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Biomedical subjects

L B Kaban

Publications and source records attributed to L B Kaban.

At least 37 records · Page 2Linked to original sources
PubMed2000

Extended genioplasty: long-term cephalometric, morphometric and sensory results.

The incision, dissection, osteotomy design and fixation are important technical considerations when performing a genioplasty. The purpose of this study was to describe an extended genioplasty technique and to evaluate stability of position, form, surface area of the chin and incidence of postoperative sensory deficit. Records of 15 consecutive adult patients who underwent the extended genioplasty procedure were reviewed. The technique included incision in the labial vestibule from 2nd premolar to 2nd premolar, dissection, mobilization and retraction of the mental nerves, osteotomy parallel to the occlusal plane extending proximally to the antegonial notch and rigid fixation. Lateral cephalograms pre- and postoperatively and at the latest follow-up (> 6 months) were analyzed by linear and computer morphometric measurements to evaluate changes in position, shape and surface area of the chin. Neurosensory data from examination or questionnaire were recorded. Immediately postoperatively (T1), mean advancement in the sagittal plane was +8.7 mm and increase in surface area was +1.1 cm2. At the end of follow-up (T2), there were no significant changes (T2-T1) in chin position or surface area. Inferior border form was rated as smooth in all cases. Neurosensory evaluation revealed that 12/12 patients evaluated had functional sensory return at T2.

Adult↗
PubMed2000

Minimally invasive orthognathic surgery: endoscopic vertical ramus osteotomy.

The endoscopic procedure for placement and activation of a distraction device for mandibular advancement has been previously reported. The purpose of this study was to demonstrate the feasibility of endoscopic exposure, dissection and osteotomy for mandibular set-back. Two cadaver and three anesthetized minipigs were used in this study. Access to the mandibular ramus was achieved through a 2.0 cm submandibular incision. The dissection was carried sharply to the mandible and completed in the subperiosteal plane. Visualization was achieved using a 2.7 mm diameter endoscope (Karl Storz, Germany). Landmarks were identified and a custom-made retractor was inserted into the sigmoid notch. A vertical ramus osteotomy was created (bilaterally) from the sigmoid notch to the mandibular angle. The mandible was set back (average 6 mm) and fixed using 2.0 mm diameter, bicortical screws. Live animals were sacrificed three weeks postoperatively. The mandibles were examined clinically and radiographically to verify proper osteotomy position and clinical union. In all animals, exposure, accurate identification of landmarks, osteotomy placement and screw fixation were achieved. In the live animals (n=3), union between the proximal and distal segments was documented by clinical and radiographic examination. This study demonstrates the feasibility of the EVRO procedure for mandibular set-back in a minipig model.

Animals↗
PubMed1999

Percutaneous stereotactic differential radiofrequency thermal rhizotomy for the treatment of trigeminal neuralgia.

PURPOSE: The purpose of this study was to evaluate the effectiveness of radiofrequency thermal rhizotomy (RTR) for trigeminal neuralgia, after failure of pharmacological management. PATIENTS AND METHODS: Two hundred fifteen patients underwent RTR from 1991 to 1996 and were prospectively evaluated. These patients were characterized by age, sex, side of the face, and division(s) involved. Patients were evaluated for pain relief, recurrence requiring or not requiring reoperation, and the type and rate of complications. They were followed-up by serial clinical evaluation and telephone interview. Patients were categorized into groups: 1) Successful result: excellent, good pain relief; and 2) Unsuccessful result: fair, poor, or no pain relief. The RTR group was compared with historical controls. Follow-up ranged from 9 to 68 months (mean, 32 months) and results were evaluated at early and long-term follow-up. RESULTS: At early follow-up (defined as immediately postoperatively to 6 months), pain relief of excellent or good quality (successful result) occurred in 198 of 215 patients (92%). Fair or poor or no pain relief (unsuccessful result) occurred in 17 (8%) patients. At long-term follow-up (>6 months to 68 months), recurrence of pain that required reoperation occurred in 24 patients (11%) and recurrence of pain that did not require reoperation (medically managed) occurred in 34 patients (16%). Dysesthesia developed in 18 patients (8%); seven patients (3%) had dysesthesia alone (medically managed) and 11 patients (5%) had dysesthesia with recurrence of pain (medically or surgically managed). "Anesthesia/analgesia dolorosa" developed in four patients (1.8%) and was medically managed. At long-term follow-up, 83% of patients had good to excellent pain relief (successful result). There were no mortalities, no significant morbidity, and a low rate of minor complications. CONCLUSION: With the use of this specific diagnostic approach and management algorithm, patients with trigeminal neuralgia can be successfully managed.

