Timing and sequence of emergence of permanent teeth in the Jordanian population.

OBJECTIVES

Population-specific standards of tooth emergence are essential resources for various fields of clinical and forensic dentistry. To date, such standards have not been provided for the Jordanian population. This study aimed at providing the timing and sequence of emergence of the permanent dentition in the Jordanian population.

METHODS AND RESULTS

Using multistage clustered sampling, 1240 males and 1432 females aged 4-16 years from kindergartens and primary schools in the northern, middle and southern regions of Jordan were examined for emergence of permanent teeth. The subjects were classified into 1-year age groups. For a given tooth, "present" teeth were counted and expressed as a frequency relative to the total of subjects within a given age group. Using Probit regression (SPSS version 16), the median emergence age per tooth was calculated for the total sample and for both genders. No statistically significant differences were detected between sides. In addition, mandibular teeth were generally found to emerge earlier than the corresponding maxillary teeth. However, the difference in mandibular precedence was not statistically significant in all corresponding inter-maxillary tooth pairs. Furthermore, permanent teeth were found to emerge sooner in females than in males although the inter-gender differences were non-statistically significant for first molars and central incisors.

CONCLUSIONS

The first standards of timing and sequence of permanent tooth emergence specific to the Jordanian population were provided and found to be consistent with those of Caucasian populations. These standards aid managing patients in paediatric dentistry, planning orthodontic therapy and forensic age estimation.