The purpose of this study is to investigate the distributions of elements and compounds in metals. The hardened surface and powder of gallium alloy (Gallium Alloy GF^®) were examined by scanning electron microscopy (SEM) and electron probe x-ray microanalysis (EPMA). In SEM examination, two different types of light areas and one type of dark area were observed on the surface. The characteristic round or oval light areas (cores) were enclosed with a certain width of margin by the dark portion (core-matrix) and light portion (matrix) of irregular shape and occupied the outer periphery. On the core portion, Ag, Cu, Sn and Pb were detected and it was estimated that this portion consisted of nonreacted alloy particles. On the core-matrix portion, Sn, Ag, Ga, Cu, and Pb were detected, and it was presumed by plane analysis that there were Cu-Ga, Pb-Ga and Ag-Ga phases in this portion. On the matrix portion, Ga, Cu, Pb, Sn, Ag and In were detected. It was also found that this portion was mostly occupied in the Ag-In and Sn phases.

Radiographicai characterization of the mandibular morphology was undertaken in 8 patients admitted to Iwaki National Sanatorium with Duchenne type muscular dystrophy (DMD) in a comparison with 12 adults having normal occlusion as controls. Lateral cephalograms and standardized X-ray photographs of the temporomandibular joint (TMJ) taken by an “AX aligner” were used and morphological features were measured geometrically. The quantitative data were statistically analyzed. No differences were found in the lengths of the mandibular corpus, ramus and gonial angle between the DMD patients and controls. In DMD patients, the anterior length of the nasal floor was significantly shorter than that of the controls. The position of the mandible was protrusive to the cranium. The mandibular plane angle indicated a clockwise rotation, and the lower incisors inclined labially due to hypertrophy of the tongue. The anterior inclination of the condyle (AIC) was significantly smaller with DMD patients than in the controls, but the depth of the mandibular fossa (DMF) did not differ between them. In the controls, there were significant correlations among the mandibular corpus, ramus, gonial angle and AIC, but there were no such correlations in the DMD patients. These results lead us to the following conclusions. Normal growth of the mandible maintains a balanced relationship among the corpus, ramus, gonial angle and condylar configuration. The anterior inclination of the condyle, not observed in the DMD patients, is regarded as the result of remodeling of TMJ with normal developments of the masticatory muscle function.

The formation of common trunks by the lingual artery and other branches arising from the external carotid artery was examined. The X-ray films of 238 sides of the head and neck (115 right and 123 left sides) in which the lingual arteries could be clearly identified by contrast radiography were chosen from 261 Japanese cadavers which had been used for anatomical training from 1980 to 1991. The formation of linguofacial trunk was found in 31.9±5.9% (right side 31.3±8.5% and left side 32.5±8.4%), that of thyreolingual trunk in 3.8±2.4% (right side 1.7±1.4% and left side 5.7±4.1%) and thyreolinguofacial trunk in 0.4±0.8% (right side 0.9±1.7% and left side 0%). There were no differences between the right and left sides or between sexes in the appearance ratios of these common trunks. In three cases, a long common trunk was formed by the lingual artery and facial artery from the external carotid artery. In one case in these three common trunks on which detailed anatomical dissection was performed, the linguofacial trunk was branched into the lingual artery and facial artery at the anterior region of the submandibular gland and the lingual artery entered into the tongue through the mylohyoid muscle. The origins of the lingual artery and facial artery at the external carotid artery were displaced in two cases. A connecting branch was formed between the facial artery and thyreolingual trunk in one case.

A 55-year-old man presented at our department with a dermoid cyst which occurred in left floor of the mouth. The mucous membrane at the site of the lesion was normal in color. The cyst was soft, elastic and fluctuant. In examination of the intracystic fluid by exploratory puncture, the amylase level was 100IU/l. It was less than that in the fluid from ranula (73×10⁶~1,300 × 10⁶IU/ℓ). Macroscopically, the extirpation of specimen had a cystic lesion, and histopathologically it was composed sebaceous glands, hair follicles and smooth muscles existing in part of the fibrous connective tissue of the cyst wall. The diagnosis of dermoid cyst was thus established. It is suggested that when a dermoid cyst in floor of the mouth is encountered, amylase analysis is very useful for clinical differentiation from sublingual and submental ranula.