Adult↗
PubMed1999

Endoscopic mandibular osteotomy, and placement and activation of a semiburied distractor.

PURPOSE: The purpose of this study was to demonstrate the feasibility of endoscopic placement and activation of a semiburied distraction device in the porcine mandible. MATERIALS AND METHODS: Sixteen cadaver and two live anesthetized minipigs were used in this study. Access to the mandible was gained through two 1.0-cm submandibular incisions used for a working port and a visualization port. Under endoscopic visualization, dissection was carried sharply to the mandible and completed in the subperiosteal plane. Landmarks were identified through the endoscope, and a mandibular angle osteotomy was created. A semiburied distractor was then implanted, fixed to the mandible, and activated to create a bone gap. Finally, the site was explored through a submandibular incision to verify the accuracy of the endoscopic procedure. RESULTS: Endoscopic exposure; accurate identification of landmarks; creation of an osteotomy; and placement, fixation, and activation of a semiburied distractor were achieved in all 18 specimens. The inferior alveolar nerve was identified as the bone gap was expanded. CONCLUSION: The results of this study indicate that the endoscopic approach described here allows exposure and osteotomy of the mandible, and placement, fixation, and activation of a distractor. In the future, this technique will be used with totally buried, miniature distraction devices.

Animals↗
PubMed1999

Evaluation of a semiburied, fixed-trajectory, curvilinear, distraction device in an animal model.

PURPOSE: This study evaluated a new small, buried distractor, capable of curvilinear movement while following a fixed trajectory. The geometrical basis for such devices and the 3-dimensional treatment planning system required to make buried distractors practical are discussed. MATERIALS AND METHODS: A curved rack and worm-gear device, based on the design of a hose clamp, was constructed to produce a curved distraction path, and this distractor was tested in 2 minipigs using a protocol with zero latency and 1 mm/d x 7 days of distraction. Serial standardized lateral cephalograms were used to verify distractor function and path. RESULTS: Curvilinear distraction was documented by clinical examination and serial cephalometric analysis in the 2 minipigs. Observed angulation of the margins of the wedge-shaped distraction gap conformed to the calculated angulation based on the fixed radius of curvature of the distractor. CONCLUSION: Distraction along a curved trajectory using a small, semiburied, curvilinear device of novel design is feasible in the minipig mandible.

Animals↗
PubMed1999

Fine-needle aspiration biopsy of intraosseous jaw lesions.

PURPOSE: This study assessed diagnostic accuracy, determined reasons for error, and evaluated modifications to improve the reliability of fine-needle aspiration biopsy (FNAB) of primary jaw lesions. PATIENTS AND METHODS: This was a retrospective review of 32 FNABs of intraosseous jaw lesions performed at the Massachusetts General and Children's Hospital between 1993 and 1998. A consistent, standardized technique was used, and each case was evaluated for 1) adequacy of cells to allow diagnosis, 2) presence of malignant cells, and 3) correlation between FNAB diagnosis and the final histopathology. RESULTS: Material obtained by FNAB was adequate for evaluation in 30 of 32 cases. No complications were reported. Malignant cells were found in 5 of 30 cases. FNAB diagnosis was confirmed by histopathology in all 5 of these specimens (100% accuracy). The FNAB diagnosis of benign lesions was confirmed in 17 of 25 cases (68%). The most common benign lesions were odontogenic cysts, ameloblastomas, and fibro-osseous and giant cell lesions. Incorrect diagnosis was related to lack of architectural context of the FNAB material, sampling of a nonrepresentative part of a large lesion, and inadequate quantity or quality of the aspirate. CONCLUSIONS: FNAB is a useful technique to distinguish between malignant and benign intraosseous jaw lesions. Its simplicity, suitability as an outpatient procedure, rapidity of interpretation, and minimal morbidity potentially make it the diagnostic tool of choice in the hospital setting.

Biopsy, Needle↗
PubMed1999

Antiangiogenic therapy of a recurrent giant cell tumor of the mandible with interferon alfa-2a.

