Advertisement

Quantitative Prediction of Change in Chin Position in Le Fort I Impaction

  • Jayalakshmi JayakumarEmail author
  • N. Jayakumar
  • Bobby John
  • P. G. Antony
Original Article
  • 3 Downloads

Abstract

Background

Vertical maxillary excess, a dentofacial deformity present in a large proportion of population impute an increased lower facial height due to increased maxillary height. This results in a clockwise rotation in the mandible, and the chin advances posteriorly and inferiorly. Le Fort I superior repositioning of the maxilla begets movement of pogonion point anteriorly and cranially. Cephalometric analysis helps to access change in position of chin following Le Fort I impaction. In our study, from this analysis a formula was defined to perceive the exact amount of this change in chin position along the vertical and sagittal plane as a result of autorotation.

Materials and Methods

This experimental study assessed 45 patients with vertical maxillary excess over a period of 2 years and 6 months (January 2016–May 2018) in Government Medical College Hospital, Kottayam, Kerala, India. The planned procedure was Le Fort I superior impaction for correction of vertical maxillary excess. Pre-operative cephalograph was taken initially. Post-operative cephalograph after 3 months was then compared with initial pre-operative cephalograph to assess the change in position of the pogonion and menton.

Results

Forty-five participants were studied. The multiple regression model was applied to predict the changes in the chin (dependent factor) according to the vertical change in the maxilla (predictive factor). For every 1 mm change in the maxilla vertically, the chin was estimated to move 0.59 vertically. For a standard deviation increase of 1 in the position of the maxilla, the chin moved superiorly by 0.744 of the standard deviation. For every 1 mm of vertical change in the maxilla, the chin could be expected to move 0.22 mm horizontally. For a standard deviation increase of 1 in the maxillary position, the chin advanced by 0.273 of the standard deviation.

Conclusion

This study draws to a conclusive finding that the movement of maxilla in the superior direction has an effect on the repositioning of the chin in the anterior and cranial directions. This has led to a formulation that 1 mm of superior impaction of maxilla results in 0.6 mm of vertical and 0.2 mm of sagittal movement of chin. This might help to have a glance of future chin position and aid in deciding the need for mandibular surgery.

Keywords

Autorotation Le Fort I impaction Chin Maxillary osteotomy 

Notes

Funding

None.

Compliance with Ethical Standards

Conflict of interest

None.

Ethical approval

The institutional ethical committee approved this experimental study.

References

  1. 1.
    Ming TC (2006) Spectrum and management of dentofacial deformities in a multiethnic Asian population. Angle Orthod 76(5):806–809Google Scholar
  2. 2.
    Naini FB, Gill DS (2008) Facial aesthetics: 1. Concepts and canons. Dent Update 35(2):102–104CrossRefGoogle Scholar
  3. 3.
    Arabion H, Tabrizi R, Fattahi H, Khaghaninezhad M, Bahramnia F (2015) Spatial changes of the chin in the vertical and sagittal planes after superior repositioning of the Maxilla. J Craniofac Surg 26(3):e249–e253CrossRefGoogle Scholar
  4. 4.
    Wang Y, Ko EW, Huang C, Chen Y (2006) The inter-relationship between mandibular autorotation and maxillary LeFort I impaction osteotomies. J Craniofac Surg 17(5):898–904CrossRefGoogle Scholar
  5. 5.
    Schendel SA, Eisenfeld JH, Bell WH, Epker BN (1976) Superior repositioning of the maxilla: stability and soft tissue osseous relations. Am J Orthod 70(6):663–674CrossRefGoogle Scholar
  6. 6.
    Lee D, Bailey L, Proffit WR (1996) Soft tissue changes after superior re- positioning of the maxilla with Le Fort I osteotomy: 5-year follow up. Int J Adult Orthod Orthognath Surg 11:301–311Google Scholar
  7. 7.
    Steinhäuser S, Richter U, Richter F, Bill J, Rudzki-janson I (2008) Profile changes following maxillary impaction and autorotation of the mandible. J Orofacial Orthoped 69(1):31–41CrossRefGoogle Scholar
  8. 8.
    Fish LC, Epker BN (1980) Surgical-orthodontic cephalometric prediction tracing. J Clin Orthod 8:119–125Google Scholar
  9. 9.
    Stoker NG, Epker BN, Peter J, Hospital S, Worth F et al (1974) The posterior maxillary ostectomy: a retrospective study of treatment results. Int J Oral Surg 3:153–157CrossRefGoogle Scholar

Copyright information

© The Association of Oral and Maxillofacial Surgeons of India 2019

Authors and Affiliations

  • Jayalakshmi Jayakumar
    • 1
    Email author
  • N. Jayakumar
    • 1
  • Bobby John
    • 1
  • P. G. Antony
    • 1
  1. 1.Department of Oral and Maxillofacial SurgeryGovernment Dental College KottayamKeralaIndia

Personalised recommendations