Corpus: Gingiva

Gum or gingiva is the part of the oral mucosa that surrounds the tooth crowns and adheres to the free edges of the alveolar processes of the upper and lower jaw.

The gums are for the most part closely fused with the periosteum of the alveolar processes of the jaws. It tightly surrounds the teeth at the border between the root part and the crown and exchanges numerous fibres with the alveolar periosteum.

Based on mobility, a clinical distinction can be made between attached and free gingiva. The portion known as free gingiva protrudes over the alveolar margins. Between the individual teeth, the free gingiva is raised towards the interdental papilla (papilla interdentalis). There is a gap a few millimetres deep between the crown of the tooth and the gingival margin, which is known as the gingival sulcus.

As the gingiva has no submucosa, it cannot move and is therefore firmly fused to the periosteum. It is a glandless and cutaneous mucosa with a slightly keratinised (parakeratinised) squamous epithelium. Due to its structure and high regenerative capacity, the gum heals without scarring in the event of injury.

The inside of the gingival sulcus is covered with an epithelium known as the inner marginal epithelium. This in turn can be divided into two sections - sulcular epithelium and adhesive epithelium. The sulcus epithelium glides freely on the crown, while the adhesive epithelium is connected to the enamel or cervical cementum by hemidesmosomes.

If the gingival sulcus exceeds its physiological depth, a pocket is formed (periodontal pocket). If the adhesive epithelium between the gingiva and tooth becomes detached (e.g. due to wounds or food impaled in periodontal pockets), bacteria can migrate into the gap and attack the periodontium.

• Salomon FV, Geyer H, Uwe G. 2008. anatomy for veterinary medicine. 2nd, updated and expanded edition. Stuttgart: Enke Verlag in MVS Medizinverlage Stuttgart GmbH & Co. KG. ISBN: 978-3-8304-1075-1
• Nickel R, Schummer A, Seiferle E. 2004. Lehrbuch der Anatomie der Haustiere, Band II: Eingeweide. 9th, unchanged edition. Stuttgart: Parey in MSV Medizinverlage Stuttgart GmbH & Co. KG. ISBN: 978-3-8304-4152-6