A mandibular denture is a removable prosthetic device designed to replace missing teeth and surrounding tissues in the lower jaw (mandible). This device becomes necessary when individuals experience significant tooth loss due to decay, disease, or trauma, compromising their ability to chew and speak effectively. The primary function of a lower denture is to restore the function of the mouth and improve facial aesthetics. This dental appliance is custom-made to rest on the gum ridge and surrounding soft tissues, providing a foundation for artificial teeth.
Defining the Mandibular Denture
The mandibular denture consists of a gum-colored base, typically acrylic resin, with artificial teeth attached. For partial dentures, the base may incorporate a metal framework, often a cobalt-chromium alloy, to provide strength and stability. This prosthetic base is shaped to sit atop the alveolar ridge, the remnant of the bone that once held the natural teeth. Unlike an upper jaw denture (maxilla), a lower denture is shaped like a horseshoe to accommodate the tongue.
The design of a lower denture presents unique challenges because of the anatomy of the mandible. The lower arch offers less surface area for the denture base compared to the broad palate available for an upper denture, which relies on suction for retention. The constant movement of the tongue and the muscles in the floor of the mouth can easily dislodge the lower appliance. Traditional mandibular dentures often rely on gravity and the wearer’s surrounding musculature to maintain a secure fit, sometimes requiring denture adhesive.
Classifications of Lower Dentures
Mandibular dentures have three main variations that address different levels of tooth loss and stability needs. Complete dentures are designed for individuals who have lost all teeth in the lower arch. This prosthetic rests entirely on the gum tissue and underlying bone, replacing the natural teeth and providing support to the facial muscles.
Partial dentures are the preferred option when a person retains some healthy natural teeth in the lower jaw. The prosthetic replaces only the missing teeth and is held in place by clasps or other precision attachments that attach to the remaining natural teeth. The metal framework often used in partial dentures contributes to their stability and durability.
Implant-supported dentures, often called overdentures, represent a modern and stable solution, particularly for the lower jaw. This design involves surgically placing dental implants into the jawbone, which serve as anchors for the denture. The denture “snaps” onto these implants, offering improved retention and chewing efficiency compared to conventional lower dentures. Because the implants act like tooth roots, they stimulate the jawbone, slowing the natural process of bone loss (resorption) that occurs after teeth are removed.
The Process of Getting Fitted
The process of receiving a mandibular denture begins with an initial consultation and oral examination. During this appointment, preliminary impressions are taken using a mold material, such as alginate, to create a model of the patient’s mouth. This model is then used by a dental laboratory to fabricate custom impression trays that ensure an accurate final impression.
The next phase involves taking a final impression of the gum ridge and recording the bite registration. The bite registration determines the proper relationship and vertical height between the upper and lower jaws when the mouth is closed. Following this, a wax try-in, complete with the selected artificial teeth, is created to allow the patient and dentist to assess the fit, appearance, and alignment. The final denture is fabricated in acrylic and delivered at a subsequent fitting appointment.
Daily Care and Adaptation
Proper daily care maintains the longevity of the mandibular denture and the health of the underlying oral tissues. The appliance should be cleaned daily using a soft-bristled brush and a non-abrasive denture cleaner to remove food particles, plaque, and bacteria. It is important to handle the denture over a soft towel or a basin of water, as the prosthetic is delicate and can break if dropped.
Most dentures need to be removed at night to allow the gum tissues to rest and prevent the appliance from warping. When not in the mouth, the denture must be stored in water or a specialized soaking solution to keep it moist and retain its shape. The adaptation period for a new lower denture involves adjusting to a new way of speaking and eating, and minor sore spots may develop, requiring adjustments from the dentist. Regular dental check-ups are important to monitor the fit of the denture and check for any changes in the gum and bone structure.