IOTN Grade 5 (Very Great)
This grade indicates a severe need for treatment and can be classified as follows:
| 5i | Impeded eruption of teeth (except for third molars) due to crowding, displacement, the presence of supernumerary teeth, retained deciduous teeth and any pathological cause. |
| 5h | Extensive hypodontia with restorative implications (more than 1 tooth missing in any quadrant) requiring pre-restorative orthodontics. |
| 5a | Increased overjet greater than 9mm. |
| 5m | Reverse overjet greater than 3.5mm with reported masticatory and speech difficulties. |
| 5p | Defects of cleft lip and palate and other craniofacial anomalies. |
| 5s | Submerged deciduous teeth. CONVENTION: Not recorded unless only two cusps remain visible and/or adjacent teeth are severely tipped towards each other and closely approximated. |