Biomechanical influences of head posture on occlusion: an experimental study using finite element analysis.
Motoyoshi M, Shimazaki T, Sugai Tatsuyoshi, Namura S 2002. Biomechanical influences of head posture on occlusion: an experimental study using finite element analysis. European Jour Orthodontics; 24:319-326.
Summary: The biomechanical influences of head posture on the cervical column and craniofacial complex during masticatory simulation were quantified using three-dimensional (3D) finite element analysis. Three models were constructed to examine relationships between the position of the head and malocclusion:
• Model A: standardized cervical column curve
• Model B: forward inclined posture (forward head position)
• Model C: backward inclined posture (backward head position)
Results:
• Model A: stress converged at the atlas
• Model B: stress converged at the anterior edge of the vertebral body of C4
• Model C: stress converged at the spinous processes of C6 and C7
Conclusion:
Alteration of head posture was directly related to stress distribution on the cervical column.
Change in the occlusal state may not alter the head position.
Comment by Prof Rothbart – this study provides an insightful look at the interrelationships between head posture and cervical stress loads. Concurrently, the authors noted an inconsistent link; occlusion altering the head position. However, they made no comment on the reverse link; head position (forward or backward) altering the occlusion (Class II or Class III respectively), which I see frequently in my clinical practice, as do other clinicians and researchers (see citations below).
1. Mohl ND 1976. Head posture and its role in occlusion. NY State Dental Journal; 42:17-23.
2. Solow B, Tallgren A 1977. Dentoalveolar morphology in relation to craniocervical psoture. Angle Orthodontist; 47:157-164.
3. Ozbek M, Koklu M 1993. Natural cerical inclination and craniofacial structure. Amer Jour Orthodontics Dentofacial Orthopedics; 104:584-591.