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Biomedical subjects

Yu-Ray Chen

Publications and source records attributed to Yu-Ray Chen.

At least 37 records · Page 2Linked to original sources
PubMed2004

Microtia reconstruction with adjuvant 3-dimensional template model.

For auricular reconstruction of external auricle, the goals of the surgery are (1) in the fabrication of the morphologically complete 3-dimensional costal cartilage framework (3-dimensional frame) of the auricle, and (2) in the attainment of ample skin surface area to cover the grafted 3-dimensional frame, so that more than satisfactory results can be achieved. In review of the published literature, the cartilage framework used for auricular reconstruction is either insufficient or incomplete in the fabrication of the anatomic structures or inappropriate in proportion. We herein introduce the 3-dimensional resin template model (3-dimensional template model) and 3-dimensional frame used in our daily surgical practice. The 3-dimensional template model is proportionally fabricated with all the essential morphologic structures of the auricle. It can be used intraoperatively for reference in fabricating the 3-dimensional frame and simulation of the surgery. The 3-dimensional template model is very useful as an adjuvant tool in adjusting the skin flaps, prevention of mistake in fabrication of the 3-dimensional frame, and for educational purposes of junior resident surgeons.

Acrylic Resins↗
PubMed2004

The position of the inferior alveolar nerve at the mandibular angle:: an anatomic consideration for aesthetic mandibular angle reduction.

Mandibular angle reduction is a popular contouring surgery in Asia. Avoidance of injury to the inferior alveolar nerve is crucial during these procedures. Anatomic data regarding the position of the nerve in the mandibular angle area are sparse. The purpose of this study was to use 3-dimensional computed tomographic data to evaluate the nerve in patients with prominent mandibular angles and to compare the nerve position with a normative group. A total of 28 female and 5 male adult patients who presented with a complaint of prominent angles or a "square-face" look, as well as 20 female and 22 male adult normal subjects were included, for a total of 150 hemimandibles for extraction of the inferior alveolar nerve. The nerve and the mandible were displayed. Point O was defined on the oblique line along the anterior cortex of ramus, where it intersected with a line extending from the alveolar arch. From the O point, linear distances were defined, including horizontal distances to the posterior cortex, oblique distances to the gonion, and the vertical distances to the inferior cortex. Mandibular width was defined as the distance between the 2 gonion points. Results demonstrated significant differences mainly in the oblique distances (ie, from the O point to the nerve [O1], from the nerve to the gonion [O2], and from the O point to the gonion [O1-O2]) in both female and male patients. The O2 distance was 23.69 mm versus 20.66 mm in women and 27.30 mm versus 23.28 mm in men (square face vs norm). The mandibular width was significantly larger in the male square-face patients, but the difference was not significant between the female groups. These results provide useful information for surgeons planning mandibular angle reduction. These findings suggest that the mandibular contouring procedure should be aimed at correcting regional osseous dysmorphology in the angle area and improving the relationship to the chin, rather than merely reducing the mandibular width.

Adult↗
PubMed2004

Computer-aided reconstruction of traumatic fronto-orbital osseous defects: aesthetic considerations.

BACKGROUND: In addition to functional goals, a satisfactory aesthetic outcome is important for reconstruction of fronto-orbital osseous defects. The purpose of this study is to report on a method for presurgical fabrication of custom implants using 3-dimensional (3-D) imaging data and computer-assisted manufacturing techniques. METHODS: Preoperative 3-D computed tomography data were processed and displayed for evaluation of defects. Implants were created by a computer-aided design/computer-aided manufacturing (CAD/CAM) program. A rapid prototyping system was applied for production of the physical models. Rehearsal of surgery was performed using the implants and skull models. Negative castings were created and were used during the operations to prepare the surgical implant utilizing methyl methacrylate. Traumatic fronto-orbital defects in 4 patients were reconstructed using this method. The follow-up period ranged from 29 to 55 months. RESULTS: Results showed that the custom implants perfectly fit the defects during the operation. Symmetry and normal fronto-orbital contours were achieved. There were no peri- or postoperative complications. All patients were satisfied with the results. CONCLUSIONS: Computer-aided presurgical simulation and fabrication of implants is a reliable and effective method for the reconstruction of traumatic fronto-orbital defects, with reduced anesthesia time and improved aesthetic outcomes.

