Full Facial Allotransplantation Including the Temporomandibular Joints: A Radiologic and Anatomical Cadaveric Study.

BACKGROUND: Facial allotransplantation including the temporomandibular joints may improve the functional outcomes in face transplant candidates who have lost or damaged this joint. METHODS: Linear and angular measurements were taken in 100 dry skulls and mandibles and in 100 three-dimensionally-reconstructed facial computed tomographic scans to determine the variability of the temporomandibular joint, glenoid fossa, and mandible. A vascular study was performed in six fresh cadaveric heads, followed by harvest of the face allograft in three heads. Next, four heads were used for mock transplantation (two donors and two recipients). The full facial allograft included four different segments: a Le Fort III, a mandibular tooth-bearing, and two condyle and temporomandibular joint-bearing segments. Statistical analysis was performed using SAS software. RESULTS: In only one-third of the skulls, the condylar shape was symmetric between right and left sides. There was a wide variability in the condylar coronal (range, 14.3 to 23.62 mm) and sagittal dimensions (range, 5.64 to 10.96 mm), medial intercondylar distance (range, 66.55 to 89.91 mm), and intercondylar angles (range, 85.27 to 166.94 degrees). This high variability persisted after stratification by sex, ethnicity, and age. The temporomandibular joint was harvested based on the branches of the superficial temporal and maxillary arteries. The design of the allograft allowed fixation of the two condyle and temporomandibular joint-bearing segments to the recipient skull base, preserving the articular disk-condyle-fossa relationship, and differences were adjusted at the bilateral sagittal split osteotomy sites. CONCLUSION: Procurement and transplantation of a temporomandibular joint-containing total face allograft is technically feasible in a cadaveric model.

Análisis experimental mediante vibrometría láser doppler en huesos temporales de cadáver fresco de una nueva prótesis de maleovestibulopexia / A new malleostapedotomy prosthesis. Experimental analysis by laser doppler vibrometer in fresh cadaver temporal bones

Introducción y objetivos. Confirmar en temporales frescos de cadáver el comportamiento óptimo teórico (previamente determinado en un modelo computadorizado del oído medio humano) de una nueva prótesis de sustitución osicular total así como objetivar la facilidad de colocación de la misma. Finalmente comprobamos su estabilidad tras ser colocada puesto que el diseño de esta nueva prótesis evita, teóricamente, su movilización o extrusión al anclarse directamente en el mango del martillo. Material y métodos. En el estudio analizamos, mediante vibrometría láser doppler, el comportamiento mecanoacústico de una nueva prótesis de recambio osicular total en el oído medio humano utilizando 10 huesos temporales de cadáver fresco. Resultados. El diseño de la prótesis impide su desplazamiento o extensión y facilita su colocación en el oído medio. La función de transferencia de los temporales a quienes se implantó la nueva prótesis se superpone con la del oído medio intacto antes de la colocación de la prótesis lo que sugiere un comportamiento mecanoacústico óptimo de la misma. Conclusiones. La prótesis de titanio evaluada en este estudio presenta un comportamiento mecanoacústico superponible al del oído medio intacto, lo que se suma a la facilidad de colocación y estabilidad posquirúrgica conviertiéndola en un diseño de prótesis a tener en cuenta ante una reconstrucción osicular total (AU)

Introduction and objectives. One of the problems with total ossicular replacement prostheses is their stability. Prosthesis dislocations and extrusions are common in middle ear surgery. This is due to variations in endo-tympanic pressure as well as design defects. The design of this new prosthesis reduces this problem by being joined directly to the malleus handle. The aim of this study is to confirm adequate acoustic-mechanical behaviour in fresh cadaver middle ear of a new total ossicular replacement prosthesis, designed using the finite elements method. Methods. Using the doppler vibrometer laser, we analysed the acoustic-mechanical behaviour of a new total ossicular replacement prosthesis in the human middle ear using 10 temporal bones from fresh cadavers. Results. The transfer function of the ears in which we implanted the new prosthesis was superimposed over the non-manipulated ear. This suggests optimum acoustic-mechanical behaviour. Conclusions. The titanium prosthesis analysed in this study demonstrated optimum acoustic-mechanical behaviour. Together with its ease of implantation and post-surgical stability, these factors make it a prosthesis to be kept in mind in ossicular reconstruction (AU)

