Where is the mandible?
The mandible forms the lower jaw and supports the lower teeth. A temporomandibular joint on each side connects it to the skull. Muscles move the jaw when you open and close your mouth and chew.
The upper jaw is called the maxilla. Distinguishing the upper jaw, lower jaw, and jaw joints makes clinical descriptions easier to follow. Mandible refers to the bone; the joints allow it to move.
Sources: NCI Dictionary: Mandible · NIDCR: Temporomandibular Disorders
What is mandibular advancement?
Mandibular advancement means moving the lower jaw forward. In oral appliance therapy, it describes a device holding the jaw in a forward position during sleep to help keep the upper airway open.
How far the jaw is advanced is part of the individual treatment assessment. The term does not mean that everyone should use the same setting or that the farthest possible position is the goal. Function, comfort, and treatment response must all be considered.
Sources: AADSM updated standards, April 2025
Reading the term in a clinical note
If a note says the appliance provides mandibular advancement, you can read it as saying that it holds the lower jaw forward. That sentence does not explain how far, how the position was measured, or whether testing has shown an adequate treatment response.
If a description is unclear, ask your clinician to show which part of the mouth is involved. A simple explanation or sketch can help distinguish a finding involving the teeth, bite, muscles, or joints.
An anatomical word does not select a treatment
A reference to the mandible is not, by itself, a diagnosis or a recommendation for a particular appliance. Ask what the information means in the overall evaluation and whether it needs follow-up.
This glossary entry explains the names of structures and movements. The oral appliance guide covers treatment selection, fitting, and effectiveness checks.
EXPLORE THE EVIDENCE
Sources and further reading
These sources support the explanations. General information does not replace an individual healthcare assessment.
- NCI Dictionary: Mandible Mandible is lower jawbone, supports lower teeth and is involved in chewing and movement.Source checked October 28, 2026
- NIDCR: Temporomandibular Disorders Jaw joint and muscle disorders; limited evidence for splints for TMD pain; avoid permanently bite-changing appliances; stop and contact clinician if the splint causes pain.Source checked October 28, 2026
- MedlinePlus: Malocclusion of Teeth Definition of occlusion and clinical assessment of tooth contacts.Source checked October 28, 2026
- AADSM updated standards, April 2025 The 2025 standards for medical and dental collaboration, in-person dental assessment, appliance fitting and ongoing monitoring.Source checked October 28, 2026