Do malocclusion and orthodontic treatment impact oral health? A systematic review and meta-analysis

Duration of orthodontic treatment with clear aligners versus fixed appliances in crowding cases: a systematic review

OBJECTIVE

To critically appraise and assess the currently observed evidence about the difference in orthodontic treatment duration between clear aligners and fixed appliances in crowding cases.

MATERIALS AND METHODS

An electronic search without limitations was conducted from inception to June 2023 covering nine databases: The Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Scopus, Web of Science, Google Scholar, Trip, CINAHL via EBSCO, EMBASE via OVID and ProQuest. Randomized controlled trials (RCTs) and matched non-randomized studies were included in this systematic review. Risk of Bias was assessed via Cochrane's tool (RoB 2) for RCTs and ROBINS-I tool for non-randomized studies. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework was employed to evaluate the overall quality of evidence.

RESULTS

Out of the 3537 articles initially identified, ten eligible studies were included in this systematic review; six were RCTs. Only one study offered extraction-based treatment, while the other nine adopted non-extraction treatments. According to the GRADE, there is low evidence that treatment duration in mild to moderate crowding cases with clear aligners is similar to that in fixed orthodontic appliances. Meta-analysis was not administered due to high inconsistency.

CONCLUSIONS

Based on currently available information, there was no significant difference in the treatment duration between the CA and FA groups in mild to moderate crowding cases. Further well-performed RCTs, especially in severe cases, are required.

CLINICAL RELEVANCE

Time efficiency is an essential outcome measure for clinical orthodontic practice. While the type of appliance used is a critical determinant of treatment duration, orthodontists should be aware of other factors that can significantly impact treatment time, such as patient and treatment-related factors.

Electromyography: Processing, Muscles' Electric Signal Analysis, and Use in Myofunctional Orthodontics

Electromyography, commonly known as EMG, utilizes superficial or needle electrodes to record and analyze the fundamental electrical characteristics of skeletal muscles, determining whether the muscles are contracting. The motor unit, which consists of a collection of group muscle fibers and the motor neurons that govern them, is the structural basis of EMG. Three types of electrode are used in EMG which are needle electrode, fine wire electrode, and surface electrode. A significant amount of literature indicates that the correction of muscle function affects the relationships between teeth within the same jaw and between the jaws on opposing sides. The mechanism of action in myofunctional appliance therapy is linked to neuromuscular and skeletal adaptations resulting from altered function in the orofacial region. Both myofunctional therapy and orthodontics aim to address abnormal muscular behavior, restore abnormal muscle activity, and maintain proper alignment in various areas, including the lips, lower jaw, and tongue. This knowledge is essential for functions such as swallowing, speaking, chewing, and respiration as well as for minimizing incorrect movements and positioning. This article aims to describe the application of surface EMG as a diagnosis tool for assessing muscle activities in various orthodontic disorders, such as class II malocclusion open bite, crossbite, maxillary constriction, cleft lip and palate (CLP), and temporomandibular dysfunction, in patients. The electrodes used in EMG can be utilized to detect bioelectric activity in the muscles of the jaws and abnormalities in jaw movement. Analyzing EMG data is vital for obtaining a comprehensive understanding of the masticatory muscle system.

Systematic Review and Meta-Analysis of the Index of Orthognathic Functional Treatment Need for Detecting Subjects with Great Need for Orthognathic Surgery

Index of Orthognathic Functional Treatment Need (IOFTN) Identifies patients with greatest need for orthoganthic surgery. This systematic review looks into the available evidence on prevalence of patients with great treatment need (IOFTN 4&5) who had orthognathic surgery in previous studies. Literature search of the major electronic databases was carried out for articles published between 2014 and September 2023, looking for "Index of Orthognathic Functional Treatment Need","Orthognathic Surgery","IOFTN", "Epidemiology" and "Dentofacial Deformity". The prevalence of patients identified with IOFTN grades of 4&5 was calculated. A random-effect model was employed and the Forest and Galbraith plots were produced. The pooled prevalence estimate for subjects with IOFTN scores of 4&5 was calculated. The heterogeneity among studies was assessed with the I2 statistics. In total, 14 retrospective studies conducted between 2015 and 2019 in 7 countries (UK, New Zealand, Iran, Pakistan, Turkey, Malaysia, Japan) were included, reporting on 1339 orthognathic patients. The sample sizes ranged from 30 to 200. Only 7 studies reported on the subcategories of the IOFTN for grades 1, 2&3. The prevalence of orthognathic patients with IOFTN scores of 4 & 5 ranged from 79% to 100%. The heterogeneity I2 statistics was 16%. The pooled prevalence estimate for subjects with IOFTN scores of 4&5 was 92% (95% CI, 0.91-0.94%). According to this meta-analysis, IOFTN successfully identified 92% of patients who underwent orthognathic surgery with a great need for treatment (Grade 4 & 5). To enhance the identification of patients with well-compensated malocclusions, previous orthodontic treatment, or extreme occlusal deviations (e.g., proclination or retroclination of incisors), it would be advantageous to employ additional means alongside IOFTN for assessing orthognathic need in this group.

