Teeth

Tooth Development - General Aspects.- A. General Arrangement of the Dental Tissues and Their Embryological Derivation.- B. Formation of Odontogenic Sites in the Developing Mouth.- I. Interactions Between Odontogenic Epithelium and Ectomesenchyme.- II. Primordia for the Different Classes of Teeth.- III. Early Innervation and Blood Supply.- C. Structural Formations in Mouth Development.- I. Tooth Germ, General Morphological and Histological Features of the Enamel Organ and Dental Papilla.- II. Dental Lamina, Enamel Niche and Accessory Laminae.- III. Labial and Vestibular Laminae.- IV. Linguoalveolar Sulcus.- V. Dental Follicle and Early Alveolus.- D. The Development of the Crown and its Morphology.- I. Developmental Integuments of the Enamel Surface.- E. Development of the Periodontium.- I. Outline of Root Formation.- II. The Periodontal Ligament.- III. Epithelial Rests of Malassez.- F. The Developmental Positions of the Teeth in the Jaws.- I. The Deciduous Teeth.- II. The Successional Teeth.- III. The Permanent Molars.- IV. Growth Retardation.- G. Developmental Anomalies.- References.- Tissue Changes During Tooth Eruption.- A. Tissue Changes During Eruption.- I. The Pre-Eruptive Phase.- II. The Eruptive Phase.- 1. The Development of the Periodontal Ligament During the Eruptive Phase.- 2. Adaptation of the Alveolar Bone to Eruption.- 3. Alterations in the Tissues Overlying the Erupting Tooth.- III. The Intra-Oral Phase.- B. Mechanisms of Tooth Eruption.- I. The Collagen Contraction Hypothesis.- II. The Periodontal Fibroblast Contraction/Motility Hypothesis.- III. The Vascular/Tissue Fluid Pressure Hypothesis.- References.- Development of Dentine and Pulp.- A. Introduction.- B. The Dental Papilla.- C. The Internal Dental Epithelium and the Preameloblasts.- D. The Dental Basement Membrane.- E. Epithelio-Mesenchymal Interactions.- F. The Odontoblast and the Odontoblastic Process.- I. Differentiation of the Odontoblasts.- II. The Cell Body of the Differentiated Odontoblast.- III. The Odontoblastic Process.- IV. The Metabolism of the Odontoblast.- 1. Collagen Biosynthesis.- 2. Glycoprotein and Fibronectin Biosynthesis.- 3. Proteoglycan Biosynthesis.- 4. Biosynthesis of ?-Carboxyglutamic Acid (GLA)-Containing Proteins.- 5. Phosphoprotein Biosynthesis.- 6. Calcium and Phosphate Metabolism.- 7. Degradative Activities of the Odontoblasts.- G. Predentine.- H. The Process of Mineralization.- I. Matrix Vesicles.- II. Alkaline Phosphatases.- III. The Concept of Epitaxy.- IV. The Role of Various Non-Collagenous Proteins.- V. The Role of Lipids.- J. The Development of Coronal Dentine.- I. Intertubular Dentine.- 1. Mantle Dentine and the Dentinoenamel Junction.- 2. Circumpulpal Dentine.- II. Peritubular Dentine.- K. The Development of Root Dentine.- L. The Development of the Pulp.- References.- Structure and Ultrastructure of Dentine.- A. Basic Anatomy.- B. Physical and Chemical Characteristics.- C. Classification of Different Types of Dentine.- D. The Odontoblast and Their Processes.- I. The Odontoblast Cell Body.- II. The Odontoblastic Process.- E. Predentine.- F. The Dentinal Tubules and Their Contents.- I. The Periodontoblastic Space.- II. The Lamina Limitans.- III. The Enamel Spindles.- G. Peritubular Dentine.- H. Intertubular Dentine.- J. Dentinoenamel and Cementodentinal Junctions.- K. Interglobular Dentine.- L. Granular Layer of Tomes.- M. Incremental Lines and Neonatal Lines.- N. Translucent Dentine.- O. Regular and Irregular Secondary Dentine.- References.- Structure and Ultrastructure of the Dental Pulp.- A. Basic Anatomy.- B. Pulpal Cells.- I. The Odontoblasts.- II. The Fibroblasts.- III. Other Pulpal Cells.- C. Extracellular Matrix of the Pulp.- D. The Cellular Organization of the Pulp.- I. The Odontoblastic Layer.