Components of overbite correction in lingual orthodontics: molar extrusion or incisor intrusion?

OBJECTIVE: The aim of this study was to evaluate the components of overbite correction with the lingual Incognito((R)) technique. MATERIALS AND METHODS: The study was based on 45 files of patients with overbite treated with the Incognito((R)) technique. The evaluation of overbite correction is assessed by comparing lateral cephalograms before and after treatment using QuickCeph 2000((R)) software. All the statistical calculations were performed using Statview II software for Mac((R)). RESULTS: The results revealed the efficiency of the Incognito((R)) technique in overbite correction despite the absence of bite planes in the majority of cases. The components of this correction are, in order: intrusion of mandibular incisors, extrusion of mandibular molars, weak extrusion of maxillary molars and stability of the maxillary incisors. These were the results commonly found in previous studies on small samples. The study also demonstrated an increase of lower face height in extraction and non-extraction cases. CONCLUSION: The Incognito((R)) technique is very efficient in overbite correction. As the main component of overbite correction is mandibular incisor intrusion, it seems crucial from the esthetic point of view to evaluate the smile line when overbite correction is needed.