Transposition: accept, extract or correct? Roberto Ciarlantini. Episode 64. November 25th 2020

Transposition: accept, extract or correct? Roberto Ciarlantini

Join me as I summarise Roberto’s lecture looking at transpositions.

Roberto describes 2 cases of true transpositions, treatment options, mechanics and methods of camouflage.

Transposition: defined an anomaly in which 2 adjacent teeth have interchanged their position in the arch Peck 1993

Classification: 1995 by Peck and Peck 

1. True transposition: root and crown
2. False transposition: crown only

Up to 2003 the majority of orthodontists accept transposition and this figure changed as currently most orthodontist tend to correct transpositions.

Case 1 Maxillary canine-premolar transposition – camouflage

Treatment:

1. Interceptive early RME spontaneous correction of maxillary canine-premolar transposition Maspero 2016 86% corrected.
2. Premolar camouflage: Although Sandler 2017 no difference in canine and premolar aesthetics for professionals and lay people transposition are different:

• Gingival height of the canine high compared to the premolar, if we don’t grind the canine tip,
  1. Check smile line, low smile line = result will be acceptable by the patient.
  2. End with slight intrusion in the premolar – so gingival height matches the canine Build up the premolar to make It look longer

Case 2 Maxillary canine-premolar transposition, canine high – correction

Treatment:

• Cannot apply conventional mechanics through the center of resistance of the canine due to vertical position
• Sectional wire:
  • Wire from 1^st molar to 1^st premolar (bypass canine)
  • Bent back on itself to then engage the canine (in the premolar position)
  • = Class 6 Geometry (burstone) allowing intrusion of the canine during meisalization and by passing the premolar
• Torque: Need to keep the root palatal
• Apply couple one wire and with another wire he prevents the crown movement
• Auxiliary springs like warren spring or Goodman springs
• Single root torque to a tooth

Mandibular arch transpositions

• Less demanding to correct the lower arch transpositions due to decreased aesthetic requirements
• Word of caution to correct transition: Limited bucco-lingual width

References

1. Danielsen JC, Karimian K, Ciarlantini R, Melsen B, Kjær I. Unilateral and bilateral dental transpositions in the maxilla—dental and skeletal findings in 63 individuals. Eur Arch Paediatr Dent [Internet]. 2015 Dec 1 [cited 2020 Nov 18];16(6):467–76. Available from: https://link.springer.com/article/10.1007/s40368-015-0196-6
2. Leonardi R, … MF-TEJ of, 2011 undefined. An association between sella turcica bridging and dental transposition. academic.oup.com [Internet]. [cited 2020 Nov 18]; Available from: https://academic.oup.com/ejo/article-abstract/33/4/461/398881
3. Bodner L, Bar-Ziv J, Becker A. Image accuracy of plain film radiography and computerized tomography in assessing morphological abnormality of impacted teeth. Am J Orthod Dentofac Orthop. 2001 Dec 1;120(6):623–8.
4. Maspero C, Giannini L, Galbiati G, … MF-M, 2016 undefined. Effect of rapid palatal expansion in early tratment and spontaneous correction of maxillary canine-first premolar transposition. europepmc.org [Internet]. [cited 2020 Nov 18]; Available from: https://europepmc.org/article/med/27075370
5. Shapira Y, Finkelstein T, Kadry R, Schonberger S, Shpack N. Mandibular Symmetrical Bilateral Canine-Lateral Incisors Transposition: Its Early Diagnosis and Treatment Considerations. Case Rep Dent [Internet]. 2016 [cited 2020 Nov 18];2016:1–6. Available from: https://www.hindawi.com/journals/crid/2016/5043801/abs/
6. Sandler P. Extraction of maxillary canines: Esthetic perceptions of patient smiles among dental professionals and laypeople. 2017 [cited 2020 Nov 19]; Available from: http://derbyhospitals-nhs.archive.knowledgearc.net/handle/123456789/1160
7. Ciarlantini R, Dentofacial BM-AJ of O and, 2007 undefined. Maxillary tooth transposition: correct or accept? Elsevier [Internet]. [cited 2020 Nov 19]; Available from: https://www.sciencedirect.com/science/article/pii/S0889540607004994