Carmen Lorente1,2, Pedro Lorente3, Maria Perez-Vela3, Cristina Esquinas4, Teresa Lorente5,3. 1. Department of Human Anatomy and Histology, University of Zaragoza, Zaragoza, Spain. carmen@lorenteortodoncia.com. 2. Lorente Orthodontic Clinic, Paseo Constitución 29 (local), 50001, Zaragoza, Spain. carmen@lorenteortodoncia.com. 3. Lorente Orthodontic Clinic, Paseo Constitución 29 (local), 50001, Zaragoza, Spain. 4. Valle de Hebrón Hospital Research Institute, Paseo del Valle Hebron, 119-129, 08035, Barcelona, Spain. 5. Department of Human Anatomy and Histology, University of Zaragoza, Zaragoza, Spain.
Abstract
BACKGROUND: Eruption disturbances of permanent molars are uncommon; however, it is important to treat them as soon as they are diagnosed. The main objective was to analyze the effectiveness of the "miniscrew-supported pole technique," a surgically assisted orthodontic procedure to force the eruption of impacted/retained second molars (M2s) when there are indicators of complex molar inclusion. An observational prospective study was carried out during a 2-year period. Sociodemographic, clinical and low-dose scanner variables were taken at baseline (T0). Follow-up variables (T1) were the time between surgery and tooth eruption, radiographic measurements, debonding of buttons, failure rate of miniscrews and success rate of eruption. RESULTS: A total of 21 patients (mean age of 13.9 years) with 24 retained/impacted M2s were recruited; 13 molars were maxillary (54.2%) and 11 (45.8%) were mandibular. Six (25%) were impacted molars and 18 (75%) primarily retained. At T0, molar angulation was mesial in six molars (25%), distal in five molars (20.8%) and 13 molars were vertically positioned (54.2%). Infraocclusion degree was moderate in four (16.7%) molars and severe in 20 (83.3%). Only three (12.5%) third molars were removed due to lack of space. All M2s managed to erupt, achieving a success rate of 100%; however, two molars of the same patient did not achieve occlusion. The period of eruption after surgery was 126.8 (117.3) days. Anatomical radicular alteration was the only variable independently related to a longer time of treatment (p = 0.027). CONCLUSIONS: The pole technique, using one mesial miniscrew and simple orthodontic mechanics, applies forces that succeed in erupting complicated retained/impacted M2s in a short period of time and with a low failure rate.
BACKGROUND: Eruption disturbances of permanent molars are uncommon; however, it is important to treat them as soon as they are diagnosed. The main objective was to analyze the effectiveness of the "miniscrew-supported pole technique," a surgically assisted orthodontic procedure to force the eruption of impacted/retained second molars (M2s) when there are indicators of complex molar inclusion. An observational prospective study was carried out during a 2-year period. Sociodemographic, clinical and low-dose scanner variables were taken at baseline (T0). Follow-up variables (T1) were the time between surgery and tooth eruption, radiographic measurements, debonding of buttons, failure rate of miniscrews and success rate of eruption. RESULTS: A total of 21 patients (mean age of 13.9 years) with 24 retained/impacted M2s were recruited; 13 molars were maxillary (54.2%) and 11 (45.8%) were mandibular. Six (25%) were impacted molars and 18 (75%) primarily retained. At T0, molar angulation was mesial in six molars (25%), distal in five molars (20.8%) and 13 molars were vertically positioned (54.2%). Infraocclusion degree was moderate in four (16.7%) molars and severe in 20 (83.3%). Only three (12.5%) third molars were removed due to lack of space. All M2s managed to erupt, achieving a success rate of 100%; however, two molars of the same patient did not achieve occlusion. The period of eruption after surgery was 126.8 (117.3) days. Anatomical radicular alteration was the only variable independently related to a longer time of treatment (p = 0.027). CONCLUSIONS: The pole technique, using one mesial miniscrew and simple orthodontic mechanics, applies forces that succeed in erupting complicated retained/impacted M2s in a short period of time and with a low failure rate.