Objective: To investigate if caries in the pre-treatment early mixed dentition is associated with caries development in the permanent dentition during orthodontic treatment. Material and Methods: We included 41 consecutive patients (29 girls, 12 boys) with a pre-treatment documentation in the mixed (mean age 9.4 years) and a post treatment documentation in the permanent dentition (age 14.9 years) (two-phased treatment time 4.5 (±1.6) years). The DMFT/S indices were calculated. High-risk and low-risk groups were defined according to dmfs + DMFS score before treatment. Results: Initial dmft/s + DMFT/S (SD) was 5.15 (3.60) and 8.32 (6.64); final DMFT/S was 2.76 (2.84) and 3.01 (3.20). The missing (because of decay) second deciduous molars were most powerfully associated with caries increment during treatment, showing significant correlations to second premolars (r = 0.47, p = 0.003), while fillings on second deciduous molars seem to influence the prevalence of fillings on permanent molars (r = 0.44, p = 0.001). The increment at surface level was 2.01 (2.61) in the whole sample and 2.60 (3.81) in the high-risk group (4 boys, 6 girls). Compared to the low-risk group (10 girls), post-treatment caries experience was significantly higher in the high-risk group (p = 0.029). Boys were more at risk than girls (p = 0.005). Conclusions: Children with elevated caries experience in the early mixed dentition are exposed to higher caries risk during orthodontic treatment. Thus, in prevision of treatment, caries should already be assessed in the mixed dentition, so that an extended prophylaxis program can be initiated.
Although caries prevalence in children and young adults decreased dramatically in industrialized countries during the 1970s and 1980s [
Therefore, patients with high demineralization and caries risk should be identified before starting orthodontic treatment, so that they can benefit from an extended prophylaxis program before and during the treatment. The first step in this approach is to determine valid predictors for individual demineralization and caries development during orthodontic treatment. Among the clinical variables in patients without orthodontic treatment, past caries experience in deciduous teeth is one of the most significant predictors of future caries development [
Thus, the objective of the present study is to investigate if caries experience in the early mixed dentition is associated with the development of caries in the permanent dentition during orthodontic treatment.
Our hypothesis is that children with higher caries experience in the mixed dentition are more at risk to develop caries in the permanent dentition during orthodontic treatment.
The subjects were selected among the files of patients having finished their orthodontic treatment during the years 2003 to 2008 at our university clinic. Informed consent was obtained from the children’s parents and ethical approval to use the data was obtained by the university hospital ethical research committee. Inclusion criteria to enter our study were radiographs and study casts to be available from the
a) initial pre-treatment documentation, taken in the early mixed dentition (deciduous molars not shed out physiologically; lower deciduous canines may have been shed out due to permanent canines starting eruption);
b) final documentation, taken in the permanent dentition after orthodontic treatment.
Forty-one patients, 29 girls and 12 boys met the inclusion criteria. Their mean age before starting orthodontic treatment was 9.4 ± 1.1 years and 14.9 ± 1.6 years at the final documentation after orthodontic treatment (
Patients | Years (mean, SD) | |||
---|---|---|---|---|
Number | Age pre-treatment | Age post-treatment | Treatment duration | |
Girls | 29 | 9.2 (0.93) | 14.7 (1.43) | 4.6 (1.65) |
Boys | 12 | 9.6 (1.30) | 15.3 (2.00) | 4.4 (1.54) |
All | 41 | 9.4 (1.08) | 14.9 (1.61) | 4.5 (1.60) |
The index used for measuring caries experience was the dmft/s on deciduous and the DMFT/S on permanent teeth, assessing the number of decayed, missing and filled teeth/tooth surfaces. On the pre-treatment radiographs taken in the mixed dentition, the deciduous molars (04, 05) and the permanent first molars (6) were assessed. On the post treatment radiographs taken in the permanent dentition, the bicuspids (4, 5) and permanent molars (6, 7) were assessed. The condition of the occlusal, mesial and distal surface was recorded for each tooth.
The presence of erupted and unerupted teeth was assessed on the orthopantomograms and verified on study casts. Patient records were examined in order to discern missing teeth due to caries from missing teeth due to trauma, extraction for orthodontic reasons, undermining resorption or agenesis.
The presence of caries (d, D) and fillings (f, F) was assessed on bitewing radiographs (
A high-risk and a low-risk group were created by sorting the patients according to initial dmfs + DMFS score before treatment. Approximately 25% (10/41) (4 boys, 6 girls) of the patients with the highest number of surfaces affected were included into the high-risk group. The patients with the lowest caries experience before treatment (25%, 10/41; 10 girls) were included into the low-risk group.
The dmft/s and DMFT/S indices (the sum of decayed, missed and filled teeth/surfaces in temporary and permanent dentition) were calculated and descriptive analysis as well as correlation (Kendall tau) and multiple linear
regression analyses were performed (SPSS, version 15.0, Inc. Chicago IL). Mann-Whitney U-test was used to determine any significant difference between the groups. The level of statistical significance was set at 0.05. Two months after the initial evaluation, the radiographs of 20 randomly selected patients were re-assessed by one author (VS). Unweighted kappa statistics was performed to measure the reproducibility.