Update on the surgical management of temporomandibular joint-centered tendon sheath giant cell tumor with intradural extension: introducing a cost-effective method in using temporal bone for skull base reconstruction in preventing brain hernia.

Tendon sheath giant cell tumor is an idiopathic proliferative and destructive disease of the synovium. It is rare and tends to arise in large joints, for example, knee and ankle, but it can also arise in temporomandibular joints (TMJs). Because of its destructive nature, immediate treatment upon diagnosis is recommended. Radical resection proved to be an excellent choice for superior local control. However, the unfavorable anatomic location of TMJ and infratemporal fossa tumor with intradural extension make such a resection impractical. Hereby, we reported a case of resection of a TMJ tendon sheath giant cell tumor with intradural extension using a transcranial approach. This involves a complex radical resection with subsequent reconstruction. Transposition of temporal bone flap is a novel state-of-the-art technique in reconstructing the middle fossa floor defect by providing a three-dimensional rigid architecture to support the brain. Temporal bone flap is a reliable plug for rigid support in preventing brain hernia and cerebrospinal fluid leak. Despite its complexity, this cost-effective technique is relatively straightforward to learn and is applicable across all socioeconomic groups.

Endoscopic procurement of tympano-ossicular allografts: alternative to the transcranial or retroauricular technique.

A tympano-ossicular tissue bank complying with European Union regulations on human allografts is feasible and critical to assure that the patient receives tissue which is safe, individually checked and prepared in a suitable environment. The transcranial procurement technique has become the standard approach to procure tympano-ossicular allografts since the 1970s because it can provide en bloc allografts. Over the last 10-20 years, en bloc allografts have been abandoned and only the malleus (hammer) is left attached to the tympanic membrane. This modification enables introduction of the transmeatal procurement technique. Transmeatal procurement using readily available nasal 0° and 30° endoscopes is a feasible alternative which avoids contact with the dura mater and is not esthetically invasive to the donor. It involves a more time-consuming procurement but avoids the need for preparation of the temporal bone plug and is therefore generally more time-efficient.

Histopathologic assessment of fibrosis and new bone formation in implanted human temporal bones using 3D reconstruction.

OBJECTIVE: To evaluate new bone formation and fibrosis in implanted human temporal bones and relate that to neurosensory elements preservation. STUDY DESIGN: Human temporal bone histopathology study. SETTING: Temporal bone laboratory. SUBJECTS AND METHODS: Ten human temporal bones from eight patients with multichannel cochlear implants and one single-electrode implant were examined under light microscopy and reconstructed with AMIRA 4.1 3D reconstruction software. Volumes of new bone formation, fibrosis, and patent area were calculated in each bone. RESULTS: The amount of fibrosis and new bone formation postimplantation varied among bones. There were no statistically significant relationships between age at implantation or duration of implantation and the overall amount of new tissue in the implanted ear. There was a relationship between total amount of new tissue and preservation of neurosensory elements only in segment I of the cochlea (Rho=-0.75, P

Human temporal bones versus mechanical model to evaluate three middle ear transducers.

A life-size mechanical middle ear model and human temporal bones were used to evaluate three different middle ear transducers for implantable hearing aids: the driving rod transducer (DRT), the floating mass transducer (FMT) or vibrant sound bridge, and the contactless transducer (CLT). Results of the experiments with the mechanical model were within the range of the results for human temporal bones. However, results with the mechanical model showed better reproducibility. The handling of the mechanical model was considerably simpler and less time-consuming. Systematic variations of mounting parameters showed that the angle of the rod has virtually no effect on the output of the DRT, the mass loading on the cable of the FMT has a larger impact on the output than does the tightness of crimping, and the output level of the CLT can be increased by 10 dB by optimizing the mounting parameters.

