Fundamentals of Oral Histology and Physiology

Arthur R. Hand, Marion E. Frank

• Publisher: Wiley-Blackwell
• Year: 2014
• ISBN:
  9781118938300
• Edition: 1
• Topic: Medicina
• Subtopic: Salute e chirurgia orale

Fundamentals of Oral Histology and Physiology is a landmark new text streamlining the essentials of histology and physiology into one clinically accessible textbook. Written for predoctoral dental students, the book brings together structure, function, and clinical correlations for maximum retention and ease of use.

Assuming a background in basic biologic sciences, this text focuses on the histology and physiology that students need to know to practice dentistry and to understand and evaluate the current literature, without repeating basic information learned in other courses. Fundamentals of Oral Histology and Physiology concentrates on Oral Structures and Features, including Development, Teeth, Tooth and Jaw Support, Mucosal Structure and Function, and Effectors.

Chapter 1
Oral Structures and Tissues

Arthur R. Hand¹ and Marion E. Frank²

¹ Department of Craniofacial Sciences and Cell Biology, School of Dental Medicine, University of Connecticut

² Department of Oral Health and Diagnostic Sciences, University of Connecticut

The oral cavity and its component cells, tissues, and structures constitute a unique and complex organ system and environment. Of necessity, we study its various parts individually, but the health and function of the components of the oral cavity depend upon and influence one another. Importantly, the oral cavity relies on as well as influences the health and function of the entire body.

The oral cavity is the gateway to the body, and most of the substances that enter our bodies do so through the oral cavity. It is exposed to the physical insults of mastication, hard objects and various food substances, and extremes of temperature. A variety of chemicals, including those present in foods and drinks and produced by commensal and pathogenic organisms, affect the oral cavity. It functions in alimentation, respiration, innate and immune defense, special and general sensation, speech, and human interactions. The tissues and structures of the oral cavity are subject to unique as well as general disease processes. Diseases originating in the oral cavity can have systemic effects; likewise, systemic diseases can affect the oral cavity and the first signs and symptoms of many diseases may appear in the mouth.

The oral cavity

The readily visible components of the oral cavity include the lips (labia), the inside of the cheeks (bucca), the teeth and gums (gingivae), the hard and soft palates, the floor of the mouth, and the tongue (Fig. 1.1). Not visible, but clearly important, are the muscles, nerves, blood vessels, glands, joints, and especially the bones of the upper (maxilla) and lower (mandible) jaws that provide support for and function with the visible components. The oral cavity begins at the junction of the vermilion border of the lips and the mucosa lining the inside of the lips, and extends posteriorly to the palatoglossal folds or arch. Beyond the palatoglossal folds are the palatopharyngeal folds and the beginning of the oropharynx, where the digestive and respiratory tracts come together. The palatine tonsils are located in the tonsillar fauces between the palatoglossal and palatopharyngeal folds. The lymphoid tissue of the palatine tonsils, along with that of the pharyngeal tonsil (adenoids) and the lingual tonsils, guards the entrance to the oropharynx. Anteriorly, the respiratory tract (nasal cavity) is separated from the oral cavity by the hard palate, and posteriorly by the soft palate. The hard palate has an arch-like shape that varies in width and height among individuals. It also plays an important role in manipulation and mastication of food, and in speech. The soft palate functions to seal the oropharynx from the nasopharynx during swallowing and speech. However, during exhalation, receptor cells that detect odors in the olfactory mucosa are activated by oral vapors moving from the posterior oral to posterior nasal cavity through the nasopharynx, effectively expanding the mouth. It is this retronasal route that gives food and drink the odors that contribute much to flavor perception.

Figure 1.1 Diagram illustrating the anatomy and main structures of the oral cavity.

(Modified from Tortora, G.J. & Grabowski, S.R. 2000. Principles of Anatomy and Physiology, 9^th edition, Wiley, New York. Reproduced by permission of John Wiley & Sons.)

The lips and cheeks are separated from the alveolar processes of the maxilla and mandible that support and hold the teeth by a space called the vestibule. The vestibule is limited posteriorly by the ramus of the mandible, and superiorly and inferiorly by the mucolabial and mucobuccal folds. The mucosal lining of the vestibule is continuous with the mucosa of the lips and cheeks, and with the mucosa covering the alveolar processes (Fig. 1.2). Folds (frena [singul...