[Two rare complications in patients with bone-anchored hearing aids]. / Zwei seltene Komplikationen bei Patienten mit knochenverankerten Hörgeräten.

In our program of bone-anchored hearing aids we experienced two rare complications: a child with a hearing aid fell on her head and got an intrusion of the bone-screw into the intracranial space with a fracture of tabula externa and interna. There were no further intracranial complications, no hematoma or infection. The screw was explanted immediately with oto-microsurgical instruments and diamond burrs. The site of the screw was covered with a local skin flap. There were no complications in wound healing and the child got a second implant on the other side. A patient got an infection of his bone fixation screw and we took out the external fixation but left in place the bone screw, which was obviously still well fixed and the adjacent bone was without signs of infection. There was good secondary wound healing with local and systemic antibiotics. With almost completely healed external wound the patient got an intracranial abscess, that needed neurosurgical drainage. After long-time antibiotic treatment the patient is well again.

Immunophenotypic analysis of normal mucosa and squamous cell carcinoma of the oral cavity.

Detection of tumor-associated alterations in peritumoral normal mucosa may give insight into the molecular pathogenesis of oral cancer. In the present study, 100 archival oral squamous cell carcinomaswith adjacent nontumorous mucosa were immunohistochemically investigated with antibodies against p53, Mdm2, Bcl-2, WAF1, MIB1, epidermal growth factor receptor (EGF-R), and various CD44 isoforms. Additionally a standardized argyrophilic nucleolar organizer region (AgNOR)-associated proteins analysis was performed. No correlation was found between p53, Mdm2, Bcl-2, and WAF1 immunophenotypes of the respective tumors and adjacent mucosa. The proliferation-associated markers MIB1 and AgNORs showed a statistically significant sequential increase from normal to dysplastic mucosa to invasive carcinoma. Investigation of various CD44 adhesion molecules revealed a highly variable expression pattern in overt carcinomas with a significantly decreased expression of CD44 v4 and v9 variants and unaltered strong expression of v5 and v6 isoforms compared with normal oral epithelium. We conclude that proliferation markers (MIB1 and AgNORs), as well as selected CD44 isoforms, represent useful markers for the assessment of precancerous lesions. They may be utilized for screening patients at high risk for the development of oral cancer.