A 57-year follow-up of occlusal changes, oral health, and attitudes toward teeth

The consequences of living with a severe malocclusion: A review of the literature

AIM

To facilitate the orthognathic shared decision-making process by identifying and applying existing research evidence to establish the potential consequences of living with a severe malocclusion.

METHODS

A comprehensive narrative literature review was conducted to explore the potential complications of severe malocclusion. A systematic electronic literature search of four databases combined with supplementary hand searching identified 1024 articles of interest. A total of 799 articles were included in the narrative literature review, which was divided into 10 themes: Oral Health Related Quality Of Life; Temporomandibular Joint Dysfunction; Masticatory Limitation; Sleep Apnoea; Traumatic Dental Injury; Tooth Surface Loss; Change Over Time; Periodontal Injury; Restorative Difficulty; and Functional Shift and Dual Bite. A deductive approach was used to draw conclusions from the evidence available within each theme.

RESULTS

The narrative literature review established 27 conclusions, indicating that those living with a severe malocclusion may be predisposed to a range of potential consequences. With the exception of Oral Health Related Quality Of Life, which is poorer in adults with severe malocclusion than those with normal occlusions, and the risk of Traumatic Dental Injury, which increases when the overjet is >5 mm in the permanent and 3 mm in the primary dentition, the evidence supporting the remaining conclusions was found to be of low to moderate quality and at high risk of bias.

CONCLUSION

This article summarises the findings of a comprehensive narrative literature review in which all of the relevant research evidence within a substantive investigative area is established and evaluated. Notwithstanding limitations regarding the quality of the available evidence; when combined with clinical expertise and an awareness of individual patient preferences, the conclusions presented may facilitate the orthognathic shared decision-making process and furthermore, may guide the development of the high-quality longitudinal research required to validate them.

Occlusal changes in orthodontically treated subjects 40 years after treatment and comparison with untreated control subjects

INTRODUCTION

The objective of this study was to compare the aging changes of the dental arches in orthodontically treated and untreated subjects after a 4-decade follow-up period.

METHODS

This retrospective study analyzed 2 groups. The treated group comprised 29 patients (11 male, 18 female) presenting with Class I or Class II malocclusions orthodontically treated with extractions of 4 first premolars. Dental models taken at pretreatment (12.84 years), posttreatment (14.95 years), and long-term posttreatment (51.37 years) were evaluated. The untreated (control) group consisted of 22 untreated patients with dental models taken at 13.32, 17.82, and 60.95 years of age. The dental models were digitized, and the following variables were evaluated: Little irregularity index, intercanine, interpremolar and intermolar widths, arch length, arch perimeter, overjet, and overbite. Interphase comparison of the treated group was performed with repeated measures analysis of variance and Tukey tests. Intergroup comparisons were performed using t tests (P <0.05).

RESULTS

Crowding was corrected with treatment but relapsed significantly in the long term. Intercanine width increased with treatment and decreased in the long term. Interpremolar and intermolar widths, arch perimeter, and length decreased with treatment and continued to decrease long-term posttreatment. Overjet and overbite were corrected with treatment and remained stable in the long term. From posttreatment to long-term posttreatment, a greater crowding increase was observed in the treated group than in the untreated group. The treated group demonstrated a greater decrease in mandibular intercanine and maxillary and mandibular interpremolar widths than the untreated sample. Overbite increased in the treated group and decreased in the untreated group. The multiple regression analysis showed that previous 4-premolar extractions orthodontic treatment is significantly associated with anterior crowding in the long term.

CONCLUSIONS

In the long-term, the treated patients showed relapse of crowding and a decrease in arch form. Long-term changes of treated patients were different from untreated subjects. Relapse might have contributed to greater changes in incisor crowding and arch widths observed in the treated patients.

[Long-term stability and relapse of deep bite correction: a systematic review]

INTRODUCTION

 Deep overbite is one of the most common malocclusions and is the most difficult to treat successfully. The real challenge remains the stability of long-term deep overbite correction. A search through the scientific literature revealed only one systematic review on this subject. Given the recent publications on the stability of deep bite correction and the development of new processes designed to avoid relapse of these treatments, this one existing systematic review needs to be updated. The purpose of the present systematic review is to evaluate the long-term stability of deep overbite correction.

MATERIALS AND METHODS

 Electronic databases were searched and nonelectronic journals were manually explored for papers on long-term stability and relapse of deep overbite correction. Articles deemed appropriate for inclusion in this review were selected and analyzed. Their scientific quality was assessed and the data they contained were extracted and summarized.

