Could mastication modify the shape of the orbit? A scannographic study in humans
Since prehistory, changes of the facial skeleton have been related to the modification of diet. More recent studies have shown changes in the morphology of the mandible and maxilla due to variations of strain during mastication. The temporal muscle (TM) is a strong masticatory muscle, with its insertions extending through the temporal fossa. Our objective is to observe the relations between the TM and the lateral orbital wall (LOW) which could indicate an influence of mastication on the shape of the LOW.
We conducted a retrospective study using 100 CT scans. The length of the lateral orbital wall (LLOW), the angle between LOW and the medial orbital wall (MOW), the cross-sectional areas of LOW and of the TMs were measured on both sides of each CT scan. The correlation between TMs and other three parameters was studied by Pearson correlations.
A correlation was found between TMs and LOWs, a lower with LLOW, and a very weak and negative correlation between LOW/MOW angle.
Anatomical knowledge about TM and investigation of masticatory strains lead us to think that mastication have minimal effect on the morphology of the LOW, only on the frontal process of zygomatic. This may explain, in part, why the LOW is the strongest wall of the orbit.
KeywordsOrbit Mastication Temporal muscle Lateral orbital wall
MA: project development, data collection, manuscript writing. JMF: manuscript writing. NG: data collection. KC: data collection. CC: project development. LG: project development, manuscript writing.
Compliance with ethical standards
Conflict of interest
The authors declare no conflict of interest.
- 4.Ducasse A (2007) Surgical orbital anatomy. Oculoplastics and orbit. Springer, New York, pp 73–97Google Scholar
- 14.Sicher H, Tandler J (1928) Anatomie für zahnärzte. J. Springer, BerlinGoogle Scholar
- 17.Wachtler F, Jacob M (1986) Origin and development of the cranial skeletal muscles. Bibliotheca Anatomica 29:24–46Google Scholar
- 18.Weijs WA, Hillen B (1985) Cross-sectional areas and estimated intrinsic strength of the human jaw muscles. Acta Morphol Neerl Scand 23:267–274Google Scholar
- 20.Wong A, Woods M, Stella D (2016) Three-dimensional computed tomographic assessment of mandibular muscles in growing subjects with different vertical facial patterns. Aust Orthod J 32:2–17Google Scholar