- II. The Subodontoblastic Layer.- III. The Central Pulp.- E. Innervation and Dentine-Pulp Sensitivity.- I. Histological Nerve Distribution in the Pulp-Dentine Complex.- II. Microscopic and Fine Structure of Pulpal and Dentinal Nerve Fibrils.- III. Dentine-Pulp Sensitivity.- 1. The Odontoblast as a Receptor Cell.- 2. The Hydrodynamic Hypothesis.- 3. Direct Neural Stimulation.- F. Vascular Supply.- I. Blood Vessels.- II. Pulpal Lymphatics.- G. Age Changes and Pulpal Calcifications.- References.- Enamel.- A. Introduction.- B. Gross Anatomy.- I. Distribution.- II. Naked-Eye and Magnifying-Glass-Range Features.- C. Microscopy and Technical Methodology for the Study of Enamel.- I. Light Microscopy.- 1. Sectioning Enamel for Light Microscopy.- 2. Examination of Ground Sections in Light Microscopy.- 3. Reflected-Light Microscopy of Well-Polished Section Surfaces.- II. Transmission Electron Microscopy of Enamel.- 1. Sectioning Enamel for Transmission Electron Microscopy.- 2. Transmission Electron Microscopy of Replicas.- 3. Ion-Beam Thinning.- III. Electron Diffraction of Enamel Crystals.- 1. Isolation of Enamel Crystallites.- 2. Electron Diffraction.- 3. Origin of Contrasts.- IV. Scanning Electron Microscopy.- 1. Scanning Electron Microscopy of Enamel.- a) Secondary Electrons.- b) Back-Scattered Electrons.- c) Cathodoluminescence.- 2. Sample Preparation.- a) Sample Preparation Procedures for Adult Enamel.- b) Preparative Procedures for Immature Enamel.- 3. X-ray Emission Microanalysis.- a) Characteristic X-ray Emission.- b) Wavelength-Dispersive X-ray Analysis.- c) Energy-Dispersive X-ray Analysis.- V. X-ray Microscopy and Microradiography.- 1. Contact and Projection Microradiography.- 2. Scanning X-ray Microscopy.- 3. X-ray Diffraction.- D. Development of the Tooth Germ Prior to Enamel Formation.- I. The Tooth Germ.- II. Ameloblast Differentiation and the Pre-ameloblast.- E. Enamel Formation.- I. The Fully Differentiated Ameloblast.- II. Ultrastructural Detail Within Secretory-Phase Enamel.- III. Discontinuities in the Crystal Orientation Pattern.- IV. Amelogenins and Other Matrix Components (Biochemistry, Histochemistry, Histology and Retention During Maturation).- V. Histology of Demineralised Enamel Matrix.- VI. Histological and Histochemical Changes with Maturation.- F. Enamel Crystals and Prisms.- I. Crystal Chemistry of the Inorganic Component of Enamel.- II. Size and Shape of Enamel Crystallites.- III. Crystal Orientation and the Existence of Prisms.- 1. The Enamel-Dentine Junction.- 2. Majority-Phase Enamel Secretion.- 3. Development of a Prism-Free Surface Layer.- 4. Modal Crystallite Orientation.- 5. Explanation of Crystallite Orientation in 3-D as a Function of the Developmental Enamel Surface Morphology.- 6. Prism Patterns.- a) The Characteristic Profiles of the Developing Enamel Surface and the Three Packing Arrangements of Prisms.- b) Pattern 1 Enamel: Complete Prism Boundaries.- c) Patterns 2 and 3: Incomplete Prism Boundaries.- d) Pattern 2 Enamel.- e) Pattern 3 Enamel.- f) Distribution of Principal Prism Types.- g) Arcades or Arches in Human Enamel Pattern 3 Prisms: A Question of Depth or Decussation?.- h) The Prism Boundary Discontinuity.- i) Seams, Pseudo-prisms and Evolution.- IV. Incremental Phenomena.- 1. Cross-striations and/or Varicosities.- 2. The Incremental Lines or Brown Striae of Retzius.- 3. Neonatal Line.- 4. Development of Cross-striations.- V. General Directions of the Prisms as Seen in Low-Powered Light Microscopy.- 1. Prism Orientations.- 2. Prism Decussation.- a) Movement of Ameloblasts.- b) Extreme Decussation in the Rat Incisor.- c) Other Mammals.- d) Human Enamel.- e) Functional Significance.- G. The Enamel-Dentine Junction.- I. The Shape of the Junction.- II. Features Originating at the Enamel-Dentine Junction.