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Current controversies in late incisor crowding


, : Current controversies in late incisor crowding. Annals of the Academy of Medicine, Singapore 24(1): 129-137

Although the terminology is mildly controversial, late incisor crowding (tertiary crowding, late secondary crowding, post-adolescent crowding) is widely regarded as a normal maturation event which is likely to affect most individuals to some extent. Disagreement arises when attempts are made to quantify the change and to predict the timing of the crowding. Most young adults experience some degree of loss of incisor alignment, usually near the anticipated emergence time for the third molars, and almost characteristically it is the lower anterior teeth which best demonstrate the phenomenon. Unfortunately, the physiological crowding changes are frequently confused with orthodontic treatment relapse. Greater controversy surrounds the aetiology of the undesirable crowding changes and despite many attempts we are still not in the enlightened position of explaining, predicting or preventing the problem (except by permanent retention). It is illogical to assume a single cause as the beguilingly simple observation of crowding belies the complexity of possible interacting factors. Perhaps it is a capricious combination of: tooth size and arch form; facial growth pattern (differential soft tissue and skeletal maturation); continuing late growth rotations; cumulative effects of resting, functional and parafunctional soft tissue pressures; lack of compensating attrition; and an ill-defined, mesially acting force emanating from the back of the dental arch. Many theories have attempted to resolve the mystery of the mesially acting force, including: pressure from erupting third molars; an inherent mesial migration; continuing mesial and occlusal dental drifting; maturation and contraction of periodontal soft tissues (particularly the transseptal fibres); the anterior component of occlusal forces; and the lower anterior arch contracting influence of the incisor overbite.

US$29.90

PMID: 7605082


Other references

Ahmad, Nazir, 1959: Studies on ankylostomiasis in West Pakistan. The prevalence of hookworm infection in 20 villages of Shakargarh tehsil area and 5 villages of Lahore area was investigated. The infection rates were 21.6 and 12.9% respectively. The differences noted in infection rates of various age and sex gro...

Liu, J.-Song; Sun, R.-Yong; Wang, D.-Hua, 2007: Digestive tract morphology in three rodent species. Chinese Journal of Zoology 42.1 (Feb 20): 8-13

X.G.Lin; L.K.; W.J.e; Mattos, C.A. de; Zheng XinXiong; Xue HongGang; H.Q.aoLing; Liu JinYan; Zhu JiaHong; Matto, C.C. de, 2002: Sequence analysis of N gene among 19 rabies virus street isolates from China. Part of the N gene was sequenced in 19 street rabies viruses isolated from dogs, humans, and deer in China since 1969. Chinese street rabies viruses could be classified into 4 groups. Similarities of these groups were 83.45-88.62%. There was a clo...

Timmons, Tom J., 1987: Growth and year-class success of yellow perch following impoundment. Proceedings of the Annual Conference Southeastern Association of Fish and Wildlife Agencies. October 4-7; 41: 205-213

Varadan K.M.; Ramamoorthy B., 1980: Mobile nutrients in some cereal crops. Mobile nutrients are quantified and expressed as percentage of the total quantity in cereals like rice [Oryza sativa], wheat [Triticum aestivum] and bajra [Pennisetum typhoides] using isotopic dilution technique. Mobile quantity of P and K are mor...

Hafez, A.H.; Megalla, S.E.; Mohran, M.A.; Nassar, A.Y., 1985: Aflatoxin and aflatoxicosis: V. The kinetic behaviour of dietary aflatoxins in colostrum drawn from cows postpartum. This work was conducted in order to study the kinetic behaviour of dietary aflatoxins in the colostrum of a pregnant cow exposed to contaminated feeds for a short period. In this study, two pregnant cows received a single dose of dietary aflatoxin...

Ciavatta, L.; D.T.mmaso, G.; Iuliano, M., 2002: Hydroxo sulfate complexes of iron (III) in solution. The ternary Fe (III)-OH(-)-SO4(2-) complexes have been investigated at 25 degrees C in 3 M NaClO4 by potentiometric titration with glass electrode. The metal and sulfate concentrations ranged from 2.5 x 10(-3) to 0.03 M and from 5.10(-3) to 0.060...

Anonymous, 1976: Pine beetle battle in Denver. Weeds trees and turf: 15 (7) 18

Neuman M.G.; Eshchar J.; Cotariu D.; Ben Sason R.; Ziv E.; Bar O.H.; Ishay J.S., 1985: Hepatotoxicity of hornets vespa orientalis venom sac extract in isolated perfused rat liver. The changes in the activity of some enzymes in parenchymal liver cells were measured in the perfusate of rat isolated liver after a single envenomation with 2 different doses of Hornet's (V. orientalis) venom sac extract (VSE). The maximal ob...

Jochim, M.; Jones, S., 1987: Monoclonal antibodies to epizootic hemorrhagic disease virus antigen. A method for preparing hybrid cell lins (hybridomas) which secrete monoclonal antibody which is group-specific to epizootic hemorrhagic disease virus antigen and which does not react to antigenically-related bluetongue virus antigen is disclosed....