Introduction: Orthodontic side effects can complicate the long-term use of mandibular advancement devices (MADs) in the treatment of patients with snoring and obstructive sleep apnea. The aim of this study was to find predictors of dental side effects from monoblock MADs.
Methods: Four hundred fifty patients, who consecutively received treatment with either soft elastomeric or hard acrylic devices, were followed up after 5.4 +/- 0.8 years (mean +/- SD). The continuing patients responded to questionnaires and had dental examinations and plaster casts made.
Results: Twenty-seven patients had moved or died during the follow-up period. Two hundred thirty-six of the remaining 423 patients (56%) continued treatment, and 187 of them reported compliance rates of > or = 50% at night. A small reduction in overjet of < 1 mm was associated with a deepbite with an overbite of > 3 mm and an overjet of < or = 3 mm (odds ratio [OR] = 7.5; P = .015), nasal congestion (OR = 2.9; P = .005), or the use of a soft elastomeric device (OR = 2.7; P = .014) controlled for age, sex, treatment time, and mandibular displacement. A small reduction in overbite of < 1 mm was related to a small opening of the mandible of < 11 mm (OR = 2.5; P = .008).
Conclusions: Orthodontic side effects might be predictable on the basis of initial characteristics in dental occlusion and the design of MADs.