Radiographic observations on root resorption in the primary dentition

Area of Science:

• Pediatric Dentistry
• Dental Radiology
• Human Anatomy

Background:

• Root resorption is a key process in primary dentition development.
• Accurate assessment of root resorption is crucial for clinical decision-making in pediatric dentistry.
• Existing data for Japanese children's primary tooth root resorption stages are limited.

Purpose of the Study:

• To establish standardized charts for primary tooth root resorption stages in Japanese children.
• To analyze factors influencing root resorption timing, including sex, arch, and tooth type.
• To correlate primary root resorption with permanent tooth calcification stages.

Main Methods:

• Analysis of 11,167 panoramic radiographs from Japanese children (5,759 boys, 5,408 girls).
• Categorization of root resorption into 1/4, 1/2, and 3/4 stages based on Fanning's criteria.
• Comparison of resorption patterns between sexes, arches (maxilla/mandible), and tooth types (anterior/molar).
• Correlation of primary root resorption with successional permanent tooth calcification stages.

Main Results:

• Symmetrical root resorption observed between contralateral primary teeth.
• Girls exhibited earlier root resorption stages compared to boys.
• Mandibular teeth showed earlier resorption stages than maxillary teeth.
• Resorption duration (1/4 to 3/4) varied between maxillary and mandibular molars and anterior teeth.
• Specific correlations were found between primary root resorption stages and permanent tooth crown/root development.

Conclusions:

• Standardized charts for primary tooth root resorption in Japanese children were successfully developed.
• These charts provide valuable reference data for clinical applications in pediatric endodontics and orthodontics.
• The findings highlight significant variations in root resorption timing influenced by sex, arch, and tooth type.