Orthodontic headgear is an external dental appliance used to correct complex alignment issues, often in conjunction with traditional braces. It provides anchorage outside of the mouth, generating substantial force that internal devices cannot achieve alone. The primary function of headgear is to apply controlled pressure to the teeth and jaws to guide movement and modify skeletal growth patterns. It is typically prescribed for younger patients whose bones are still developing, allowing orthodontists to correct severe bite problems.
The Mechanical Action of Headgear
The fundamental principle behind headgear is the utilization of an external anchor point—the back of the head or neck—to apply a precise, reciprocal force to the teeth and jaw structures. This leverage is necessary because attempting to move a large segment of the jaw using only the teeth as anchors would result in unwanted movement of those anchor teeth. The headgear creates a stable, immovable base against which the desired force can be generated, adhering to Newton’s third law of motion.
Headgear is designed to produce two distinct types of biological changes: dental movement and orthopedic movement. Dental movement, also known as orthodontic correction, involves shifting the position of individual teeth within the jawbone, typically requiring a force of about 350 to 450 grams per side. Orthopedic movement modifies the growth direction and relationship of the jaw bones themselves. This skeletal correction requires a heavier force, generally 500 grams or more per side, and is most effective during the active growth phases of a child or adolescent.
The application of this heavy, sustained force allows the orthodontist to slow down the growth of one jaw or encourage the forward development of the other, redirecting the patient’s natural growth trajectory. By controlling the line of action of the force relative to the teeth’s center of resistance, the appliance can prevent the upper molars from moving forward or push them backward. The precise engineering of the straps and attachments determines the exact direction of the force, allowing for movements that are either distal (backward), intrusive (upward), or extrusive (downward).
Specific Types and Their Targeted Corrections
The type of headgear prescribed depends on the specific malocclusion, or “bad bite,” that needs correction. The three major variations are categorized by the direction of the force applied and their external anchorage point. Each type is engineered to solve a particular skeletal or dental discrepancy that braces alone cannot overcome.
High-Pull Headgear
High-Pull Headgear uses a strap that anchors high on the back and top of the head, connecting via a facebow to the upper jaw. This configuration applies an intrusive and distal force, which helps control vertical growth of the maxilla (upper jaw) and drives the upper molars upward and backward. It is primarily used for patients with deep overbites or excessive vertical facial height, and can help close an open bite by preventing the downward eruption of the back teeth.
Cervical-Pull Headgear
Cervical-Pull Headgear utilizes a strap that wraps around the patient’s neck, pulling the upper jaw backward and slightly downward. This is the most common type used to correct an overjet, where the upper front teeth protrude significantly, or a Class II malocclusion. The downward and backward pull on the upper molars helps move them distally and restricts the forward growth of the upper jaw during development.
Reverse-Pull Headgear
A contrasting appliance is the Reverse-Pull Headgear, often called a Facemask, which targets an underbite or Class III malocclusion. This device features a vertical frame that rests on a forehead pad and a chin cup, using rubber bands to exert a forward-pulling force on the upper jaw. The objective is to encourage the maxilla to grow forward, bringing the upper jaw into proper alignment with a protruding lower jaw.
Compliance and Required Wear Time
The success of headgear treatment is directly proportional to the patient’s adherence to the prescribed wearing schedule. Unlike fixed braces, the appliance must be worn for a specific number of hours every day. Orthodontists typically recommend wearing the headgear for a minimum of 10 to 14 hours daily to achieve the necessary biological response for skeletal changes.
This extended daily wear is necessary because the heavy forces required for orthopedic change need a continuous, long-duration application to be effective. For many patients, the most practical solution is to wear the appliance throughout the evening and while sleeping. Studies indicate the evening hours, particularly between 6 PM and midnight, are optimal for skeletal changes. Failure to consistently meet the prescribed hours can result in the loss of treatment progress and an increase in the total time required for treatment.
The treatment period with headgear can range from several months to a few years, depending on the severity of the jaw discrepancy. Patients are advised to keep the appliance on during quiet activities at home, but to remove it for contact sports or rigorous physical activity to ensure safety. Maintaining a rigorous schedule is the single most significant factor in completing treatment successfully and avoiding more invasive procedures later in life.