Clinical evaluation of periodontal status in subjects with multibracket appliances and the role of age and gender during initial months of fixed orthodontic treatment.

Background: During fixed orthodontic treatment, the presence of various fixed appliances like brackets in the oral cavity for a long period leads to various changes in the oral microflora, ultimately affecting the periodontal health of the teeth. Hence, the current study was performed to clinically assess the periodontal status of the subjects undergoing fixed orthodontic treatment and to evaluate the role of age and gender during the first 6 months of treatment. Materials and
Methods: Forty-one subjects (26 females and 15 males) in the age range of 12-28 years scheduled for fixed orthodontic treatment were included in the study. Twenty-eight subjects were adolescents with a mean age of 13.96 years and 13 were adults with a mean age of 22.38 years. Plaque index (PI) and gingival index (GI) were recorded at the beginning and the end of 1, 2, 3, and 6 months of the treatment, and pocket probing depth (PPD) was evaluated at the start and after 6 months of fixed orthodontic treatment.
Results: The study showed a statistically significant increase in the mean values of PI (1.10 ± 0.264) and GI (0.929 ± 0.220) over a period of 6 months when compared with the baseline mean values, i.e., 0.557 ± 0.224 and 0.423 ± 0.329, respectively (P < 0.001). The mean PPD values exhibited no significant change. Effect of orthodontic treatment on adolescents/adults and between genders did not statistically differ. Conclusions: Fixed orthodontic treatment with multibracket appliances significantly increases plaque accumulation leading to significant inflammatory changes in the gingival tissues without any significant changes in the clinical probing depths of the pockets regardless of age and gender. Copyright:

INTRODUCTION

During fixed orthodontic treatment, various components such as brackets, ligature wires, elastics, and archwires serve as the retentive sites for rapid plaque accumulation which causes an increase in level of microorganisms, leading to the risk of gingivitis and periodontitis. This ultimately results in loss of periodontal connective tissue attachment if preventive measures are not followed. All these changes in the periodontium adversely affect remodeling which is the basis of orthodontic treatment, thus hampering the success of orthodontic treatment.[12] Hence, evaluation of periodontal status is most crucial in subjects undergoing fixed orthodontic treatment.[3] As plaque is the main etiological factor of all periodontal diseases, so periodontal status can be evaluated by studying the pattern and rate of plaque accumulation and changes in gingival color, consistency, texture, and size over a period of time, as these signify various stages of gingival and periodontal diseases. Majority of the related studies have evaluated the results of oral hygiene control measures on the plaque control during orthodontic treatment.[24567] Some of them have examined the effect of fixed orthodontic appliances on either salivary properties or on subgingival microflora.[89101112] Most of the available studies have compared the effects of fixed orthodontic treatment before, in between, and after the treatment.[21314] Few studies have evaluated the pattern of plaque accumulation and changes in gingival health at one time during the course of orthodontic treatment.[1516] More frequent assessment of periodontal health, especially during the initial period, is required. Some of the earlier studies have used plaque index (PI) and gingival index (GI) with or without probing depth.[89131617] Pocket probing depth (PPD) with bracket as the reference point has rarely been assessed.[2] Besides, the available literature on this subject has evaluated the parameters either on adolescents or on adults or a group comprising both.[291617181920] Very few studies have compared the effect of fixed orthodontic treatment on adults and adolescents.[21] There still exists a need to study the effect of fixed orthodontic treatment on adolescents versus adults for better understanding of the topic. Furthermore, gender-based comparisons are also required as few studies have suggested that females showed lesser plaque retention as compared to males.[22] Hence, the present study was aimed to assess plaque accumulation and changes in the gingival health of the subjects by recording PI, GI, and PPD of subjects undergoing fixed orthodontic treatment during the first 6 months of treatment and to evaluate the effect in adolescents versus adults and to assess the role of gender.

