Timing for extraction of permanent first molars in school aged children: a pilot study

Area of Science:

• Dentistry
• Orthodontics
• Pediatric Dentistry

Background:

• Extraction of permanent first molars (P1Ms) is a common orthodontic procedure.
• The timing of P1M extraction can influence the degree of tooth movement, such as tipping and rotation of adjacent teeth.
• Understanding the impact of extraction timing on permanent second molar (P2M) development is crucial for treatment planning.

Purpose of the Study:

• To evaluate the outcomes of P1M extraction in children based on P2M dental calcification stages.
• To compare the mesial tipping of P2Ms in early versus late extraction groups.
• To determine the optimal timing for P1M extraction to minimize adverse effects.

Main Methods:

• Retrospective study analyzing 406 panoramic radiographs (PRs) of children aged 7-14 years with single P1M extraction.
• Selection of 29 children with pre- and post-treatment PRs.
• Classification into Early Extraction (EE) (Nolla Grades 5-7) and Late Extraction (LE) (Nolla Grades 8-10) groups based on P2M calcification.
• Measurement of neighboring tooth inclination on extraction and contralateral sides using post-extraction PRs.
• Statistical analysis using Mann-Whitney U test (p < 0.05).

Main Results:

• A significant mesial tipping tendency of P2Ms towards the extraction side was observed in both EE and LE groups (p > 0.05).
• No statistically significant difference in maxillary P2M mesial inclination was found between the extraction and contralateral sides in the LE group.
• The study indicates that P2M tipping occurs irrespective of the calcification stage at the time of P1M extraction.

Conclusions:

• The timing of P1M extraction, based on P2M calcification, does not prevent mesial tipping of the P2M.
• Dental age assessment is critical for determining ideal extraction timing to ensure proper occlusal maintenance.
• Further research may be needed to explore other factors influencing P2M movement post-extraction.