Prevalence of malocclusions in 8- and 9-year-old children in Germany-Results of the Sixth German Oral Health Study (DMS 6)

Early orthodontic treatment need over a 10-year period and evaluation of short-term intervention stability

OBJECTIVE

Early orthodontic treatment with cost reimbursement within the framework of the German statutory health insurance (GKV) is only possible for a strictly defined malocclusion group as defined by the orthodontic indication groups (KIG). It is not yet clear whether the application of the KIG criteria and corresponding successful early orthodontic interventions result in no or significantly less need for treatment in the late mixed dentition or in the permanent dentition. This study therefore investigated short-term intervention stability from a 10-year-period.

MATERIALS AND METHODS

Between 2009 and 2019, n = 661 patients were diagnosed with indication groups D (increased overjet), M (reversed overjet), B (scissors bite), K (crossbite), or P (lack of space) including orthodontic treatment need. N = 70 patients (35 female, 35 male) met the inclusion criteria of the study and had received early orthodontic treatment with a mean duration of 15.44 ± 2.20 months. Orthodontic indication groups (KIG) were evaluated at the beginning (aged 7.99 ± 1.44 years) and the end of early orthodontic treatment (aged 9.63 ± 1.49 years) and at a voluntary control or the beginning of additional orthodontic treatment (aged 11.85 ± 1.72 years). The evaluation included established procedures for categorization of orthodontic indication groups and their respective classification. Statistics included Chi-square test and Kendall´s tau-b. The level of significance was set at p < 0.05.

RESULTS

The results showed reversed overjet in 44.3% and crossbites in 41.4% of the patients as most common indication for early orthodontic treatment. At the end of early orthodontic treatment, no orthodontic treatment need was present in 87.1%. At the late mixed dentition, the treatment result of early orthodontic treatment was stable in N = 61 out of N = 70 patients.

CONCLUSIONS

The results of our study confirm preventive benefits of early orthodontic treatment, especially in patients with transverse anomalies or reversed overjet.

CLINICAL RELEVANCE

A short-term orthodontic intervention with correct indication during primary or early mixed dentition can prevent or reduce further treatment need during late mixed or permanent dentition, and should therefore not be postponed.

Age-dependent prevalence of malocclusions requiring treatment according to the KIG classification : A multipart cross-sectional study over a 10-year period from the district of Viersen/North Rhine

BACKGROUND AND AIM

Patients with statutory health insurance (SHI) in Germany must undergo an assessment of orthodontic treatment need using the "Kieferorthopädische Indikationsgruppen" (KIG; orthodontic indication groups) classification system since 2002. A treatment need only exists if anomalies of a certain degree of severity are present. The aim of this study was to evaluate the age-dependent prevalence and percentage distribution of KIG grades requiring treatment in patients with SHI before the age of 18 over a 10-year period.

PATIENTS AND METHODS

Between 2012 and 2021, treatment indication existed for 1951 (1025 female, 926 male) out of 2288 patients with SHI in the cohort of this study before the age of 18 according to current SHI guidelines. The KIG classification was based on the highest existing KIG grade. There were no multiple classifications. The patient cohort was divided into three patient groups (PG) according to chronological age for analysis: PG 1 < 10 years of age (early treatment), PG 2 10 to < 13 years of age (main treatment) and PG 3 13 to < 18 years of age (late treatment).

RESULTS

In PG 1 (454 patients), the KIG classifications D (26.5%), K (25.5%), M (19.4%), and P (18.0%) dominated. In PG 2 (998 patients), classifications D (33.2%), predominated, whereas K (7.5%) and M (5.9%) rarely occurred. The classifications E (12.6%) and P (13.3%) appeared quite frequently. Transverse deviations occurred only about half as often in PG 2 as in PG 1 and PG 3. In PG 3 (499 patients), the classification E (17.6%) was particularly common, while P (2.6%) was rare. The proportion of KIG grades 5 decreased depending on age: 19% in PG 1, 13.5% in PG 2, 10.4% in PG 3. The prevalence of sagittal classifications was highest in all age groups (45.9% in PG 1, 39.1% in PG 2, 31.5% in PG 3).

