FORMA FEATURE / CHIN & JAWJaw angle: measurements, ratios, and research
The gonial region is where the ascending ramus meets the mandibular body. A surface-photo angle is not interchangeable with an X-ray skeletal gonial angle.
How jaw angle is measured
In a true profile, estimate the angle between posterior ramus and lower mandibular-border tangents. Soft tissue obscures both lines; do not read it from a three-quarter portrait.
Ratios, ranges & competing claims
130° — Preferred in a published male-jaw survey
An Internet survey using photographs preferred a 130° profile jaw angle.
Study: A single survey using simplified, unbalanced rating scales, designed to inform implant contours; not a universal anatomical target. The ideal male jaw angle—An Internet survey
115–120° — A sharper forum preference
One forum post lists 115–120° as its preferred range. Another guide gives 115–130°.
Forum claim: No controlled raters, standardized measurement, or validated outcome. The disagreement is itself a reason not to treat a forum interval as settled evidence. In-depth ratio discussion
Practical takeaway
Prioritize a clear corner within the whole jaw outline.
The published survey provides a concrete angle preference. Compare it with ramus slope and mandibular-body slope before using the sharper forum ranges.
What changes the answer
The corner angle is formed by two directions: changing either can produce the same number. Soft tissue and head rotation can hide the corner even when the underlying geometry is angular.
Connected facial features
Explore the interactive atlas and compare this feature with both fixed reference views.