Changes in lateral standing posture following orthognathic surgery: a cohort study

Area of Science:

• Orthodontics and Maxillofacial Surgery
• Skeletal Biology
• Biomechanical Engineering

Background:

• Musculoskeletal and neuromuscular alterations influence standing body posture, especially in the head and neck.
• Orthognathic surgery, a procedure to correct jaw irregularities, may affect craniofacial and cervical alignment.

Purpose of the Study:

• To prospectively evaluate the effects of single-jaw orthognathic mandibular surgery on standing head posture.
• To analyze changes in craniovertebral and Frankfort angles post-surgery in relation to malocclusion class.

Main Methods:

• A prospective cohort study involving 31 patients undergoing orthognathic mandibular surgery.
• Pre- and post-operative cephalometric and photographic evaluations of habitual posture.
• Measurement of craniovertebral and Frankfort angles using MB-Ruler software and analysis of mandibular positional changes.

Main Results:

• The craniovertebral angle significantly increased in Class II malocclusion patients and decreased in Class III patients.
• The Frankfort angle significantly increased in both Class II and Class III groups.
• Class II patients exhibited reduced forward head posture and improved neck posture, whereas Class III patients showed a slight increase in forward head posture.

Conclusions:

• Orthognathic surgery alters head and neck posture, with differential effects based on malocclusion class.
• While beneficial for Class II malocclusion, the surgery may induce a slight forward head posture tendency in Class III patients.
• The natural head position is modified by orthognathic surgery, generally promoting a more upright posture.