- 1. Spindles.- 2. Tufts.- 3. Lamellae.- 4. Enamel Tubules.- H. Mature Enamel Surface Features.- I. Fissures.- II. Prism-Free Enamel and Smooth Areas.- III. Pits, Perikymata and Imbrication Lines.- IV. Cervical Margins.- V. Brochs.- VI. Surface-Overlapping Projections and Isolated Deep Pits.- VII. Regional Differences in the Enamel Surface.- VIII. Cement on the Enamel Surface.- IX. Calculus on the Enamel Surface.- J. Maturation of the Enamel and Eruption of the Crown.- I. Maturation and Maturation Ameloblasts.- II. Information from Rodent Incisor Studies.- 1. Main Features.- 2. Transitional Zones.- 3. Ruffle-Ended Ameloblasts.- 4. Smooth-Ended Ameloblasts.- 5. Labelling Studies.- 6. Cyclical Phenomena.- III. Studies on Rooted Teeth.- IV. Mechanisms of Maturation and Matrix Removal.- V. End of Maturation - Variations in Composition.- VI. Eruption or Emergence.- VII. Post-eruptive Maturation.- K. Functional Changes in Enamel.- I. Wear.- II. Erosion.- L. Pathology.- I. Acquired and Inherited Disorders.- II. Linear Hypoplasias.- III. Hypoplastic Grooves.- IV. Hypoplastic Pits.- V. Dental Fluorosis.- VI. Enamel Caries.- VII. Iatrogenic Cutting and Fracturing.- VIII. Acid-Etching.- References.- Special Aspects of Biomineralization of Dental Tissues.- A. Does a Correlation Exist Between the Fundamental Processes of Enamel, Dentine, and Cementum Mineralization Which Might Lead to a General Calcification Theory?.- B. Fundamental Aspects of Enamel Mineralization.- I. Mineralization in an Ordered, Ionotropic Gel.- II. Calcium (and Phosphate) Transport.- III. Current Ideas About the Morphological Aspects of Crystal Nucleation and Crystal Growth in Enamel.- 1. The Prevailing Theory on the Morphology of Crystal Nucleation and Crystal Growth in Enamel.- 2. Aspects of Our Own Ideas Concerning the Morphology of Crystal Nucleation and Crystal Growth in Enamel.- 3. Does the Enamel Crystal Develop from One Nucleus or from Several Nuclei?.- IV. Description of the Matrix Macromolecules in Enamel.- 1. General Chemical Characterization.- 2. Possible Crystalline, Paracrystalline Structure of the Enamel Proteins.- 3. Amino-Acid Sequence Analysis for Active Sites for Ca-Phosphate Nucleation.- V. Crystal Structure of the Developing and Mature Enamel Crystallites.- 1. Existence of a Primary Ca-Carbonate Mineral.- 2. Existence of a Primary Apatite with Strong Lattice Distortions.- 3. Primary Existence of an Octocalciumphosphate.- C. Fundamental Aspects of Dentine Mineralization, and, in Part, of Cementum, Bone and Cartilage.- I. General Aspects of Enamel and Dentine Mineralization.- II. Mineralization of the Matrix Vesicles.- 1. Development and Morphology of Matrix Vesicles.- 2. Histochemical and Chemical Characterization of the Components of the Matrix Vesicles.- 3. Analysis of the Fine Structure and the Pathway of the Matrix Vesicles by Means of Staining with Bi3+ Ions.- 4. Mineralization of the Matrix Vesicles and Their Immediate Neighborhood.- a) Mineralization in the Matrix Vesicles.- b) Extravesicular Mineralization; Radial Arrangement of the Elongated Crystallites.- III. Mineralization of the Collagen Fibers.- 1. General Aspects.- 2. Relation to the Paracrystalline Collagen Structure.- a) Morphological Observations and Measurements of Mineralized Collagen.- b) Collagen Structure.- c) Mineralization on the Surface of the Collagen Fibers.- IV. Extracollagenous Mineralization.- 1. General Aspects.- 2. Types of Maeromolecules of the Noncollagenous Regions.- a) Phosphoproteins.- b) Proteoglycans.- c) Glycoproteins.- d) ?-Carboxyglutamic Acid-Containing Proteins and Gla-Proteins, e.g., Osteocalcin.- D. Conclusion: Differences and Similarities in Mineralization in Enamel, Dentine, and Other Hard Tissues, and a General Calcification Theory.- References.- Author Index.