Caries Experience of the Patients Referred for an Orthodontic Consultation.

OBJECTIVE OF WORK: Caries represents a significant public health problem. Caries free dentition and good oral hygiene are prerequisites for inclusion into orthodontic treatment. The objective of this research was to assess oral health of the patients referred for an orthodontic assessment. SUBJECTS AND METHODS: In this cross sectional study, dental records of 351 patients aged 6-23 years (55% females), were referred to an orthodontist by a general dentist during 2014 and 2015 in Rijeka, and the records were subsequently analyzed. Prevalence of caries, caries experience and active caries related to gender and dentition type were analyzed.
RESULTS: In subjects with the mixed dentition, who were referred to an orthodontist, caries prevalence was 68% in deciduous teeth, caries experience was 3.6, and active caries was present in 2.4 teeth; in permanent teeth in mixed dentition the values were 21%, 1.3 and 0.4., respectively. Regarding the mixed dentition, the values in subjects' permanent dentition were as follows: 28%, 5.5, and 1.5. Caries was more frequent in deciduous teeth, and there were more fillings in permanent teeth compared to deciduous teeth. There were no gender related differences.
CONCLUSIONS: Oral health of children and adolescents referred to an orthodontic consultation is not satisfactory. General dentists frequently refer patients with caries to an orthodontic consultation. However, the presence of caries postpones inclusion into orthodontic treatment. It is important to begin raising general dentists' awareness of the need to refer to an orthodontist only those patients who have healthy dentition and good oral hygiene.

Introduction

Dental caries still represents a significant public health problem. It is the most common childhood chronic disease which leads to pain, masticatory and pronunciation difficulties, systemic diseases and lower quality of life (, ). Oral health implies daily performance of procedures that prevent oral tissue diseases (, ). Before any active orthodontic treatment, it is necessary that the patient has established satisfactory oral hygiene and cured all carious lesions, both on deciduous and permanent teeth (). If teeth are not cured, orthodontic appliance cannot have controlled anchorage. Also, if a caries lesion were possibly covered with parts of fixed orthodontic appliance, anaerobic environment would lead to progressive tooth destruction as a result of dental caries (). Once the white spot lesion occurs, it is advised to treat it immediately; otherwise it would be more difficult or even impossible to re-mineralize such tooth after the end of orthodontic treatment (-). The problem of patients referred to an orthodontic office with active caries was recognized in the past (). Such patients take up the time which could be spent more usefully on actual orthodontic treatment, instead of counting caries.

Malocclusions caused by consequences of tooth decay lead to increased need for restorative and orthodontic therapeutic procedures (). An obvious example is the lack of space for alignment of the permanent lateral teeth. The transition from the healthy primary to the well-aligned permanent dentition is possible due to the leeway space, i.e. difference between the sum of the mesiodistal widths of the deciduous cuspid and molar teeth, and their successors. Thus, well-preserved deciduous teeth are the best space maintainers (), therefore, it is of greatest importance to keep deciduous teeth healthy (i.e. caries free). Loss of leeway space leads to mesial migration of first permanent molars after the exfoliation of second deciduous molars, lack of space for positioning permanent successor teeth and significant shortening and transverse constriction of dental arch. This type of malocclusion is easily preventable with regular controls at dental offices and treatment of decayed deciduous teeth, especially those from the leeway space group. In prevention of various malocclusions caused by the loss of space due to caries, the role of general dentists is of the greatest importance (, ). Furthermore, the class III malocclusion, moderate to severe cross-bite, as well as severe increased overjet and overbite would benefit from early treatment, because they seem not to improve spontaneously with the transition from the mixed into the permanent dentition ().

An objective of an orthodontic treatment is not only to establish optimal occlusion but also to improve the health of the hard and soft oral tissues. Nevertheless, parts of the orthodontic appliance make suitable spots for development of dental caries (). White spot lesion is one of the most common and serious side effects of orthodontic treatment. Sometimes it can be found even during the first month of active therapy. These lesions appear more often in patients with fixed than removable orthodontic appliances and are most commonly located on upper incisors and canines as well as lower canines and premolars (, ). Poor oral hygiene can extend orthodontic treatment on average for two months ().

The objective of this research was to assess oral health of patients referred to orthodontists and to compare the relationship between gender and dentition type with prevalence and severity of dental caries.

