Anomalies associated with hypodontia of the permanent lateral incisor and second premolar.

Apart from the molars the most commonly congenitally absent tooth is the second premolar followed by the permanent lateral incisor. From a total of 5127 patients, congenital absence of the permanent lateral incisor occurred with a frequency of 2.2 per cent and absence of the second premolar with a frequency of 3.4 per cent. In association with hypodontia of these teeth other dental anomalies were observed. Absence of other teeth was observed as the most likely associated dental anomaly. Other anomalies recorded included disturbances in spacing of the dentition, and problems associated with tooth eruption and exfoliation.

Agenesis of the second premolar in males and females: distribution, number and sites affected.

One of the most common anomalies of the dentition is congenitally absent second premolars and this form of hypodontia may occur as an isolated trait or in association with a syndrome. Using radiographs and clinical examinations, hypodontia of second premolars was assessed in 176 subjects (80 male and 96 female). Distribution of the hypodontia was assessed according to site and number missing in males and females. No significant differences were observed in males and females with respect to the number of premolars absent, sites affected or symmetry of the agenesis. Agenesis of a single second premolar was the most common form of this hypodontia with absence of three second premolars occurring least frequently.

Interleukin-1 and interleukin-1 inhibitor production by human adherent cells stimulated with periodontopathic bacteria.

This study examined the effect of the putative periodontopathic bacteria Bacteroides gingivalis and Fusobacterium nucleatum on the production of interleukin-1 (IL-1) and IL-1 inhibitors by human plastic-adherent mononuclear cells from normal donors. Fusobacterium mortiferum was used as a non-oral, non-pathogenic control organism. Unstimulated adherent cells spontaneously secreted an IL-1 inhibitor, whereas stimulation with B. gingivalis induced the synthesis and secretion of IL-1. With both fusobacteria IL-1 was present in the intracellular environment, whereas the predominant secretory product was either IL-1 or an IL-1 inhibitor. These results suggest that bacteria are capable of modulating cytokine production by monocytes and may thereby alter the local immune response.