Standards for permanent teeth emergence time and sequence in Lithuanian children, residents of Vilnius city.

BACKGROUND. Up-to-date population specific standards on the timing and sequence of emergence of the permanent teeth are essential in planning medical care for children. To the best of authors' knowledge, data about emergence time of permanent teeth in Lithuanian children has not been provided. OBJECTIVE. To provide the first standards of permanent teeth emergence time and sequence in Lithuanian children, citizens of Vilnius. MATERIAL AND METHODS. In a cross-sectional study, data were collected from 3596 Lithuanian children, 4 to 16 years of age in randomly selected kindergartens and secondary schools of Vilnius city. During dental examination all erupted permanent teeth, except third molars, were recorded. MiniTab15 statistical software was used to calculate clinical eruption time of permanent teeth. Different comparisons were made to detect inter-jaw, inter-gender and inter-population differences. RESULTS. The earliest teeth to erupt in both genders are lower central incisors around the age of six. The first stage of mixed dentition ends with the eruption of upper lateral incisors around the age of 8 in boys and a half of year earlier in girls. Second transitional period starts after the emergence of first premolars or lower canine in girls and upper first premolar in boys at the age of 9.5. The last tooth to erupt in both genders is the upper second molar at the age of twelve. No significant differences have been found between right and left sides in either jaw. Lower permanent teeth tended to emerge significantly earlier than the upper ones, except for premolars and first molars. Girls preceded boys by 4 to 5 months on average. Lithuanian children on average showed earlier emergence time, especially in premolars, but resemble German and Finnish populations more closely. CONCLUSIONS. No significant asymmetry in permanent teeth emergence time has been found in either jaw. Lower permanent teeth, showed earlier clinical eruption than in the upper jaw in both genders. Lithuanian girls were clearly advanced in permanent teeth emergence than compared to boys. Lithuanian children showed earlier permanent teeth emergence time, especially in premolar region, than children from other countries.