Management of an impacted maxillary central incisor with dilacerated root

Dilaceration is a comparatively uncommon dental deformity generally characterized by an angulation between crown and root, and consequently causing non-eruption of the tooth. Dilaceration generally occurs following trauma to the apices of deciduous dentition, which lies close to the permanent tooth buds. As a result, surgical extraction used to be the first choice when making the treatment plan for a case with severely dilacerated teeth. This case report presents the orthodontic alignment of a permanent maxillary right central incisor in an 8-year-old boy who had an impacted inverted maxillary central incisor, with distoangular root dilaceration through the crown. Following surgical exposure with the closed-eruption technique and appropriate orthodontic traction, the tooth was successfully aligned into the dental arch and the root was radiologically shown to be straightened and relatively well developed. The impacted dilacerated incisor diagnosed in the early mixed dentition should be treated with the aid of orthodontic traction

Validity assessment and determination of the cutoff value for the Index of Complexity, Outcome and Need among 12-13 year-olds in Southern Chinese / 国际口腔科学杂志·英文版

To validate the use of the Index of Complexity, Outcome and Need (ICON) in assessing orthodontic treatment need among 12-13 year-olds in southern China, we determined the threshold value of ICON based on Chinese orthodontists' judgments. The samples consisted of 335 students in grade 7 from 16 randomly selected middle schools in Chengdu, China. Three associate professors provided ICON scores for each participant and the results were compared with the gold standard judgments from 25 experts on treatment needs. Based on the gold standard, 195 casts belonged to the treatment category, while the rest 140 belonged to the no-treatment category. With the international cutoff point of 43, the sensitivity and specificity of the ICON score were 0.29 and 0.98.The best compromise between sensitivity and specificity in Chengdu, compared with the gold standard, was found at a cutoff point of 29, and the sensitivity and specificity were 0.88 and 0.83. When used to evaluate the treatment need of 12-13 year-olds in southern China, the international ICON cutoff value did not correspond well with Chinese orthodontists' judgments; a lower cutoff value of 29 offered a greater sensitivity and specificity with respect to expert orthodontists' perception of treatment need.