Isabela Ribeiro Madalena1, Guido Artemio Marañón-Vásquez2, Marjorie Ayumi Omori1, Emerson Tavares de Sousa3, Heitor Albergoni da Silveira4, Jorge Esquiche León5, Flares Baratto-Filho6, Sandra Yasuyo Fukada Alves7, Maria Bernadete Sasso Stuani1, Paulo Nelson-Filho1, Christian Kirschneck8, Erika Calvano Küchler9,10. 1. Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Avenida Do Café S/N, Campus da USP, Ribeirão Preto, SP, 14040-904, Brazil. 2. Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Federal University of Rio de Janeiro, Cidade Universitária, Rua Prof. Rodolpho Paulo Rocco 325, Rio de Janeiro, RJ, 21941-617, Brazil. 3. Department of Health Sciences and Pediatric Dentistry, Piracicaba Dental School, University of Campinas, Avenida Limeira 901, Areião, Piracicaba, SP, 13414-903, Brazil. 4. Department of Diagnosis and Surgery, Araraquara Dental School, São Paulo State University, Rua Humaitá, Araraquara, CentroSP, 168014801-903, Brazil. 5. Department of Stomatology, Public Health and Forensic Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Avenida Do Café S/N, Campus da USP, Ribeirão Preto, SP, 14040-904, Brazil. 6. School of Dentistry, University of the Joinville Region, Rua Paulo Malschitzki, s/n, Joinville, SC, 89219-710, Brazil. 7. Department of Biomolecular Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida Do Café S/N, Campus da USP, Ribeirão Preto, SP, 14040-904, Brazil. 8. Department of Orthodontics, University Medical Centre of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany. 9. Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Avenida Do Café S/N, Campus da USP, Ribeirão Preto, SP, 14040-904, Brazil. erikacalvano@gmail.com. 10. Department of Orthodontics, University Medical Centre of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany. erikacalvano@gmail.com.
Abstract
OBJECTIVES: To assess the influence of estrogen deficiency on tooth eruption rate (TER) and gene expression of estrogen receptor alpha and beta (ERα and ERβ) in the odontogenic region of teeth with continuous formation in a rat model. MATERIALS AND METHODS: Ovariectomies (OVX; n = 25) and sham surgeries (SHAM; n = 25) were performed in female Wistar rats when animals were 25 days old. The TER of the lower incisors, both in impeded (hyperfunction condition) and unimpeded (trimmed incisal edge-hypofunction condition) conditions, was evaluated using standardized digital photographs acquired every 48-72 h for 3 weeks (35th-53rd day of life), using a camera coupled to a stereomicroscope. Quantitative real-time PCR was performed to evaluate the relative gene expression of ERα and ERβ in the odontogenic region. RESULTS: The OVX group showed a significant reduction in TER when compared to the SHAM group, only in the impeded condition (p = 0.03). There was no statistically significant difference between the groups in ERα gene expression (p = 0.33). ERβ showed a significantly higher gene expression in the OVX group (p ≤ 0.05). CONCLUSIONS: Estrogen deficiency decreases TER in teeth under impeded condition. Estrogen deficiency also increases ERβ gene expression in the odontogenic region of teeth with continuous formation. CLINICAL RELEVANCE: Hormonal disturbances affecting estrogen levels can cause alterations in dental formation and teeth eruption.
OBJECTIVES: To assess the influence of estrogen deficiency on tooth eruption rate (TER) and gene expression of estrogen receptor alpha and beta (ERα and ERβ) in the odontogenic region of teeth with continuous formation in a rat model. MATERIALS AND METHODS: Ovariectomies (OVX; n = 25) and sham surgeries (SHAM; n = 25) were performed in female Wistar rats when animals were 25 days old. The TER of the lower incisors, both in impeded (hyperfunction condition) and unimpeded (trimmed incisal edge-hypofunction condition) conditions, was evaluated using standardized digital photographs acquired every 48-72 h for 3 weeks (35th-53rd day of life), using a camera coupled to a stereomicroscope. Quantitative real-time PCR was performed to evaluate the relative gene expression of ERα and ERβ in the odontogenic region. RESULTS: The OVX group showed a significant reduction in TER when compared to the SHAM group, only in the impeded condition (p = 0.03). There was no statistically significant difference between the groups in ERα gene expression (p = 0.33). ERβ showed a significantly higher gene expression in the OVX group (p ≤ 0.05). CONCLUSIONS: Estrogen deficiency decreases TER in teeth under impeded condition. Estrogen deficiency also increases ERβ gene expression in the odontogenic region of teeth with continuous formation. CLINICAL RELEVANCE: Hormonal disturbances affecting estrogen levels can cause alterations in dental formation and teeth eruption.