The agreement between the first and the repeated measurement was excellent when evaluating bitewing radiographs for decay (κ = 0.95) and fillings (κ = 1.00).
At the pre-treatment documentation all first permanent molars and almost all permanent incisors (95.1%) had erupted. By the end of the treatment all permanent teeth had erupted except for 4.9% of the second molars and all third molars.
There were more girls (29) than boys (12) in our sample (
The percentage of caries free patients (dmfs/dmfS = 0) was 9.8% (n = 4) at the initial documentation and 22.0% (n = 9) at the end of orthodontic therapy.
At tooth level, pre-treatment caries experience in the mixed dentition was 5.15 (SD 3.60) and post-treatment caries experience in the permanent dentition was 2.76 (SD 2.84). At surface level (
Before treatment, in the mixed dentition, 54.0% of the deciduous molars and 27.4% of the first permanent molars were affected by caries. Over six times more surfaces were affected on the deciduous molars than in permanent first molars (
After treatment, in the permanent dentition, 41.4% of the first permanent molars were affected by caries, thus 14% more than before the orthodontic treatment. When recording the caries experience after treatment, about two out of the three surfaces affected were on the first molars and the remaining one was on the second premolars or molars (
The overall increment of caries experience during treatment was 2.01 (2.61). On average, one new surface was affected on a first molar and one new surface either on a second premolar or second molar (
Caries experience pre-treatment: Number of affected tooth surfaces | ||||
---|---|---|---|---|
Decayed | Missing | Filled | dmfs/DMFS | |
Tooth type | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) |
04 | 1.83 (2.05) | 0.51 (1.49) | 1.32 (2.21) | 3.66 (3.14) |
Occlusal | 0.61 (0.86) | . | 0.66 (1.09) | 1.27 (1.28) |
Proximal | 1.22 (1.47) | . | 0.66 (1.17) | 1.88 (1.71) |
05 | 1.81 (1.96) | 0.44 (1.27) | 1.41 (2.33) | 3.66 (3.34) |
Occlusal | 0.61 (1.02) | . | 0.78 (1.24) | 1.39 (1.50) |
Proximal | 1.20 (1.21) | . | 0.63 (1.26) | 1.83 (1.61) |
6 | 0.27 (0.55) | 0.0 (0.0) | 0.73 (1.30) | 1.00 (1.43) |
Occlusal | 0.17 (0.50) | . | 0.66 (1.24) | 0.83 (1.24) |
Proximal | 0.10 (0.30) | . | 0.07 (0.35) | 0.17 (0.54) |
Sum (04, 05, 6) | 3.91 (3.20) | 0.95 (2.37) | 3.46 (4.70) | 8.32 (6.64) |
Caries experience post treatment: Number of affected tooth surfaces | ||||
---|---|---|---|---|
Decayed | Missing | Filled | DMFS | |
Tooth type | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) |
4 | 0.04 (0.22) | 0.0 (0.0) | 0.0 (0.0) | 0.04 (0.22) |
Occlusal | 0.02 (0.16) | . | 0.0 (0.0) | 0.02 (0.16) |
Proximal | 0.02 (0.16) | . | 0.0 (0.0) | 0.02 (0.16) |
5 | 0.44 (1.03) | 0.0 (0.0) | 0.04 (0.31) | 0.48 (1.05) |
Occlusal | 0.12 (0.40) | . | 0.02 (0.16) | 0.15 (0.42) |
Proximal | 0.32 (0.79) | . | 0.02 (0.16) | 0.34 (0.79) |
6 | 0.64 (0.83) | 0.0 (0.0) | 1.29 (1.74) | 1.93 (1.79) |
Occlusal | 0.54 (0.78) | . | 1.07 (1.44) | 1.61 (1.46) |
Proximal | 0.10 (0.37) | . | 0.22 (0.69) | 0.32 (0.88) |
7 | 0.34 (0.62) | 0.0 (0.0) | 0.22 (0.76) | 0.56 (1.03) |
Occlusal | 0.27 (0.50) | . | 0.22 (0.76) | 0.49 (0.87) |
Proximal | 0.07 (0.35) | . | 0.0 (0.0) | 0.07 (0.35) |
Sum (4, 5, 6, 7) | 1.46 (1.80) | 0.00 (0.0) | 1.55 (2.13) | 3.01 (3.20) |
dmfs/DMFS (mean, SD) | |||||
---|---|---|---|---|---|
Group | Number | (Female, male) | Pre-treatment | Post-treatment | Increment |
High risk | 10 | (4 m, 6 f) | 18.10 (4.72) | 5.00 (4.40) | 2.60 (3.81) |
Low risk | 10 | (10 f, 0 m) | 1.20 (1.23) | 2.00 (2.40) | 2.00 (2.36) |
All patients | 41 | (29 f, 12 m) | 8.32 (6.64) | 3.01 (3.20) | 2.01 (2.61) |
Caries increment: Number of new affected tooth surfaces | ||||
---|---|---|---|---|
Decayed | Missing | Filled | DMFS | |
Tooth type | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) |
4 | 0.04 (0.22) | 0.0 (0.0) | 0.0 (0.0) | 0.04 (0.16) |
Occlusal | 0.02 (0.16) | . | 0.0 (0.0) | 0.02 (0.16) |
Proximal | 0.02 (0.16) | . | 0.0 (0.0) | 0.02 (0.16) |
5 | 0.44 (1.03) | 0.0 (0.0) | 0.05 (0.31) | 0.48 (1.05) |
Occlusal | 0.12 (0.40) | . | 0.02 (0.16) | 0.15 (0.42) |
Proximal | 0.32 (0.79) | . | 0.02 (0.16) | 0.34 (0.79) |
