Individual changes in malocclusion from adolescence to 35 years of age

Published evidence regarding association between malocclusion and orthodontic treatment on oral health is inconclusive

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

Macey R, Thiruvenkatachari B, O'Brien K, Batista KBSL. Do malocclusion and orthodontic treatment impact oral health? A systematic review and meta-analysis. Am J Orthod Dentofacial Orthop. 2020;157(6):738-744.e10. doi:10.1016/j.ajodo.2020.01.015.

SOURCE OF FUNDING

Government: Public Health England or the National Health Service.

TYPE OF STUDY/DESIGN

Systematic review with meta-analysis of data.

Relapse of incisor crowding: a visit to the Prince of Salina

The management of the retention period after comprehensive orthodontic treatment is of great importance, as a primary goal of clinician. Considerable controversy still surrounds the problem of stability after the retention period. Many studies analyze factors associated to the presence of crowding or incisor irregularity and find predictive features on its relapse. Most studies have reported little o no correlation between the treatment changes in the biological parameters - clinical, biometric (irregularity index, intermolar width, intercanine width, arch length, overjet, overbite), or cephalometric variables- that ocurred and the posttretament and postretention changes that may predict their future development. This article provides a bibliographical overview on the relapse of dental alignment in treated cases. In a brief historical introduction, the first studies on the long-term stability of orthodontic results are analysed. The article then goes on to assess studies that focus attention on anteroinferior alignment before finally studying relapse of upper crowding. It concludes by making some final comments in the light of the bibliography provided and the differents schools regarding retention needs and methods.

Relationship between impacts attributed to malocclusion and psychological stress in young Japanese adults

Identifying risk factors is important to prevent a wide range of health-damaging behaviours and to improve the quality of life of young people. The aim of this study was to investigate the relationship between impacts on daily performance attributed to malocclusion and psychological stress in healthy young Japanese adults. Medical and oral health data were collected during a cross-sectional examination conducted by the Health Service Center of Okayama University. Systemically healthy non-smoking students aged 18 and 19 years (n = 641; 329 males and 312 females) were included. Malocclusion was defined using a modified version of the Index of Orthodontic Treatment Need (IOTN). The impacts on daily performance attributed to malocclusion and psychological stress were assessed using self-reported questionnaires, the condition-specific oral impacts on daily performances (CS-OIDP), and the Hopkins Symptoms Checklist. Mann-Whitney U- and chi-square tests and structural equation modelling (SEM) were used for statistical analysis. Forty per cent of subjects had a malocclusion (n = 255). Subjects with impacts on daily performance had a significantly higher prevalence of malocclusion than those without impacts (P < 0.001). SEM showed that psychological stress, especially interpersonal sensitivity and depression, was significantly correlated with CS-OIDP and malocclusion. Negative impacts on daily performance attributed to malocclusion may contribute to psychological stress in young Japanese adults.

Relationship between malocclusion and heart rate variability indices in young adults: a pilot study

OBJECTIVES

Heart rate variability (HRV) has been used to assess sympathetic and parasympathetic modulation of heart rate. Chronic stress relates to reduced HRV. Malocclusion has effects on quality of life, which can lead to chronic stress. Therefore, we hypothesized that malocclusion, as chronic stress, may contribute to reduced HRV. The aim of this study was to investigate the relationship between malocclusion and HRV indices in healthy young adults.

METHODS

Thirty-seven non-smoking healthy subjects, aged 22 to 25 years, were examined. Malocclusion was defined by Angle classification. HRV indices included root mean square of successive differences, low frequency (LF), high frequency (HF) and ratio of LF to HF. The effects of malocclusion on quality of life and mental health were assessed using self-reported questionnaires, the condition-specific Oral Impacts on Daily Performances index (CS-OIDP) and the Hopkins Symptoms Checklist (HSCL), respectively.

RESULTS

Significantly lower score of HF and higher heart rate (HR) level and CS-OIDP score were observed in subjects with malocclusion (n = 17) compared to those in the control subjects (n = 20) ( P <0.05). There was a positive correlation between HR and score of "anxiety" in HSCL ( P <0.05).

