Biochemical and morphological substantiation of the connective tissue hypothesis of mandibular third molar eruption

Korshunov AS1,4, Vagner VD2, Belskaya LV3, Kuryatnikov KN1,4, Serov DO4, Krasnov VA4, Tigranyan GO1, Bondar IA1
About authors

1 Omsk State Medical University, Omsk, Russia

2 Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia

3 Omsk State Pedagogical University, Omsk, Russia

4 City Clinical Dental Polyclinic № 1, Omsk, Russia

Correspondence should be addressed: Andrey S. Korshunov
Kosareva, 34, Omsk, 644043, Russia; ur.liam@885081_k_yerdna

About paper

Author contribution: Korshunov AS — study planning, literature analysis, data interpretation, clinical data acquisition, manuscript writing; Vagner VD — study planning, literature analysis, data interpretation; Belskaya LV — study planning, biochemical investigations, manuscript writing; Kuryatnikov KN — clinical data acquisition, literature analysis, data interpretation, manuscript writing; Serov DO — clinical data acquisition, data interpretation, literature analysis; Krasnov VA — clinical data acquisition, sample preparation for assessment; Tigranyan GO, Bondar IA — sample preparation for assessment, data analysis.

Compliance with ethical standards: the study was approved by the Ethics Committee of the Omsk State Medical University (extract from the protocol № 113 of 26 November 2019); the informed consent was submitted by all study participants or their legal representatives.

Received: 2023-07-31 Accepted: 2023-08-23 Published online: 2023-08-31

Studying the mechanism underlying tooth eruption is an important and promising area due to the increased incidence of the diseases associated with tooth eruption abnormalities or difficulties that can result in purulent and septic complications. The study was aimed to explore variability and structural features of the hard tissue mineral component and organic matrix in mandibular third molars being at different stages of tooth eruption. Microscopic examination and biochemical testing of the enamel, dentin, and dentin–enamel junction of the study participants’ (n = 67; females aged 14–36) mandibular third molars were performed by scanning electron microscopy and Fourier transform infrared (FT-IR) spectroscopy. The association of the tooth eruption stage with the hard tissue structural features, such as the degree of mineralization and the size of dentinal tubules, orientation and size of the enamel prisms, was revealed. There were significant differences in the mandibular third molar hard tissue water content, which was demonstrated by metabolic processes and maturation rate (p < 0.05). According to the IR spectroscopy data, intensity of the collagen absorption bands in the enamel increases with age, while in dentin it decreases (1202, 1249, and 1342 cm–1). Furthermore the combination of the reduced intensity of the 1202 cm–1 band with the increase in the 1342 cm–1 dentin–enamel junction band confirms the important role it plays as a link between the enamel and dentin due to its metabolic, shock-absorbing, protective, and nutritional functions. The findings demonstrate significant changes in the wrapping and orientation of the collagen fibrils and fibers in the hard tissue, which affect primary spatial orientation and mandibular dental topography.

Keywords: IR spectroscopy, connective tissue dysplasia, biochemistry, eruption, enamel, dentin, dentin–enamel junction