CONCLUSIONS

The distribution of KIG classifications requiring treatment was not homogeneous, but age dependent. The differences were particularly evident in the early treatment group and may be due to the limited applicability of the KIG classification system in patients before late mixed dentition. With increasing age at initial examination, the prevalence of sagittal classifications decreased, while that of vertical classifications increased. Still, the sagittal classifications D and M occurred most frequently in all age groups. The KIG classification D was always the most common in all patients until the age of 18.

A longitudinal study of the probability of developing malocclusion in children using a Bayesian analysis

INTRODUCTION

This study evaluated the probability of developing malocclusions in mixed dentition.

METHODS

A longitudinal study was conducted with 598 children (aged 5 years) in deciduous dentition. The children were followed for 3 years until mixed dentition (aged 8 years). Overjet, overbite, and transversal relations were evaluated. Bayesian models were used to analyze the data and estimate the parameters.

RESULTS

The parameter θ was used for the distributions, indicating the probability of presenting a given condition with a credibility index (ICr) of 95%. After 3 years of follow-up, 121 children were reevaluated. The results showed that children have a high probability of malocclusion in mixed dentition. There was a higher probability of developing an increased overjet in the mixed dentition of 20.5% (ICr 95%, 13.6-28.4) to 48.3% (ICr 95%, 39.1-57.7) and a higher probability of having a normal overbite in the deciduous dentition and a lower probability in the mixed dentition (ICr 95%, 9.2-21.3).

CONCLUSIONS

Considering the probabilistic model of Bayesian analysis, children with normal overjet in the deciduous dentition may show an increased overjet in the mixed dentition. Concerning overbite, children may present an anterior open bite during the transition between deciduous and mixed dentition, as well as self-correction of deep overbite in mixed dentition. Furthermore, they may present a posterior crossbite during the mixed dentition when there is a normal transverse relationship in the deciduous dentition.

Prevalence of malocclusions requiring treatment according to the KIG classification : A multipart cross-sectional study over a 20-year period in the district of Viersen/North Rhine

BACKGROUND AND AIM

In Germany, the reimbursement of orthodontic treatment costs within the framework of the statutory health insurance (GKV) was restricted on 01 January 2002 by the introduction of the orthodontic indication groups (KIG). The aim of this study was to evaluate the prevalence of findings requiring treatment in a specialist practice over a 20-year period. The results were then compared with data from existing older studies.

PATIENTS AND METHODS

The distribution of treatment-eligible KIG (KIG classifications grades 3-5) among patients with statutory health insurance in an orthodontic practice in North Rhine was determined over a 20-year period (2002-2021) after the introduction of the KIG system. This period was additionally scrutinized in four 5‑year periods according to the operating cycles of the practice. Findings were classified into the highest of 19 possible KIG treatment needs levels. Multiple classifications were not made.

RESULTS

Orthodontic treatment was indicated in a total of 4537 (2393 female, 2144 male) patients according to current statutory health insurance guidelines. The KIG classification "D" (increased overjet) was the most frequent within the observed 20 years with 24.3%. Among 11 KIG classifications, 86.1% of the 6 most frequent and 13.9% of the 5 rarest findings were observed constantly over all periods. Of 19 possible indications, "D4" was the most frequent with 19.6%. Of 4537 patients, 20.7% had KIG grade 3, 63.6% KIG grade 4 and 15.7% KIG grade 5. The prevalence of sagittal deviations "D" and "M" was 35.0%, transverse "B" and "K" 17.9% and vertical "O" and "T" 3.7%. Tooth position anomalies "E" and "P" had a share of 24.6%.

CONCLUSIONS

The present study confirms existing findings as well as the nationwide data of the National Association of Statutory Health Insurance Dentists (KZBV) from 2020: The sagittal deviations "D" (increased overjet) and "M" (negative overjet) represented the most frequent findings with KIG D4 as the most common classification. The prevalence and age distribution of KIG grades 3-5 requiring treatment corresponded to nationwide comparative data.

