Opinions of American and Swedish orthodontists about the role of erupting third molars as a cause of dental crowding.
OBJECTIVE
To compare the opinions of Swedish orthodontists and American orthodontists regarding the association between third molar eruption and dental crowding.


METHODS
A survey was distributed to Swedish orthodontists (n = 230) asking their views on the force exerted by erupting third molars, its relationship to crowding, and their recommendations for prophylactic removal. Results were compared with those from a similar study conducted in the United States. Chi square analysis was used to determine differences in responses to questions between Swedish and American orthodontists. P < or = .05 was considered significant.


RESULTS
Both Swedish and American orthodontists believed that lower third molars were more likely than upper third molars to cause force (65% and 58% for Swedish and American orthodontists, respectively) and crowding (42% and 40%, respectively). No statistically significant differences were seen between the answers of American and Swedish orthodontists regarding the role of upper and lower third molars in causing crowding. Although only 18% of Swedish orthodontists "generally" or "sometimes" recommended prophylactic removal of mandibular third molars, 36% of American orthodontists "generally" or "sometimes" recommended removal (P < .0001).


CONCLUSIONS
Most orthodontists in the United States and Sweden do believe that erupting lower third molars exert an anterior force; however, they also believe that these teeth "rarely" or "never" cause crowding of the dentition. The reason that more American orthodontists recommend prophylactic removal of mandibular third molars remains unexplained.
Tüfekçi
E
E
Department of Orthodontics, School of Dentistry, Virginia Commonwealth University, Richmond, VA, USA. etufekci@vcu.edu
Svensk
D
D
Kallunki
J
J
Huggare
J
J
Lindauer
S J
SJ
Laskin
D M
DM
D001291:Attitude of Health Personnel; D001696:Biomechanical Phenomena; D003815:Dentists / Q000523:psychology*; D006801:Humans; D008310:Malocclusion / Q000209:etiology* / Q000517:prevention & control; D008334:Mandible; D008437:Maxilla; D008964:Molar, Third / Q000503:physiopathology* / Q000601:surgery; D009970:Orthodontics; D013314:Stress, Mechanical; D013548:Sweden; D014078:Tooth Eruption / Q000502:physiology*; D014081:Tooth Extraction; D014481:United States