Lingual braces belong to the specialty of orthodontics, a branch of dentistry focused on diagnosing, preventing, and treating dental and facial irregularities. The primary clinical goal of lingual orthodontic therapy is to correct malocclusion (improper bite alignment) and dental crowding (overlapping or misaligned teeth) while providing maximum cosmetic concealment. The mechanism relies on continuous mechanical traction exerted by custom-shaped brackets and archwires attached behind the teeth, triggering controlled bone remodelling in the periodontal ligament (the connective tissue supporting the teeth).

The lingual braces placement process follows a precise multi-step clinical protocol: 1. Impression and Scanning: High-resolution digital intraoral scans or silicone impressions are taken to construct a 3D physical or digital model of the patient's dentition. 2. Virtual Setup and Fabrication: Orthodontists digitally position teeth into ideal alignment, and custom lingual brackets with tailored base geometries are milled or printed alongside custom robotically bent archwires. 3. Prophylaxis and Etching: The lingual tooth surfaces are cleaned with pumice, rinsed, dried, and treated with acid-etch gel to create microscopic retention pores. 4. Adhesive Application: Primer and light-cure composite bonding resin are applied to the tooth surface and bracket bases. 5. Indirect Bonding Transfer: A custom silicone or thermoformed transfer tray containing all brackets is placed over the dental arch, ensuring exact placement accuracy. 6. Curing and Tray Removal: High-intensity curing light solidifies the adhesive, and the transfer tray is carefully sectioned and removed. 7. Archwire Insertion: Initial flexible nickel-titanium archwires are engaged into the bracket slots and secured using ligatures or self-ligating clips.

• Complete Cosmetic Concealment: Brackets and archwires are positioned entirely on the lingual aspect of the teeth, making them invisible during routine social and professional interactions.
• Bite Opening Efficiency: Anterior lingual brackets create an intrinsic bite-plane effect, accelerating deep bite resolution compared to conventional labial braces (Papageorgiou et al., 2014).
• Reduced Labial Enamel Decalcification: Enamel demineralisation and white spot lesions are confined to the interior tooth surfaces, protecting the primary visible enamel surfaces from irreversible cosmetic damage (Artun, 1982).
• Precise 3D Biomechanical Control: Modern CAD/CAM lingual systems provide exact root control and precise final alignment equivalent to standard labial fixed appliances.

Initial physical adaptation lasts approximately 7 to 14 days, during which patients experience soft tissue irritation on the margins of the tongue and mild dental soreness following mastication. Speech changes, primarily mild lisping (difficulty pronouncing sibilant sounds like 's' and 'z'), typically resolve within 2 to 4 weeks as the tongue adapts to the reduced intraoral volume (Hohoff et al., 2003). Long-term recovery and treatment duration mirror standard fixed appliances, ranging from 12 to 36 months depending on initial clinical complexity, followed by permanent retention protocols.

Lingual braces treat a wide spectrum of orthodontic issues, including Class I malocclusion (normal bite alignment with tooth crowding or spacing), Class II malocclusion (overjet or overbite where the upper teeth sit excessively forward), and Class III malocclusion (underbite where lower teeth extend past upper teeth). They are also indicated for deep bite (excessive vertical overlap of front teeth), open bite (lack of vertical contact between upper and lower teeth), mid-line discrepancies, rotation of teeth, and pre-prosthetic alignment before dental implant or crown restoration.

Pre-treatment preparation involves a comprehensive orthodontic evaluation: 1. Clinical Examination: Assessment of temporomandibular joint (TMJ) function, facial aesthetics, and dental occlusion. 2. Diagnostic Imaging: Panoramic radiograms to evaluate root morphology, cephalometric radiograms to analyze skeletal relationships, and 3D intraoral scans. 3. Periodontal Stabilization: Resolution of active gingivitis, periodontitis, or dental caries; professional dental cleaning and calculus removal are mandatory prior to bracket bonding. 4. Oral Hygiene Training: Pre-procedure instruction on specialized interdental brushing, flossing threaders, and water flossing techniques tailored to lingual appliances.

Risks and complications associated with lingual braces are categorized by clinical severity: 1. Common/Mild: Temporary speech alteration (slight lisping lasting 2-4 weeks), transient tongue irritation and ulceration, mild tooth soreness for 3-5 days after wire adjustments. 2. Uncommon: Gingival inflammation due to plaque accumulation behind brackets, bracket debonding from mechanical force during chewing, localized enamel decalcification around bracket margins. 3. Rare/Serious: Severe root resorption (shortening of tooth roots during tooth movement), permanent periodontal attachment loss in patients with pre-existing untreated periodontitis, pulp necrosis requiring root canal therapy (rare, associated with prior tooth trauma).

The clinical journey begins with comprehensive diagnostic imaging, including digital intraoral scanning and panoramic radiograms to evaluate root morphology and bone density. Next, custom lingual brackets and archwires are fabricated using three-dimensional computer-aided design or indirect bonding setups. During the placement procedure, teeth are etched and bonded using indirect transfer trays. Patients enter an adaptation phase lasting two to four weeks, during which temporary speech alterations and lingual discomfort occur. Periodic adjustments take place every four to six weeks. Treatment concludes with appliance removal, enamel polishing, and mandatory retention therapy using fixed or removable retainers.