Subjects and methods

Dental records of 405 consecutive patients, who were referred to their first orthodontic examination to the Orthodontic Clinic in the Clinical Hospital Center in Rijeka, Croatia between January 1st 2014 and December 31st 2015, were analyzed in this cross-sectional study. Patients with only primary dentition (N=54) were excluded from further analysis. Patients were aged 6-23 years (median age was 11, interquartile range 9-13), 55% of them were females. All patients were examined when they had their first appointment in the orthodontic office. Clinical examination of the hard tissues was performed under artificial light, with a dental mirror and a dental probe. All present teeth were inspected, and a detailed record of the findings was saved together with their informed consent. Dental caries was diagnosed according to the WHO recommendations (). Data were collected retrospectively, from the existing orthodontic charts, and used for further analyses. Age, gender, carious, extracted and filled teeth as well as sealed pits and fissures in the mixed and permanent dentition were identified for each patient. Furthermore, the prevalence of active caries lesions (percentage of subjects with at least one active caries lesion), the prevalence of healthy dentition (percentage of subjects who were caries free), the prevalence of subjects who had sealed pits and fissures (percentage of subjects with sealed teeth), dental caries experience (mean number of teeth with any form of caries experience), severity of active dental caries (mean number of teeth with active caries lesions) and severity of extracted and filled teeth were evaluated. In addition to that, the index of past caries experience based on the number of decayed, missing, and filled deciduous (indicated by lower-case “dmft” letters) or permanent (indicated by capital “DMFT” letters) teeth was determined.

The difference in prevalence of subjects with active caries lesions, the prevalence of those with healthy dentition, the prevalence of subjects who had sealed pits and fissures between genders, separately in deciduous and permanent teeth, was analyzed using the χ2 test. The t-test was used to analyze the difference in caries experience, severity of active caries and severity of extracted and filled teeth of deciduous and permanent teeth between genders. Effect size, i.e. the size of the difference between genders was quantified with Cramer V for χ2 and with equation r=√t2/ (t2+df) for the t-test. To interpret effect size, Cohen’s criteria were used: r= 0.1-0.3= low; r= 0.3-0.5= medium; r= >0.5= high. A statistical analysis was performed with IBM SPSS 22 software (IBM Corp., Armonk, USA) with significance at p< 0.05.

Results

There were no statistically significant differences within the dentition types between genders, although the permanent dentition was found to be slightly more frequent in females (Table 1).

Table 1

Distribution of the dentition types between genders

			dentition types		total	p	V
			mixed	permanent
gender	male	N	102	56	158
		% gender	64.6	35.4	100.0
		% dentition	48.3	40.0	45.0
	female	N	109	84	193
		% gender	56.5	43.5	100.0
		% dentition	51.7	60.0	55.0	0.127	0.082
total		N	211	140	351
		% gender	60.1	39.9	100.0
		% dentition	100.0	100.0	100.0.

The prevalence of healthy permanent dentition of children referred to orthodontist (DMFT=0) was 39% (Figure 1). Within mixed dentition, there were 20% of children who had caries free deciduous teeth and 50% of them had caries free permanent teeth. Altogether, 39% of subjects were caries free, considering both dentition types (Figures 2, 3 and 4).

Figure 1

Distribution of the caries experience of the permanent teeth in mixed and permanent dentition (in range from 0 to 18) among participants (displayed as percentage)

Figure 2

Distribution of the caries experience of the deciduous teeth in mixed dentition (in range from 0 to 7 +) among participants (displayed as percentage)

Figure 3

Distribution of the caries experience of the permanent teeth in mixed dentition (in range from 0 to 7) among participants (displayed as percentage)

Figure 4

Distribution of the caries experience in the permanent dentition (in range from 0 to 18) among participants (displayed as percentage)

The prevalence of the active caries on the permanent teeth of children referred to orthodontist was 40%, while there was, on average, one tooth with active carious lesion (Table 2 and 3). Within mixed dentition, the prevalence of active caries lesions on deciduous teeth was 68%, with almost three teeth, on average, having active caries lesions. The prevalence of the active caries on the permanent teeth in the mixed dentition was 21%. Altogether, the prevalence of active caries on permanent teeth, both in mixed and permanent dentition was 29% (Table 2).

Table 2

Prevalence of the subjects with the active caries of the permanent teeth regarding the dentition type

			active caries of the permanent teeth		total	p	V
			yes	no
dentition type	mixed	N	45	166	211
		% dentition	21.3	78.7	100.0
		% active caries	44.6	66.4	60.1
	permanent	N	56	84	140
		% dentition	40.0	60.0	100.0
		% active caries	55.4	33.6	39.9	p<0.001	0.202
total		N	101	250	351
		% dentition	28.8	71.2	100.0
		% active caries	100.0	100.0	100.0