6 | 0.37 (0.94) | 0.0 (0.0) | 0.56 (0.74) | 0.93 (1.17) |
Occlusal | 0.37 (0.94) | . | 0.41 (0.92) | 0.78 (1.01) |
Proximal | 0.00 (0.00) | . | 0.15 (0.42) | 0.15 (0.48) |
7 | 0.34 (0.62) | 0.0 (0.0) | 0.22 (0.76) | 0.56 (1.03) |
Occlusal | 0.27 (0.50) | . | 0.22 (0.76) | 0.49 (0.87) |
Proximal | 0.07 (0.35) | . | 0.0 (0.0) | 0.07 (0.35) |
Sum (4, 5, 6, 7) | 1.19 (1.99) | 0.0 (0.0) | 0.82 (1.14) | 2.01 (2.61) |
No statistically significant correlations were found between overall caries experience in the mixed dentition before orthodontic treatment and increment in caries experience in the permanent dentition after orthodontic treatment. When focusing on the dmft score of deciduous molars, correlations were found with the score of the second premolars and first molars (r = 0.30, p = 0.022 and r = 0.28, p = 0.024, respectively). Second deciduous molars score taken apart was correlated with the score at first permanent molars after treatment (r = 0.38, p = 0.003). At surface level, correlations were obtained between the first deciduous molars’ proximal fillings and the proximal fillings experience on the first permanent molars after treatment (r = 0.48, p = 0.001). Decayed permanent first molars before treatment (proximal lesions) were significantly correlated to caries increment during orthodontic treatment on the second molars (also proximal lesions) (r = 0.31, p = 0.045). When deciduous molars were missing because of caries, especially the second ones, their score was significantly correlated to caries experience or fillings on the second premolars (r = 0.47, p = 0.003). Pre-treatment fillings on the second deciduous molars seem to influence the prevalence of fillings on first molars after treatment (r = 0.44, p = 0.001).
By performing a multiple regression analysis, a significant model emerged (adjusted R2 = 0.179, F3, 37 = 3.907, p = 0.016) where the variable sex (B = 0.492, p = 0.004) could explain 17.9% of the variability in overall caries increment. This model could not be improved significantly by the combination with further variables (age, treatment duration, caries experience).
The present longitudinal cohort study revealed a significant positive association between caries experience in the early mixed and in the permanent dentition during orthodontic treatment. Due to the retrospective character of our study, caries detection was purely based on bitewing radiographs, where we achieved very good reproduci- bility. Although this is the standard method for approximal caries detection [
In the present study, pre-treatment caries experience in the mixed dentition was relatively high (5.15 at tooth level, 8.32 at surface level), when compared to Scandinavian children (2.43 and 3.53 [
In contrast to the associations found in the literature for various dentition stages (without orthodontic treatment: 5 vs. 10 year olds [
During orthodontic treatment, when oral hygiene is more challenging, an increment in caries experience of 2.01 was observed in the entire sample. In the high-risk group, the increment was more elevated (2.60), but statistical significance was not reached neither in respect to the entire sample (2.01) nor in respect to the low risk group (2.00). However, post-treatment caries experience was significantly higher in the high-risk (5.00) than in the low-risk group (2.00). In accordance with the study of Hansel Petersson [
Children with elevated caries experience in the early mixed dentition, especially on deciduous second molars and permanent first molars, are exposed to a higher risk to develop caries in the permanent dentition during orthodontic treatment (mainly on the second premolars and first molars). Caries increment was higher in boys than in girls. Thus, in the light of the findings in this retrospective study and in prevision of orthodontic treatment, caries activity should be assessed in the mixed dentition, in order to already involve the patient in an extended prophylaxis program.
ValbonaSoumas,StavrosKiliaridis,Christine B.Staudt, (2015) Is Caries in the Early Mixed Dentition Associated with Caries Development during Orthodontic Treatment?. Journal of Biosciences and Medicines,03,25-32. doi: 10.4236/jbm.2015.311003