Posterior tooth shortness occurs when the hard structure of the teeth is lost over time. This progressive destruction of the outer enamel and underlying dentin is often referred to as pathological tooth wear. While minor wear is normal with age, accelerated loss leads to visibly shorter back teeth and can severely compromise oral function. Understanding the distinct causes of this structural loss is the first step toward effective treatment and halting its progression.
Mechanical Wear: The Role of Grinding and Clenching
The most significant mechanical cause of posterior tooth shortness is bruxism, which involves involuntary clenching or grinding of the teeth. This tooth-to-tooth wear, classified as attrition, is an unconscious habit often related to stress, anxiety, or sleep disorders. The forces generated during bruxism are far greater than those used for normal chewing.
The back teeth, specifically molars and premolars, are most affected because they are designed for crushing food and receive the brunt of these excessive forces. Sleep bruxism involves prolonged grinding, while awake clenching focuses intense pressure on the posterior teeth. This constant, high-pressure contact erodes the cusps and biting surfaces, resulting in the flat, shortened appearance characteristic of severe attrition.
Chemical Erosion and Abrasive Habits
Beyond mechanical forces, the structure of the back teeth can be chemically dissolved through erosion, which is the loss of mineralized tissue due to non-bacterial acids. This chemical attack softens the enamel, making it highly susceptible to wear from normal chewing forces. Intrinsic acid sources, such as chronic gastroesophageal reflux disease (GERD) or frequent vomiting, expose the teeth to highly corrosive stomach acid.
External sources of acid also contribute to this softening, primarily from consuming highly acidic foods and drinks like sodas, sports drinks, and citrus fruits. When erosion is combined with mechanical wear, the rate of tooth structure loss accelerates. Abrasion involves mechanical wear from foreign objects, such as using a hard-bristled toothbrush, aggressive brushing, or abrasive toothpastes, which contributes to the overall shortening of the teeth.
Symptoms and Health Impact of Severe Tooth Shortness
The consequences of severe tooth shortness extend beyond cosmetic concerns, impacting the structural harmony of the entire jaw system. As the enamel wears away, the underlying dentin, a softer, more porous tissue, becomes exposed. This exposure often leads to dentine hypersensitivity, causing sharp pain or discomfort when consuming hot, cold, or sweet substances.
Continued loss of tooth structure results in a reduction of the occlusal vertical dimension (OVD), bringing the upper and lower jaws closer together. This change can strain the muscles of mastication and alter the position of the temporomandibular joints (TMJ). This may lead to chronic jaw pain, headaches, or a clicking sensation. Over time, the reduced OVD can also affect facial aesthetics, sometimes giving the lower third of the face a collapsed or sunken appearance.
Professional Treatment and Prevention Strategies
Addressing short back teeth requires a professional diagnosis to determine the underlying cause, whether mechanical, chemical, or a combination of both. For patients diagnosed with bruxism, the primary preventive treatment is often a custom-fitted occlusal splint or night guard. This appliance creates a physical barrier between the teeth, absorbing the intense forces of grinding and clenching to prevent further attrition.
Mitigating chemical erosion involves identifying and managing the acid source, which may include dietary counseling to reduce acidic intake or medical consultation for conditions like GERD. Once the destructive process is stabilized, the lost tooth structure can be restored to its original height and contour. Restorative methods include dental bonding, which uses a tooth-colored resin, or more durable options like crowns and onlays. These restorations rebuild the tooth and reestablish a stable vertical dimension, protecting the remaining structure and restoring comfortable function.