Comparison Between Treacher Collins Syndrome and Pierre Robin Sequence: A Cephalometric Study

Cleft Palate Craniofac J. 2021 Jan;58(1):78-83. doi: 10.1177/1055665620937499. Epub 2020 Jul 2.


Objective: The aim of this study was to compare the dentoskeletal pattern of Treacher Collins syndrome (TCS) and nonsyndromic Pierre Robin sequence (PRS).

Design: Retrospective.

Setting: Single center.

Patients: Eighteen patients diagnosed with TCS (Group TCS) or PRS (Group PRS) in rehabilitation treatment at a single center. Group TCS was composed of 9 patients (4 male, 5 female) with a mean age of 12.9 years (standard deviation = 4.8). Group PRS was composed of 9 patients paired by age and sex with group TCS.

Main outcome measure(s): Cone beam computed tomography-derived cephalometric images taken before the orthodontic or the orthodontic-surgical treatment were analyzed using Dolphin Imaging (Dolphin Imaging 11.0 & Management Solutions). Variables evaluating the cranial base, the maxillary and mandibular skeletal components, maxillomandibular relationship, the vertical components and the dentoalveolar region were measured. Intergroup comparisons were performed using t tests. The significance level considered was 5%.

Results: Intergroup differences in the mandible size and growth pattern were observed. Group TCS showed a smaller mandibular length (Co-Go, Co-Gn) and a higher palatal plane (SN-Palatal Plane) and mandibular plane angles (SN-Go.Gn) compared to group PRS. No differences between TCS and PRS were observed for the sagittal position of the maxilla, maxillomandibular relationship, and dental components.

Conclusions: Treacher Collins syndrome presented a decreased mandible and a more severe vertical growth pattern compared to PRS.

Keywords: Pierre Robin sequence; cephalometry; craniofacial morphology; mandibulofacial dysostosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cephalometry
  • Female
  • Humans
  • Male
  • Mandible / diagnostic imaging
  • Mandibulofacial Dysostosis* / diagnostic imaging
  • Pierre Robin Syndrome* / diagnostic imaging
  • Retrospective Studies