When a denture shifts from its intended position, resulting in an “off center” appearance, it affects both confidence and daily function. This misalignment can manifest as a noticeable change in smile aesthetics, along with difficulty in chewing or speaking clearly. A loose or shifting appliance signals that the foundation it rests upon has changed. This change in fit is a common occurrence for denture wearers and indicates that professional attention is needed to restore stability and comfort.
Common Reasons Dentures Become Misaligned
The primary factor contributing to denture misalignment is alveolar bone resorption. After natural teeth are lost, the jawbone that once anchored the tooth roots no longer receives stimulation, causing the bone tissue to gradually shrink and change shape over time. This loss of bone volume alters the ridge upon which the denture sits, meaning the appliance no longer conforms to the underlying anatomy. Even a small amount of resorption can cause the appliance to move or tilt.
The soft tissues of the mouth, specifically the gum tissue, also undergo natural changes that affect denture stability. Gum tissue can shrink, become irritated, or shift over time, especially if the denture begins to apply uneven pressure due to a poor fit. This change in the mucosal surface decreases the suction and retention needed to hold the denture firmly in place. Furthermore, the material of the denture itself can contribute to fit issues.
Repeated daily wear and tear can cause minor imperfections, such as hairline cracks or chips, that distort the original shape of the plastic base. Denture material is also susceptible to warping if mishandled, such as by soaking the appliance in water that is too hot or allowing it to dry out completely for extended periods. These material changes or minor damages create gaps between the denture and the gum tissue, allowing the appliance to shift and become off center.
Immediate Steps When Dentures Shift
If you notice your denture has suddenly shifted, a quick self-assessment can help determine the immediate cause. First, remove the appliance and check the fitting surface and your palate for any trapped food particles or debris that might be interfering with the seal. If the denture appears clean and undamaged but still feels loose, using a denture adhesive can provide temporary stabilization. Apply the adhesive sparingly in a few dots or thin strips to the clean, dry fitting surface of the denture before seating it firmly in your mouth. The adhesive should only be considered a short-term measure until you can see your dental professional for a permanent adjustment.
It is important to caution against attempting any do-it-yourself repairs, such as filing the denture or using household glues or tools. Modifying the appliance with non-dental materials can permanently damage the acrylic, compromise the structural integrity, and make professional repair or relining impossible.
Professional Solutions for Misalignment
When misalignment is caused by changes in the oral anatomy, a dental professional will typically recommend a reline to resurface the fitting area of the denture. A reline involves adding new acrylic material to the inner surface of the base to accurately match the current contours of your gum ridge, thereby restoring the snug fit and stability. There are two main types of relines, each suited for different needs: soft and hard.
Soft Reline
A soft reline uses a pliable, rubber-like polymer material that remains flexible after curing, acting as a cushion for sensitive or irritated gum tissue. This option provides immediate comfort and is often used as a temporary solution or for patients with severely resorbed or tender ridges.
Hard Reline
A hard reline utilizes a durable, rigid acrylic, similar to the original denture material, which offers a long-lasting and precise fit for stable tissue. Hard relines are typically performed in a dental laboratory to ensure maximum accuracy and durability, often providing a functional fit for up to two years.
For more extensive misalignment or when the denture base is structurally compromised, cracked, or severely worn, a rebase procedure may be necessary. Rebasing is a comprehensive process where the entire acrylic base material is replaced while preserving the existing denture teeth. This procedure provides the existing teeth with a brand-new foundation custom-fitted to the patient’s current anatomy, making it the closest option to fabricating a new denture without the cost of new teeth.
If the denture is over five to seven years old, if the teeth are significantly worn down, or if the jawbone changes are too substantial, a professional may recommend complete new denture fabrication. A new appliance allows for a full re-evaluation of the bite, aesthetics, and overall fit, accounting for all anatomical changes. Minor issues, like small pressure spots or slight interferences, can often be addressed with simple chairside adjustments, which involve carefully grinding and polishing small amounts of the acrylic for immediate relief.