Chris Chan describes his favourite positions for TADs, buccal shelf, Ramus TAD, Infrazygomatic and anterior TADs.
Buccal shelf TAD: Class 3
- Buccal shelf TAD in the L6-7 region
- Whole arch distalisation – en mass retraction lower arch to TAD
- Distalises lower arch
- Moment: counterclockwise = change occlusal plane
- Class 2 elastics to lower TAD to prevent upper incisor proclination
- Self ligation – allows freedom between teeth – similar to MEAW
- Finite analysis showed CoR at the lower canine region = greater moment
Buccal shelf TAD: Scissor bite posterior quadrant
- Complete scissor bite and over-erupted upper posterior teeth
- Buccal shelf TAD in the L6-7 region
- Powerchain from bracket to TAD – upright molars
- TAD upper posterior segment to intrude
- Won AJODO case prize 2018
Failure of buccal shelf screw Park 2004
- Buccal shelf TAD 7%
- Conventional mandibular TADs – between roots = 19%
Insertion of buccal shelf TAD
- Upright
- Mucogingiva – makes no difference as TAD is upright
Ramus TAD: Impacted 2nd molar
- Use of Ramus TAD – 2x14mm – due to medial pterygoid muscle presence
- Eyelet with powerchain threaded through –
Maxillary TAD Infrazygomatic crest IZC: Distalisation
- Insertion at mucogingival junction
- Initially 90 degrees when hit bone oblique angle significant approx. 60-70 degrees
- 2mm x 12mm
- Between 6-7
- Not in between the roots, no requirement to remove / replace
- Head left 5mm from the gingiva
Gummy smile with anterior TADs
- Distal to upper central incisors 1.5 x 8mm
- Power chain to intrude
References:
- http://iaoi.pro/asset/files/jdo_vol_55.pdf
