The perception that some individuals possess “long teeth” results from two distinct biological processes. The first involves the actual, structural size of the tooth itself, largely determined by genetics and development. The second, and more frequent cause, is the exposure of the tooth’s root surface due to changes in the surrounding gum and bone tissue, creating the illusion of greater length. Understanding which mechanism is at play is key to addressing the concern.
True Tooth Size: Developmental and Genetic Factors
In some cases, a tooth appears long because it is genuinely larger than the average size, a condition known as macrodontia. This developmental difference is a structural variation where the enamel and dentin layers form a crown that is physically oversized. The size of an individual’s teeth is primarily an inherited trait, meaning genetic factors significantly influence the dimensions of the dental structures.
Types of Macrodontia
Macrodontia can manifest in several ways, often categorized by the extent of the size difference.
A very rare form is true generalized macrodontia, where all teeth in the mouth develop larger than the normal range. This is sometimes linked to systemic conditions like pituitary gigantism, which involves an excess of growth hormone.
More common is localized macrodontia, where only one or two teeth, typically the incisors or molars, are noticeably larger than their neighbors.
A third category is relative generalized macrodontia, which is not a true size anomaly but an illusion. In this scenario, the teeth are a normal size, but the jaw structure is smaller than average. This makes the teeth appear disproportionately large within the limited space.
The Appearance of Length: Root Exposure from Gum Recession
The most frequent reason people notice their teeth looking longer, particularly as they age, is the progressive loss of gum tissue, known as gingival recession. This process exposes the root surface, which is normally covered and protected by the gums and bone. While the anatomical crown is covered by hard, white enamel, the root is covered by a much softer material called cementum. When the gumline pulls back, it reveals the root surface beneath the enamel, creating the optical effect of a longer tooth.
Causes of Recession
One main contributor to this loss of tissue is aggressive tooth brushing. This mechanical trauma physically wears away the delicate gum tissue over time.
Another significant cause is periodontal disease, a bacterial infection that destroys the supporting structures of the teeth, including the gum tissue and the underlying jawbone. As the bone loss progresses, the gums lose their foundation and recede, widening the gap between the tooth and the gumline.
Consequences of Exposure
Exposed root surfaces carry functional consequences beyond just the aesthetic change in tooth length. The cementum covering the root is much thinner and more porous than the enamel. This leads to an increase in tooth sensitivity, especially to hot, cold, or sweet stimuli. Furthermore, the exposed root is highly vulnerable to root decay because cementum is not as durable as enamel.
Addressing the Causes of Long Teeth
The approach to managing the appearance of long teeth depends entirely on whether the cause is structural size (macrodontia) or tissue recession. For macrodontia, cosmetic and restorative options focus on reshaping the existing structure or altering its visible size.
Treatment for Macrodontia
One common treatment is enamel shaping or contouring, where a small amount of the tooth’s enamel is carefully reduced. This decreases the overall length and width, improving proportionality with adjacent teeth.
For more significant size differences, porcelain veneers can be placed on the front surface of the tooth to create an entirely new, smaller appearance. In cases where macrodontia causes severe crowding or bite issues, orthodontic treatment or, in rare instances, extraction may be necessary to restore balance.
Treatment for Gum Recession
When the appearance of length is due to gum recession, treatment focuses on stopping the tissue loss and covering the exposed root. The first action involves identifying and correcting the underlying cause, such as switching to a softer toothbrush and a gentle brushing technique. Treating periodontal disease through deep cleaning procedures is also necessary.
To physically cover the exposed root, a periodontist may perform a gum grafting procedure. This involves transplanting healthy tissue from the roof of the mouth or using donor material to restore the gumline. Newer, less invasive techniques, such as the Pinhole Surgical Technique or laser therapy, also aim to shift the existing gum tissue or promote tissue regeneration.