CONCLUSIONS

The data showed an association between malocclusion and lower HRV. Based on our results, orthodontic treatment might contribute not only to improvement of oral esthetic and functional problems but also to improvement of stress and HRV indices.

Long-term development of malocclusion traits in orthodontically treated and untreated subjects

INTRODUCTION

The purposes of this study were to analyze long-term changes in malocclusion traits and to compare the development in orthodontically treated and untreated subjects.

METHODS

The sample comprised 308 adolescents in the intermediate, late mixed, or early permanent dentition who were examined clinically at the ages of 8 to 17 years and again 25 years later. The treated subgroup of 58 subjects had received orthodontic treatment with fixed or removable appliances or both. All subjects had a full complement of teeth, except a subgroup of 19 who had premolar extractions as a part of their orthodontic treatment plan.

RESULTS

The prevalence of maxillary overjet was significantly reduced in the untreated group and the treated subgroups. The prevalence of distal molar occlusion was significantly reduced in the subgroup treated without extractions. Comparison of treated and untreated groups in terms of changes over time showed that development was significantly more favorable in all treatment categories regarding maxillary overjet, and in the nonextraction category regarding distal molar occlusion. Subjects treated without extractions had less favorable development than did untreated subjects regarding molar crossbite.

CONCLUSIONS

The long-term benefit of orthodontic treatment, with or without extractions, was confirmed regarding maxillary overjet, and the lasting effect of nonextraction treatment was confirmed regarding the distal molar relationship. The pattern of changes in treated and untreated subjects indicated that long-term development and individual variation can to some extent conceal the effects of a brief orthodontic intervention.

Development of occlusal traits and dental arch space from adolescence to adulthood: a 25-year follow-up study of 245 untreated subjects

INTRODUCTION

The purpose of this study was to examine longitudinally the development of specific occlusal traits and space conditions in an Icelandic sample.

METHODS

The sample comprised 245 adolescents examined clinically in the late mixed or permanent dentition and again 25 years later. All subjects were orthodontically untreated, and all had the full complement of teeth at both examinations.

RESULTS

A significant increase in the prevalence of mandibular anterior crowding and mesial molar relationships and a decrease in the prevalence of excessive overjet and maxillary anterior spacing were seen. The persistence of malocclusion traits ranged from 17.9% to 53.4% for maxillary anterior spacing and crowding, mandibular spacing, overjet, overbite, and distal molar occlusion, whereas anterior mandibular crowding and molar crossbite were still found in 72.7% and 75.0%, respectively, at the second examination. Normal occlusal traits and space conditions at adolescence stayed mostly unchanged, with the exception of 11.2% of the subjects, who developed mandibular anterior crowding between the first and second examinations.

CONCLUSIONS

Deterioration of normal occlusal traits and space relationships was uncommon in this study, whereas self-correction of malocclusion traits and space anomalies was relatively frequent.

Patients' perceptions, treatment need, and complexity of orthodontic re-treatment

The aim of the present study was to investigate the subjective perception and objective treatment need and complexity of patients seeking orthodontic re-treatment. One hundred subjects (66 females, 34 males, age 26.7+/-8.2 years) seeking re-treatment were asked to complete a questionnaire which was constructed based on pilot interviews with 15 patients. The questions focussed on treatment experiences, retention procedures following the first course of treatment, and expectations of and motivations for re-treatment. A visual analogue scale (VAS 0-10) was used. The 're-treatment' group was matched with an untreated control group by age, gender, and the first consultation date. The study models of both groups were scored with the Index of Complexity, Outcome, and Need (ICON). Analysis of variance was used for across-time comparisons of VAS scores of patient's perception of their dental appearance, paired t-test for comparisons of the motivation VAS scores between the first treatment and re-treatment, and Mann-Whitney test for comparisons between the re-treatment and control groups. Eighty-eight patients (26.3+/-8.4 years) completed the questionnaire. After the initial treatment, 36 per cent of the patients did not have any retention measures. The mean VAS scores for dental aesthetics at the start and end of the initial treatment were 2.3+/-2.1 and 6.6+/-2.7, respectively. The scores for the present situation and expected results of re-treatment were 4.1+/-2.7 and 8.8+/-1, respectively. These scores differed significantly from each other. Seventy-nine pairs of models were matched for evaluation of treatment need and complexity. The mean ICON scores of the re-treatment group were significantly lower than the controls (45+/-21 versus 57+/-24), the aesthetic component being the main contributing factor to this difference (25+/-16 versus 36+/-18). Both groups showed a treatment need (ICON>43), with the untreated controls having a relatively higher complexity. These results indicate that patients seeking re-treatment had a good perception of dental aesthetics, strong motivation, and an objective treatment need.

