Go to Talking Prevention start page

Regional Anatomy – Back to Basics

As dental professionals our knowledge of the anatomy of the structures of the head and neck should be second to none;  but I don’t think that I am alone in my inability to recollect the finer detail of the blood supply to the head and neck !  Does that matter in our day to day work I ask?  Perhaps not, but it does us all good to revisit the basics to aid us in our understanding of new developments within  the profession.  ‘Knowledge advances by steps and not by leaps’ said Lord Macauly, a nineteenth century English Historian , and the history of our research into the aetiology and pathogenesis of periodontal disease exemplifies this slow and more often than not,  uncertain process. 

The following  questions will concentrate on the periodontium because that is where most of our readers spend most of their clinical time and efforts.  Reading the questions carefully is the clue here.. the correct answers are all there…in your head and within the text below.

The Periodontium

The periodontium has four components; the gingivae, the alveolar bone, the periodontal ligament and the cementum. Knowledge of the periodontal tissues in health is essential to an understanding of its behaviour in disease and so cast your mind back to dental school and see how much of the finer detail of these very familiar tissues you can recall but to aid you the following diagrams should help stir up the grey cells.

The Gingival Blood and Nerve Supply

The gingiva has a rich blood supply derived from three sources detailed in Fig 1 . These link in the gingiva to form capillary loops in the connective tissue papillae between the epithelial rete pegs.

The rich gingival blood supply derives from: A) Periodontal ligament, B) Alveolar bone, C) Supraperiosteal vessels.

The Gingival Fibres

The connective tissue of the gingiva is organised to keep the gingival margin tight around the neck of the tooth and to maintain the integrity of the dentogingival attachment . The arrangement of these fibres is complicated, but they have been described as being divided into several discernible groups of collagen fibres detailed in fig 2.

Gingival fibre groups: A) Circular fibres, B) Dentogingival fibres, C) Alveolar creset fibres, D) Trans-septal fibres.

The Gingival Margin

The marginal gingiva forms a cuff 1-2mm wide around the neck of the tooth and is the external wall of the gingival crevice, which is 0-2mm deep.

The interdental gingiva in the shape of a "col" reflects the countours of the tooth contact area.

The Periodontal ligament

The ligament consists of well-organised collagen fibre bundles, about 5µm in diameter, in a ground substance matrix through which vessels and nerves course.

Periodontal ligament fibre bundles: A) Alveolar crest, B) Horizontal, C) Oblique, D) Apical.