We report a 5-year-old girl with a large rapidly growing giant cell tumor of the mandible that recurred 2 months after the first surgical excision and 3 months after a second resection. An angiogenic protein, (bFGF), was abnormally elevated in her urine. The patient was treated with interferon alfa-2a for 1 year because this agent inhibits angiogenesis by suppressing bFGF overexpression in infantile hemangiomas and in other human tumors. During this time the bone tumor regressed and disappeared, the urinary bFGF fell to normal levels, and the mandible regenerated. She has remained tumor-free and has been off therapy for 3 years at this writing. This first successful use of interferon alfa-2a to treat a mandibular tumor in a child demonstrates: 1) low grade tumors that overexpress bFGF may respond to interferon alfa-2a, in a manner similar to life-threatening infantile hemangiomas; 2) antiangiogenic therapy, given without interruption for 1 year, was safe and effective in this patient; and 3) treatment may be continued for 1 year without the development of drug resistance.

Antineoplastic Agents↗
PubMed1999

Simultaneous maxillary and mandibular distraction osteogenesis with a semiburied device.

Distraction osteogenesis is a technique utilizing natural healing mechanisms to generate new bone; it is commonly used to lengthen the hypoplastic mandible. Distraction of the maxilla and mandible as a unit is an obvious extension of the technique. We describe the application of a semiburied distractor to simultaneously lengthen the mandible and maxilla and level a canted occlusal plane in three cases. The indications for bimaxillary distraction are reviewed, including its advantages, disadvantages and limitations.

Adolescent↗
PubMed1998

The impact of mucositis on alpha-hemolytic streptococcal infection in patients undergoing autologous bone marrow transplantation for hematologic malignancies.

BACKGROUND: Antibacterial prophylaxis with quinolone antibiotics has resulted in an increase in streptococcal infections among bone marrow transplantation (BMT) recipients with myelosuppression. Oral ulceration (mucositis), which frequently occurs as a consequence of chemotherapy, has been implicated as a significant portal of entry for streptococci. The objectives of this study were to confirm the correlation between mucositis and streptococcal bacteremia, determine the risk associated with this correlation, and evaluate the impact of mucositis and streptococcal bacteremia on hospital course and costs associated with autologous BMT. METHODS: This was a retrospective, case-control study in which the charts of autologous BMT recipients treated for hematologic malignancies between 1990 and 1996 were reviewed. Twenty-four patients were identified who met the criteria of autologous BMT; their blood cultures confirmed (x2) alpha-hemolytic streptococcal sepsis. A control group of 45 without positive cultures was matched by gender, age, diagnosis, and treatment to the study group. RESULTS: The results confirm that ulcerative mucositis is a significant risk factor for alpha-hemolytic streptococcal bacteremia among autologous BMT patients. Of the 24 patients with bacteremia, 15 of 24 (62%) had ulcerative mucositis, compared with 16 of 45 (36%) of patients in the control population (P < 0.05). Patients with ulcerative mucositis were found to be three times as likely to develop alpha-hemolytic streptococcal bacteremia as those without ulcerative mucositis (odds ratio=3.02). Both independently and as a cofactor associated with bacteremia, mucositis adversely affected the length of hospital stay (LOS). Of all the patients studied, those with oral ulcerations had a LOS of 34 days, compared with 29 days for patients without oral ulcerations (P < 0.05). Of patients in the study group, those with oral ulcerations stayed in the hospital 6 days longer than patients without oral ulcerations (40 days vs. 34 days, P < 0.05). CONCLUSIONS: Oral ulcerative mucositis is a significant, common, and important risk factor for alpha-hemolytic streptococcal bacteremia in BMT recipients with myelosuppression; it results in longer hospital stay and increased costs.

Adult↗
PubMed1998

Sensory abnormalities associated with mandibular fractures: incidence and natural history.

PURPOSE: The aims of this study were to determine the incidence of inferior alveolar nerve (IAN) abnormalities in patients with mandibular fractures and to document the natural history and spontaneous recovery rate in patients with a sensory disturbance. PATIENTS AND METHODS: This was a retrospective evaluation of patients (n = 150) with mandibular fractures at risk for IAN injury admitted to the Oral and Maxillofacial Surgery Service between 1985 and 1995. The inclusion criteria were: 1) fractures between the mandibular and mental foramina, 2) availability of the results of a post-injury, preoperative sensory examination, and 3) at least 1 year follow-up. Fracture characteristics, physical examination findings, hospital course, operative treatment, and follow-up were documented. Patient interviews were conducted to determine the incidence of long-term sensory disturbance and associated morbidity. The results were evaluated with chi-square analysis. RESULTS: Fifty-six percent of patients (84 of 150) had a post-injury/pretreatment IAN abnormality. Patients with sensory disturbance had a significantly higher frequency of displaced fractures than those without sensory disturbance (P < .001). Sixteen of 24 patients (66.7%) with an abnormal post-injury/ pretreatment sensory examination reported a permanent sensory deficit (mean follow-up, 74.3 months); 55% of these patients complained of impairment. CONCLUSIONS: The incidence of postinjury IAN deficits in patients with mandibular fractures was greater than 50% and was related to fracture displacement. One third of these patients regained normal sensation; the remaining two thirds reported a persistent sensory deficit. A significant number of these patients complained of discomfort and impairment after a mean follow-up of greater than 6 years.

