Department of Teratology
Laboratory of Odontogenesis
Research topics
- Investigation of tooth development under normal, pathological and experimental conditions.
Findings on tooth development (odontogenesis) help in understanding the molecular control of organogenesis, the origin of tooth anomalies, and the evolution of an animal species. Recently, odontogenesis investigations have also focused on the possibilities for biological tooth replacements. To design such replacements, an understanding of the factors that promote or inhibit tooth development is essential. Previous studies of the Laboratory have revealed that the embryonic mouse dentition provides an ideal system for studying such factors, since it contains not only the germs of functional teeth, but also several types of rudimentary (vestigial) tooth primordia. These vestigial primordia are either incorporated into developing functional teeth or suppressed by epithelial apoptosis. We have interpreted some supernumerary teeth in mouse mutants as atavisms based on the revitalization of rudimental tooth anlagen. Vestigial odontogenous structures are also present in humans (see Fig. 8, page 25) and in other mammals. The inhibited tooth-forming capacity at specific loci of the mammalian dentition suggests that there might be a natural substrate responsive to the controlled stimulation of tooth regeneration.
Present studies
- Odontogenesis in wild type mice – model of the normal development of mammalian dentition;
- comparative odontogenesis studies;
- development of tooth anomalies in mice with genetic alterations;
- experimental odontogenesis studies – role of growth activating or inhibiting factors in primordial tooth organ cultures in vitro;
- Developmental dynamics of tooth development. Fluorescence transgenic mouse embryos and time lapse microscopy are used to study morphological and molecular events during tooth development in real time.
These studies are made in collaboration with H. Lesot (INSERM U-595, Strasbourg, France) and O. D. Klein (Departments of Orofacial Sciences and Pediatrics, UC, San Francisco, USA).
The results can help to elucidate the origin of tooth anomalies and to develop methods of tooth regeneration and engineering.
Origin of the double upper lateral incisor in humans.
(A) Scheme of the embryonic human face with a unilateral left-sided cleft of the lip and jaw (green arrow). The medial nasal (mn) and the maxillary (mx) facial processes are fused on the right and not fused on the left side. ln – lateral nasal process, md – mandibular process.
(B) Scheme of the human upper jaw arch viewed from the oral cavity. On the right site, the mn (red) and mx (yellow) fuse. At the fusion site, the lateral deciduous incisor (i2) develops (dotted line), containing material from both facial processes. On the left side, non-fusion of the mn and mx results in a jaw cleft and the non-fusion of the dental epithelia, which leads to the formation of two i2.
(C) Double deciduous lateral incisors i2 (arrow) in a patient with a left-sided alveolar cleft after surgical treatment (from the archive of the Clinic of Plastic Surgery, Prague). The midline is shaded. i1 – deciduous central incisor; c – deciduous canine.
