Uprighting of Mandibular Second Molar with Modified Lingual Arch

Abstract

Lingual tipping of mandibular molars can complicate orthodontic treatment because direct bonding and archwire engagement may be difficult, particularly when the discrepancy between adjacent buccal surfaces is severe. This case report describes the use of a modified lingual arch to upright a severely lingually tipped mandibular left second molar while maintaining anchorage during initial alignment and levelling. A 15-year-old male patient presented with irregularly placed teeth, a convex facial profile, Angle Class II malocclusion with subdivision on the right side, an average-to-vertical growth pattern, and a lingually tipped mandibular left second molar. Because the patient was unwilling to accept a temporary anchorage device, a modified lingual arch was fabricated with hooks distal to the first-molar tubes. A lingual button was bonded to the tipped molar, and an elastomeric chain delivering an approximate force of 150 g was engaged from the molar to the lingual-arch hook. The resulting force system provided buccal and downward force components for molar uprighting. The mandibular second molar was uprighted in approximately 3 months, allowing direct engagement of a continuous archwire. The appliance also enabled segmental mechanics for the remaining dentition. Follow-up orthopantomographic evaluation showed a more vertical eruption path of the mandibular third molar, with no reported adverse root effects. This case demonstrates the clinical utility of a simple, fixed, cost-effective modified lingual arch for selected cases in which conventional bonding or skeletal anchorage is not feasible.