Initial arch wires used in orthodontic treatment with fixed appliances

BACKGROUND

Initial arch wires are the first arch wires inserted into fixed appliance at the beginning of orthodontic treatment. With a number of different types of orthodontic arch wires available for initial tooth alignment, it is important to understand which are most efficient and which cause the least amount of root resorption and pain during the initial aligning stage of treatment. This is the third update of a Cochrane review first published in 2010.

OBJECTIVES

To assess the effects of initial arch wires for the alignment of teeth with fixed orthodontic braces, in terms of the rate of tooth alignment, amount of root resorption accompanying tooth movement, and intensity of pain experienced by patients during the initial alignment stage of treatment.

SEARCH METHODS

We searched Cochrane Oral Health's Trials Register, CENTRAL, MEDLINE, Embase, and two ongoing trials registries on 4 July 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of different initial arch wires used to align teeth with fixed orthodontic braces. We included people with full-arch fixed orthodontic appliances on the upper arch, lower arch, or both arches.

DATA COLLECTION AND ANALYSIS

Two independent review authors were responsible for study selection, data extraction, and assessment of risk of bias in included studies. We contacted corresponding authors of included studies to obtain missing information. We resolved disagreements by discussion between the review authors. Our main outcomes were alignment rate (movement of teeth in mm), root resorption, time to alignment, and intensity of pain measured on a 100-mm visual analogue scale (VAS). We pooled data from studies with similar interventions and outcomes using random-effects models. We reported mean differences (MDs) with 95% confidence intervals (CIs) for continuous data, risk ratios (RRs) with 95% CIs for dichotomous data, and alignment rate ratios with 95% CIs for time-to-event data. Two independent review authors assessed the certainty of evidence. We resolved disagreements by discussion between the review authors.

MAIN RESULTS

We included 29 RCTs with 1915 participants (2581 arches) in this review. Studies were generally small (sample sizes ranged from 14 to 200 participants). Duration of follow-up varied between three days and six months. Eleven studies received funding, six received no funding, and 12 provided no information about funding sources. We judged eight studies at high risk of bias, nine at low risk, and 12 at unclear risk. We grouped the studies into six main comparisons. Multistrand stainless steel wires versus wires composed of other materials Six studies with 409 participants (545 arches) evaluated multistrand stainless steel (StSt) wires versus wires composed of other materials. We are very uncertain about the effect of multistrand StSt wires versus other wires on alignment rate (4 studies, 281 participants, 417 arches; very low-certainty evidence). There may be little to no difference between multistrand StSt wires and other wires in terms of intensity of pain (MD -2.68 mm, 95% CI -6.75 to 1.38; 2 studies, 127 participants, 127 arches; low-certainty evidence). Conventional nickel-titanium wires versus superelastic nickel-titanium wires Four studies with 266 participants (274 arches) evaluated conventional nickel-titanium (NiTi) wires versus superelastic NiTi wires. There may be little to no difference between the different wire types in terms of alignment rate (124 participants, 124 arches, 2 studies; low-certainty evidence) and intensity of pain (MD -0.29 mm, 95% CI -1.10 to 0.52; 2 studies, 142 participants, 150 arches; low-certainty evidence). Conventional nickel-titanium wires versus thermoelastic copper-nickel-titanium wires Three studies with 210 participants (210 arches) evaluated conventional Ni-Ti versus thermoelastic copper-nickel-titanium (CuNiTi) wires. We are very uncertain about the effects of the different arch wires on alignment rate (1 study, 66 participants, 66 arches; very low-certainty evidence). There may be little to no difference between conventional NiTi wires and thermoelastic CuNiTi wires in terms of time to alignment (alignment rate ratio 1.30, 95% CI 0.68 to 2.50; 1 study, 60 participants, 60 arches; low-certainty evidence). Superelastic nickel-titanium wires versus thermoelastic nickel-titanium wires Twelve studies with 703 participants (936 arches) evaluated superelastic NiTi versus thermoelastic NiTi wires. There may be little to no difference between superelastic NiTi wires and thermoelastic NiTi wires in alignment rate at four weeks (MD -0.28 mm, 95% CI 0.62 to 0.06; 5 studies, 183 participants, 183 arches; low-certainty evidence). We are very uncertain about the effects of the different wires on root resorption (2 studies, 52 participants, 312 teeth; very low-certainty evidence). Superelastic NiTi wires compared with thermoelastic NiTi wires may result in a slight increase in time to alignment (MD 0.5 months, 95% CI 0.21 to 0.79; 1 study, 32 participants, 32 arches; low-certainty evidence) but are probably associated with a slight increase in intensity of pain (MD 6.96 mm, 95% CI 1.82 to 12.10; 3 studies, 94 participants, 138 arches, moderate-certainty evidence). Single-strand superelastic nickel-titanium wires versus coaxial superelastic nickel-titanium wires Three studies with 104 participants (104 arches) evaluated single-strand superelastic NiTi versus coaxial superelastic NiTi wires. Use of single-strand superelastic NiTi wires compared with coaxial superelastic NiTi wires probably results in a slight reduction in alignment rate at four weeks (MD -2.64 mm, 95% CI -4.61 to -0.67; 2 studies, 64 participants, 64 arches, moderate-certainty evidence). Different sizes of nickel-titanium wires Two studies with 149 participants (232 arches) compared different types of NiTi wires. There may be little to no difference between different sizes of NiTi wires in terms of pain (low-certainty evidence).

