Essential Clinical Oral Biology

Stephen Creanor, Stephen Creanor

• Publisher: Wiley-Blackwell
• Year: 2016
• ISBN:
  9781118939666
• Edition: 1
• Topic: Medizin
• Subtopic: Mundhygiene & Zahnchirurgie

Essential Clinical Oral Biology is an accessible guide to oral biology, introducing the scientific knowledge necessary to succeed in clinical practice.

• Student-friendly layout with clinical photographs throughout
• Each chapter has clearly defined key topics and learning objectives
• Covers the essentials: what you need to know and why
• Companion website featuring interactive MCQs, teaching presentations and downloadable images

Chapter 1
An Introduction to the Human Dentition

Stephen Creanor

Key Topics

• Overview
• Descriptive terms applied to the human dentition
• Tooth nomenclature and the FDI tooth index

Learning Objectives

• To be familiar with the terms describing the various aspects of the dentition
• To be aware of the indices used in the charting of teeth and in particular the FDI tooth index

Overview

This chapter will introduce you to a series of terms which are applied to the various surfaces of the human dentition. Such terms are used constantly within the clinical scenario to describe the exact location of dental disease and the extent of dental restorations and so on. You must become familiar with these terms – you will be expected to know them in clinic. You should be familiar with the major characteristics of each tooth type, to enable you to identify the following:

• Is the tooth permanent (secondary) or primary (deciduous)?
• Has the tooth come from the upper or lower arch?
• Is the tooth a central or lateral (incisor), or a first or second (premolar) or a first, second or third (molar)?
• Is the tooth from the right or left side of the mouth?
• What is the tooth type (incisor, canine, etc.)?

All teeth have a crown and normally have one, two or three roots. The shape of the crown and the number of roots any tooth might have are both usually governed by the site within the oral cavity from where the tooth has come. The crown of a tooth is usually the only part of a tooth that is visible from a clinical examination of the mouth (Figure 1.1). The tip of the root is called the apex and usually has one or more holes (foramen/pl. foramina) through which blood vessels and nerves pass into and out of the dental pulp.

Figure 1.1 Clinical photograph of a normal healthy dentition, gingivae and oral mucosa.

(Source: Dr Rachael McKeown. Reproduced with permission of Dr McKeown)

There are two arches within the oral cavity – an upper or maxillary arch and a lower or mandibular arch (Figures 1.1 to 1.3). The upper arch may be named the maxillary arch, since the roots of the maxillary or upper teeth can be found attached to the upper jaw bone – the maxilla. Likewise, the lower arch may be named the mandibular arch, since the roots of the mandibular or lower teeth can be found attached to the lower jaw bone – the mandible. An anterior (front) view and a lateral (side) view of a human skull can be seen in Figures 1.2 and 1.3.

Figure 1.2 Illustrates an anterior (front) view of the human skull. From Head and Neck Anatomy for Dental Medicine. 2010. Ed. EW Baker. Thieme Medical Publishers, Inc.

Figure 1.3 Illustrates a lateral (side) view of the human skull. From Head and Neck Anatomy for Dental Medicine. 2010. Ed. EW Baker. Thieme Medical Publishers, Inc.

The permanent dentition consists of 32 teeth:

• 8 incisors, 4 canines, 8 premolars and 12 molars
  The primary dentition consists of 20 teeth:
• 8 incisors, 4 canines and 8 molars

Descriptive Terms

Remember when viewing a patient, you would refer to the upper right, for example, as the patient's upper right and not your right! The midline of the two arches is a common reference point – this is the line dividing right and left central incisors – see Figures 1.1 and 1.2.

The dentition may be split into either four quadrants or six sextants. Both terms are commonly used within clinical dentistry. When the dentition is split into quadrants, each “quadrant” will normally contain a maximum of eight permanent teeth or five primary teeth – a quarter of the dentition. In the case of the permanent dentition, this is made up of two incisors and one canine (which make up the anterior teeth) and two premolars and three molars (which make up the posterior teeth). In the case of the primary dentition, this is made up of two incisors and one canine (the anterior teeth) and two molars (the posterior teeth). The quadrants are referred to as upper right (UR) and upper left (UL), and lower right (LR) and lower left (LL).

The system used in this book will be similar to the Palmer notation (see below). The quadrant will be given first, as above, where UR will be the patient's upper right quadrant, and so on. Permanent teeth are numbered 1–8, with 1 being the permanent central incisor and 8 being the permanent third molar. Primary (or deciduous) teeth are referred to as A–E, with A being the primary central incisor and E being the primary second molar.

Within some clinical disciplines, the dentition is split into six sextants. Each “sextant” may contain approximately one sixth of the teeth – the mandible and the maxilla each contain...