Table 3

Severity of the healthy teeth and caries experience regarding the dentition type

	dentition type
	mixed	permanent
severity of the healthy deciduous teeth	5.5±4.3
severity of the active caries of the deciduous teeth (d)	2.5±2.9
severity of the filled deciduous teeth (f)	1.0±1.6
caries experience of the deciduous teeth (df)	3.6±3.2
severity of the healthy permanent teeth	13.0±5.0	22.8±4.0
severity of the active caries of the permanent teeth (D)	0.4±0.8	1.1±2.1
severity of the extracted permanent teeth (M)	0.01±0.2	0.2±0.5
severity of the filled permanent teeth (F)	0.9±1.4	2.9±3.3
caries experience of the permanent teeth (DMF)	1.3±1.6	4.2±4.1

Caries experience was slightly higher in the mixed than in the permanent dentition (on average, 4 deciduous and 1 permanent teeth in the mixed dentition and 4 permanent teeth in the permanent dentition experienced caries) (Table 3). The difference regarding the caries experience between genders was not significant (Table 4). There was slightly higher severity of healthy and filled deciduous teeth within the male population and slightly higher severity of active deciduous caries within the female population.

Table 4

Severity of the healthy teeth and caries experience in relation to gender

	gender		p*	r**
	male	female
severity of the healthy deciduous teeth	6.0±4.4	5.0±4.1	0.091	0.120
severity of the active caries on the deciduous teeth (d)	2.3±2.6	2.7±3.1	0.345	0.060
severity of the filled deciduous teeth (f)	1.1±17	0.9±1.5	0.498	0.050
caries experience of the deciduous teeth (df)	3.4±3.0	3.7±3.3	0.614	0.030
severity of the healthy permanent teeth in the mixed dentition	12.5±5.1	13.5±4.9	0.123	0.110
severity of the active caries of the permanent teeth (D) in the mixed dentition	0.4±0.8	0.4±0.9	0.773	0.020
severity of the extracted permanent teeth (M) in the mixed dentition	0.01±0.1	0.02±0.2	0.687	0.030
severity of the filled permanent teeth (F) in the mixed dentition	1.0±1.4	0.8±1.4	0.383	0.060
caries experience of the permanent teeth (DMF) in the mixed dentition	1.4±1.6	1.2±1.6	0.399	0.060
severity of the healthy teeth in the permanent dentition	22.7±3.8	22.9±4.2	0.766	0.025
severity of the active caries (D) in the permanent dentition	1.3±2.6	1.0±1.7	0.364	0.077
severity of the extracted teeth (M) in the permanent dentition	0.1±0.3	0.2±0.7	0.100	0.140
severity of the filled teeth (F) in the permanent dentition	2.9±3.1	2.9±3.4	0.975	0.003
caries experience (DMF) in the permanent dentition	4.3±3.7	4.1±4.4	0.820	0.019

*p < 0.05 statistically significant difference

**value r was calculated via equation r=√t2/ (t2+df)

The prevalence of pits and fissure sealing in children and adolescents referred to an orthodontist was 13.4% and was equal for both dentitions and genders. On average, 0.3 ± 0.9 teeth were sealed in the entire sample, equally in both dentitions and genders. Within the children and adolescents who had at least 1 sealed tooth, there were on average 2.1 ± 1.4 sealed teeth, equally in both dentitions and genders.

Discussion

This research points to the fact that Croatian dentists refer both children and adolescents with unhealthy teeth to an orthodontist, which postpones their inclusion in the orthodontic treatment. Almost 70% of children are referred to orthodontist with decayed deciduous teeth and 40% with decayed permanent teeth. The patients referred to an orthodontist have, on average, three carious permanent teeth and one carious deciduous tooth. One in 3.5 patients has active caries, as opposed to one in 5 in a previous similar study (). According to these data, the severity of caries experience in Croatia is above the goals set by the World Health Organization (WHO) (). In 2000, a goal for 12-year olds was the DMFT below three, and for year 2010 below one (). However, the fact that needs to be considered is that patients who are referred to an orthodontist have supposedly healthy dentition, as well as other soft tissues and, also, good oral hygiene, as evaluated by their referring dentists. These observations were confirmed by the research conducted during years 2008 and 2009 in the same region, where six- and seven-year olds had prevalence of dental caries on deciduous teeth 75% (3.7 carious teeth on average) and on permanent teeth 12% (0.1 carious teeth on average) before starting school ().

The WHO goals for 2020 are to reduce the severity of dental caries and increase the percentage of six-year olds who are caries free as well as to reduce the percentage of the patients who eventually lose a tooth due to dental caries ().

Caries strikes the primary teeth more often because both enamel and dentin of the primary teeth are thinner than those of the permanent teeth. Also, children are fond of sweetened food and drinks (i.e. saturated with carbohydrates) hence, they have the reduced capability of oral hygiene maintenance (). Also, caries is often more severe on the deciduous teeth than on the permanent teeth. The fact is that caries is often detected too late; when it has progressed to a later stage and/or is not properly treated due to the poor cooperation. The findings from this study show that permanent teeth get treated more often with dental fillings and preventive measures than deciduous teeth.