Are malocclusions more prevalent and severe now? A comparative study of medieval skulls from Norway

INTRODUCTION

The prevalence of malocclusion in modern populations is higher than in excavated samples from ancient times. Presently, more than 30% of children and adolescents in the Scandinavian countries receive orthodontic treatment. The aims of this study were to describe the prevalence and severity of malocclusions in a sample of medieval Norwegians, to evaluate the need for treatment by using the Norwegian need for orthodontic treatment index (NOTI), and to compare these findings with a modern sample already analyzed with the same index.

METHODS

The material consisted of 85 male and 61 female medieval skulls from abandoned and later excavated graveyards of 16th century Oslo that were evaluated with the NOTI.

RESULTS

Only 36% of the medieval group showed objective assessed needs for orthodontic treatment, compared with 65% of the present-day sample. Among the skulls, the objective needs for treatment were 27% for the males and 49% for the females. No sex differences related to severity or prevalence of malocclusion were found in the modern sample. The medieval sample arranged according to severity was great need (B), 7%; obvious need (C), 29%; and little/no need (D/E), 64%. The findings in the modern sample were B, 20%; C, 44%; and D/E, 35%. The female skulls showed greater severity and prevalence than the male skulls. No skull had very great need (A).

CONCLUSIONS

This study indicates a significant increase in both the prevalence and the severity of malocclusions during the last 400 to 700 years in Oslo, Norway. Furthermore, although no sex differences were found in the modern sample, females had both a higher prevalence of malocclusions and more severe malocclusions than did males in the past.

Orthodontic treatment experience and prevalence of malocclusion traits in an Icelandic adult population

INTRODUCTION

The objectives of this study were to record the extent of orthodontic treatment and the prevalence of occlusal anomalies in an adult sample in Iceland.

METHODS

The study was based on a random sample of 829 subjects, 342 men and 487 women, aged 31 to 44 years, who completed questionnaires about their orthodontic treatment experiences and were available for clinical examination.

RESULTS

Complete dentitions in both jaws were present in 52.8% of the women and 45.3% of the men at the examinations. Significantly higher percentages of the women had received orthodontic treatment of some kind (24.3% compared with 16.9% for the men) and treatment with fixed appliances (16.0% compared with 9.5% for the men). Malocclusion traits were recorded with a standardized method, describing sagittal and vertical incisor relationships, sagittal and transverse molar relationships, and mandibular and maxillary space conditions. The results showed that 45.5% of the subjects had no malocclusions, 33.9% had 1 malocclusion trait, and 20.5% had 2 to 4 traits. The most frequent malocclusion traits were distal molar occlusion (27.7%), mandibular anterior crowding (13.4%), molar crossbite (11.9%), excessive overbite (11.8%), maxillary anterior crowding (7.1%), mesial molar occlusion (6.9%), and excessive overjet (5.3%). The prevalences of mandibular overjet, mesial occlusion, and scissors-bite were significantly higher in the men than in the women.

CONCLUSIONS

The prevalences of malocclusion traits were similar in treated and untreated subjects, except for a significantly lower prevalence of overjet and a higher prevalence of molar crossbite in the treated group. Comparison with other studies showed low prevalences of overjet, overbite, open bite, and maxillary and mandibular spacing and crowding; other variables fell within the ranges of prevalence in previous surveys.

The impact of malocclusion and its treatment on quality of life: a literature review

AIM

The aim of this paper is to review the literature relating to the impact of malocclusion, and the treatment of malocclusion, on physical, social and psychological health (i.e. quality of life, QoL).

DESIGN

English-language papers, including cross-sectional studies, retrospective and prospective longitudinal studies, randomized controlled trials, and reviews and meta-analyses were reviewed to determine the impact of malocclusion and its treatment on QoL.