Adult↗
PubMed2004

Endoscopically assisted removal of tumors in the frontal region.

BACKGROUND: Advancements in endoscopic surgery, due in part to patient demands and in part to provision of superior medical care by surgeons, have significantly contributed to improvements in patients' quality of life. An endoscopic operation is minimally invasive, associated with faster recovery, and produces less postoperative morbidity. It is a well-accepted procedure in the field of plastic surgery. By applying the principle of endoscopic surgery used in facelift operations, we performed tumor excision in the forehead region. METHODS: Two 1.5-cm slit incisions were made in the anterior hairline. One incision was to allow access for the 4.0-mm, 30 degrees endoscope, and the other was for surgical instrumentation. These incisions, determined by the plane of dissection, were more superficial and below the subgaleal layer for soft tissue tumors and deeper into the subperiosteal layer for bone tumors. With good illumination and magnified monitor viewing, the tumors could clearly be visualized and were completely excised. RESULTS: Seven patients with either dermoid cysts (3), osteomas (2), or lipomas (2) underwent endoscopically assisted procedures. In all cases, tumors were successfully excised with no acute or chronic complications. The average postoperative follow-up period was 7 months. No incidence of tumor recurrence was reported. All patients were satisfied with the resultant forehead contour and surgical scars. CONCLUSIONS: The main advantage of this procedure is the fact that it is minimally invasive, thus reducing the incidence of injury to the neurovascular structures of the forehead as well as minimization of scar visibility. In conclusion, an endoscope-assisted approach is a good alternative method for managing benign soft-tissue and bone tumors in the forehead and brow region.

Adolescent↗
PubMed2003

Endoscopic orbital surgery.

Various applications of endoscopy to orbital surgery are described in this article. The endoscopic approach offers improved surgical exposure, enhanced illumination, simultaneous visualization of operative field by multiple members of surgical team, and superior cosmesis compared with conventional surgical interventions. The procedure can be performed with minimal morbidity. The endoscopic orbital surgery, however, is technique dependent and should be performed only by surgeons who are familiar with orbital anatomy and basic endoscopic technique. It would be beneficial to surgeons to have previous experience in the traditional technique before adopting endoscopic orbital surgery to their armamentarium.

Decompression, Surgical↗
PubMed2003

Palatal surface area measurement: comparisons among different cleft types.

The purpose of this study was to use three-dimensional imaging methods to measure the palatal surface of unrepaired cleft patients. The surface area of the palate was defined and measured on three-dimensional computed tomography images of dental plaster models in four different groups of cleft patients at 3 months of age. There were 30 unilateral complete cleft lips and palates (UCLP), 27 bilateral complete cleft lips and palates (BCLP), 23 isolated cleft palates of incomplete form (CP), and 19 unilateral cleft lips without cleft palates (UCL). These patients were nonsyndromic, unoperated, and without other major deformities. The dental casts were scanned, and the computed tomography data were transferred to an imaging laboratory for processing and reconstruction of three-dimensional images. Surface area of the palate was delineated, which was defined as within the alveolar crest and the line connecting both tuberosities. In UCLP and BCLP, the edge of cleft formed the medial boundary of the area for each palatal shelf, and the palatal surface area was the combination of both palatal shelves and the premaxillary area in BCLP group. The surface area was measured. Repeated definition and measurement tasks were performed for calculation of errors. The imaging data management and measurement were performed using the Analyze program (Biomedical Imaging Resource, Mayo Foundation, MN). In addition, linear distances were measured between the canine points on the alveolar crest (line C) and the tuberosity points (line T). The measurements were compared among the different groups. Analysis of variance and multiple comparisons were used for statistical analyses. The results showed that the mean error between repeated area definitions and measurements in this study was 1.86%. The bilateral complete cleft lip and palate (BCLP) and unilateral complete cleft lip and palate (UCLP) groups had significantly smaller palatal surface area than the unilateral cleft lip without cleft palate (UCL) and isolated cleft palate of incomplete form (CP) groups. There was no significant difference between the BCLP and UCLP groups. Line C and line T distances were significantly longer in BCLP and UCLP groups than in UCL and CP groups. The findings suggest that compared with UCL and CP patients, there is an intrinsic tissue deficiency in the palate/maxilla of BCLP and UCLP patients.

