Hypothalamic Obesity Reduces of Orthodontic Tooth Movement and Causes Alterations in the Dental Pulp of Female Rats
Janaina Ahmann Spenassatto
Postgraduate Program in Dentistry, Center of Biological and Health Sciences, Western Paraná State University (UNIOESTE), Rua Universitária, 2069 – Universitário District, Cascavel, Paraná, Brazil and Laboratory of Tissue Biology and Reproduction, Center of Biological and Health Sciences, Western Paraná State University (UNIOESTE), Rua Universitária, 2069 – Universitário District, Cascavel, Paraná, Brazil.
Isabela Zibetti
Postgraduate Program in Dentistry, Center of Biological and Health Sciences, Western Paraná State University (UNIOESTE), Rua Universitária, 2069 – Universitário District, Cascavel, Paraná, Brazil and Laboratory of Tissue Biology and Reproduction, Center of Biological and Health Sciences, Western Paraná State University (UNIOESTE), Rua Universitária, 2069 – Universitário District, Cascavel, Paraná, Brazil.
Alexandre Lopes Paes
Laboratory of Tissue Biology and Reproduction, Center of Biological and Health Sciences, Western Paraná State University (UNIOESTE), Rua Universitária, 2069 – Universitário District, Cascavel, Paraná, Brazil.
Camylle Magalhães Martins
Laboratory of Tissue Biology and Reproduction, Center of Biological and Health Sciences, Western Paraná State University (UNIOESTE), Rua Universitária, 2069 – Universitário District, Cascavel, Paraná, Brazil.
Elaine Manoela Porto
Postgraduate Program in Dentistry, Center of Biological and Health Sciences, Western Paraná State University (UNIOESTE), Rua Universitária, 2069 – Universitário District, Cascavel, Paraná, Brazil and Laboratory of Tissue Biology and Reproduction, Center of Biological and Health Sciences, Western Paraná State University (UNIOESTE), Rua Universitária, 2069 – Universitário District, Cascavel, Paraná, Brazil.
João Paulo de Arruda Amorim
*
Postgraduate Program in Dentistry, Center of Biological and Health Sciences, Western Paraná State University (UNIOESTE), Rua Universitária, 2069 – Universitário District, Cascavel, Paraná, Brazil and Laboratory of Tissue Biology and Reproduction, Center of Biological and Health Sciences, Western Paraná State University (UNIOESTE), Rua Universitária, 2069 – Universitário District, Cascavel, Paraná, Brazil.
*Author to whom correspondence should be addressed.
Abstract
Aims: To evaluate whether hypothalamic obesity, when associated with induced tooth movement, can influence the histological structure of the dental pulp in rats.
Type of Study: Experimental research.
Methodology: Forty female pups of Wistar rats were obtained from the Central Animal Facility of the Western Paraná State University. Twenty pups received daily subcutaneous injections of monosodium glutamate (4 g/kg/day) in the cervical region during the first five days of life to induce obesity (MSG group). The remaining twenty animals received injections of hyperosmotic saline solution (1.25 g/kg/day) and served as the non-obese control group (CTL). The animals were then divided into four experimental groups (n = 10/group): Group 1: Non-obese rats not subjected to induced tooth movement (CTL); Group 2: Non-obese rats subjected to induced tooth movement (CTL + ITM); Group 3: Obese rats not subjected to induced tooth movement (MSG); Group 4: Obese rats subjected to induced tooth movement (MSG + ITM). At 97 days, all animals were weighed and euthanized.
Results: Obese animals in the MSG+ITM group exhibited a higher Lee index and increased retroperitoneal and perigonadal fat deposits compared to the CTL+ITM group (P < 0.05). They also showed a lower rate of tooth movement than the non-obese animals in the CTL+ITM group (P<0.05). Furthermore, obese animals subjected to tooth movement (MSG+ITM) demonstrated more frequent occurrences of mild inflammatory infiltrate, increased cellularity, and dystrophic and hemodynamic changes compared to the other groups.
Conclusion: Hypothalamic obesity associated with induced tooth movement leads to reduced tooth movement and increased occurrences of inflammatory infiltrate, as well as dystrophic and hemodynamic changes in the dental pulp.
Keywords: Obesity, orthodontic tooth movement, periodontal tissue