Lip Line Analysis
Evaluating lip position and movement for smile design planning.
Lip line analysis evaluates how much tooth and gum tissue is displayed during smiling and speaking. The upper lip line is classified as: low (shows less than 75% of upper teeth), average (shows 75-100% of teeth with interdental papillae), or high (shows full teeth plus gingival tissue). Approximately 10% of people have a high lip line, more common in females. Key measurements include: smile line (curvature of upper teeth relative to lower lip), upper lip length at rest, lip mobility (distance from rest to full smile), and interlabial gap at rest. These measurements guide treatment decisions — a patient with a high lip line needs impeccable gum aesthetics, while a low lip line patient can tolerate metal margins or less-than-perfect gum contours. Lip dynamics also change with age as the upper lip drops and the lower lip rises, shifting the visible smile zone.