A night guard is a common dental appliance, but its classification often causes confusion. Many people assume any mouthpiece worn at night must be a form of orthodontics, the field primarily associated with straightening teeth. The term “night guard” can describe several devices, some purely protective and others performing a corrective function. The classification depends on the appliance’s primary mechanism and its intended goal: passive stabilization or active structural change.
The Purpose of Standard Night Guards
A standard night guard, often classified as a stabilization splint or occlusal guard, is primarily a protective device. Its main function is to create a durable, non-interfering barrier between the upper and lower dental arches. This physical separation is designed to manage the effects of bruxism, the involuntary clenching or grinding of teeth that typically occurs during sleep.
The appliance acts as a cushion, absorbing and distributing the intense forces generated by the jaw muscles during episodes of parafunctional activity. By preventing direct tooth-on-tooth contact, the guard protects the enamel from excessive wear, chipping, and fracture. It also promotes muscle relaxation, which can help alleviate the jaw pain, headaches, and muscle soreness associated with temporomandibular joint (TMJ) disorders.
The stabilization splint’s core mechanism is passive; it holds the jaw in a fixed, comfortable position without attempting to shift the alignment of the teeth or the permanent relationship of the jawbones. This design ensures that while the teeth and joints are protected from damage, the appliance does not induce any controlled or permanent change in the patient’s bite structure. Therefore, this appliance is typically considered a general dentistry or prosthodontic treatment, not an orthodontic one.
Goals of Orthodontic Correction
The defining characteristic of orthodontic correction is the controlled application of force to actively change the position of teeth or modify jaw relationships. This treatment relies on a specific biological process called bone remodeling, which occurs in the alveolar bone surrounding the tooth roots. Appliances like braces or clear aligners exert continuous, light pressure on the teeth.
On the compressed side of the tooth root, specialized cells called osteoclasts are signaled to resorb (break down) the bone tissue. Simultaneously, on the opposite, tension side, osteoblasts deposit new bone, effectively reforming the tooth socket. This coordinated breakdown and rebuilding of bone allows the tooth to safely migrate through the jawbone into a corrected position.
The goal is to resolve malocclusion, which involves correcting problems with tooth alignment, spacing, and the overall bite relationship between the upper and lower jaws. Orthodontic treatment is a process of deliberate, sustained movement designed to achieve permanent structural change. This active, bone-remodeling mechanism fundamentally distinguishes it from the passive buffering role of a standard stabilization splint.
Distinguishing Stabilization from Movement Appliances
A night guard is not typically an orthodontic appliance because its purpose is passive protection, but the line can blur with certain specialized devices. An appliance designed to reposition the lower jaw is sometimes called a mandibular advancement or repositioning splint. These devices actively hold the jaw forward to alleviate TMJ joint pressure or manage sleep apnea. This constitutes a corrective, orthopedic action that falls under the broader scope of dentofacial orthopedics.
Another key distinction is the orthodontic retainer, which is often worn only at night but is a direct extension of orthodontic treatment. Retainers are passive devices that prevent the teeth from shifting back to their original positions after the active movement phase is complete. While they do not actively move teeth, they are considered an integral part of the total orthodontic process, classified as a passive retention appliance.
Ultimately, the classification rests on the intended physiological effect. A true night guard is a stabilization device meant to mitigate damage and reduce muscle tension. Any appliance designed to actively move teeth, change the structural position of the jaw, or maintain a new position achieved by prior movement, possesses a corrective function that ties it directly to orthodontics or dentofacial orthopedics.