Adult↗
PubMed1998

Gore-Tex tubing as a conduit for repair of lingual and inferior alveolar nerve continuity defects: a preliminary report.

PURPOSE: This report describes the results of using a Gore-Tex (Gore Company, Flagstaff, AZ) tube as a conduit for repair of continuity defects in the inferior alveolar or lingual nerves. PATIENTS AND METHODS: Seven nerve repairs were performed in five patients (M:F = 1:4) with an age range of 16 to 56 years. The duration from injury to repair ranged from 4 to 30 months. Two inferior alveolar and five lingual nerves were repaired. RESULTS: All seven patients had anesthesia by objective testing preoperatively and had a continuity defect at the time of operation. The size of the defects ranged from 2 to 15 mm. Two of the seven patients had some return of sensation, occurring in defects of 3 mm or smaller. CONCLUSION: The results of this pilot study indicate that Gore-Tex tubing may not be effective in the repair of continuity defects except in those defects 3 mm or smaller, in which it may act as a protective barrier membrane rather than as a conduit.

Adolescent↗
PubMed1998

Midfacial growth after costochondral graft construction of the mandibular ramus in hemifacial microsomia.

PURPOSE: The purpose of this study was to document vertical midfacial growth after costochondral graft mandibular ramus construction in children with type IIB and type III hemifacial microsomia (HFM). METHODS: This is a retrospective study of 33 children who underwent costochondral graft (CCG) construction for mandibular type IIB (abnormal, small, and medially displaced ramus, n = 19) and mandibular type III (absent ramus and glenoid fossa, n = 14) HFM, between 1980 and 1990. Types I and IIA patients were not included because their milder mandibular deformities were lengthened by osteotomy. Mean age at operation was 6.2 (2 to 10) years, and the mean follow-up period was 5.5 (1 to 13.5) years. Occlusal cant, piriform angle, and intergonial angle were measured on the most current posteroanterior (PA) cephalogram. The ratio of unaffected to affected ramus length was determined on the most current panoramic radiograph. Patient outcomes were classified based on the occlusal cant at the latest follow-up: group 1, successful result with a symmetrical maxilla (occlusal cant of <5 degrees); group 2, acceptable result (occlusal cant > or =5 degrees but <8 degrees), and Group 3, failure (occlusal cant > or = 8 degrees). OMENS scores were calculated for each patient: each of the five major anatomic deformities of HFM (orbital, mandibular, auricular, neural, and soft tissue) were graded 0 to 3 and summed. The mean differences in age at operation and OMENS scores between groups were calculated (ANOVA). RESULTS: At the end of follow-up, patients defined as having a successful result (group 1) had a mean occlusal cant of 2 degrees, a mandibular length ratio of 1.0, and an intergonial angle of 2 degrees. However, the final piriform angle was 7 degrees, indicating less vertical midfacial growth than maxillary alveolar growth. These patients were older at the time of operation (mean age, 6.7 years), and their mean OMENS score (6.3) was significantly lower (P = .004) than in patients in group 2 (mean age at operation, 6.3 years; mean OMENS score, 6.8) and group 3 (mean age at operation, 5.8 years; mean OMENS score, 7.8). In group 2, the occlusal cant, mandibular length ratio, and intergonial and piriform angles did not improve. In group 3, the occlusal cant and piriform angle became worse during the follow-up period. CONCLUSIONS: The results of this study indicate that after construction of the ramus and condyle in type IIB and III HFM patients, vertical midface growth is secondary to a combination of midfacial and alveolar growth. Patients operated on at an older age were more likely to have a successful long-term result. Finally, the severity of the overall deformity, as reflected in a higher OMENS score, appeared to be an important factor in the response to early correction.

Age Factors↗
PubMed1998

The in utero correction of unilateral coronal craniosynostosis.

