To compare the actual sum of canine and premolars and that predicted from three mixed dentition prediction methods in orthodontic patients at the Aga Khan University Hospital (AKUH), Karachi.
Cross-sectional comparative study.
Orthodontic clinic at the Aga Khan University Hospital from June 2002 to December 2007.
Data were collected using pretreatment records including orthodontic files and plaster casts of 121 orthodontic patients. Digital caliper was used to measure the mesiodistal widths of permanent teeth from 1st molar to 1st molar in mandibular arch, and central incisors and 1st molars in maxillary arch. The methods of Tanaka and Johnston, Moyers, and Bernabé and Flores-Mir were used to predict the mesiodistal widths of the canine and premolars. Comparison between the actual and predicted sum of the mesiodistal widths of canine and premolars was made for each prediction method, using paired sample t-test.
There were 45 males and 76 females with average ages of 13.3+/-1.3 and 13.4+/-0.8 years respectively. For males statistically significant differences were found for Moyers at the 75th percentile and Bernabé and Flores-Mir method whereas for females only the Bernabé and Flores-Mir's method showed significant results. However, no significant difference was found in both genders for Tanaka and Johnston method.
In the studied orthodontic patients for males Moyers 50th percentile and Tanaka and Johnston methods could be used; while for females Moyers 75th percentile and Tanaka and Johnston methods were applicable for mixed dentition analysis.
[Show abstract][Hide abstract] ABSTRACT: During mixed dentition period discrepancy between spaces available and required in the arch
is predicted so that teeth can erupt freely with good alignment. Mixed dentition space analysis is done
for this purpose in which size of unerupted canine and premolars is predicted. Accurate prediction is
very important regarding correct orthodontic diagnosis and treatment planning. Prediction equation
and or tables based on size of already erupted permanent teeth are the most widely used methods. Tooth
size varies in different racial and ethnic groups and among genders so prediction equation and tables
specific to each population for both male and female must be made. Mandibular incisors; combination
of mandibular incisors and mandibular 1st molars; and mandibular incisors and maxillary 1st molars
have been used worldwide. Recent studies have reported that mandibular incisors are not the best
predictors and sum of mandibular incisors and maxillary 1st molars are even more accurate predictor
for the estimation of size of unerupted teeth. In Pakistani population combination of mandibular
incisors and maxillary 1st molar have not been employed so study must be conducted to estimate which
combination of group of teeth is more accurate for the estimation of size of unerupted canine and
premolars in local population.
[Show abstract][Hide abstract] ABSTRACT: Moyers analysis is widely used for analyzing mixed dentition, however, the accuracy of its theoretical probability tables has been recently questioned. Taking into consideration the fact the mixed dentition analysis is of paramount importance to precisely determine the space needed for alignment of canines and premolars, this research aimed at objectively assessing in the literature such an important step for orthodontic diagnosis.
A computerized search involving articles published on PubMed and Lilacs between 1990 and September, 2011 was conducted in accordance with the method described in the Cochrane 5.1.0 handbook.
The research resulted in a sample composed of 629 articles. The inclusion criteria were: Articles using the Moyers analysis with a sample greater or equal to 40 patients. Conversely, the exclusion criteria were: Dental casts of patients with syndromes or oral cleft, researches conducted with a literature review, only, or clinical case reports and researches conducted before 1990. For this systematic review, 19 articles were selected.
Based on the literature available, we can conclude that Moyers mixed dentition analysis must be carefully used, since the majority of the articles analyzed showed that the probability of 75% was not as accurate as expected, leading to the need of adapting the probability levels depending on the study population.
Dental Press Journal of Orthodontics 12/2013; 18(6):100-5. DOI:10.1590/S2176-94512013000600015
[Show abstract][Hide abstract] ABSTRACT: Estimation of the mesiodistal dimensions of the unerupted canines and premolars in the early mixed dentition is a necessary diagnostic aid in space management. Tanaka-Johnston analysis was developed for North American children. Anthropological study reveals that tooth size varies among different ethnicities. The present study was performed to evaluate the validity of Tanaka-Johnston method of mixed dentition arch analysis in Mumbai school children.
(1) To determine the correlation between the sum of the mesiodistal widths of the permanent mandibular incisors and combined mesiodistal widths of the permanent mandibular and maxillary canines and premolar in Mumbai school children. (2) To examine the applicability of Tanaka-Johnston method of prediction.
Dental casts of maxillary and mandibular arches of 300 children, 147 boys and 153 girls within the age group of 12-15 years, with permanent dentitions were fabricated. The mesiodistal crown dimensions of teeth were measured with a dial caliper. Tanaka-Johnston method of mixed dentition arch analysis was performed for the study population, and statistical analysis was done.
Descriptive statistics including the mean, standard deviation, range, and standard error were calculated and tabulated.
Tanaka-Johnston's equation when applied to the data available for Mumbai school children, it was observed that it slightly overestimates the tooth size.
(1) There was a positive correlation between the width of mandibular incisors and mandibular and maxillary canines and premolars. (2) The Tanaka-Johnston prediction method was not accurate for a sample of Mumbai school children.
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