Development and structural characteristics of pseudoosteodentine in the Pacific cutlassfish, Trichiurus lepturus

Depending on the mineralization pattern of dentine, teeth can be divided into three histological types (orthodont, osteodont, and pseudoosteodont type). However, the development and structural characteristics of pseudoosteodentine has not been systematically investigated yet. Here, the teeth of Trichiurus lepturus were selected for revealing a maturation process during pseudoosteodentine formation and describing ultrastructural details of pseudoosteodentine architecture. Micro-computed tomography, scanning electron microscopy, hematoxylineosin, Masson staining and immunohistochemistry using a dentine sialophosphoprotein (DSPP) antibody were used to analyze the microstructure and the development of the dentine. Compared with Muraenesox cinereus orthodentine, the ultrastructure of pseudoosteodentine, dentine development, the localization and migration of odontoblasts during odontogenesis in T. lepturus were observed in detail. In pseudoosteodentine, orthodentine and osteodentine all contain similar tubule-like structures and tubule openings. Labeled by DSPP immunohistochemistry for secretory odontoblasts, the organic matrix of pseudoosteodentine forms in two stages: secreting matrix by orthodentine odontoblasts with inverted nuclear polarity and the formation of osteodentine by stellate odontoblasts throughout the dental papilla. Our findings increase the understanding of the odontogenesis and structure of pseudoosteodentine and might provide a new model for the study of biomineralization and tooth development.

Automated summary

This study investigates the maturation process and ultrastructural details of pseudoosteodentine formation in the teeth of Trichiurus lepturus. Different imaging and staining techniques were used to analyze the microstructure and development of dentin. The study observed the development and localization of odontoblasts during odontogenesis in T. lepturus and found that pseudoosteodentine, orthodentine, and osteodentine have similar tubule-like structures. The findings provide a deeper understanding of tooth development and biomineralization processes.