Table 1. DHC uses a 5-level scale depending on the degree of malocclusion.

Degree of malocclusion according to DHC	Clinical findings
Grade I	No need for orthodontic treatment (variations in occlusion are quite small including displacements less than 1 mm)
Grade II	Minimal need for treatment (overjet greater than 3.5 mm but less than 6 mm with labial competence at rest; reverse overjet greater than 0 mm but less than or equal to 1 mm; overbite greater than 3.5 mm without gingival contact; anterior or posterior crossbite with less than or 1 mm displacement of ICP and CP position; open lateral or anterior bite greater than 1 mm but less than or equal to 2 mm; displacement of teeth greater than 1 mm but less than or equal to 2 mm)
Grade III	Moderate need for treatment (overjet greater than 3.5 mm but less than or equal to 6 mm with labial incompetence at rest; reverse overjet greater than 1 mm but less than or equal to 3.5 mm; overbite with gingival contact but no signs of trauma; anterior or posterior crossbite with less than or 1–2 mm displacement of ICP and CP position; open lateral or anterior bite greater than 2 mm but less than or equal to 4 mm; tooth displacement greater than 2 mm but less than or equal to 4 mm)
Grade IV	The essential need for treatment (overjet greater than 6 mm but less than or equal to 9 mm; reverse overjet greater than 3.5 mm but without masticatory or speech problems; reverse overjet greater than 1 mm and less than or equal to 3.5 mm, but with masticatory problems or difficulty speaking; anterior or posterior crossbite with more than 2 mm displacement ICP and CP position; displacement of teeth greater than 4 mm; deep traumatic bite)
Grade V	Extreme need for treatment (defects such as cleft lip or palate; incision larger than 9 mm; reverse incision greater than 3.5 mm and masticatory problems or difficulty speaking; obstructed tooth eruption (with the exclusion of third molars) due to dental cavities, presence of supra-numerary teeth, retained teeth, and other pathological causes; extensive hypodontia with prosthetic problems (absence of more than one tooth in each quadrant, and need for pre-prosthetic treatment)