[Clinical and X-ray assessment of different modes for correcting orbital bottom defects in posttraumatic deformities of the middle one-third of the facial skeleton].

The paper describes the evolution and consequences of different modes of eliminating orbital bottom defects and deformities that develop in posttraumatic deformities due to bone fractures of the facial mid-skeleton. Spiral computed tomography of this portion of the facial skeleton has demonstrated that the optimum results of restoration of the orbital bottom and those of elimination of eyeball displacement give the use of osteoplasty with a split parietal bone graft.

Cranial bone grafts in cerebrospinal fluid leak and encephalocele repair: a preliminary report.

BACKGROUND: With the introduction and subsequent widespread acceptance of endoscopic surgery, otolaryngologists are increasingly being called on to care for patients with cerebrospinal fluid rhinorrhea and meningoencephaloceles. Patients with large encephaloceles and skull base defects present a special challenge. We present our experience with cranial bone grafts in treating this important entity. METHODS: Our clinical experience was reviewed from 1998 to 2001. Review parameters included defect size, cranial bone graft harvest site and size, and graft appearance on postoperative follow-up. RESULTS: Results revealed that 20 patients underwent defect repair with cranial bone graft. The average defect was approximately 0.92 x 0.7 cm; nine defects were located in the ethmoid roof, eight defects were in the sphenoid, and three defects were in the posterior table of the frontal sinus. Donor sites included 2 parietal, 3 frontal, and 15 temporal (mastoid). Grafts healed well and all defects remained closed on endoscopic and computerized tomographic follow-up. All donor sites healed well. CONCLUSION: Our experience indicates that cranial bone graft is an excellent material for endoscopic reconstruction of skull base defects. It confers special advantages in large defects, in defects with complex three-dimensional characteristics, and in patients with cerebrospinal fluid leaks associated with an elevated intracranial pressure.

Middle-ear mechanics of Type III tympanoplasty (stapes columella): I. Experimental studies.

OBJECTIVE: To investigate the mechanics of Type III tympanoplasty by developing a cadaveric temporal bone model. BACKGROUND: Type III stapes columella tympanoplasty involves the placement of a tympanic membrane graft, usually made of temporalis fascia, directly onto the stapes head. The procedure is usually done in conjunction with a canal wall down mastoidectomy. Postoperative hearing results vary widely, with air-bone gaps of 10 to 60 dB. The structural features responsible for the wide range in hearing results have not been systematically investigated. METHODS: Canal wall down Type III procedures were performed in eight cadaveric temporal bones. Acoustic stimuli were presented in the ear canal, and round window velocity VRW (used as an index of hearing) was measured, while systematically varying stapes mobility, mechanical properties of tympanic membrane graft, and tightness of connection between tympanic membrane graft and stapes. The effect of interposing a thin cartilage disc between the tympanic membrane graft and stapes head was also assessed. RESULTS: When the middle ear was aerated and the stapes was mobile, VRW was 15 to 30 dB lower than in an intact, normal ear. Stapes fixation led to a significant reduction in VRW; reduction was greatest at low frequencies. There was little effect of varying the tightness of connection between the tympanic membrane graft and stapes head. Sound energy was transmitted from the graft to the stapes as long as the graft was in physical contact with the stapes head. Different tympanic membrane graft materials with a range of mechanical properties (stiffness and mass) resulted in little variation in VRW. Interposing a thin cartilage disc between the tympanic membrane graft and stapes improved VRW in the lower frequencies by 5 to 10 dB. The authors hypothesize that the disc acted to increase the effective vibrating area of the graft. CONCLUSIONS: The feasibility of using a cadaveric temporal bone model to study the mechanics of Type III tympanoplasty was demonstrated. A mobile stapes and aerated middle ear were essential for a successful Type III tympanoplasty. There was little effect of varying the mechanical properties of the tympanic membrane graft or changing the tightness of connection between the graft and stapes head. Improved results were achieved by interposing a thin cartilage disc between the graft and stapes head to increase the effective vibrating area of the graft.

