The effects of a corticotomy on space closure by molar protraction using TSADs in patients with missing mandibular first molars

Mandibular molar protraction using round Australian wire and miniscrew anchorage with modified corticision in an adult with first molar loss: A case report

A 27-year-old adult female presented with the chief complaint of bilateral mandibular first molar absence and strongly preferred to use wisdom teeth rather than prosthetic replacements. Treatment was carried out using a round Australian wire fixed orthodontic technique. The second and third molars were mesially moved with a bilateral terminal helical loop combined with curved tip-back bends in Australian wire. Miniscrew anchorage was placed in the mandibular premolar area to assist in the protraction of the second and third molars. Additionally, a modified cortical drilling technique was employed to accelerate tooth movement. A neutral molar relationship was established while maintaining the patient's facial profile.

Cantilever-aided bodily protraction of a mandibular molar with clear aligner: A finite element analysis

OBJECTIVE

To analyse the biomechanics of molar protraction through clear aligner therapy (CAT) with and without a buccal cantilever.

METHODS

Models were composed of mandible, lower dentition, periodontal ligaments, attachments, a buccal cantilever, and clear aligner. Four groups were designed: (1) control (aligner only), (2) aligner+buccal cantilever with buccal class II traction, (3) aligner+buccal cantilever with buccal class II and lingual class II tractions, (4) aligner+buccal cantilever with buccal horizontal traction named buccal class I, buccal class II, and lingual class II tractions.

RESULTS

CAT alone caused mesial tipping, lingual tipping, and intrusion of mandibular second molar. Adding the buccal cantilever on the mandibular second molar with 100-g buccal class II traction was effective in preventing the mesial tipping of mandibular second molar, but resulted in a greater lingual tipping tendency. Further addition of lingual class II traction prevented aforementioned lingual tipping and bodily protraction was achieved in sagittal dimension, while buccal tipping was present. Bodily protraction without buccolingual tipping was achieved through clear aligner, buccal class II, lingual class II, and buccal class I tractions, and the stress concentrated on the alveolar bone was reduced.

CONCLUSION

CAT produced mesial tipping, lingual tipping, and intrusion of mandibular molar during protraction. The incorporation of the buccal cantilever into the clear aligner improves the biomechanical effect of molar protraction. Bodily molar protraction can be achieved with a judicious combination of buccal class II, lingual class II and buccal class I tractions with clear aligner and buccal cantilever.

Clear aligner treatment of an adult open bite with bilateral missing mandibular first molars through molar protraction with Albert cantilever arms

Premature loss of first permanent molars is a common occurrence in clinical practice, leading to abnormal occlusion and inefficient mastication for patients. This case report presented the orthodontic retreatment of a 32-year-old female patient who suffered from premature loss of mandibular bilateral first molars. The mesial tipping of the mandibular second molars led to an occlusal interference, resulting in a clockwise rotation of the lower jaw and an anterior open bite (AOB). We achieved long-distance molar mesialization using clear aligners with Albert cantilever arms. After 42 months of treatment, the patient's occlusion and facial profile significantly improved. The cantilever combined with the cleat aligner treatment has been clinically effective for the protraction of mandibular posterior teeth, extending the field of application of clear aligners.