The Handicapping Labio-Lingual Deviation (HLD) Index was developed to fill the need for a simple, reproducible and valid method for identifying patients with a physical handicap arising from dental abnormalities.


(1) Measurements are taken using a Boley gauge with results read to the nearest millimeter.

(2) Overjet and overbite are measured with the teeth in the centric relationship.

(3) Mandibular protrusion is read from the labial surface of the lower incisor to the labial surface of the upper incisor.

(4) A reverse overbite is included with overbite.

(5) Open bite = absence of occlusal contact in the anterior region; it is measured from dental edge to edge.


Traumatic deviations include:

(1) loss of premaxilla segment due to burns or by accident

(2) effects of extensive osteomyelitis

(3) extensive surgery

(4) other gross abnormalities


Labio-lingual spread:

(1) If only a single protruded or lingually displaced tooth are present, then the measurement is from the incisal edge of the tooth to the where that edge should be in the normal arch.

(2) If one or more teeth protrude and a one or more teeth are lingually displaced, then the total distance between the incisal edges of the most protruding and most lingually displaced should be measured.

(3) Only one labio-lingual spread should be entered for the index. If multiple teeth are affected, all should be measured but only the maximal value should be entered. This will give the patient the benefit of the greatest deviation.




cleft palate


severe traumatic deviations


overjet in mm


overbite in mm


mandibular protrusion in mm

(mm) * 5

open bite in mm

(mm) * 4

ectopic eruption in anterior teeth

(number) * 3

anterior crowding, maxilla

(number) * 5

anterior crowding, mandible

(number) * 5

labio-lingual spread in mm (maximum)




HLD score =

= SUM(all points assigned)



• minimum score: 0

• maximum score: > 80

• A score >= 13 is considered to constitute a physical handicap.

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