Temporoparietal fascia: an anatomic and histologic reinvestigation with new potential clinical applications.

Temporoparietal fascia constitutes a very important structural unit from both an aesthetic and a reconstructive surgical point of view. A histologically supported anatomic study was conducted for the reappraisal of the anatomic relationships and clinical application potentials of the data obtained. Anatomy of the temporoparietal fascia was investigated on 20 sides from 10 cadavers. After dissections, necropsies were obtained to demonstrate histologic features of the temporoparietal fascia. The outer part of the temporoparietal fascia is continuous with the superficial musculoaponeurotic system (SMAS) in the inferior border and with orbicularis oculi and frontalis muscles in the anterior border. Therefore, plication of the temporoparietal fascia can increase tightness of the SMAS, orbicularis oculi, and frontalis muscle in rhytidectomy. The frontal branches of facial nerve were noted to course parallel to the frontal branch of the superficial temporal artery, lying deeper to the temporoparietal fascia within the innominate fascia. In the view of these findings, conventional subfascial dissection, which is performed to protect frontal branches of the facial nerve, is not reasonable during the temporal part of rhytidectomy. Careful subcutaneous dissection just under the hair follicles is more appropriate to avoid nerve injury and also provides excellent exposure of the temporoparietal fascia for plication in rhytidectomy with protection of the auriculotemporal nerve and the superficial temporal vessels. Furthermore, two layered structures of the temporoparietal fascia are very suitable to insert a framework into the temporoparietal fascia for ear reconstruction to eliminate some of the shortcomings of Brent's technique. A thin muscle layer was also noted within the outer part of the temporoparietal fascia below the temporal line; the term "temporoparietal myofascial flap" would, therefore, be more accurate than "temporoparietal fascial flap." Finally, the innominate fascia and the deep temporal fascia can be elevated with the two layers of the temporoparietal myofascial flap to obtain a well-vascularized, four-layered myofascial flap based on the superficial temporal vessels. This multilayered flap can be used to reconstruct all defects when fine, pliable, thin, multilayered flaps are required.

Masking the protrusion of the receiver-stimulator of electronic implants in otology.

Protrusion of the receiver-stimulator of a cochlear implant or a piezoelectric implantable hearing aid (IHA) was masked using bone dust applied in the gap between the receiver and the surrounding bone, making a smooth transitional border. The bone dust was then fixed with fibrin glue. Bone pâté (a mixture of bone dust and fibrin glue) was also used to fix the lead wire of a cochlear implant at the region of the posterior tympanotomy and to fasten an IHA vibrator holder to the temporal bone. Over the past two years, the use of these techniques in six patients with cochlear implants and two patients with IHAs has resulted in gratifying results; the edge of the receiver remained flush in all cases. They have been free from problems such as infection of the wound, necrosis of the overlying skin, and protrusion or migration of the receiver.

Surgical treatment of recurrent mandibular dislocation by augmentation of the articular eminence with cranial bone.

PURPOSE: This article describes the use of calvarial bone grafts to augment the height of the articular eminence to treat recurrent mandibular dislocation. PATIENTS AND METHODS: Eight patients with mandibular recurrent dislocation were studied clinically, radiographically, and with magnetic resonance imaging (MRI) immediately before surgery, and at 1 week, 6 months, and 1 year after the operation. All the patients were treated with a modification of the Lindemann-Norman technique, performing an oblique osteotomy in the articular eminence and placing a calvarial graft into the osteotomy to augment the height of the eminence. RESULTS: During 18 months of follow-up, no cases of dislocation were noted. CONCLUSION: The results of this study indicate that the surgical technique presented has very low morbidity and predictable outcomes.

