Expression analysis of zinc-metabolizing enzymes in the saliva as a new method of evaluating zinc content in the body: two case reports and a review of the literature.

BACKGROUND: The activity level of alkaline phosphatase, a zinc-requiring enzyme in the serum, is used to indicate zinc nutritional status; however, it does not correlate with serum zinc levels or subjective symptoms of taste disorder in many cases. Hence, this study focused on the total activity of alkaline phosphatase, a zinc-requiring enzyme. The total alkaline phosphatasa activity level in the saliva was measured before and after zinc supplementation, and the results were compared with serum zinc levels. CASE PRESENTATION: This study included patients with hypozincemia, specifically a patient with zinc-deficient taste disorder (patient 1: a 69-year-old Japanese woman) and a patient with glossodynia with zinc deficiency (patient 2: an 82-year-old Japanese woman). Saliva samples were collected, and blood tests were performed before and after zinc supplementation. Subjective symptoms and serum zinc levels were simultaneously evaluated. Zinc supplementation was performed using zinc acetate hydrate or Polaprezinc. CONCLUSIONS: Total alkaline phosphatase activity levels were found to be associated with serum zinc levels and subjective symptoms. A further study with a higher number of patients is necessary to confirm whether total alkaline phosphatase activity levels more accurately reflect the amounts of zinc in the body than serum zinc levels.

High masticatory ability attenuates psychosocial stress: A cross-sectional study.

Mastication interventions have previously been shown to alleviate acute stress. However, the relationship between masticatory performance and stress response among individuals remains unclear. This study aimed to examine the relationship between masticatory ability and stress response in young women by measuring the autonomic nerve function and salivary α-amylase activity during psychosocial stress. Eighty women (aged 20.0 ± 1.9 years) were divided into either a low or high masticatory performance group, and the Trier Social Stress Test was conducted. Moreover, the autonomic function was measured at rest, immediately before stress, immediately after stress, and 10 min after stress. The salivary α-amylase activity was also measured at rest, 5 min after stress, and 15 min after stress. The visual analog scale (VAS) was used for subjective stress evaluation. There was a significant increase in the autonomic balance of both groups immediately before stress loading, but whilst the high masticatory ability group showed a return to resting-state levels after stress loading, the low masticatory ability group showed elevated levels after stress loading. Salivary α-amylase activity significantly increased 5 min after stress loading in the low, but not high, masticatory ability group. Furthermore, the VAS scores for tension and confusion after stress were significantly higher in the low masticatory ability group than in the high masticatory ability group. Our findings suggest that high masticatory performance may contribute to alleviating psychosocial stress. This is the first study to clarify the relationship between habitual masticatory performance and psychosocial stress suppression in young women.

An infant case of intraoral penetrating injury with a toothbrush causing retropharyngeal and upper mediastinal emphysema.

A 2-year-old male child who was running and fell with a toothbrush in his mouth suffered an injury to the inside of his right cheeks. His mother noticed that the toothbrush had impaled his mouth, and removed it. On arrival, a wound was observed on the right cheeks and palate. His general condition was good. However, computed tomography revealed emphysema from the left side of epipharynx to the upper mediastinum. This patient shows the importance of not only checking the medical history and performing a physical examination but also performing an imaging examination.