Authors’ response

We thank Drs Thiesen and Kim for their interest on our article, “Evaluation of facial hard and soft tissue asymmetry using cone-beam computed tomography,” in the February issue of the American Journal of Orthodontics and Dentofacial Orthopedics .

In our study, we stated that patients with less than 4 mm of soft-tissue menton deviation from the midsagittal reference line by clinical evaluation were categorized as symmetric, and those with 4 mm or more deviation were categorized as asymmetric. Haraguchi et al mentioned that faces having skeletal deviations of more than 4 mm are more likely to be judged with soft tissue asymmetry. We know that some authors accept 2 mm of bone and soft tissue deviation as asymmetric. However, other studies recognized 4 mm of menton deviation as the limit to distinguish the asymmetry and the control groups.

It was reported that thin soft tissue layers such as in the menton region are related to the underlying skeletal units in a 1:1 ratio. Consequently, a 4-mm skeletal deviation may demonstrate approximately the same extent of soft tissue asymmetry. As mentioned in the article, the findings also agree that positive correlations were present between angular as well as linear measurements from the hard and soft tissue menton. Indeed, individual characteristics such as the weight of the patient may influence the results. Lee et al mentioned that soft tissue chin deviation angular measurements for the control, mild, and severe asymmetry group were 1.1°, 2°, and 3.64°, respectively. In our study, the angular measurements of the chin deviation were identical for the control group (1.1°); this supported the control group selection. On the other hand, the chin deviation of the asymmetry group was 2.79°, categorizing this group as a moderate asymmetric group, and not a severe one.

Overall, we have mentioned that the control group also showed mild asymmetries. In further studies, facial asymmetry evaluated with more subgroups (such as soft tissue menton deviations of 0-1 mm, 1-2 mm, 2-3 mm, 3-4 mm and so on) to distinguish the exact limits of control and asymmetry may be advisable.

References

  1. 1. Nur R.B., Çakan D.G., and Arun T.: Evaluation of facial hard and soft tissue asymmetry using cone-beam computed tomography. Am J Orthod Dentofacial Orthop 2016; 149: pp. 225-237
  2. 2. Haraguchi S., Takada K., and Yasuda Y.: Facial asymmetry in subjects with skeletal Class III deformity. Angle Orthod 2002; 72: pp. 28-35
  3. 3. Ramirez-Yañez G.O., Stewart A., Franken E., and Campos K.: Prevalence of mandibular asymmetries in growing patients. Eur J Orthod 2011; 33: pp. 236-242
  4. 4. Kim J.Y., Jung H.D., Jung Y.S., Hwang C.J., and Park H.S.: A simple classification of facial asymmetry by TML system. J Craniomaxillofac Surg 2014; 42: pp. 313-320
  5. 5. Severt T.R., and Proffit W.R.: The prevalence of facial asymmetry in the dentofacial deformities population at the University of North Carolina. Int J Adult Orthodon Orthognath Surg 1997; 12: pp. 171-176
  6. 6. Cevidanes L.H., Alhadidi A., Paniagua B., Styner M., Ludlow J., Mol A., et al: Three-dimensional quantification of mandibular asymmetry through cone beam computerized tomography. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; 111: pp. 757-770
  7. 7. Fong J.H., Wu H.T., Huang M.C., Chou Y.W., Chi L.Y., Fong Y., et al: Analysis of facial skeletal characteristics in patients with chin deviation. J Chin Med Assoc 2010; 73: pp. 29-34
  8. 8. Kwon T.G., Park H.S., Ryoo H.M., and Lee S.H.: A comparison of craniofacial morphology in patients with and without facial asymmetry—a three dimensional analysis with computed tomography. Int J Oral Maxillofac Surg 2006; 35: pp. 43-48
  9. 9. Baek S.H., Cho I.S., Chang Y.I., and Kim M.J.: Skeletodental factors affecting chin point deviation in female patients with class III malocclusion and facial asymmetry: a three-dimensional analysis using computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007; 104: pp. 628-639
  10. 10. Jung Y.J., Kim M.J., and Baek S.H.: Hard and soft tissue changes after correction of mandibular prognathism and facial asymmetry by mandibular setback surgery: three- dimensional analysis using computerized tomography. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 107: pp. 763-771
  11. 11. McCance A.M., Moss J.P., Fright W.R., Linney A.D., and James D.R.: Three dimensional analysis techniques—part 1: three dimensional softtissue analysis of 24 adult cleft palate patients following Le Fort I maxillary advancement: a preliminary report. Cleft Palate Craniofac J 1997; 34: pp. 36-45
  12. 12. Lee M.S., Chung D.H., Lee J.W., and Cha K.S.: Assessing soft-tissue characteristics of facial asymmetry with photographs. Am J Orthod Dentofacial Orthop 2010; 138: pp. 23-31
Only gold members can continue reading. Log In or Register to continue

Related posts:

  1. Adenomatoid odontogenic tumor: An outdated report
  2. Reprise:Very rapid orthodontic treatment
  3. Correction
  4. Effect of orthodontic treatment on the upper airway volume in adults
  5. Nickel-free vs conventional braces for patients allergic to nickel: Gingival and blood parameters during and after treatment
  6. Accuracy and mechanical properties of orthodontic models printed 3-dimensionally from calcium sulfate before and after various postprinting treatments

Stay updated, free dental videos. Join our Telegram channel
Tags:
Apr 4, 2017 | Posted by in Orthodontics | Comments Off on Authors’ response

VIDEdental - Online dental courses
Get VIDEdental app for watching clinical videos