AUTHORS' CONCLUSIONS

Superelastic NiTi wires probably produce slightly more pain after one day than thermoelastic NiTi wires, and single-strand superelastic NiTi wires probably have a lower alignment rate over four weeks compared with coaxial superelastic NiTi wires. All other evidence on alignment rate, root resorption, time to alignment, and pain is of low or very low certainty in all comparisons. Therefore, there is insufficient evidence to determine whether any particular arch wire material or size is superior to any other. The findings of this review are imprecise and unreliable; well-designed larger studies are needed to give better estimates of the benefits and harms of different arch wires. Orthodontists should exercise caution when interpreting the findings of this review and be prepared to adapt their treatment plans based on individual patient needs.

Prevalence of KIG-grades 3-5 in an orthodontic practice in North Rhine Westphalia compared with results of the DMS•6 and with KZBV data

BACKGROUND AND AIM

The prevalence of tooth and jaw malocclusions in 8- to 9-year-olds was surveyed in a nationwide setting as part of the orthodontic module of the Sixth German Study on Oral Health (DMS•6), using the orthodontic indication groups (KIG) as index. Aim of this study was the detection of the prevalence of malocclusions requiring treatment according to the KIG index in statutorily insured patients of an orthodontic practice in North Rhine Westphalia, Germany, and to compare results with corresponding DMS•6 and KZBV data.

PATIENTS AND METHODS

Between 2017-2021, n = 953 statutorily insured patients called for an initial consultation and subsequent determination of the KIG-classification and -grades. The malocclusions were classified and graded in the highest possible KIG-grade according to valid SHI guidelines. Multiple classifications were not recorded. KIG-grade > 3 according to the valid guidelines was detected in n = 815 patients. Since the DMS•6 does not contain information on KIG classifications "U" and "S", their inclusion was waived despite evaluation, leaving data from n = 683 patients for analysis and comparison.

RESULTS

During the study period, n = 235 patients (34.4%) had KIG-classification "D". More than 10% were classified as "K" (120 patients, 17.6%), "P" (98 patients, 14.2%), "M" (89 patients, 13.0%), and "E" (81 patients, 11.9%). Of 16 possible classifications with KIG-grade > 3, "D4" was the most common with 26.6% (182 patients). The results confirm the findings from the multicentric DMS•6 from2021 and corresponding KZBV data from 2020.

CONCLUSIONS

Sagittal deviations described by classifications "D" and "M" represent with 47.4% almost half of the malocclusions with treatment need. KIG-grade D4 is the most frequent classification. There were no regional deviations of the prevalence of KIG-grades 3-5 in the district of Viersen / North Rhine compared with the national average, not even when scrutinizing a five-year-period.

