A Case of Ancient Schwannoma in Retromaxillary Area Removed with Le Fort I Osteotomy Approach

Schwannoma, which manifests as a smooth and solitary, encapsulated lesion, originates from the nerve sheaths of Schwann cells. Ancient schwannoma, a rare histologic variant of schwannoma, characterized by its distinctive degenerative changes. Basically, treatment entails complete removal of the mass, with maximal safeguarding of the nerve. However, depending on tumor size and extent, complete removal can be problematic. Le Fort I osteotomy in orthognathic surgery is widely utilized and can be effective to remove the skull base tumors. A 25-year-old woman presented with stabbing pain of 1-2 seconds duration occurring every two hours in the interior of the right face, which condition had persisted for one year. Magnetic resonance imaging showed mass lesion in the right retromaxillary area. Mass in retromaxillary area was removed by Le Fort I osteotomy. Pathologic examination confirmed the diagnosis of ancient schwannoma. In the course of a six-month follow-up, neither recurrence nor malocclusion was observed.

A Case of Cochlear Implantation in a Patient with Mutation in the Coagulation Factor C Homology Gene(W117R) / 대한이비인후과학회지

The autosomal dominant deafness disorder at the DFNA9 locus has been described and the clinical aspects extensively characterized, showing adult-onset, progressive sensorineural hearing loss and vestibular dysfunction. DFNA9 is caused by mutations of the human Coagulation factor C homology (COCH)gene. COCH encodes cochlin, a highly abundant secreted protein of unknown function in the inner ear. Several mutations have been identified so far: P51S, V66G, G87W, G88E, V104del, I109T, I109N, W117R, A119T, M512T, C542F, C542T. We hereby report a case of cochlear implantation in a 55-year-old man with bilateral sensorineural hearing loss, which is caused by a mutation in COCH gene (W117R).

Rat Mastoid Bullae Obliteration with Hydroxyapatite: Histopathologic Results with Various Size of Hydroxyapatite / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Mastoid obliteration is the technique developed to reduce cavity problems after canal wall down mastoidectomy. Different materials have been explored for the technique, and of the variety of materials that have been used for mastoid obliteration, hydroxyapatite has gained particular attention. Hydroxyapatite can be made into a specific particle size, which affects the postoperative result. The aim of this study is to evaluate the histopathologic findings of mastoids obliterated with various particle sizes of hydroxyapatite in the temporal bullae of rat. Materials and Method: Rat bullaes were obliterated with hydroxyapatite and diversified into different particle sizes. In group 1, the mastoids were obliterated with Mimix(R) powder and in groups 2, 3, 4 with Bongros(R). The particle sizes were 0.3-0.6 mm, 0.6-1.0 mm and 1.0-3.0 mm each. After 3 months, the mastoids were examined under the microscope. RESULTS: In group 1, a new bone was formed in a consecutive fashion from the mastoid wall toward the center of the mastoid; there was no inflammation, with the new bone formation constituting 15%. In group 2, 3, 4, the proportion of new bone formation was higher than in the group 1, and constituted 40%, 55% and 60%, respectively. Inflammation was more severe when the particle size became larger. CONCLUSION: New bone formation was faster if larger hydroxyapatite particles were used; however, inflammation also increased. The powder form of hydroxyapatite was slow in new bone formation, but there was little inflammation. We therefore think that the hydroxyapatite is a very safe material.

Histologic Serial Changes of Obliterating Materials in the Rat Temporal Dorsal Bullae / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Mastoid obliteration surgery is a modern trend for otitis media either with or without cholesteatoma. The aim of our study is to evaluate histologic changes and effectiveness over time resulting from different obliterating materials and the existence of mucosa in the temporal dorsal bullae in rats. MATERIALS AND METHOD: Rats were divided into two groups. One group had the mucosa removed and was treated with trichloroacetic acid (TCA). The other group with mucosa remaining was untreated. The temporal dorsal bullae of the two groups of rats were obliterated with Mimix(R) (hydroxyapatite cement), Regenafil(R) (demineralized bone matrix), cartilage chip, and bone chip. Three months and again six months after the implantation, 5 animals in each group were examined. A histological study was performed to evaluate inflammation, new bone formation, and mucocele formation within the bullae. RESULTS: The group that had Mimix(R) implanted had a high inflammatory reaction, low implanted material resorption and cyst formation. The group with Regenafil(R) implanted had high cyst formation and more cyst formation with the passage of time. The group with bone chip implanted had high new bone formation, but also high cyst formation. The group that had cartilage chip implanted had high new bone formation, low implanted material resorption and low cyst formation. CONCLUSION: Cartilage chip is the only material that should be used in the air cell with mucosa remaining. Demineralized bone matrix and bone chip should not be used in the air cell with mucosa remaining. Hydroxyapatite cement should not be used due to severe inflammation.

