Describe headgear indications, biomechanical effects, and compliance considerations.

• A. Indicated to distalize maxillary molars or restrict maxillary growth in growing patients; applies a distalizing force via the occipital/temporal unit; heavy reliance on patient compliance.
• B. Indicated for cosmetic whitening of teeth with no biomechanical effect.
• C. Indicated to advance the mandible in fixed appliances.
• D. Indicated to rotate incisors only.

Answer: (A)

Headgear is used to apply a posteriorly directed external force to the maxilla, anchoring through the skull to distalize the maxillary molars and to restrain forward growth of the maxilla in growing patients. The main biomechanical effect is a combination of dental and skeletal changes: the molars move backward, which helps correct a Class II relationship, and, depending on the headgear vector (often via an occipital/temporal connection), there can be a referral of eruption or growth patterns that reduces anterior maxillary advancement. Because the treatment relies on how many hours per day the patient wears the appliance, compliance is crucial; insufficient wear dramatically reduces effectiveness and extends treatment time.

This aligns with the indications for headgear: distantizing the upper molars and limiting maxillary forward growth in growing patients, using a skull-based anchor to transmit the force. The other statements fall short because cosmetic whitening has no biomechanical effect, advancing the mandible isn’t achieved with headgear in fixed appliances, and rotating incisors isn’t the primary action of headgear.