MATERIALS AND METHODS

The present prospective study was approved by the Institutional Research and Ethics Committee of Government Medical College and Hospital, Chandigarh (IEC/2017/19). Subjects reporting to the Department of Dentistry of the institute for fixed orthodontic therapy were selected by following the simple random sampling method. Among the subjects examined, 41 subjects (26 females and 15 males) fulfilling the below-mentioned criteria were recruited in the study. The inclusion criteria were as follows: (1) indication for full-mouth multibracket fixed orthodontic treatment, (2) the presence of full complement of permanent dentition, and (3) good general health condition. The exclusion criteria were as follows: (1) patients taking drugs such as corticosteroids, immunomodulators, or medications that can cause gingival enlargements, (2) patients with active periodontal disease and/or caries, (3) smokers/alcoholics, and (4) the presence of any condition or risk factor that can affect the oral health of the subjects, for example, cleft lip and/or palate. Before commencing the study, written informed consent was obtained from all the participants. The subjects selected were in the age range of 12–28 years (mean age: 16.63 years), and out of them, 28 were adolescents (<18 years of age) with a mean age of 13.96 years (range: 12–17 years) and 13 were adults (18 years or above) with a mean age of 22.38 years (range: 18–28 years). All subjects were treated by the same orthodontist, and a similar fixed orthodontic appliance, 0.018” slot MBT (Mc Laughlin, Bennet, Trevesi) prescription was applied with a light-cured bonding agent.

The periodontal health of the selected subjects was evaluated by recording the PI, GI, and PPD. PI by Silness and Loe, 1964,[23] and GI by Loe and Silness, 1963,[24] were scored on 20 teeth – premolars, canines, and incisors in both the arches. The teeth were examined on their mesiofacial, middle facial, and distofacial aspects with a probe under a good light source. Both PI and GI for one tooth were calculated by adding score of three surfaces and divided by three (number of tooth surfaces). The mean PI and GI for each subject was calculated by adding values for each tooth and then divided by number of teeth. PI and GI for all the subjects were recorded before the placement of the appliances. Thereafter, all subjects were provided regular oral hygiene instructions. Subsequent recordings of PI and GI were done at the end of 1, 2, 3, and 6 months of orthodontic treatment.

PPD is defined as the distance from the gingival margin to base of the clinical pocket. Change in the PPD was calculated by using gingival border of the brackets as a stable reference point for measurement. To simplify the procedure, assessments were made on six representative teeth (three in each arch) with a Williams periodontal probe, as shown in Figure 1. The teeth in the maxillary arch were right second premolar (15), right central incisor (11), and left second premolar (25) and in the mandibular arch were right second premolar (45), left central incisor (31), and left second premolar (35). The details of PPD measurement are shown in Figure 2. Two measurements – “a” and “b” – were recorded on these teeth at three points – as close as possible to the mesial proximal contact area, middle of the bracket, and as close as possible to the distal proximal contact area. The point “a” represented probing depth from the clinical base of the gingival pocket to gingival edge of the bracket whereas “b” represented probing depth from the gingival margin to the gingival edge of the bracket, and finally, change (c) in PPD was calculated as their difference, i.e., “a-b.” For each tooth, “a” and “b” were calculated as the mean of the three points and average PPD for each subject was the mean “a-b” for six representative teeth. Two readings were taken: first, on the start of the orthodontic treatment immediately after placing the brackets, and second, after 6 months of treatment. The recordings of all the subjects before treatment (T1) were compared with the successive readings taken thereafter. All clinical measurements were performed by a single examiner, a periodontist included in the study.

