The temporal bone appears to be involved with secondary malignant processes in discrete histologic patterns with rather characteristic clinical presentations. Five distinct types of involvement can be recognized: isolated metastasis from a distant primary tumor; direct extension from a regional primary tumor; meningeal carcinomatosis; leptomeningeal extension from an intracranial primary tumor; and leukemic or lymphomatous infiltration. The typical histopathological patterns are described with correlative clinical symtomatology. Differential diagnosis is considered, and guidelines for surgical management are discussed.

Silent (masked) otitis media refers to usually chronic pathological conditions behind an intact tympanic membrane which may be clinically “undetected” or “undetectable.” Correlations are described for pathological changes in temporal bones and clinical considerations for 1. silent otitis media associated with Hemophilus influenzae meningitis in infants, 2. silent otitis media — the continuum, 3. silent otitis media — sequelae, and 4. chronic silent otitis media.

The history of exploratory tympanotomy is somewhat obscure. Methods and findings of exploratory tympanotomy were described and assessed for unexplained conductive and occasional sensorineural hearing losses. Of 316 recent cases positive findings leading to diagnosis and therapy occurred in all 250 cases of conductive hearing losses and in 43 of 63 cases of sensorineural hearing losses. In decreasing order of occurrence findings were sequelae of otitis media, otosclerosis, oval and round window changes including perilymph leakage, congenital and traumatic fixation and disarticulation of ossicles. These observations and indications are discussed.

The results of previous studies on the effects of nicotinamide levels on chick limb mesodermal cell expression have indicated that there may exist a metabolic gradient situated radially across the limb which has a controlling influence on whether a limb cell will differentiate into either a myogenic or chondrogenic phenotype. This study investigates the possible role of the vascular pattern in establishing such a metabolic gradient. Observations are reported which show that prospective myogenic and chondrogenic areas become differentially vascularized before the onset of molecular differentiation, thus indicating that the vascular pattern is capable of establishing metabolic gradients across the limb. Furthermore, predictions based on these results have been tested and verified in vitro. The hypothesis is presented that the spatial differentiation of cartilage and muscle in the developing chick limb is under the controlling influence of gradients of metabolic potential which can be established by the differential vascularization of the limb.

\s=b\This study retrospectively examines 551 patients with 597 orbital floor fractures for sequelae of enophthalmos and diplopia. Ocular injuries are associated with 6.9% of the fractures. Nondisplaced orbital floor fractures have been treated with observation alone, resulting in an incidence of sequelae of zero in 263 patients. Displaced fractures that had not undergone surgery have resulted in an incidence of sequelae of 18 (34%) in 53 patients. Displaced fractures that had undergone orbital floor exploration have resulted in an incidence of sequelae of 29 (10.3%) in 281 patients. Only one mild loss of visual acuity has complicated the 281 surgical procedures. It is concluded that orbital floor exploration is not indicated in patients with nondisplaced fractures of the orbital floor and that orbital floor exploration is a safe and effective means of reducing the complications associated with displaced fractures of the orbital floor. (Arch Otolaryngol 1982;108:184-186) Fractures of the orbital floor may occur as isolated injuries or as a component of midface facial frac¬ tures. Before 1940, orbital floor frac¬ tures were not regularly addressed in the literature that described treat¬ ment of maxillofacial trauma. Conse¬ quently, treatment was inadequate, and enophthalmos and diplopia were relatively common sequelae. As a result of the work of Converse and Smith1 in 1950, awareness of this problem increased, and surgeons became aggressive in its therapy. Exploration of orbital floor fractures became routine, and complications occurred, eg, ectropion and loss of visual acuity, leading many clinicians to condemn this routine exploration.Controversy has subsequently aris¬ en as to the proper approach to orbital floor fractures. At one end of the spectrum, early exploration of orbital floor fractures is advocated (ie, within seven to ten days) in all cases before irreversible scarring and loss of peri-