The third molar as an age marker in adolescents: new approach to age evaluation.

Adolescence is a relatively short period between childhood and adulthood. It is very difficult to determine adulthood based on biological indicators. The third molar may be considered a potential age marker for the period between the ages of 16-21.

Third molar as an age indicator in young individuals.

The authors developed a method of chronological age estimation in young individuals on the basis of third molar developmental stage. The new method is based on the finding that time course of third molar development depends on the number of assessed third molars. That means, in individuals with 1 to 3 third molars agenesis the development of founded third molars is delayed in comparison with individuals having all third molars present.

Development of third molar in the Czech population.

The third molar development was studied on the basis of 1700 panoramic radiographs analysis of randomly selected individuals in the age ranging between 5-21 years inclusive. Each age group consisted of 100 probands--50 boys and 50 girls. The characteristics of the third molar development were following: time of dental follicle formation--dynamics of development--the most frequent stages of third molar development in individual age groups-- intraindividual differences and symmetry of development--incidence of 1-4 third molars agenesis--relation between the third molar development and the dental age--differences in the third molar development between individuals with all four third molars present and individuals with 1-3 third molars agenesis--ntersexual differences.

Agenesis of third molars in young Czech population.

The aim of this study is to evaluate the incidence of third molars agenesis in the Czech population. One thousand patient's panoramic radiographs of the pedostomatological department of Second Stomatological Clinic of The First Faculty of Medicine, Charles University, has been analyzed. The age of probands was ranging between 12 to 21 years inclusive.

Anomalous maxillary lateral incisor--the only product of dental lamina, difficult classifiable in the time. Symptom of hypodontia syndrome non-described until present time.

The authors described anomalous development of maxillary lateral incisor non-yet published in stomatologic literature. Diagnostics and clinical findings of the anomaly and the prognosis of the affected tooth they based on the description of six longitudinal observed patients. The principal symptom of the anomaly is the disturbance of time-plan of the tooth development.

[Exchange of dentition and its control. Overview of current knowledge and personal experience].

Physiological dentition exchange is often interfered with exogenous and endogenous factors. For this reason it must be steadily regulated. The authors present complex view on this topic based on literature studies and own experiences.

Studies on agenesis of third molars amongst populations of different origin.

This study contains information on the occurrence of agenesis of one to four third molars among the population and ethnic groups of Europe, North America, Africa and Asia (Japan), based on the results of investigations carried out by dozens of authors. Recent discoveries have been supplemented with corresponding data concerning the skeletal remains of the jaws of individuals living from the ice age to the middle ages. The results show unbelievably large diversities as regards the frequency of agenesis of third molars in different populations from practically zero (Tasmania) to nearly 100% (Mexican Indians).

[Prevalence of mineralization disorders in dental tissues in children in fluoridated regions of Kladno].

The authors subjected to dental examinations a group of children aged 12-13 years from the Kladno area and surrounding rural communities. The children from Kladno drank from birth fluoridated water from the water mains, while the rural children, where well water had a minimum fluoride content, had to rely on sodium fluoride tablets. In all children the prevalence of non-carious changes of dental tissues was assessed, the cariosity (DMF), oral hygiene (OHI) and the state of the gingiva (PI).

[Analysis of environmental indicators in relation to structural disorders of dental tissues].

An epidemiological investigation revealed a high incidence of structural disorders of dental tissues in the child population of Prague. While hypoplastic disorders are steadily diminishing, there is an ever rising trend of hypomineralization. The observed disorders of hypomineralization are becoming a serious clinical problem.

[Comparative study of the prevalence of disorders of impaired structure of dental tissues in school children and university students].

The authors examined a group of 573 Prague children aged 12-15 years. In addition to the incidence of disorders of the structure of dental tissues they investigated the coriosity (DPE), oral hygiene (OHI) and condition of the gingiva (PI). Their main interest was focused on impaired mineralization of dental tissues the incidence of which is indemic in Prague children.