More than 60% of permanent teeth, as well as 80% of deciduous teeth have had caries experience, which confirms the fact that the awareness of importance of having healthy oral structures is low. High scores of caries experience are most probably a result of poor oral hygiene habits, low frequency of regular dental check-ups as well as low rate of both preventive and curative treatments on the deciduous teeth.

The female participants had slightly higher scores of caries experience on their deciduous teeth, more teeth with active caries and less healthy deciduous teeth than male participants, whereas male participants had higher scores of caries experience and less healthy teeth in the permanent dentition. This can be explained by the fact that girls suffer from dental anxiety more often than boys. Yet, while growing up girls tend to understand the importance of oral health in a better way than their male counterparts. Also, girls adopt better hygiene habits than boys thus increasing the degree of co-operation with dentists ().

The comparison of the prevalence and severity of caries, caries experience and severity of treated deciduous and permanent teeth lead to a conclusion that the emphasis should be put on both preventive and curative measures of deciduous teeth. The permanent teeth are more often treated with dental fillings than deciduous teeth, which can be interpreted by a widespread a widespread belief that deciduous teeth are not to be treated because they will fall out anyway. Part of the problems associated with uncured carious deciduous teeth may be attributed to unsatisfactory organization of the public dental health system. Consequently, the majority of patients receive restorative treatments rather than preventive measures. Due to the discrepancy between a large number of patients and a small number of dental teams, there are longer waiting lists and longer time spans between the two consecutive visits, thus creating the situation in which clinical cases often do not get suitable treatment on time. Furthermore, general dental practitioners, who have the contract with Croatian National Health Insurance Company (Croatian acronym HZZO), have a monthly financial limit regarding dental procedures; surpassing the monthly maximum could lead to financial losses. Besides, the vast majority of orthodontic specialists’ chair time paid by the HZZO is spent on counting the patients’ carious teeth, which contributes to the inefficient use of public money.

There were fluctuations in the carious permanent dentition of 12-year olds in Croatia from 1968 to 1999 (). In 1968, there were not any children with caries free dentition and the mean DMFT score was 7. After 1968, caries experiences of the children had a descendant rate and in year 1991 the mean DMFT score was 2.6 (29% of the children had caries free dentition). However, due to the Croatian war for the independence (from 1991 to 1995), annulment of preventive measures and privatization of dental offices, severity of caries experience increased to the DMFT mean of 3.5 in 1999 (15% of the children had caries free dentition) (). An equally descending trend of severity of caries experience from year 1985 to 1992 has been perceived in the city of Zagreb, where 6-year olds had mean dmft score 5.9 in 1985 and 4.4 in 1992. Also, the prevalence of children with the caries free dentition increased in the same period from 16 to 27% ().

Severity of caries experience in Croatia has an increasing rate in relation to age (from age of 7 until 14), but has no relation to gender (). In 2009, children and adolescents, aged 11-14 and 15-18 in year 2006 in the city of Zagreb, had slightly higher values of caries experience and severity of active caries in relation to children referred to an orthodontist in this study (, ). Severity of the caries experience in the period from 2013 to 2015 on deciduous teeth of the 6-year olds in Croatia can be monitored by the Central Health Informational System of the Republic of Croatia (Croatian acronym CEZIH). In this period, the mean dmft score was 4.1, whereas for the permanent teeth of 12-year olds, the DMFT score was 4.2 (). In 2015, the Croatian Dental Chamber has conducted a national survey, and as a result the mean DMFT score of 12-year olds was 4.5 (prevalence of active caries was 51%) (). Recently, the countries from the eastern European region, according to the WHO data, have shown a slow but positive trend in caries reduction. In Croatia, this trend was reversed ().

Dental caries and its consequences are the most common reasons for tooth loss in Croatia in every age group. Therefore, it is necessary to raise the public awareness about the importance of having good oral health at every age. General dentists should spend more time educating patients about the maintenance of the good oral hygiene and require regular check-ups so that teeth can be treated timely, if necessary (). In spite of its simplicity and great cost/benefit ratio, preventive teeth sealing is not used to the extent scientific data would recommend. Within the health insurance funds available for dentistry, redistribution from the curative to the preventive measures might be beneficial to the improvement of the oral health.

Conclusions

Oral health of the children and the adolescents who are referred to an orthodontist in Croatia is poor. Out of 3.5 children, one child has caries, and one in 7.5 children has preventive tooth sealant. The referral of the caries active children and adolescents to the orthodontist presents loss of the specialist’s time and postpones the commencement of children’s orthodontic treatment. General dentists should bear in mind the fact that only patients with healthy dentition and good oral hygiene should be referred to an orthodontist. Preventive measures of timely and effective care should be employed.