Transoral negative-pressure catheter drainage of a retropharyngeal and mediastinal abscess.

PURPOSE: A retropharyngeal abscess (RPA) is an extremely rare entity in adults that has a tendency to spread vertically and cause a mediastinal abscess. Traditionally, immediate aggressive drainage is recommended via a transcervical or transthoracic approach for the treatment of a retropharyngeal abscess with mediastinal extension. Here, we present a case of a retropharyngeal and mediastinal abscess using a transoral negative-pressure catheter drainage approach. PATIENTS AND METHODS: A 24-year-old woman was admitted with a 4-day history of severe sore throat and painful swallowing. Computed tomography identified a retropharyngeal abscess extending to the upper posterior mediastinum. We performed transoral negative-pressure catheter drainage. RESULTS: The postoperative course was uneventful. The patient reported a rapid improvement in symptoms and had a good tolerance of the catheters in the nasal cavity. At 2 years postoperatively, physical examinations revealed no recurrence or surgical complications. CONCLUSIONS: Transoral negative-pressure catheter drainage is a minimally invasive operation for the treatment of RPA in adults with or without a mediastinal abscess. This method could be recommended as an alternative approach in such cases.

Selection of optimal expansion angle and length of an expandable implant in the osteoporotic mandible: a three-dimensional finite element analysis.

PURPOSE: To identify from a biomechanical point of view the optimal parameters for an expandable implant in the osteoporotic mandible, a three-dimensional finite element model (FEM) of an expandable implant was created with variations in expansion angle and expansion length. MATERIAL AND METHODS: FEMs of osteoporotic posterior mandibular segments with an expandable implant were created. An axial load of 100 N and a buccolingual load of 30 N were applied to the implant. The expansion angle ranged from 0 to 4 degrees, and the expansion length ratio ranged from 1/6 to 5/6. The maximum equivalent stress (max EQV stress) in jawbone and the implant-abutment complex and the maximum displacement in the implant-abutment complex were evaluated. RESULTS: With changes in the expansion angle and expansion length ratio, the max EQV stress in cortical and cancellous bone increased by 12.4% and 73.9%, respectively, under axial loading, respectively, and by 38.6% and 69.1%, respectively, under buccolingual loading. The max EQV stress in the implant-abutment complex increased by 65.3% and 160% under axial and buccolingual loading, respectively. Maximum displacement in the implant-abutment complex increased by 3.66% and 19.73% under axial and buccolingual loading, respectively. CONCLUSION: Expansion angles and the expansion length ratio favored stress distribution in jawbone under axial and buccolingual loads, respectively. An expansion angle between 1.5 and 2.5 degrees and an expansion length ratio between 2/6 and 3/6 provided optimal biomechanical properties for an expandable implant in the osteoporotic mandible.

A new gliotoxin analogue from a marine-derived fungus Aspergillus fumigatus Fres.

A new gliotoxin analogue (1), as well as four known compounds gliotoxin (2), bisdethiobis (methylthio) gliotoxin (3), bis-N-norgliovictin (4) and didehydrobisdethiobis (methylthio) gliotoxin (5), were isolated from a culture of marine-derived fungus Aspergillus fumigatus Fres. The structure of 1 was determined on the basis of spectroscopic methods. All five compounds were evaluated for the cytotoxic effects on tsFT210 cell line by the SRB method.

Multiplanar and combined distraction osteogenesis for three-dimensional and functional reconstruction of unilateral large maxillary defects.

We have developed a new way of three-dimensional and functional reconstruction of unilateral large maxillary defects by multiplanar and combined distraction osteogenesis of the zygoma, maxillary alveolar process, and hard palate. In the first procedure we started the internal curvilinear distraction osteogenesis of the left zygoma in one patient who had had a left maxillectomy to rebuild midfacial bony support. In the second procedure, the internal curvilinear distraction osteogenesis of the maxillary anterior alveolar process and straight distraction osteogenesis of the right hard palate were used to restore the posterior alveolar process and left palate. In the third procedure, the distracted zygoma and alveolar process were connected by a small local bone graft. The important lost maxillary bony architecture was re-established three-dimensionally and resulted in a natural facial appearance, normal speech and swallowing, and good foundation for chewing. This may be the first example of three-dimensional and functional reconstruction of unilateral large maxillary defects that did not require bone grafts from other anatomical areas.

[Application of multislice helical computed tomography in maxillofacial distraction osteogenesis].

OBJECTIVE: To develop the method and investigate the value of the application of multislice helical computed tomography (CT) in the maxillofacial distraction osteogenesis. METHODS: Twelve cases of maxillofacial distraction osteogenesis (3 in zygoma, 2 in maxilla, and 7 in mandible) were scanned by the multislice helical CT, then the reconstruction of three dimensional and fault image and the relative measurement were carried out to study the effect of distraction and osteogenesis. RESULTS: The three dimensional image provided clear and high resolution stereoscopic view that the effect of distraction osteogenesis could be evaluated easily and exactly. The fault image could be set up in private computer by Mimics and the measurements, such as distance, thickness and density, could be performed as expected. The effect of 12 cases was satisfied, and the average distracted distance was 16.73 mm. CONCLUSION: Basing on multislice helical CT scanning, the high resolution image reconstruction and relative measurement data could be obtained which could meet the need of clear and direct observation. Its application in the maxillofacial distraction osteogenesis is expecting and promising.

Evaluation of a new semiburied curvilinear distraction device in dogs.

We developed a semiburied, curvilinear distraction device for use in osteogenesis in the reconstruction of maxillofacial defects. The device was tested in two dogs, which had segmental defects made in the maxilla and zygoma. The residual zygoma was distracted with the device. The bony transport discs were distracted about 12mm around an arc, and the new bone formed well in the distracted gap. The semiburied curvilinear distraction device has proved to be reliable for internal curvilinear distraction. Its clinical applicability needs to be studied further.

[Segmental reconstruction of maxillary defects by arced distraction osteogenesis of zygoma].

OBJECTIVE: To study the possibility of segmental maxillary regeneration by arced distraction osteogenesis of zygoma. METHODS: The distraction of zygoma with the internal arced devices was performed in 2 dogs to simulate the reconstruction of maxillary defect. The zygoma was distracted about 12 mm, and the process of new bone formation was studied by histology and scanning electron microscopy. RESULTS: The transport disk was distracted about 12 mm around the arc. After 8 weeks of consolidation, the density of new bone was close to that of normal bone. CONCLUSIONS: The segmental maxillary regeneration by arced distraction osteogenesis of zygoma is possible.