Figure 1

Pocket probing depth being measured with a Williams periodontal probe

Figure 2

Measurements for calculating pocket probing depth with a Williams periodontal probe. a – Mean of three points (from bottom of gingival pocket to gingival edge of the bracket). b – Mean of three points (from the gingival margin to the gingival edge of the bracket). c = (a-b) Pocket probing depth

Statistical analysis

Continuous data were given as mean ± standard deviation and range or median and interquartile range, as appropriate. Normality of quantitative data was checked by measures of Kolmogorov–Smirnov tests of normality. As the distribution of subjects in the age and gender groups was uneven, we applied nonparametric Mann–Whitney U-test for statistical analysis of the two groups. For time-related variables of normally distributed data of PIANOVA followed by post hoc multiple comparison test, Bonferroni was carried out. For variables of skewed data, Wilcoxon signed-rank test was applied. Analysis was conducted using the Statistical Package for the Social Sciences version 22.0 software (IBM Corp.; Armonk, NY, USA). P < 0.05 was considered statistically significant.

RESULTS

Out of the 41 subjects, 28 subjects were adolescents (<18 years of age) with a mean age of 13.96 years and 13 were adults (18 years or above) with a mean age of 22.38 years. Furthermore, out of the total subjects, 26 were female and 15 were male.

Table 1 shows the mean value of PI at baseline and successive visits. During the study, it was observed that the mean value of PI increased from baseline value at T0 0.557 ± 0.224 to 1.10 ± 0.264 at T6, i.e. at 6 months. PI showed a progressive increase at various intervals except between T2 (1.06 ± 0.389) and T3 (0.987 ± 0.339) where PI showed a slight decrease. The mean difference of PI values at later appointments with respect to baseline value showed a highly significant increase (P < 0.001).

Table 1

Mean values of plaque index at various time periods (n=41)

Time periods	PI (mean±SD)
T0	0.557±0.224 (0.13-1.03)
T1	0.948±0.335 (0.27-1.76)
T2	1.06±0.389 (0.48-2.19)
T3	0.987±0.339 (0.37-1.82)
T6	1.10±0.264 (0.54-1.64)

SD – Standard deviation; PI – Plaque index; T0 – Before bonding; T1 – After 1 month; T2 – After 2 months; T3 – After 3 months; T6 – After 6 months;

n – Number of subjects

Table 2 depicts the mean difference of PI between various visits. It shows that PI values did not show a significant difference between later versus previous values, i.e., (T2-T1), (T3-T1), (T6-T1), (T3-T2), (T6-T2), (T6-T3).

Table 2

Mean difference of plaque index within various time periods with P values

	T1	T2	T3	T6
T0	T1-T0	T2-T0	T3-T0	T6-T0
Mean±SE	0.390±0.0698	0.507±0.0698	0.429±0.0698	0.543±0.0698
P	<0.001***	<0.001***	<0.001***	<0.001***
T1		T2-T1	T3-T1	T6-T1
Mean±SE		0.117±0.0698	0.039±0.0698	0.153±0.0698
P		0.946 (NS)	1 (NS)	0.293 (NS)
T2			T3-T2	T6-T2
Mean±SE			-0.077±0.0698	0.036±0.0698
P			1 (NS)	1 (NS)
T3				T6-T3
Mean±SE				0.114±0.0698
P				1 (NS)

***Significance P<0.001. T0 – Before bonding; T1 – After 1 month; T2 – After 2 months; T3 – After 3 months; T6 – After 6 months; SE – Standard error;

NS – Nonsignificant; P – Probability

As shown in Table 3, the mean value of GI exhibited an increase from 0.423 ± 0.329 at baseline to 0.929 ± 0.220 at 6 months, which is more than double the baseline value.

Table 3

Mean values of gingival index at various time periods (n=41)

Time periods	GI (mean±SD)	Median
T0	0.423±0.329 (0.00-1.32)	0.370
T1	0.687±0.315 (0.285-1.48)	0.585
T2	0.794±0.253 (0.35-1.29)	0.790
T3	0.814±0.240 (0.37-1.40)	0.878
T6	0.929±0.220 (0.265-1.41)	0.970

SD – Standard deviation; GI – Gingival index; T0 – Before bonding; T1 – After 1 month; T2 – After 2 months; T3 – After 3 months; T6 – After 6 months;

n – Number of subjects

Table 4 shows the mean difference of GI between various visits. The mean difference of GI values at later appointments with respect to baseline value was highly significant (P < 0.001). Contrary to PI, GI scores showed a significant difference (P < 0.01) between later versus previous GI values except for T3-T2.