Chewing ability and associated factors in older adults in Germany. Results from GEDA 2019/2020-EHIS

BACKGROUND

Oral well-being is an important component of general well-being and quality of life, as it is greatly influenced by the ability to chew and speak, and thus by central factors of social interaction. Because quality of life and participation are important factors for health in older age, the aim of this article was to examine the chewing ability, including associated factors, for the older population in Germany on the basis of a nationally representative sample.

METHODS

Database is the German Health Update (GEDA 2019/2020-EHIS), a population based cross-sectional survey of the Robert Koch Institute. In the telephone interview, participants aged 55 years and older were asked: "Do you have difficulty biting and chewing on hard foods such as a firm apple? Would you say 'no difficulty', 'some difficulty', 'a lot of difficulty' or 'cannot do at all/ unable to do'?" Prevalences and multivariate prevalence ratios (PR) were calculated with 95% confidence intervals (95% CI) from log-Poisson regressions. Sociodemographic, health-, behavioral- and care-related characteristics were investigated as associated factors.

RESULTS

The analyses were based on data from 12,944 participants (7,079 women, 5,865 men). The proportion of people with reduced chewing ability was 20.0%; 14.5% had minor difficulty, 5.5% had major difficulty. There were no differences between women and men. The most important associated factors for reduced chewing ability were old age (PR 1.8, 95% CI 1.5-2.1), low socioeconomic status (PR 2.0, 95% CI 1.7-2.5), limitations to usual activities due to health problems (PR 1.9, 1.6-2.2), depressive symptoms (PR 1.7, 1.5-2.1), daily smoking (PR 1.6, 95% CI 1.3-1.8), low dental utilization (PR 1.6, 95% CI 1.4-1.9), and perceived unmet needs for dental care (PR 1.7, 95% CI 1.5-2.1).

CONCLUSIONS

One fifth of adults from 55 years of age reported reduced chewing ability. Thus, this is a very common functional limitation in older age. Reduced chewing ability was associated with almost all investigated characteristics. Therefore, its prevention requires a holistic view in the living environment and health care context of older people. Given that chewing ability influences quality of life and social participation, maintaining or improving chewing ability is important for healthy aging.

Frequency and severity of malocclusions in patients with statutory health insurance in a German orthodontic practice in North Rhine Westphalia - a multi-part cross-sectional study over a 20-year period

OBJECTIVE

Since 2002, patients with statutory health insurance in Germany must undergo an assessment of orthodontic treatment need using the "Kieferorthopädische Indikationsguppen" (KIG; orthodontic indication groups) classification system. According to this system, tooth and jaw misalignment are divided into 11 subgroups and five grades. The objectives of this study were to determine the distribution of KIG classifications in patients with statutory insurance of a German orthodontic practice (North Rhine, Germany) and to analyze changes over a 20-year period.

MATERIALS AND METHODS

Since the introduction of the KIG index in 2002, 4940 statutorily insured patients over a 20-year period (2330 m, 2610 f, min 3.2, max 49.5 years, peak between 10 and 12 years) were classified at their first appointment. According to the valid guidelines of the statutory health insurance (GKV), the division was made into the highest possible KIG classification. Multiple entries were thus not made. In accordance with the operating cycles of the practice, the progression was divided into four 5-year periods.

RESULTS

Over a 20-year period, 24.98% of the patients were assigned to the classification "D". 86.52% of the patients were among the 6 most frequently ("D", "E", "K", "S", "P" and "M", > 10% each) and only 13.49% among the 5 least frequently recorded classifications ("U", "B", "T", "O" and "A", < 5% each).

CONCLUSION

The distribution of the 6 most frequent and the 5 least frequent KIG classifications was constant over a 20-year-period. Among all possible tooth and jaw misalignment variants, the sagittal classifications "D" and "M" represent the most frequent malocclusions.

CLINICAL RELEVANCE

The results and their comparison with historical data show that both frequency and severity of tooth and jaw misalignment with orthodontic treatment need appear identical for patients with statutory health insurance over a 20-year period.