in four patients and lower lid shortening was seen in three patients treated using open reduction and internal fixation. CONCLUSIONS: To the authors' knowledge, this is the first study to objectively show that the open reduction and internal fixation technique results in superior positioning of the orbitozygomatic complex in moderate-energy orbitozygomatic complex fractures compared with the Gillies repair. Although negative sequelae from surgical access were substantial, recently introduced transconjunctival and upper lid blepharoplasty incisions will minimize these drawbacks.

Adult↗
PubMed2004

An epidemic of methicillin-resistant Staphylococcus aureus soft tissue infections among medically underserved patients.

HYPOTHESIS: A high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in soft tissue infections presents a treatment challenge. DESIGN: Retrospective analysis. SETTING: The San Francisco General Hospital Integrated Soft Tissue Infection (ISIS) Clinic. PATIENTS: Patients treated at the ISIS Clinic from July 1, 2000, to June 30, 2003. MAIN OUTCOME MEASURES: Information on patient demographics, surgical procedures, microbiologic studies, and antibiotic treatments was obtained for all patients treated in the ISIS Clinic. Microbial data and antibiotic susceptibility pattern of S aureus, treatment outcome, and antibiotic prescribed were analyzed for all evaluable patients. RESULTS: The ISIS Clinic treated 6156 unique patients for 12,012 episodes of infection. In this cohort, 5164 (84%) were either homeless or had no health insurance. More than half of the patients (58%) were injection drug users, but most had only 1 prior visit to the clinic (62%). Patients underwent a surgical procedure 7707 times (64%). Of the 837 positive cultures obtained, S aureus was recovered 695 times (83%), and 525 (63%) of the cultures contained MRSA. Therefore, a full 76% of all S aureus isolated was MRSA. In a subset analysis of 622 cultures collected prospectively from consecutive patients, 282 (45%) grew organisms, of which 256 (91%) were S aureus. MRSA represented 59% of all S aureus isolated. Homelessness and injection drug use were risk factors for infection by S aureus and MRSA. In another subgroup of patients with soft tissue infections that required admission to the hospital, MRSA was recovered from the cultures in 149 patients. In these patients with MRSA, 44 (30%) only received a beta-lactam antibiotic, inactive against MRSA, and had full resolution of their infection. CONCLUSIONS: The prevalence of MRSA soft tissue infections in the medically underserved ISIS Clinic cohort is extremely high. The transmission of the MRSA seems to be in the community. Antibiotic therapy directed at MRSA may not be needed in a large number of patients with these soft tissue infections. Studies to identify the source and cause of this MRSA outbreak are urgently needed. Clinical trials to examine the need for antibiotic therapy in soft tissue infections should be conducted.

Community-Acquired Infections↗
PubMed2004

Traumatic arch injury: indications and an endoscopic method of repair.

The unique strategic position of the zygomatic arch makes it an important surgical landmark in facial fracture repair. Because of the numerous negative sequelae associated with the traditional coronal approach to the arch, it has frequently been omitted as a point of reduction and fixation. Endoscope-assisted repair allows accurate zygomatic arch restoration without the setbacks of coronal access. The indications for arch repair include markedly displaced isolated arch fractures, complex zygoma fractures with arch comminution, and Le Fort III level fractures. In complex zygoma fractures, the arch helps accurately restore midface projection and width and serves as an additional stable anchor point. In Le Fort III fractures, restoration and fixation of the arch are essential components of the repair necessary to stabilize the maxillary dentition to the cranial base. Endoscopic arch repair is a novel, technically challenging procedure that requires a different set of surgical skills and considerable training. Implementation of appropriate teaching programs and further advances in instrument development will overcome the steep learning curve associated with this technique and encourage its use.

Adult↗
PubMed2003

Endoscopic mandibular condyle fracture repair.

Treatment of mandibular condyle fractures remains a controversial issue. Arguments center on the relative merits of open versus closed treatment. In the past decisions were largely based on philosophy, anecdotal experience, and retrospective case series with short follow-up. Well-designed studies have now begun to appear in the literature and suggest improved results after open, anatomic reduction and fixation. Many surgeons are still hesitant about liberally applying the open approach due to the resultant facial scarring and the risk of facial nerve injury. Developments in endoscopic technology have recently been applied to facial fracture repair. The endoscopic approach to mandibular condyle fracture repair reduces the risk of facial nerve injury, and dramatically reduces facial scarring, compared with standard open approaches. We feel that the reduced morbidity of the endoscopic approach may allow the benefits of anatomic reduction and rigid fixation to be offered to a larger proportion of patients with mandibular condyle fractures. Technical and technological advances are expected to aid in the dispersal of these techniques in the future.

Contraindications↗
PubMed2002

Incorporation of titanium mesh in orbital and midface reconstruction.

Several authors have demonstrated the safety and effectiveness of titanium in orbital reconstruction. One question posed by clinicians is what happens to large pieces of titanium in communication with the paranasal sinuses or nasal-oral-pharyngeal area. This question becomes increasingly relevant as titanium is used to reconstruct extensive defects for which the destruction of bony architecture requires the placement of mesh in proximity to these areas. The objective of this study was to examine the gross and histologic soft-tissue response to large segments of titanium mesh in the setting of orbital and midface reconstruction, particularly when exposed to the nasal-oral-pharyngeal area and paranasal sinuses. In this study, large segments of titanium mesh were used in eight patients to reconstruct orbital and midface defects, with direct communication between the mesh and nasal-oral-pharyngeal area and paranasal sinuses. Four patients had suffered self-inflicted gunshot wounds; as a result, much of their midface was missing, including the inferior and medial orbital floor, maxilla, nose, naso-orbital-ethmoid complex, and hard palate. Extensive sheets of titanium mesh were used to reconstruct their medial and inferior orbital walls, nasal bridge, and maxilla. In the fifth patient, titanium mesh was used to reconstruct the maxilla after resection of a squamous cell carcinoma of the nasolacrimal duct. In the sixth and seventh patients, mesh was used to reconstruct the nasal bridge after severely comminuted nasal fractures resulted in the loss of bone and mucosa. Finally, the eighth patient had titanium mesh used to replace cocaine-induced bone loss involving the left medial orbital floor and wall and part of the maxilla. On gross examination by either endoscopy or direct inspection, all eight patients had rapid soft-tissue incorporation of the titanium mesh. Initial examination typically revealed budding of soft tissue through mesh interstices, followed by progressive incorporation. One patient's mesh was covered in only 15 days. Two patients underwent biopsies of this newly formed soft tissue. One had biopsies performed at 3, 15, and 31 months after the original operation. Biopsy examination at 3 months revealed incorporation of the titanium with fibrous soft tissue covered by ciliated respiratory epithelium, goblet cells, and squamous epithelium with metaplasia. In addition, the dense, acute inflammation present at 3 months evolved into mild, chronic inflammation at 31 months. The second patient had a single biopsy 4 months after secondary orbital reconstruction for delayed enophthalmos. Biopsy examination revealed a fibrous soft-tissue sheath lined by squamous epithelium with metaplasia. Again, mild chronic inflammation was present within the soft tissue. This study provides evidence of titanium's compatibility with soft tissue. The mesh underwent progressive incorporation with soft tissue that was then resurfaced by indigenous cells, including respiratory epithelia and goblet cells. This phenomenon occurred despite communication with the nasal-oral-pharyngeal area and paranasal sinuses.

Bone Diseases↗