Table 4

Mean difference of gingival index within various time periods with P values

	T1	T2	T3	T6
T0	T1-T0	T2-T0	T3-T0	T6-T0
Mean±SE	0.263±0.254	0.371±0.314	0.390±0.372	0.506±0.443
P	<0.001***	<0.001***	<0.001***	<0.001***
T1		T2-T1	T3-T1	T6-T1
Mean±SE		0.107±0.257	0.126±0.293	0.242±0.396
P		0.006**	0.005**	0.001**
T2			T3-T2	T6-T2
Mean±SE			0.019±0.198	0.135±0.299
P			0.468 (NS)	0.006**
T3				T6-T3
Mean±SE				0.115±0.254
P				0.006**

**P<0.01, ***Significance P<0.001. T0 – Before bonding; T1 – After 1 month; T2 – After 2 months; T3 – After 3 months; T6 – After 6 months; SE – Standard error; NS – Nonsignificant; P – Probability

The mean value of PPD of six index teeth at baseline was 1.78 ± 0.501 and at the end of 6 months was 1.84 ± 0.512, the difference being nonsignificant. Comparison of the changes in the PPD values of anterior teeth with posterior teeth (represented by index teeth) over a period of 6 months also did not show any significant difference. Table 5 shows the result.

Table 5

Mean values of pocket probing depth at two time periods

	Mean±SD (T0)	Median (T0)	Mean±SD (T6)	Median (T6)	Change (T6-T0)	P
PPD (overall)	1.78±0.501 (1-3)	1.83	1.84±0.512 (0.8-3.2)	1.66	0.068±0.447	0.333
PPD 15	2.02±0.790 (0-5)	2	2.07±0.755 (0-4)	2	0.049±0.947	0.433
PPD 11	1.29±0.716 (0-3)	1	1.24±0.734 (0-3)	1	−0.049±0.835	0.696
PPD 25	1.93±0.905 (0-4)	2	2.17±1.04 (0-5)	2	0.244±1.06	0.160
PPD 35	1.85±0.882 (0-4)	2	2.07±0.959 (0-4)	2	0.220±0.852	0.108
PPD 31	1.59±1.02 (0-4)	1	1.49±0.746 (0-3)	2	−0.098±0.995	0.453
PPD 45	2.00±0.775 (0-4)	2	2.05±0.835 (1-4)	2	0.049±0.835	0.694
PPD (ant)	1.44±0.890		1.37±0.746		−0.073±0.913	0.470
PPD (post)	1.95±0.834		2.09±0.898		0.140±0.926	0.054

15 – Maxillary right second premolar; 45 – Mandibular right second premolar; 31 – Mandibular left central incisor; 11 – Maxillary right central incisor; 25 – Maxillary left second premolar; 35 – mandibular left second premolar. PPD (overall) – PPD of mean of 6 index teeth; PPD (ant) – PPD of index teeth representing anterior teeth, i.e., mean of 31 and 11; PPD (post) – PPD of index teeth representing posterior teeth, i.e., mean of 15, 25, 35, and 45. T0 – Before bonding; T6 – After 6 months. PPD – Pocket probing depth; SD – Standard deviation; P – Probability, P<0.05

None of the variables measured showed any significant difference between males and females. A comparison of adolescent and adult patients also showed no significant difference for each variable measured, as shown in Table 6.

