Table 4.

Previous studies reporting frequency of definite need for orthodontic treatment in young adults

Study	Place	n	Age	Index	Definite need	Patients with HPOT
Index for Orthodontic Treatment Need (IOTN)
Present study	Peru	281	16 – 25	AC	1.8	---
				DHC	29.9	---
Hassan (2006) [33]	Saudi Arabia	743	17–24	AC	16.1	---
				DHC	71.6	---
Soh & Sandham (2004) [15]	Asia	339 males	17 – 22	AC	29.2	---
				DHC	50.1	---
Kerosuo et al (2004) [25]	Kuwait	139	14 – 18	AC	1.4	Included
				DHC	28.1	Included
Klages et al (2004) [27]	Germany	148	18 – 30	AC	0.0	Included
Kerosuo et al (2000) [23]	Finland	281	18 – 19	AC	0.0	---
				DHC	12.8	---
Tuominen et al (1995) [21]	Finland	89	16 – 19	DHC	11.2	Included
Other Indexes for Orthodontic Treatment Need
Bernabé & Flores-Mir (2006) [28]	Peru	267	16 – 25	DAI*	32.6
Baca-Garcia et al (2004) [26]	Spain	744	14 – 20	DAI	21.1	---
Onyeasco et al (2003) [24]	Nigeria	104	16 – 25	DAI	44.2	---
Stenvik et al (1996) [22]	Norway	50	18	NOTI**	0.0	---
Searcy & hisick (1994) [20]	Sweden	576 males	18 – 24	TPI*	16.3	Included
Espeland et al (1993) [18]	Norway	100	18	NOTI	8.0	Included
Espeland et al (1993) [19]	Norway	144	17 – 18	NOTI	1.4	---

HPOT = History of previous orthodontic treatment

* Only 'severe malocclusion' and 'handicapping malocclusion' are presented

** Only 'great need' and 'very great need' are presented