RESULTS

 The rate of deep overbite relapse was 47.27%. Patients treated with the straight wire appliance showed a 67.74% relapse rate whereas those treated with the Ricketts biological progressive segmented mechanics appliance displayed a 30.38% rate. Subjects treated towards the end of adolescence presented a 14.3% rate of deep overbite relapse whereas those treated in their early teens or in adulthood had a deep overbite relapse rate of 30% and 30.8%, respectively. Intramuscular injections of botox helped obtain 100% stability in maxillofacial surgery to correct deep bite.

CONCLUSION

 Age at initiation of treatment and treatment technique are two factors impacting the long-term stability of deep overbite correction.

Prevalence of malocclusion and occlusal traits in the early mixed dentition in Shanghai, China

Background

Epidemiological data on malocclusion among Chinese children are scant. The aim of this study was to provide detailed information on the prevalence of malocclusion in early mixed dentition children in Shanghai, China.

Methods

A cross-sectional survey was conducted from September 2016 to April 2017, and 2,810 children aged 7- to 9- years were selected from 10 primary schools by cluster random sampling. Several occlusal parameters, including Angle molar relationship, overjet, overbite, open bite, anterior and posterior crossbite, midline displacement, scissors bite, and teeth crowding and spacing, were clinically registered by five calibrated orthodontic dentists.

Results

We found that 79.4% children presented one or more occlusal anomalies. Angle Class I, Class II and Class III molar relationship were recorded in 42.3%, 50.9% and 5.9% of the sample, respectively. The proportion of Class III increased from 5.0% at age 7 to 7.8% at age 9. In the sagittal plane, increased overjet >3 mm was observed in 40.8% subjects, while the prevalence of severe overjet (>8 mm), anterior edge-to-edge (zero overjet) and anterior crossbite were 5.2%, 8.1% and 10.5%, respectively. Vertically, deep overbite >2/3 overlap was found in 6.2% of the children and open bite in 4.3%. Boys exhibited a higher rate of overbite than girls. For the transversal occlusal anomalies, 36.1% of the children had a midline displacement, which was followed by posterior crossbite (2.6%) and scissors bite (1.0%). Teeth space discrepancies were also common anomalies and anterior crowding (>2 mm) affecting 28.4% of the children, while anterior spacing (>4 mm) affecting 9.5%. Girls showed a higher prevalence of anterior crowding and a lower frequency of teeth spacing than boys.

Conclusions

Our study demonstrated that malocclusion is prevalent among children in the early mixed dentition, and more health resources should be warranted to meet the challenge of prevention or early intervention of malocclusion.

Aging of the normal occlusion

OBJECTIVES

The aim of this study was to evaluate the qualitative occlusal changes in individuals with normal occlusion during a period of 47 years.

MATERIALS AND METHODS

The sample comprised dental models of 20 subjects with normal occlusion (8 males; 12 females) taken at 13.2 years (T1) and 60.9 years of age (T2). The occlusal features were evaluated with the objective grading system (OGS) and with the six keys to normal occlusion (SKNO). The subjects also answered a questionnaire on the aesthetic and occlusal self-perception at T2. Comparisons from T1 to T2 were performed with paired t- and McNemar tests (P less than 0.05).

RESULTS

OGS analysis showed a significant improvement in the marginal ridge levelling and tooth buccolingual inclination. There was a significant deterioration of the antero-posterior occlusal relationship from T1 to T2. Subjects without tooth loss showed a dental alignment worsening between time points. The marginal ridges, buccolingual inclination, and interproximal contacts improved. The SKNO analysis showed a significant deterioration of the maxillary second molars buccolingual inclination and an improvement of the maxillary second molar angulation. All patients were satisfied with their smiles, and 60 per cent of the subjects had no complaints. Dental crowding caused dissatisfaction in 35 per cent of the sample.

LIMITATIONS

A limitation of this study was the high prevalence of tooth loss in the sample from T1 to T2. Only 30 per cent of the subjects had no tooth loss in T2.

CONCLUSIONS

The aging process slightly deteriorates some occlusal features of individuals with normal occlusion. However, most individuals were satisfied with their aesthetics and occlusal comfort at the sixth decade of life.

The association between palatal rugae pattern and dental malocclusion

Introduction:

Palatal rugae complete its development during early intrauterine life, whereas dental malocclusions in permanent dentition establishes several years into the post-natal life.

Objective:

The objective of present study was to determine if there is an association between the palatal rugae pattern and Angle’s classes of malocclusion.