Table 6

Comparison of parameters between adolescent/adult and male/female groups

Parameters	Mean±SD		P	Mean±SD		P
	<18 years (adolescents) (n=28)	>18 years (adults) (n=13)		Males (n=15)	Females (n=26)
PI
T0	0.565±0.239	0.543±0.197	0.779	0.612±0.186	0.526±0.240	0.237
T1	0.971±0.320	0.900±0.371	0.575	1.033±0.313	0.898±0.343	0.217
T2	1.078±0.395	1.038±0.390	0.855	1.15±0.457	1.01±0.343	0.271
T3	0.992±0.343	0.977±0.344	0.878	1.01±0.319	0.970±0.355	0.683
T6	1.156±0.257	0.983±0.248	0.050	1.09±0.262	1.10±0.270	0.840
GI
T0	0.449±0.332	0.368±0.328	0.393	0.491±0.340	0.384±0.322	0.208
T1	0.714±0.308	0.630±0.337	0.228	0.778±0.306	0.634±0.314	0.130
T2	0.792±0.283	0.801±0.183	0.855	0.918±0.261	0.723±0.223	<0.05*
T3	0.822±0.264	0.797±0.185	0.684	0.920±0.242	0.752±0.220	0.066
T6	0.936±0.230	0.914±0.204	0.801	0.969±0.253	0.906±0.200	0.163
PPD
PPD15 T0	2.10±0.831	1.84±0.688	0.506	1.80±0.775	2.15±0.784	0.241
PPD15 T6	2.13±0.705	1.92±0.862	0.559	2.00±0.926	2.12±0.653	0.614
PPD11 T0	1.39±0.737	1.07±0.640	0.215	1.33±0.724	1.27±0.724	0.856
PPD11 T6	1.32±0.772	1.07±0.640	0.306	1.07±0.704	1.35±0.745	0.256
PPD25 T0	2.03±0.999	1.69±0.630	0.198	1.80±0.862	2.00±00.938	0.548
PPD25 T6	2.32±1.09	1.84±0.898	0.265	2.13±0.834	2.19±1.16	0.932
PPD35 T0	1.93±0.978	1.69±0.630	0.393	1.87±0.640	1.85±1.00	0.837
PPD35 T6	2.10±1.03	2.00±0.816	0.803	2.00±0.845	2.12±1.03	0.776
PPD31 T0	1.53±1.10	1.69±0.854	0.485	2.00±1.19	1.35±0.846	0.091
PPD31 T6	1.46±0.838	1.53±0.518	0.866	1.60±0.737	1.42±0.758	0.477
PPD45 T0	2.00±0.666	2.00±1.00	10.00	1.73±0.884	2.15±0.675	0.125
PPD45 T6	1.96±0.888	2.23±0.725	0.329	1.80±0.676	2.19±0.895	0.173
PPD (total) T0	1.83±0.541	1.66±0.396	0.414	1.75±0.538	1.79±0.488	0.703
PPD (total) T6	1.88±0.558	1.76±0.405	0.544	1.76±0.458	1.89±0.544	0.504

*P<0.05. T0 – Before bonding; T1 – After 1 month; T2 – After 2 months; T3 – After 3 months; T6 – After 6 months. 15 – Maxillary right second premolar; 45 – Mandibular right second premolar; 31 – Mandibular left central incisor; 11 – Maxillary right central incisor; 25 – Maxillary left second premolar; 35 – mandibular left second premolar; SD – Standard deviation; GI – Gingival index; PI – Plaque index; PPD – Pocket probing depth; n – Number of subjects; P – Probability

