The appearance of teeth marks along the sides of the tongue is medically known as a crenated or scalloped tongue. These rippled indentations are not a disease but a sign that the tongue is pressing against the teeth with excessive or sustained force. While often benign, these marks indicate that something is causing the tongue to enlarge or be habitually pressed outward. Understanding the root cause is important, as the issue can range from simple oral habits to serious underlying systemic health conditions.
What Are Teeth Marks on the Tongue?
A scalloped tongue is characterized by a wavy, ridged, or corrugated pattern that perfectly mirrors the shape of the adjacent teeth. These indentations typically run along the lateral margins of the tongue, near the molars and premolars. The mechanical cause is simple: the tongue tissue is physically compressed between the upper and lower dental arches.
The condition often results from macroglossia, the medical term for an enlarged tongue, or from relative macroglossia. True macroglossia involves an actual increase in tongue tissue volume. Relative macroglossia occurs when a normal-sized tongue appears large because the oral cavity is smaller or the tongue is positioned incorrectly. In either case, sustained pressure creates the chronic indentations.
Causes Related to Oral Habits and Jaw Position
Bruxism, or the unconscious clenching and grinding of teeth, is a frequent culprit. This activity increases the pressure inside the mouth, forcing the tongue against the teeth, especially during sleep.
A habitual tongue resting position, sometimes called tongue thrusting, can also contribute to the indentations. This involves the tongue pressing too far forward or laterally against the teeth even when a person is awake and relaxed. When teeth are crowded or misaligned, the tongue has less resting space, naturally increasing the likelihood of contact and pressure points.
Mild dehydration can cause the tongue tissue to swell slightly, increasing its size and the contact pressure against the teeth. Temporomandibular joint (TMJ) disorders, which affect the jaw hinge, may alter the jaw’s alignment and the way the tongue rests. This misalignment can lead to increased tongue-to-tooth contact or encourage clenching habits, both of which result in scalloping.
Underlying Systemic Issues Causing Swelling
When scalloping is caused by a persistent, true enlargement of the tongue, a systemic health issue is often the underlying reason. Hypothyroidism, an underactive thyroid gland, is a recognized cause. Reduced thyroid hormone levels can lead to myxedema, characterized by the accumulation of fluid in body tissues, including the tongue, causing it to swell.
Obstructive sleep apnea (OSA) is another systemic condition linked to tongue scalloping. In OSA, the tongue often swells or is poorly controlled during sleep. The repetitive effort to keep the airway open can involve the tongue pressing forcefully against the lower teeth. The presence of a scalloped tongue is considered a useful clinical predictor for sleep-breathing disorders.
Nutritional deficiencies, specifically a lack of B-vitamins like B12, riboflavin, and niacin, can lead to tongue swelling, a condition known as glossitis. These deficiencies cause inflammation and enlargement of the tongue tissue, which then presses against the teeth. Less common but more serious causes include infiltrative conditions, such as amyloidosis, where abnormal proteins deposit in soft tissues, leading to true macroglossia.
When to Seek Medical Consultation and Treatment
While a scalloped tongue is often an isolated symptom of harmless habits, professional consultation is warranted if the marks are persistent or accompanied by other symptoms. Red flags include pain, difficulty swallowing, or changes in speech. Other concerning signs are unexplained fatigue, weight changes, cold intolerance, or loud snoring suggesting a sleep disorder.
A dentist or physician will examine the tongue and review your oral habits and medical history. If a systemic issue is suspected, diagnostic steps may include blood tests to check thyroid function, screen for nutritional deficiencies (like B12 or iron), or assess for inflammatory markers. A referral for a sleep study may be suggested if sleep apnea is a possibility.
Treatment focuses on addressing the underlying cause of the pressure. For bruxism, a custom-fitted night guard can protect the tongue and teeth from clenching forces. If hypothyroidism is diagnosed, hormone replacement therapy can resolve fluid retention and reduce the size of the tongue. When nutritional deficiencies are the cause, targeted supplementation can alleviate the swelling, allowing the tongue to return to its normal size.