An Illustrated Guide to Oral Histology

Imran Farooq, Saqib Ali, Paul Anderson, Imran Farooq , Saqib Ali, Paul Anderson

• Publisher: Wiley-Blackwell
• Year: 2021
• ISBN:
  9781119669609
• Edition: 1
• Topic: Medicine
• Subtopic: Oral Health & Surgery

An Illustrated Guide to Oral Histology

Learn more about the histological presentation of diseased and normal oral tissues with this high definition illustrated dental reference

An Illustrated Guide to Oral Histology delivers a collection of high-definition histological and pathological images, presenting both diseased and normal oral tissues.

The book provides over 200 high-magnification histomicrographs of oral tissues, as well as definitions and explanations of key identifying histological and pathological features of oral tissues. Readers will also benefit from explanations of the clinical significance of particular features, numerous images of ground sections, haemotoxylin- and eosin-stained sections, and electron images. It also includes core topics such as:

• An introduction to tooth development, including the bud, cap, early bell, and late bell stages
• A thorough exploration of enamel, dentin, cementum and dental pulp
• A discussion of the periodontal ligament, including alveolar crest fibers, horizontal, oblique, apical, and inter-radicular fibers, transseptal fibers, and gingival fibers
• A guide to alveolar bone, oral mucosa, and salivary glands

Perfect for postgraduate dental students, An Illustrated Guide to Oral Histology will also be useful to undergraduate dental students, and those looking to improve their understanding of the microscopic structure of dental tissues and their pathologies.

1
Tooth Development

Saqib Ali¹, Imran Farooq¹, and Syed Ali Khurram²

¹ Department of Biomedical Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia

² Unit of Oral and Maxillofacial Pathology, School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom

Figure 1.1 H and E stained section showing tooth development.

Tooth development starts on the 37th day of gestation with the formation of primary epithelial bands in the place of future upper and lower jaws. These horse‐shoe‐shaped bands correspond to the future dental arches. These epithelial bands then form two ingrowths called dental lamina (lingually positioned) and vestibular lamina (buccally positioned). These ingrowths extend into the mesenchyme which is surrounded by the neural crest cells. The vestibular lamina proliferates within the mesenchyme and leads to the formation of the vestibule (between the cheek and tooth‐bearing portion of the jaw). The dental lamina gives rise to epithelial outgrowths toward the mesenchyme due to continuous proliferative activity which correspond to the location of forthcoming deciduous teeth. The tooth development is divided into the following stages: bud, cap, and bell (early and late). These stages along with the changes happening in the tooth germ are discussed in detail in the following sections.

1.1 Bud Stage

Figure 1.2 H and E stained section showing the bud stage of tooth development.

Figure 1.3 H and E stained section showing the bud stage of tooth development.

1.1.1 Description

The bud stage is the first stage of tooth development. It represents the first epithelial intrusion into the ectomesenchyme. The cells of the epithelium show minimal changes and the ectomesenchymal cells surround the epithelial bud. Due to the ectomesenchymal condensation (a process in which the epithelial bud propagates into the ectomesenchyme), the density of the cells increases near the epithelial outgrowth. This condensation is owed to the increased mitotic activity carried in the cells of the tooth bud and mesenchymal cells surrounding it. These buds develop at the distal side of the dental lamina and each bud represents a group of cells at dental lamina's end. The epithelial part is separated from the mesenchyme by a basement membrane. The ectomesenchyme surrounding the tooth bud is called the dental follicle or sac whereas the area directly subjacent to the condensation is called the dental papilla. The dental follicle is ultimately responsible for the formation of cementum, periodontal ligament (PDL), and alveolar bone. The dental papilla is responsible for the formation of dental pulp and dentin.

1.1.2 Key Identifying Features

The enamel organ at this stage appears roughly ovoid to spherical with poor histodifferentiation and morphodifferentiation. A typical tooth bud consists of centrally located polygonal (multiple‐shaped) cells and peripherally arranged columnar cells.

1.1.3 Clinical Significance

The successful development of the tooth depends on the interaction of epithelial and mesenchymal components. If these parts grow individually, neither will differentiate further [1]. This epithelial–mesenchymal interaction starts in the bud stage; therefore, any problem affecting the bud stage could seriously affect the development of teeth.

1.2 Cap Stage

Figure 1.4 H and E stained section showing the cap stage of tooth development.

Figure 1.5 H and E stained section showing the cap stage of tooth development.

1.2.1 Description

The cap stage is the second stage of tooth development. As the tooth bud matures, it takes part of de...