Histologic analysis of squamous cell carcinoma of the lower alveolus shows 2 basic patterns of tumor spread in relation to the mandible: an infiltrative one and an expansive one. While the tumor invades the mandible by destroying the bone or through cortical defects of some spaces in the infiltrative form, the tumor does this only by eroding the bone in the expansive form, in which the degree of bone resorption seems to be proportional to tumor advancement. A comparison between radiologic and histologic features discloses that the radiologically detected bone defects are not necessarily correlated with the patterns of bone involvement. However, most lesions with erosive bone defects show the expansive pattern histologically, and the extent of the radiologically detected bone defect is roughly in accordance with the histologic extent of bone involvement. These results lead us to believe that some squamous carcinoma of the lower alveolus could be treated successfully without sacrificing the continuity of the mandible.

Adult↗

PubMedDate not supplied

Results of surgical treatment for squamous carcinoma of the lower alveolus: segmental vs. marginal resection.

The records of 53 patients treated surgically for squamous cell carcinoma of the lower alveolar ridge were reviewed and the results of segmental and marginal resections of the mandible were compared. Analysis of these 2 treatment modalities disclosed that marginal resection was effective in controlling lower gingival cancers, with and without apparent bone involvement, if erosive bone defects that did not extend beyond the inferior alveolar canal, or invasive bone defects confined to a superficial area of the alveolar bone, were detected radiologically.

Adult↗

PubMedDate not supplied

Techniques of nasotracheal intubation with the fiberoptic bronchoscope.

When nasotracheal intubation with a fiberoptic bronchoscope is performed, the tube may be blocked in the nasal cavity or larynx, resulting in several complications including epistaxis and hoarseness. We review the causes and complications of tube blockage and discuss optimal techniques for minimizing it.

Acute Disease↗

PubMedDate not supplied

Resorbable structured porous materials in the healing process of hard tissue defects.

The long-term goal of this research is to assist the resurfacing of damaged articular cartilage. Coralline hydroxyapatite (HA) was coated with a thin film of polylactide (PLa), maintaining pore structural characteristics. Cylindrical plugs (3 x 7 mm) implanted in non-load-bearing femoral and tibial diaphyses of the rabbit indicated substantial bone ingrowth at 3 weeks, with no significant difference between coated and uncoated HA in the amount and distribution of new bone. PLa-epsilon caprolactone polymeric negative replicas of coral Goniopora (G), inserted into the rabbit femur for 4 wks, showed newly formed bone grown deeply into the pores. Tight attachment of new bone to the implant and minimal inflammatory response suggested an osteocompatible reaction. In order to maintain the desirable pore structure of G while introducing controllable degradation rate and mechanical properties, a novel technique was employed to replicate G with PLa and its co-polymers. An intermediary negative replica of G was prepared with aspirin. A co-polymer positive replica of G was then prepared by solution or melt infusion into the negative replica; the aspirin was removed by methanol. A macro- (300-500 microns) and microporous (5-15 microns) structure was prepared by freeze-drying. This replica received appreciable bone ingrowth when implanted in the rabbit tibia for 3 wks. Our results demonstrate the feasibility of creating devices with interconnected pore structures and controlled porosity, elasticity, and mechanical strength sufficient for articular cartilage application, osteocompatibility, and controlled degradation rate.

Animals↗