DISCUSSION

For optimum dental health, a stable occlusal relationship and healthy masticatory function is required, which is the primary objective of orthodontic treatment. An ideal alignment of teeth simplifies the task of maintaining good oral hygiene. Smiech-Slomkowska and Jablonska-Zrobek stated that oral ecosystem is overly complicated and oral cavity harbors more than 300 bacterial species and any external disturbance like fixed orthodontic appliances can alter the delicate balance between components of microflora in the oral environment.[25] In this study, the PI and GI were noted at baseline and 1, 2, 3, and 6 months after the beginning of orthodontic treatment. Very few studies have done monthly evaluation of the periodontal status starting immediately after the placement of multibracket appliances. This period is very crucial as it is during this period that the patient begins to adopt the meticulous oral hygiene habits essential to maintain periodontal health. Both mean PI and GI increased significantly at the end of 6 months as compared to baseline values. Naranjo et al. reported that brackets, archwires, and other components can affect the oral environment by encouraging formation of biofilm at those sites.[8] Similar results showing increase in PI and GI were found in other studies.[891626] Rakhshan and Rakhshan also found that plaque accumulation increased tremendously during active stage of orthodontic treatment.[17] Ristic et al. reported that fixed appliances have a definite influence on periodontal health in a very short period of time and found a maximum increase of all clinical and microbiological parameters at 3 months followed by decrease of all the parameters at 6 months after the beginning of orthodontic treatment. The reestablishment of host–microorganism balance was given as a possible explanation for the decrease.[9] In our study, major increase was observed within the 1st month of the placement of multibracket appliances as shown by significant increase of mean PI from 0.557 ± 0.224 at baseline to 0.948 ± 0.335 and mean increase of GI from 0.423 ± 0.329 at baseline to 0.687 ± 0.315 after 1 month. This suggests the importance of assessing the periodontal status of patients with fixed orthodontic appliances during the initial months. The mean difference of both PI and GI at various points of time with respect to baseline was also highly significant. Whereas the observations for PI were nonsignificant at subsequent appointment, there was a significant increase in the mean value of GI in between appointments. Zachrisson and Zachrisson observed that despite maintaining excellent oral hygiene, patients usually develop mild-to-moderate gingivitis within 1–2 months after appliance placement.[2] The present results ascertain that fixed orthodontic appliances make maintenance of oral hygiene more difficult causing increased accumulation of plaque and evoking local soft-tissue response in gingival tissues and subsequent gingival inflammation. Keeping in consideration the lesser number of studies conducted to reveal changes in clinical parameters of gingival health at monthly intervals during the first 6 months of fixed orthodontic treatment, the present study was aimed to diagnose damage to periodontium as early as after 1 month so as to help patients with fixed orthodontic appliances maintain a stable gingival health status throughout the orthodontic treatment. This will contribute greatly in improving their compliance and overall treatment results. In the present study, six index teeth representing each quadrant were selected to measure PPD at 3 sites on the facial surface. The values were recorded at baseline and after 6 months of bracket placement, and the changes were not significant. Sinclair et al. showed a small increase in pocket depths adjacent to brackets on incisors after 1 year of orthodontic treatment.[27] Zachrisson and Zachrisson also showed no significant change in PD and further showed that increased pocket depth during treatment was due to edematous swelling and tissue accumulation during tooth movement and not due to apical movement of gingival pockets. They concluded that reduction of pocket depth after treatment occurs due to shrinkage of hyperplastic gingiva.[2] Similar reports found that fixed orthodontic treatment may result in transient localized gingivitis, which rarely progresses to periodontitis.[2829] On comparing the effect of orthodontic treatment on adolescents and adults, no significant difference was found between the two age groups for all the parameters studied. Boyd et al., 1989, found that adolescents are likely to show significantly more plaque accumulation and gingival inflammation during fixed orthodontic treatment than adults.[21] Our study found no significant difference between males and females in accordance with a previous study.[17] Since the sample size of the age and gender groups in our study was small, therefore a larger sample size is required to get conclusive results about the role of age and gender. Periodontal evaluation based on clinical measurements has been shown to have low sensitivity and specificity, so gingival crevicular fluid biomarkers are being sought currently for early detection of changes in the periodontium. Future research could provide more information on this topic by evaluating levels of these biomarkers and their correlation with clinical indicators for gingival inflammation.

CONCLUSIONS

Fixed orthodontic treatment can cause substantial plaque accumulation and gingival inflammation without any significant increase in PPD during the first 6 months of treatment regardless of adolescents and adults and patients’ gender. Therefore, educating and motivating these patients to maintain their oral health immediately after placement of multibracket appliances and continuing it throughout the treatment is essential for achieving optimal oral hygiene.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.