Dentures are removable prosthetics designed to replace missing natural teeth and surrounding supportive tissues. The fundamental concept is the “dental arch,” which describes the natural crescent-shaped arrangement of teeth in the jaw. Understanding these arches is necessary for determining the correct denture setup, depending on the extent of tooth loss and the health of remaining oral structures.
Defining the Maxillary and Mandibular Arches
The human mouth contains two distinct dental arches: the Maxillary and the Mandibular arches. The Maxillary arch is the upper curve of teeth anchored to the maxilla (upper jawbone). This arch is fixed and provides a stable platform for prosthetic devices. The Mandibular arch is the lower curve of teeth secured to the mandible (lower jawbone), which moves freely during speech and chewing.
These two arches align precisely, a relationship known as occlusion, which is necessary for efficient biting and grinding. The upper arch naturally overlaps the lower arch slightly. Dentures must replicate the curved structure of the supporting gum and bone. The unique characteristics of each arch—the stability of the upper compared to the mobility of the lower—influence the design and function of the replacement prosthesis.
Standard Denture Setups
The number of arches in a set of dentures corresponds to the number of entire tooth rows being replaced. A complete set replaces both the upper and lower arches, totaling two arches. This option is selected when a person has lost all teeth in both the maxilla and the mandible. Each prosthetic device is custom-fabricated to cover the entire gum ridge of its respective jaw.
Alternatively, a patient may receive a single arch denture, which replaces all the teeth in only the upper or lower jaw. This is a full denture for that specific jaw. Dentures can also be partial, replacing only some missing teeth within a single arch while utilizing remaining natural teeth for support. The decision depends on a thorough evaluation of the patient’s remaining dentition and bone structure.
When Only One Arch Replacement is Required
Replacing only one arch is common when the opposing arch retains a functional and healthy set of natural teeth or existing restorations. Dentists preserve viable natural teeth because they provide superior biting strength and stability compared to a full denture. A stable, natural arch allows the new single denture to achieve proper occlusion.
A full lower (mandibular) denture presents challenges due to the constant movement of the tongue and smaller surface area for retention compared to the upper arch. If a patient must lose one full arch but can save the other, the dental team often aims to preserve the lower natural teeth. This strategy prioritizes the mechanical stability of the remaining lower jaw, ensuring the new upper denture functions effectively against a stable foundation.