Absence of melatonin during development impairs craniofacial and dental onset in rats

• Published in: Clinical oral investigations Vol. 27; no. 9; pp. 5353 - 5365
• Main Authors: Calsa, Bruno, de Camargo, Ludmilla Scodeler, Bortolança, Tainá Jaqueline, de Oliveira, Camila Andrea, Catisti, Rosana, do Amaral, Fernanda Gaspar, Santamaria-Jr, Milton
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-09-2023; Springer Nature B.V
• Subjects: Alveolar bone; Collagen (type I); Craniofacial growth; Dentistry; Down-regulation; Gene expression; Genetic crosses; Incisors; Juveniles; Maxilla; Medicine; Melatonin; Odontoblasts; Odontogenesis; Offspring; Osteogenesis; Pregnancy; Rodents; Odontogenesis; Melatonin and RANKL/OPG; Fetal programming; Osteogenesis
• ISSN: 1436-3771; 1432-6981; 1436-3771
• DOI: 10.1007/s00784-023-05155-3

Objective
Herein, we evaluated pinealectomy-induced melatonin absence to determine its effects on craniofacial and dental development in the offspring.
Design
Female Wistar rats in three groups, i.e., intact pregnant rats, pinealectomized pregnant rats (PINX), and pinealectomized pregnant rats subjected to oral melatonin replacement therapy, were crossed 30 days after surgery. The heads of 7-day-old pups were harvested for cephalometric and histological analyses, and maxillae and incisors were collected for mRNA expression analysis.
Results
The PINX pups exhibited a reduction in neurocranial and facial parameters such as a decrease in alveolar bone area, incisor size and proliferation, and an increase in odontoblasts and the dentin layer. Based on incisor mRNA expression analysis, we found that
Dmp1
expression was upregulated, whereas
Col1a1
expression was downregulated. Maxillary mRNA expression revealed that
Rankl
expression was upregulated, whereas that of
Opn
and
Osx
was downregulated.
Conclusion
Our results demonstrated that the absence of maternal melatonin during early life could affect dental and maxillary development in offspring, as well as delay odontogenesis and osteogenesis in maxillary tissues.
Clinical relevance
Our findings suggest that disruptions or a lack of melatonin during pregnancy may cause changes in craniofacial and dental development, at least in animal experiments; however, in humans, these feedings are still poorly understood, and thus careful evaluations of melatonin levels in humans need to be investigated in craniofacial alterations.