RESULTS

Malocclusion and its treatment can affect physical health in terms of pain (e.g. temporomandibular disorders, and dental and gingival trauma), speech and mastication. In terms of psychological health, malocclusion and its treatment is reported to affect self-concept. Socially, malocclusion and its treatment can affect perceived attractiveness by others, social acceptance and perceived intelligence. However, the evidence is conflicting owing to differences in study designs, population's studied and methods of assessment of psychical, social and psychological health.

CONCLUSION

Much controversy exists about the impact of malocclusion and its treatment on QoL. There is a need for a more comprehensive and rigorous assessment of the impact of malocclusion and its treatment on QoL, employing standardized, valid and reliable data collection instruments.

[The functional treatment of deep bite--the results of a long-term study]

The amount of overbite reduction and the stability of the results three to 14.5 years post-retention were analysed in a follow-up study of 60 patients who had been treated with functional appliances. To establish therapeutic and posttherapeutic changes in dento-facial relationships, plaster casts and lateral cephalograms were evaluated at the beginning, at the end of treatment and at the follow-up examination. Posttherapeutic deepening of the overbite (> 0.8 mm) was found in 54.2% of the cases, while overbite reduction remained stable in 39%. A number of skeletal and dental factors were found to be involved in overbite reduction and posttreatment deepening. In this connection, changes in the ML-NSL angle, the ML-NL angle and the gonion angle were found to be just as important as the therapeutic and posttherapeutic changes in anterior and posterior facial height and changes in the skeletal pattern. It is emphasized that strict application of retention is of the greatest importance to minimize vertical relapse.

The mandibular third molar and late crowding of the mandibular incisors--a review

The role of the mandibular third molar in late incisor crowding remains controversial. Detailed examination of frequently quoted studies indicates a small, but statistically significant relationship. The clinical relevance of this is discussed.

Mandibular dysfunction in adulthood in relation to morphologic malocclusion at adolescence

The purpose of this 20-year follow-up study was to assess whether pronounced morphologic traits of malocclusion, persisting from adolescence to about 35 years of age, imply an increased risk of persistent and severe mandibular dysfunction. In 1965-66 malocclusion was recorded in 176 adolescents; in 1981 these persons responded to a questionnaire concerning symptoms of functional disorders, and in 1986-87 malocclusion and signs of dysfunction were registered. Highly significant associations were observed between some of the self-reported symptoms and the signs registered 5-6 years later. Spearman correlation coefficients between the persistent traits of malocclusion, occurring at both examinations, and the signs of mandibular dysfunction were low in general. No association was found between the most severe and persistent functional disorders and any particular malocclusion. It is concluded that orthodontic screening of morphologic malocclusion in childhood would seem of limited value in attempts to predict mandibular dysfunction in adulthood.

Causal relation between malocclusion and caries

In this second report of a follow-up study of long-term adverse oral health effects of malocclusion it is assessed whether various occlusal and space anomalies imply an increased risk of caries. In 1965-66 malocclusion was recorded in 176 adolescents who were re-examined in 1986-87 at the age of 33-39 years. DMFS scores, in the dentition as a whole and in the segments of the dental arches, were compared between subjects displaying specified traits of malocclusion at both examinations and a comparison group comprising subjects without malocclusion at both examinations. No relationship was found between the malocclusion traits and caries prevalence.

Causal relation between malocclusion and periodontal health

The purpose of this 20-year follow-up study was to assess whether persistent traits of morphologic malocclusion imply an increased risk of periodontal disease. In 1965-66 malocclusion was recorded in 176 adolescents who were re-examined in 1986-87 at the age of 33-39 years. Markedly healthier periodontal conditions were found in women than men, in the higher social group than the lower one, and in the maxilla than the mandible. Subjects with specified malocclusion traits at both examinations were compared with subjects without malocclusion for the occurrence of calculus, gingivitis (bleeding), and pocketing. Controlling for the effect of sex and social group, periodontal disease was significantly more frequent in the maxilla in connection with crowding, extreme maxillary overjet, and cross-bite (p less than 0.05). No association was found in the mandible. The presence of certain malocclusion traits in adolescence may probably often call for special professional efforts of oral hygiene education rather than orthodontic therapy.