Comparative treatment outcomes after bilateral extractions of maxillary second molars or first premolars in patients with class II malocclusion: a retrospective study

Table 1 Descriptive statistics of the study collective (N = 53) with analytical statistics comparing pre-treatment age and duration of the orthodontic treatment between the two different groups

Variable	Group	N	M [95% CI]	SD	Min	Max	p
Age pre-treatment (years)	I	31	13.0 [12.5; 13.5]	1.4	11.1	16.3	0.275
Age pre-treatment (years)	II	22	12.6 [12.0; 13.2]	1.4	10.6	14.9	0.275
Treatment duration (months)	I	31	24.0 [21.8; 26.2]	5.9	17	37	0.126
Treatment duration (months)	II	22	21.9 [20.3; 23.5]	3.6	16	27	0.126

N number of patients, M mean, 95% CI 95% confidence interval, Min minimum, Max maximum, p p-value, I group I (extraction of maxillary second molars), II group II (extraction of maxillary first premolars)

ISSN: 1746-160X