Cleft Lip↗
PubMed2003

Simultaneous reconstruction of the secondary bilateral cleft lip and nasal deformity: Abbé flap revisited.

The purpose of this retrospective study was to review the method of using the Abbé flap for correction of secondary bilateral cleft lip deformity in selected patients with tight upper lip, short prolabium, lack of acceptable philtral column and Cupid's bow definition, central vermilion deficiency, irregular lip scars, and associated nasal deformity. A total of 39 patients with the bilateral cleft lip nasal deformity received Abbé flap and simultaneous nasal reconstruction during a period of 6 years. Mean patient age at the time of the operation was 19.1 years, and ranged from 6.6 to 38.5 years. The average follow-up period was 1.8 years. Fourteen patients had prior orthognathic operations. The Abbé flap was designed 13 to 14 mm in length and 8 to 9 mm in width and contained full-thickness tissue from the central lower lip, with a slightly narrow reverse-V caudal end. The prolabium, including the scars and central vermilion, was excised. Lengthening procedures of the upper lip segments were performed if vertical deficiency existed. Part of the prolabial skin was preserved and mobilized for columellar elongation, if indicated. Open rhinoplasty was carried out with or without cartilage graft for columella and nasal tip reconstruction. Reduction of the alar width and nostrils was achieved by a Z-plasty or excision of scar tissue at the nostril floor. The Abbé flap was then transposed cephalad, insetting into the median defect and sutured in layers. The results demonstrated no flap problems or perioperative complications. Seven patients needed further minor revisions on the nose and/or lip. Laser treatment was used to improve the lip scars in three patients. The patients were satisfied with the final outcome and found the lower lip scars acceptable. In conclusion, the described technique of Abbé flap and simultaneous rhinoplasty is an effective reconstructive method for select patients with bilateral cleft lip and nasal deformity.

Adolescent↗
PubMed2003

Endoscopically assisted repair of frontal sinus fracture.

BACKGROUND: Classic approaches to frontal sinus fracture involve bicoronal or direct forehead incisions. However, these incisions cause paresthesia, scarring, and even alopecia. In the field of plastic and reconstructive surgery, endoscopically assisted surgery is now widely accepted, particularly for esthetic surgery. It also is applied for the management of midface and lower-face fractures, but rarely for treatment of the frontal area. The authors present their experience with the repair of frontal sinus fractures using the endoscopically assisted method. METHODS: The surgery was performed with the patients under general anesthesia. Two slit incisions were placed in the hair-bearing area, through which a 4-mm 30 degrees endoscope was inserted. The subperiosteal dissection was performed toward the fracture site using an endoscopic periosteal elevator. The depressed fracture segments of the anterior table of the frontal sinus were reduced and fixed with microplates to restore the contour of the forehead. Seven consecutive patients received endoscopic correction of frontal sinus depressed fractures. RESULTS: No patients required conversion conventional bicoronal incisions. Good anatomic reduction of the fracture sites, acceptable surgical scar, and esthetic recontour were obtained in all the patients. The postoperative course was uneventful, without any complications. CONCLUSION: The endoscopically assisted method allows feasible reduction and fixation of a frontal sinus fracture. It avoids the complications of traditional methods and yields improved convalescence and esthetic results. It also helps in the diagnosis of unsuspected cerebrospinal fluid leaks. Thus, for anterior table fractures with an intact nasofrontal duct, endoscopically assisted surgery provides an alternative option of treatment.

Adult↗
PubMed2003

Three-dimensional computed tomography imaging in craniofacial surgery: morphological study and clinical applications.

Three-dimensional carniofacial CT imaging has been developed and progressed during the past two decades. The advancement of the hardware and software has made the imaging study more convenient, user friendly, and affordable. Processing and analysis of the imaging data are readily performed on personal computers. Accuracy of the 3-dimensional measurement has been validated. Collaborative study can be achieved with other departments or disciplines, such as orthopedic, otolaryngologic, and dental departments, as well as mechanical engineering department. All the data should be adequately archived as medical imaging data bank for later use. The data can be transferred for production of rapid prototyping models to enhance clinical application. Inter-center sharing of imaging data can be done through common image format. Comprehensive morphological study and clinical information may help to improve or refine treatment planning, which in turn yield better treatment outcome.

