The effect of serial extractions compared to enucleations on skeletal, dental, and soft tissues: a longitudinal evaluation

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ABSTRACT

Background

Tooth size-arch length deficiencies (TSALD) malocclusions can be treated either with or without extractions in growing patients. The extraction treatments are usually recommended in severe crowding and involve the serial extractions (SEs) or the enucleation (EE) therapies. The aim of the present retrospective study was to compare the skeletal and dental effects of serial extraction and enucleation treatments in subjects with severe crowding in mixed dentition phase.

Methods

Lateral cephalograms from patients who underwent orthodontic treatment involving serial extractions (SE group) or enucleations (EE group) were analysed. The matched control group (CG group) consisted of untreated subjects derived from the American Association of Orthodontists foundation (AAOF) Craniofacial Growth Legacy Collection Project. The initial lateral cephalograms were taken before the eruption of all the second molars (T0) and the second lateral cephalograms were taken after the completion of the extractions (T1). The primary outcome was the change of the vertical skeletal dimension evaluated using the SN to mandibular plane angle (SN-GoGn) angle from T0 to T1.

Results

A total of 68 subjects (22 males and 46 females, mean age 8.88 ± 1.26 years) satisfied the inclusion criteria and were included in the present study. A significant reduction of SN-GoGn was detected only in SE group (from 34.97 ± 5.26 to 32.70 ± 5.88; p-value = 0.019) from T0 to T1. On the other hand, no significant intra-group differences were reported for EE group (from 35.56 ± 6.50 to 35.05 ± 7.13; p-value = 0.614) and CG group (from 31.86 ± 5.29 to 31.46 ± 5.34; p-value = 0.362). Similar results were showed for maxillary to mandibular plane angle (MMPA) angle. In terms of dento-basal relations, no significant intra-group differences were observed between T0 and T1 for UIMx, IMPA, and L1-Apo in all three groups (all p-value > 0.05).

Conclusion

Based on this longitudinal cephalometric analysis, significant reduction of SN-GoGn (about 2.3°), MMPA, and gonial angle were detected only in patients who underwent serial extractions, whereas no significant variations were detected in enucleation and control groups. IMPA, L1-Apo, and UIMx measurements did not significantly change at follow-up in all three groups, thus a lingual tipping of the incisor was not detected in both serial extraction and enucleation groups.

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