The periodontium is the collection of specialized tissues that surround and support the teeth, anchoring them within the jawbones. The name originates from the Greek terms “peri,” meaning around, and “odont,” meaning tooth. This biological system acts as the foundation for a healthy mouth, ensuring teeth can withstand the forces of chewing and remain in place. The study and care of these tissues fall under the dental specialty of periodontics.
Components of the Periodontium
The periodontium is composed of four distinct tissues that work together as a single unit. The most visible component is the gingiva, commonly known as the gums. This soft tissue covers the jawbone and collars the teeth. The gingiva is made up of different types of epithelium, including keratinized tissue on its outer surface that helps it withstand the friction of eating.
Beneath the gumline, the periodontal ligament (PDL) is a group of connective tissue fibers that attaches the tooth to the bone. It acts as a shock absorber, cushioning the tooth from the pressures of biting and chewing. This ligament is composed mostly of type I collagen fibers and fibroblasts, which are cells responsible for forming and repairing the surrounding bone and cementum.
Covering the root surface of the tooth is the cementum, a hard, calcified layer of tissue. This substance is the attachment point for the fibers of the periodontal ligament, effectively locking the tooth into its socket. Cementum is less dense than the enamel found on the crown of the tooth but is necessary for the tooth’s stability. It can also adapt to wear on the biting surfaces of the teeth through a process of apical deposition.
The final component is the alveolar bone, which is the part of the jaw that forms the tooth socket. This bone is in a constant state of remodeling, responding to the forces placed upon the teeth. Bone is resorbed in areas under pressure and added in areas under tension, allowing the teeth to shift slightly without being damaged. This bone consists of a dense outer layer (compact bone) and a spongy inner layer (trabecular bone).
The Function of the Periodontium
The primary purpose of the periodontium is to provide a stable anchoring system that holds teeth firmly within the jaw. This support is not rigid; the system is designed to handle and distribute the forces generated during chewing. The periodontal ligament acts like a suspension system, allowing for controlled tooth movement while dissipating pressure across the alveolar bone. This prevents damage to both the teeth and the jaw itself.
The periodontium also serves a sensory function. The periodontal ligament has nerve endings that transmit information about pressure and pain to the brain. This feedback, known as proprioception, allows for the precise control of chewing forces. This helps to prevent excessive biting pressure that could damage the teeth or the supporting structures.
Protection is another function of this system. The gingiva creates a tight seal around the neck of each tooth, forming a barrier that prevents oral bacteria from penetrating deeper into the underlying tissues. This barrier protects the periodontal ligament and alveolar bone from infection.
Conditions Affecting the Periodontium
The most common conditions affecting the periodontium are inflammatory diseases caused by the accumulation of bacterial plaque. The initial stage is known as gingivitis. In this phase, the inflammation is confined to the gingiva, causing symptoms like redness, swelling, and bleeding gums when brushing or flossing. Gingivitis is a reversible condition that does not involve any loss of the bone or tissue fibers that hold teeth in place.
If gingivitis is not addressed, the inflammation can progress below the gum line, leading to periodontitis. This is a more serious and destructive form of gum disease. In periodontitis, the body’s chronic inflammatory response to the bacteria causes the breakdown of the periodontal ligament and the alveolar bone, creating pockets between the gums and teeth.
As periodontitis advances, the loss of support can lead to several signs:
- Receding gums, which make the teeth appear longer
- Bad breath
- The formation of pus between the teeth and gums
- Changes in how the teeth fit together when biting
Ultimately, the teeth can become loose and may eventually be lost. Unlike gingivitis, the damage caused by periodontitis is not reversible, though its progression can be managed with professional treatment.
Maintaining Periodontal Health
Maintaining the health of the periodontium relies on consistent and thorough oral hygiene practices to control bacterial plaque. The foundation of this care is brushing the teeth twice daily with fluoride toothpaste and cleaning between the teeth once a day with floss or other interdental cleaners. These actions disrupt and remove the plaque biofilm before it can trigger an inflammatory response in the gums.
While at-home care is fundamental, it cannot remove plaque that has hardened into a calcified deposit called tartar or calculus. Regular professional dental cleanings are necessary to remove this hardened material. During these visits, a dental professional can also perform a periodontal examination to monitor for any signs of disease.
Lifestyle choices also play a part in periodontal health. Smoking is a risk factor for the development and progression of periodontitis, as it impairs the body’s ability to fight infection and heal. A balanced diet contributes to overall health, which in turn supports a healthy immune response in the oral cavity. Managing systemic conditions like diabetes is also necessary, as they can influence gum health.