Craniofacial Abnormalities↗
PubMed2003

Spontaneous bone regeneration of the mandible in an elderly patient: a case report and review of the literature.

Spontaneous bone regeneration is an unexpected phenomenon that may take place in large mandibular defects secondary to trauma and tumor resection. One explanation for this unusual healing course is that it may be derived from the mechanism of fracture healing. A review of the literature presents several factors that may influence this process, such as the presence of periosteum and bony fragments, mandibular stabilization, soft tissue protection, the presence of infection, and a young age. Previous reports of spontaneous mandibular regeneration have all taken place in relatively young patients (5-35 years old). This paper reports a case of spontaneous bone regeneration in a 58-year-old woman who sustained an injury to her mandible from an explosive blast, and presents some explanations on how such an event could take place.

Bone Regeneration↗
PubMed2003

Programmed database system at the Chang Gung Craniofacial Center: part I.

BACKGROUND: A database is a system for the management of information. Databases of different forms are widely used in everyday life from telephone books to online library catalogs. The Craniofacial Center at Chang Gung Memorial Hospital has seen over 20,000 patients during the past 20 years. All of the patient records need to digitally input into a computer database. METHODS: A database was custom designed using Paradox 8. The ACDSee Photo browser and DOS linked them to the original program. The Paradox 8 was programmed to a standard mode for the diagnosis and treatment data input to prevent typographical errors. RESULTS: We collected the records of 25,200 patients from 1987 to 2002, of which 24,331 underwent operations. The data for 14,828 patients were registered as complete and/or incomplete cleft and the proportions of unilateral to bilateral and female to male are presented in Table 1. CONCLUSION: This new database system was designed to ensure the accuracy of data input using a standard model that is capable of correct data programming using the custom designed coding system for the Craniofacial Center. The system also provides easy and reliable data retrieval when using the powerful search tools.

Cleft Lip↗
PubMed2003

Programmed database system at the Chang Gung Craniofacial Center: part II--digitizing photographs.

BACKGROUND: The archival tools used for digital images in advertising are not to fulfill the clinic requisition and are just beginning to develop. The storage of a large amount of conventional photographic slides needs a lot of space and special conditions. In spite of special precautions, degradation of the slides still occurs. The most common degradation is the appearance of fungus flecks. With the recent advances in digital technology, it is now possible to store voluminous numbers of photographs on a computer hard drive and keep them for a long time. METHODS: A self-programmed interface has been developed to integrate database and image browser system that can build and locate needed files archive in a matter of seconds with the click of a button. This system requires hardware and software were market provided. RESULTS: There are 25,200 patients recorded in the database that involve 24,331 procedures. In the image files, there are 6,384 patients with 88,366 digital pictures files. From 1999 through 2002, NT400,000 dollars have been saved using the new system. CONCLUSION: Photographs can be managed with the integrating Database and Browse software for database archiving. This allows labeling of the individual photographs with demographic information and browsing. Digitized images are not only more efficient and economical than the conventional slide images, but they also facilitate clinical studies.

Craniofacial Abnormalities↗
PubMed2002

Assessment of bilateral cleft lip nose deformity: a comparison of results as judged by cleft surgeons and laypersons.

