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

Area of Science:

• Craniofacial development and genetics
• Orthodontics and maxillofacial surgery
• Pediatric dentistry

Background:

• Treacher Collins syndrome (TCS) and Pierre Robin sequence (PRS) are distinct craniofacial anomalies.
• Understanding their dentoskeletal patterns is crucial for effective treatment planning.
• Limited comparative cephalometric analyses exist between TCS and nonsyndromic PRS.

Purpose of the Study:

• To compare the dentoskeletal patterns of patients with Treacher Collins syndrome (TCS) and nonsyndromic Pierre Robin sequence (PRS).
• To identify specific cephalometric differences that may inform differential diagnosis and treatment strategies.
• To provide quantitative data on craniofacial morphology in these conditions.

Main Methods:

• Retrospective analysis of 18 patients (9 TCS, 9 PRS) undergoing rehabilitation.
• Cone beam computed tomography (CBCT) derived cephalometric analysis using Dolphin Imaging software.
• Measurement of cranial base, maxillary, mandibular, and dentoalveolar components, including vertical proportions.

Main Results:

• Significant differences were found in mandibular size and growth patterns between TCS and PRS groups.
• TCS patients demonstrated smaller mandibular length (Co-Go, Co-Gn) and increased palatal and mandibular plane angles (SN-Palatal Plane, SN-Go.Gn).
• No significant differences were observed in maxillary sagittal position, maxillomandibular relationship, or dental components.

Conclusions:

• Treacher Collins syndrome is characterized by a hypoplastic mandible and a more pronounced vertical growth pattern compared to nonsyndromic Pierre Robin sequence.
• These findings underscore distinct skeletal morphologies that may influence orthodontic and surgical management.
• Further research can explore the functional implications of these observed dentoskeletal differences.