Prediction of oral discomfort and dysfunction in lingual orthodontics: A preliminary report

Introduction: The purpose of this prospective study was to examine the influence of malocclusion on the amount of discomfort of patients who were treated with Incognito lingual brackets (T.O.P. Service, Ormco, Amersfoort, the Netherlands; ibraces in North and South America, Lingualcare, Dallas, Tex). Methods: Twenty-one female patients (mean age, 24.8 years; SD 10.7) participated in the investigation and completed a standardized questionnaire before and the day after placement of the appliance. One experienced orthodontist, blinded to the results of the questionnaires, evaluated their initial cephalograms and casts with respect to the parameters SNA, SNB, and ANB angles; overjet; overbite; maxillary and mandibular anterior contact-point displacement; crossbite; open bite; and missing teeth. Results: Malocclusion measured on the casts had no significant impact on the amount of discomfort or dysfunction reported by the patients. The SNA (r = −0.619, P = .003) and SNB (r = −0.615, P = .003) angles, however, correlated significantly with the restriction of tongue space; patients with an SNB angle that was smaller than 1 SD from the norm were significantly more prone to experience severe restriction of tongue space (P = .003). Conclusions: The SNA and SNB angles are predictors for the level of tongue-space restriction after placement of lingual brackets: the smaller the angles, the more prone the patients are to experience discomfort.