|
| Author | Study groups | Sample size | Type of study | Results |
|
| Shanley 1962 [12] | Orthodontically untreated subjects with mandibular 3rd molars:
(1) bilaterally impacted
(2) bilaterally erupted
(3) bilaterally congenitally absent | 44 | Cross-sectional | No differences between the groups |
|
| Sheneman 1969 [13] | Orthodontically treated subjects with mandibular 3rd molars:
in occlusion
unerupted
missing | 49 | Retrospective/longitudinal | More stability in patients with congenital missing 3rd molars than in those whose 3rd molars were present |
|
| Kaplan 1974 [14] | Orthodontically treated subjects with mandibular 3rd molars:
(1) bilaterally erupted into function
(2) bilaterally impacted
(3) bilateral agenesis | 75 | Retrospective/longitudinal | No differences between the groups |
|
|
Lindqvist and Thilander 1982 [15] | Orthodontically untreated subjects with mandibular 3rd molar:
Extracted on one side
Retained on the contralateral side | 52 | Prospective/longitudinal | Extraction side had a more favorable development than the control side |
|
| Richardson 1982 [16] | Orthodontically untreated subjects with mandibular 3rd molars:
(1) Bilaterally impacted
(2) Bilaterally nonimpacted | 51 | Retrospective/longitudinal | Individuals whose 3rd molars become impacted tend to have more tooth crowding |
|
| Ades et al., 1990 [17] | Orthodontically treated subjects with mandibular 3rd molars:
(1) impacted
(2) erupted into function
(3) congenitally absent
(4) Extracted at least 10 years earlier | 97 | Retrospective/longitudinal | No differences among the groups |
|
|
van der Schoot et al., 1997 [6] | Orthodontically treated subjects with 3rd molars:
(1) erupted
(2) nonerupted
(3) extracted
(4) congenitally absent | 99 | Retrospective/longitudinal | No differences among the groups |
|
| Harradine et al., 1998 [5] | Orthodontically treated subjects with 3rd molars:
(1) extracted
(2) nonextracted | 164 | Prospective/longitudinal | No differences between the groups |
|
| Little 1999 [18] | Orthodontically treated subjects with mandibular 3rd molars:
(1) impacted
(2) erupted
(3) extracted
(4) agenesis | 97 | Retrospective/longitudinal | No differences between the groups |
|
|
Buschang and Shulman 2003 [19] | Random sample of orthodontically untreated subjects as part of the Third National Health and Nutrition Examination Survey | 9.044 | Cross-sectional | Erupted 3rd molars not associated with increased tooth crowding |
|
| Niedzielska 2005 [2] | Orthodontically untreated subjects with mandibular 3rd molars:
(1) bilaterally extracted
(2) unilaterally extracted
(3) bilaterally retained
(4) unilaterally retained | 47 | Prospective/longitudinal | Retained 3rd molars associated with increased tooth crowding in relation to Ganss ratio |
|
|
Sidlauskas and Trakiniene 2006 [3] | Orthodontically untreated subjects with mandibular 3rd molars:
(1) erupted
(2) nonerupted
(3) agenesis | 91 | Cross-sectional | No differences between the groups |
|