We performed the first in utero correction of a unilateral right coronal craniosynostosis using 70-day gestation fetal lambs. The craniosynostosis was created in eight fetuses by excising their right coronal sutures, and then placing demineralized bone powder, transforming growth factor-beta, and bone morphogenetic protein-2 into the defect. Twenty-one days later, after suture fusion had occurred, four of the eight sheep were treated with a 4 mm x 12 mm strip craniectomy to open the entire synostosed right coronal suture. The edges of the excision were wrapped with 100-microm-thick Gore-Tex (W. L. Gore & Associates, Flagstaff, Ariz.) sheets to prevent bony refusion. All eight lambs then progressed to term (140 days). The skulls of four normal, unoperated, term lambs were used as controls. At 140 days, all four treated lambs had a widely patent strip craniectomy site without any evidence of bone regeneration. This in utero correction led to a marked improvement in craniofacial morphology of three of four animals when compared with the uncorrected controls with significant (p < 0.01) correction in orbital position, skull length, and shape of the frontal bone. This was in sharp contrast to the uncorrected animals, which had marked orbital elevation, compression of the anteroposterior length of the cranial vault, frontal bone flattening, and shortening of the cranial base. The fourth corrected animal also showed evidence of improvement but had some abnormal calvarial changes secondary to the development of horns, which displaced the calvaria in a downward vector. We conclude that the in utero correction of craniosynostosis is feasible and provides a significant benefit by decreasing the severity of many of the associated deformities seen with this disorder.

Animals↗
PubMed1997

Diagnosis and management of condylar resorption.

PURPOSE: This article discusses the cause, appropriate diagnostic evaluation, and management of progressive condylar resorption. PATIENTS AND METHODS: This retrospective study evaluated 28 adult patients with bilateral progressive condylar resorption. Investigation included serial clinical examination, lateral cephalograms, tomograms, and a technetium isotope bone scan when indicated. Twenty-two patients were managed by either condylectomy and reconstruction with a costochondral graft (n = 5 patients) or orthognathic surgery (n = 18 patients). One patient initially had orthognathic surgery and subsequently underwent condylectomy and costochondral grafting, making a total of 23 procedures on 22 patients. Six patients received no surgical treatment. All patients were observed at least 2 years postoperatively. RESULTS: Of the 18 patients who underwent orthognathic surgery, four again demonstrated condylar resorption with recurrence of open bite and retrognathism. Four patients had a stable result, but currently have temporomandibular joint (TMJ) symptoms, whereas 10 patients had a stable result (no change in postoperative occlusion or jaw position) without TMJ symptoms. The five cases receiving condylectomy and costochondral grafting were stable and asymptomatic, with good mandibular function. Analysis of the 18 orthognathic surgery patients showed that relapse occurred in patients having bimaxillary surgery with mandibular advancements greater than 5 mm and with a preoperative posterior ramus height of less than 35 mm. CONCLUSION: The management of progressive condylar resorption remains controversial. Orthognathic surgery in this small sample was associated with a complication rate (relapse or TMJ dysfunction) of approximately 45% (8 of 18). In contrast, condylectomy and costochondral grafting appeared to produce stable and functional results. Further long-term outcome studies for patients with condylar resorption are needed to corroborate these results.

Adolescent↗
PubMed1997

Occlusal cant in the frontal plane as a reflection of facial asymmetry.

PURPOSE: The purpose of this study was to compare subjective evaluation of occlusal canting in frontal photographs with objective radiographic measurements to determine the threshold at which a cant is recognized as abnormal. PATIENTS AND METHODS: Standardized frontal photographs (at rest and smiling) of two groups of orthognathic surgery patients were evaluated. Group 1 consisted of patients with a documented occlusal cant (n = 21), and group 2 consisted of patients with no cant (n = 22). Four untrained and five trained observers independently, and blind to the diagnoses, assessed patient photographs to judge the presence or absence of canting. These subjective results were compared with objective measurements of the angle of the occlusal plane to the true horizontal on each patient's posteroanterior (PA) cephalogram. RESULTS: The mean occlusal cant was 5.0 degrees +/- 1.6 degrees for group 1 and 1.4 degrees +/- 0.9 degree for group 2. The difference between groups was statistically significant (P < .01). Cants greater than 4 degrees were detected clinically with greater than 90% frequency by both untrained and trained observers. CONCLUSIONS: The results of this study indicate that 4 degrees is the threshold for recognition of an occlusal cant by 90% of observers. This information has significant implications for three-dimensional planning and outcome assessment in orthognathic and craniofacial surgery.

Adolescent↗