Total reconstruction of the temporomandibular joint with cryogenically preserved allograft mandibular condyle, meniscus, and fossa in the adult goat.

OBJECTIVE: The purpose of this study was to determine the feasibility of total temporomandibular joint reconstruction with the use of cryogenically preserved allograft mandibular condyle, disk, and fossa in the adult goat. STUDY DESIGN: This study consisted of an experimental group of 10 adult goats that underwent total resection of their temporomandibular joints. These animals were immediately reconstructed with cryogenically preserved mandibular condyles, disks, and fossa. These allograft were harvested from 10 donor animals matched to the recipient animal with respect to age, sex, and head dimensions. These grafts were harvested and stored at -185 degrees C for several months before implantation. At 2 years after surgery, the animals were killed. They were evaluated, clinically, radiographically, and histologically. RESULTS: Fifty percent of the eight surviving animals had a normal clinically functional joint with an intact superior joint space and viable articular surfaces. CONCLUSION: The authors conclude that this temporomandibular joint reconstruction technique is feasible in the adult goat model and is deserving of further research.

The styloid process in ossicular chain reconstruction. II: Long-term analysis.

The human cadaveric styloid process was used as a homograft material for ossicular chain reconstruction in 41 cases of chronic suppurative otitis media over a five-year period. Although technical success was achieved in about 88.23 per cent of the cases, actual patient benefit was around 70.58 per cent; this is comparable to results obtained with most other homologous graft materials. The problem of breakage while remodelling the bone has also increased the risk of transmitting the AIDS virus and consequently undermines the use of this material.

Vascularized cranial bone grafts for mandibular and maxillary reconstruction. The parietal osteofascial flap.

The authors have performed 13 cases of vascularized cranial bone grafts for reconstruction of maxillofacial defects since 1986. Two types of flaps were used: the parietal osteofascial flap pedicled to the parieto-temporal fascia based on the superficial temporal artery and the temporalis osteomuscular flap pedicled to the temporalis muscle based on the deep temporal artery. Zygomatico-orbital complex, maxilla and mandible were reconstructed and hemifacial microsomia was also treated. The results of vascularized cranial bone grafts pedicled to fascia were as good as those of grafts pedicled to muscle. There were no major complications. Two types of vascularized cranial bone grafts seem to be useful in reconstruction of maxillofacial defects with avascular recipient beds because of their good blood supply. The parietal osteofascial flap has additional advantages including easy rotation of the flap to the defect, particularly a mandibular defect, and versatile use of fascia without bulkiness for reconstruction of soft tissue defects. This flap can be designed as a full- or partial-thickness cranial bone graft with good vascularity. In this paper, our technique for mandibular and maxillary reconstruction using the parietal osteofascial flap is introduced, and the results compared with our temporalis osteomuscular flap technique are reported.

The surgical treatment of noma.

Noma is a gangrenous stomatitis affecting children from developing countries. It may leave dreadful mutilations around the mouth, with amputation of the lips, cheek, nose, lids, maxilla, palate, or mandibula. Reconstruction should take into account the size of the defect, the presence of trismus or constriction of the mandible, the age of the child, and the child's general condition. During the last 3 years, eight patients were treated at the Unit of Plastic and Reconstructive Surgery of the Hôpital Cantonal Universitaire. Except in one case, tracheostomy was avoided, thanks to intranasal intubation by fibroscopy. These children, aged 2 to 9 years, underwent 31 general anesthesias and complex reconstructive procedures, including latissimus dorsi musculocutaneous pedunculated and free flaps, cranial flaps with galea, cranial bone and skin grafts, and retroauricular temporal skin flaps. All patients were able to return to Africa with dramatic functional and cosmetic improvements. However, satisfactory mouth opening and mandibular function were not always obtained.