Reconstruction of bilateral cleft lip nose deformity is difficult and the outcome is inconsistent. This study was conducted to evaluate the gross outcome and the difference in the assessment of nasal appearance as judged by two groups of raters, cleft surgeons and laypersons. Sixty-four patients with bilateral cleft lip were selected for review. The patients' ages ranged from 5 to 30 years. All patients had undergone primary cleft lip repair and secondary nasal reconstruction, and had been followed for at least 6 months. One image for each patient, which included a digitized frontal, lateral, and worm's-eye view, was projected for evaluation by the raters. The raters included five cleft surgeons and five laypersons. A rating scheme was used in which a score of 3 was given for a good, close to normal nasal appearance, 2 for an average result that needed minor revision, and 1 for a poor result that needed major reconstruction. The scores were averaged for each patient in each group and for each group as a whole. The final outcome was judged as good, fair, or poor on the basis of the mean score for each patient. Statistical analysis was performed. The mean score for all patients was 2.08 as assessed by the laypersons and 2.18 as assessed by the cleft surgeon group. There was no statistically significant difference between the two groups. Comparisons on rating scores among different raters revealed a fair agreement on the ratings within each of the two groups. The results were found to be good in 29.7 percent, fair in 64.1 percent, and poor in 6.3 percent of patients when evaluated by the surgeons. When rated by the laypersons, the nasal appearance was found to be good in 26.6 percent, fair in 60.9 percent, and poor in 12.5 percent of patients. This difference in distribution between the two groups was not statistically significant. When comparing the results given by the two groups of assessors, there was agreement on the nasal appearance in 65.6 percent of patients, and a difference in grading in the rest. For the patients who received different grading, the surgeons rated them one grade higher in 63.6 percent and one grade lower in 36.4 percent. There was no difference in grading between any of the evaluators that reflected a two-grade discrepancy in evaluation of results. This study shows that the surgical outcome of bilateral cleft lip nose deformity repair, at the authors' institution, is less than optimal. When assessing bilateral cleft lip nose appearance, the judgment of results by cleft surgeons was similar to that of the laypersons. However, different rating of results existed within each of the two groups, supporting the importance of clearly assessing patient/parent expectations and defining realistic surgical goals.

Adolescent↗
PubMed2002

Functional results of unilateral mandibular condylar process fractures after open and closed treatment.

BACKGROUND: This retrospective study compared the functional results of unilateral mandibular condylar process fractures treated either by open reduction or by closed treatment. METHODS: Sixty-six patients with unilateral mandibular condylar process fractures were reviewed. Thirty-six patients received open reduction, and the other 30 underwent closed treatment (intermaxillary fixation only). Each group was further divided into condylar and subcondylar subgroups according to fracture level. The functional outcome was evaluated by posttreatment occlusion status, maximal mouth opening, facial symmetry, chin deviation, and temporomandibular joint symptoms. RESULTS: Patients undergoing closed treatment exhibited more condylar motility than those treated by open reduction. Patients in the condylar subgroup with open reduction presented less chin deviation (21.43%) compared with those with closed treatment (56.25%; p = 0.072). Although a greater severity of subcondylar fractures existed in patients treated with open reduction, patients treated with open reduction or closed treatment did not reveal a significantly functional difference. CONCLUSION: The present study revealed that patients with condylar neck or head fractures gained more benefits from open reduction in terms of chin deviation and temporomandibular joint pain. For subcondylar fractures, open reduction provides satisfactory functional results in patients with severely displaced fractures.

Adolescent↗
PubMed2002

Blindness as a complication of Le Fort I osteotomy for maxillary distraction.

High Le Fort I osteotomy and maxillary distraction has become an accepted method for the treatment of maxillary retrusion in children and teenagers with cleft lip and palate or craniofacial anomalies. This procedure effectively corrects the dentofacial deformity in these patients. No major surgical morbidity has been reported. During the past 4 years, 94 cleft patients with maxillary hypoplasia received Le Fort I osteotomy and distraction osteogenesis at the authors' center. Two of them developed blindness after this operation. The first case was a girl with bilateral cleft lip and palate with median facial dysplasia. She received high Le Fort I osteotomy at age 12 years 4 months to correct maxillary retrusion. Right eye swelling and ecchymosis was found after surgery. The patient complained of vision loss in that eye 2 days later. Computed tomography showed subarachnoid hemorrhage and skull base hematoma. There were no atypical fractures in the orbit, pterygoid plates, sphenoid bone, and skull base. Angiogram revealed left ophthalmic and basilar artery aneurysm. The second case was a 12-year-old boy with left cleft lip and palate. He received Le Fort I osteotomy to correct maxillary retrusion. During surgery, abnormal pupil dilatation was found after the osteotomy and down-fracture of maxilla. Emergent computed tomography found no hemorrhage or atypical fractures. Examination revealed complete left optic neuropathy and partial right abducens nerve palsy with mydriasis. Magnetic resonance imaging, magnetic resonance angiography, and repeated computed tomography revealed no sign of orbital injury, vascular problem, or abnormal fractures. The cause of blindness was unknown. In both cases, a steroid was used. Maxillary distraction was continued. Recovery of meaningful visual sense did not occur after 3 and 2 years' follow-up, respectively. A review of the literature revealed five other patients who suffered from visual loss after Le Fort I osteotomy. Inadvertent skull base fractures were identified in two cases, but a cause for the blindness was not known in the others. Induced hypotension and indirect trauma may be responsible for the optic nerve injury. In none of the cases was meaningful visual sense recovered, although high-dose steroids were given. In conclusion, a total of seven cases developed blindness after Le Fort I osteotomy. Once blindness develops, the prognosis is poor. High Le Fort I osteotomy should be performed with extreme care, and perhaps the informed consent should include visual loss as a complication of the procedure.