Methods:

A cross-sectional study was conducted on pretreatment dental casts of 184 patients. The sample was divided into the following groups: Class I, Class II div. 1, Class II div. 2, and Class III. The number of palatal rugae was recorded, bilaterally. The length, pattern and orientation of three anterior-most primary rugae on both sides were recorded.

Results:

The mean age of the study sample was 17.8 ± 5.4 years. The mean number of the palatal rugae was 11.18 ± 2.5, with significant differences among different malocclusion groups. The length of the first rugae on left side and third rugae on both sides varied significantly among the groups (p< 0.05). Similarly, the pattern of palatal rugae was also found to be significantly different among the malocclusion groups. The right sided rugae did not have any significant difference in the orientation in different malocclusion groups; however, the left sided rugae showed significant differences among the four malocclusion groups (p< 0.001).

Conclusions:

The current study showed subtle differences in the palatal rugae pattern among the Angle’s classes of malocclusion. Similarly, the length and orientation of some rugae were also found to be significantly different between malocclusion groups.

Long-term effects of Class II orthodontic treatment on oral health

AIM

To investigate the long-term (≥15 years) benefit of orthodontic Class II treatment (Tx) on oral health (OH).

SUBJECTS AND METHODS

All patients (Department of Orthodontics, University of Giessen, Giessen, Germany) who underwent Class II correction (Herbst-multibracket Tx, end of active Tx ≥ 15 years ago) and agreed to participate in a recall (clinical examination, interview, impressions, and photographs) were included. Records after active Tx were used to assess the long-term OH effects. Data were compared to corresponding population-representative age-cohorts as well as to untreated Class I controls without orthodontic Tx need during adolescence.

RESULTS

Of 152 treated Class II patients, 75 could be located and agreed to participate at 33.7 ± 3.0 years of age (pre-Tx age: 14.0 ± 2.7 years). The majority (70.8%) were fully satisfied with their teeth and with their masticatory system. The Decayed, Missing, Filled Teeth Index (DMFT) was 7.1 ± 4.8 and, thus, almost identical to that of the untreated Class I controls (7.9 ± 3.6). In contrast, the DMFT in the population-representative age-cohort was 56% higher. The determined mean Community Periodontal Index (CPI) maximum score (1.6 ± 0.6) was also comparable to the untreated Class I controls (1.7 ± 0.9) but in the corresponding population-representative age-cohort it was 19-44% higher. The extent of lower incisor gingival recessions did not differ significantly between the treated Class II participants and the untreated Class I controls (0.1 ± 0.2 vs. 0.0 ± 0.1 mm).

CONCLUSION

Patients with orthodontically treated severe Class II malocclusions had a lower risk for oral health impairment than the general population. The risk corresponded to that of untreated Class I controls (without orthodontic Tx need during adolescence).

Genetic polymorphisms underlying the skeletal Class III phenotype

INTRODUCTION

Our goal was to verify the association between candidate polymorphisms and skeletal Class III malocclusion in a well-characterized homogeneous sample set.

METHODS

Thirty-five single-nucleotide polymorphisms were studied from 10 candidate loci in 54 Class III subjects and 120 controls. Skeletal Class III characteristics included ANB angle less than 0°, SNB angle greater than 83° (mandibular prognathism), SNA angle less than 79° (maxillary deficiency), Class III molar relationship, and negative overjet. Inclusion criteria for the controls were ANB angle between 0° and 4°, Class I molar relationship, and normal overjet. Chi-square and Fisher exact tests and principal component (PC) analysis were used to determine overrepresentation of marker alleles with alpha of 0.05. Odds ratios and 95% confidence intervals were calculated.

RESULTS

MYO1H (rs10850110 A<G) (P <0.01; odds ratio, 7.44 [4.02-13.77]) was associated with an increased risk for the mandibular prognathism phenotype. These results were confirmed by PC analysis, which showed 4 PCs representing the sample variations (PC1, 37.24%; PC2, 20.02%; PC3, 12.18%; and PC4, 11.40%), and PC1 was associated with MYO1H (P <0.001). We also found by PC analysis associations between MYO1H (P <0.001) and GHR (rs2973015 A>G) (P = 0.001) with PC2 and between FGF10 (rs593307 A<G) (P = 0.001) with PC4.

CONCLUSIONS

Polymorphism in MYO1H could be used as a marker for genetic susceptibility to Class III malocclusion with mandibular prognathism, and polymorphisms in GHR and FGF were associated with maxillomandibular discrepancies. This study may contribute to improved diagnosis and further research assessing possible differences in treatment responses based on genetic polymorphisms.