Comparison of the Efficacy of Systemic and Intratympanic Steroid Treatment on Sudden Sensorineural Hearing Loss with Diabetes / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: High dose systemic steroid therapy is currently the mainstay of the treatment for sudden sensorineural hearing loss (SSNHL). However, it makes a glycemic control worse in patients with diabetes. Intratympanic steroid injection (ITSI) can result in reduced systemic steroid toxicity and higher perilymph steroid level selectively. The purpose of this study is to compare the efficacy of ITSI (IT group) with that of systemic steroid (IV group) on SSNHL with diabetes. SUBJECTS AND METHOD: Thirty eight SSNHL patients who were diagnosed with diabetes were divided into the IV group (19 patients) and the IT group (19 patients). In the IV group, prednisolone was administrated intravenously for 7 days followed by tapered doses orally for 7 days. In the IT group, dexamethasone was administrated 4 times within a 2 week-period. Hearing outcome was assessed before and after treatment. RESULTS: In the IV group, 10 patients (58.8%) showed an improvement in the pure tone audiogram (PTA), with a mean improvement of 17.6 dB (p=0.023). In the IT group, 16 patients (84.2%) showed improvement in the PTA, with the mean improvement of 25.1 dB (p=0.000). But there was no significant difference in hearing gain and the recovery rate between the two groups. And it is more difficult to control blood sugar in the IV group rather than in the IT group. CONCLUSION: ITSI treatment is as effective as the systemic steroid treatment for SSNHL patients with diabetes and it can avoid a significant side effect of systemic steroids. So it could be considered as an initial treatment for the SSNHL patient with diabetes.

A Case of Traumatic Neuroma in Infraorbital Nerve / 대한이비인후과학회지

The term "traumatic neuroma" is used to describe the nodular mass of regenerating axons and Schwann cells that develop at the end of a proximal nerve stump following partial or complete transection of a nerve. Traumatic neuromas of the head and neck are relatively rare, and pain is the main symptom. Several cases of the traumatic neuromas of the head and neck have been reported in the literature at such sites as oral cavity, maxillary division of the trigeminal nerve, the inferior alveolar of the mandible, the auriculotemporal nerve, the glossopharyngeal nerve, and the facial nerve. We experienced a 60-year-old woman with a painful mass in her right cheek, appearing 10 years after she had pricked her right cheek with an umbrella. This mass was excised and the pathologic diagnosis was traumatic neuroma. We report this case here with a review of the literature.

A Biomechanical Analysis of Surgical Procedures for Osteonecrosis of the Femoral Head using Three-Dimensional Finite Element Method: A Parametrical Analysis by Varying Physiological Loading Conditions / 대한정형외과연구학회지

Many operative procedures for osteonecrosis of the femoral head(ONFH) have been proposed, but their clinical results remain controversial to many clinicians. Recently, a new surgical procedure that incorporates cementation with polymethylmethacrylate(PMMA) after core drilling has been tried clinically. In this study, a finite element method (FEM) was employed to analyze and compare various surgical procedures of ONFH to provide a biomechanical insight by varying physiological loading conditions. Our finite element models were constructed for this purpose they included normal, necrotic, core decompressed, fibular bone grafted, and cementation models. The extent of necrotic region was determined based upon the average CT-scan data from 10 patients. The physiological load directions and magnitudes during the gait cycle were selected at the stage of heel-strike, toe-off, and average stance. The von Mises stresses were calculated and volumetric percentages of the necrotic region under different levels of stresses were analyzed for each model. Our results indicated that there were substantial increase of the necrotic region subjected to the high stress level (beyond 11 MPa) and decrease in the low stress level (below 5 MPa) with the core decompression model, an indication of a malignant stress transfer pattern. On the other hand, the exact opposite pattern of stress transfer was noted with the fibular bone graft and cementation methods suggesting that they could provide structural integrity within the necrotic region.