Abducens Nerve Diseases↗
PubMed2002

A cephalometric study of facial growth in van der Woude syndrome.

OBJECTIVE: To test the hypothesis that maxillary growth and lower lip form in patients with van der Woude syndrome (VDW) is different from patients with non-syndromic cleft lip and palate. DESIGN AND SETTING: Retrospective, case-control study at a tertiary cleft center, Chang Gung Memorial Hospital, Taipei, Taiwan. PATIENTS AND PARTICIPANTS: Records of 53 patients with VDW, who presented for treatment during the years 1968 through 1998 were obtained. Twenty-three of 53 patients had received at least one lateral cephalogram during the course of their treatment. Of these 23, in 17 it was possible to find non-syndromic case controls with identical cleft type, sex, and method of cleft palate repair, with year of birth matching within 1 year of the corresponding VDW patient. For these 17 pairs of VDW and non-syndromic cleft controls, cephalogram acquisition dates were checked to see how well the corresponding pairs matched. A total of 43 pairs of cephalograms were deemed to be acceptably matched because the ages at acquisition differed by less than 15% of the VDW patient's age. MAIN OUTCOME MEASURES: Thirteen measurements were derived from the 11 standard lateral cephalometric landmarks recorded on each cephalogram. The data were classified into five groups according to age at time of cephalogram, and sets of paired non-syndromic cleft and VDW measurements were tested for differences using a Wilcoxon signed rank sum test in two ways, first including all cleft types and then including only those patients with complete bilateral cleft lip and palate. A longitudinal growth analysis considering the movement of the skeletal A and B points was performed on the patients with complete bilateral cleft lip and palate. RESULTS: For the osseous measurements, anteroposterior maxillary length as described by the anterior nasal spine (ANS)-posterior maxillary point distance was statistically significantly shorter in the VDW patients of age 13 years and older, by 5.3 mm. Maxillary height, as described by the nasion-ANS distance was shorter in the VDW patients, closely approaching statistical significance in the age range 7 through 11 years. The lip soft tissue measurements showed significantly greater protrusion over several age ranges in the VDW patients. The longitudinal growth analysis showed a significantly more inferior vertical position of the B point in the controls. CONCLUSIONS: This study demonstrates a few statistically significant differences in maxillary growth and lip conformation between VDW and matching controls. Small sample sizes for each age group hamper the ability to fully interpret or generalize the pattern of these differences.

Adolescent↗
PubMed2002

Hereditary cleft lip/palate and Wilms tumor: a rare association.

OBJECTIVE: The association of cleft lip/palate (CLP) with other anomalies is not uncommon, but its association with Wilms tumor (WT) is very rare, especially in a familial pattern. In this report, we present a family in which six members in two generations were affected with CLP, WT, or both. PATIENTS AND RESULTS: A male patient presented with right complete CLP. He had a family history of facial cleft and abdominal tumor. Lip repair was performed at 3 months of age. An abdominal mass was noticed at 12 months of age, which proved to be WT. Surgical excision of the tumor and chemotherapy were conducted. He subsequently underwent palate repair. His father had an unrepaired microform cleft lip. Three of his aunts were known to have similar problems: one had both facial cleft and WT, one had WT only, and the other had facial cleft only. One of his cousins also was affected with WT. CONCLUSIONS: This is a unique family affected with a rare association of CLP and WT. Pedigree study revealed an autosomal dominant hereditary pattern.

Adult↗