Advancements in oral and maxillofacial surgery medical images segmentation techniques: An overview

OBJECTIVES

This article reviews recent advances in computer-aided segmentation methods for oral and maxillofacial surgery and describes the advantages and limitations of these methods. The objective is to provide an invaluable resource for precise therapy and surgical planning in oral and maxillofacial surgery. Study selection, data and sources: This review includes full-text articles and conference proceedings reporting the application of segmentation methods in the field of oral and maxillofacial surgery. The research focuses on three aspects: tooth detection segmentation, mandibular canal segmentation and alveolar bone segmentation. The most commonly used imaging technique is CBCT, followed by conventional CT and Orthopantomography. A systematic electronic database search was performed up to July 2023 (Medline via PubMed, IEEE Xplore, ArXiv, Google Scholar were searched).

RESULTS

These segmentation methods can be mainly divided into two categories: traditional image processing and machine learning (including deep learning). Performance testing on a dataset of images labeled by medical professionals shows that it performs similarly to dentists' annotations, confirming its effectiveness. However, no studies have evaluated its practical application value.

CONCLUSION

Segmentation methods (particularly deep learning methods) have demonstrated unprecedented performance, while inherent challenges remain, including the scarcity and inconsistency of datasets, visible artifacts in images, unbalanced data distribution, and the "black box" nature.

CLINICAL SIGNIFICANCE

Accurate image segmentation is critical for precise treatment and surgical planning in oral and maxillofacial surgery. This review aims to facilitate more accurate and effective surgical treatment planning among dental researchers.

Impact of malocclusions on oral health-related quality of life among adolescents

DESIGN

Systematic review and meta-analysis of randomized controlled trials, non-randomized and observational studies, and previous systematic reviews if matching PECOS strategy. The protocol of the study was registered on PROSPERO.

DATA SOURCES

An electronic search was conducted in the following five databases: The Cochrane Library, PubMed, Web of Science, Scopus, and CINAHL. The search was carried out to cover the literature up to June 15, 2022. In addition, ClinicalTrials.gov and PROSPERO were searched for detecting any relevant unpublished data and ongoing studies.

STUDY SELECTION

The review was defined in PECOS format as follows: population (P), healthy adolescents (ASA Class I or II; age 10-19); Exposure (E), malocclusion and/or need of orthodontic therapy as determined by professionals utilizing validated standardized tools such as Index of Orthodontic Treatment Need, Index of Complexity, Outcome and Need, Peer Assessment Rating, Dental Aesthetic Index, or any well-described tool; comparison (C), no malocclusion and/or need of orthodontic therapy as determined by professionals utilizing validated standardized tools; outcome (O), self-reported oral health-related quality of life (OHRQoL) using validated tools; study design (S), randomized clinical trials, non-randomized/observational studies (prospective and cross-sectional studies with untreated/no-malocclusion controls), and previous systematic reviews if matching PECOS strategy. Studies assessing ASA Class III or higher, craniofacial conditions, previous or ongoing orthodontic or surgical treatment, and case studies were excluded.

DATA ANALYSIS

Screening and data extraction and management, risk of bias (RoB), and quality assessments were conducted by four independent investigators. RoB was assessed based on the guidelines of the Swedish Agency for Health Technology Assessment and Assessment of Social Services.

RESULTS

A total of 13 studies (non-randomized studies of cross-sectional design) were included in the qualitative synthesis, of which, 4 studies were included in the quantitative synthesis. Meta-analysis showed that malocclusions (measured with DAI) in adolescents aged 11-14 years old have a negative impact on OHRQoL (measured with CPQ 11-14 short form) (number of studies = 4, rate ratio/prevalence ratio = 1.15, 95% confidence interval = 1.12-1.18, I2 = 0.03%, Q3 = 0.09, certainty level = moderate).

CONCLUSIONS

Moderate level of evidence suggests that malocclusions in adolescents have a negative impact on the oral health-related quality of life.

Psychosocial Impact of Malocclusion and Self-Perceived Orthodontic Treatment Need among Young Adult Dental Patients

OBJECTIVES

 To investigate the psychosocial impact of malocclusion and self-rated and clinician-rated orthodontic treatment need on young adult patients in the Western Province of Saudi Arabia.

MATERIALS AND METHODS

 Eighteen- to 30-year-old patients (n=355) attending a tertiary dental care facility were included. Three instruments were used for data collection: (1) Psychosocial Impact of Dental Aesthetic Questionnaire (PIDAQ), (2) aesthetic component of the Index of Orthodontic Treatment Need (IOTN-AC), self-rated and clinician-rated, and (3) clinician-rated Dental Aesthetic Index (DAI). Data analysis included descriptive statistics, Kruskal-Wallis test, Mann-Whitney U-test, and multiple linear regression analysis.

RESULTS

 Females were significantly more impacted than males on all domains with the exception of the dental self-consciousness domain. For both the self-rated and clinician-rated IOTN and the DAI, it was found that the more severe the malocclusion, the higher the impact on all domains except for the dental self-confidence domain, which showed that patients with mild malocclusions were more affected than those with moderate and severe malocclusions. Significant associations were observed between independent variables (age, sex, self-rated IOTN, and DAI) and total PIDAQ score.

CONCLUSIONS

 Perceived psychosocial impact of dental aesthetics is directly related to severity of malocclusion (self-rated and clinician-rated) for all domains of the PIDAQ accept the DSC, and females showed higher psychosocial impact than males. Clinicians should consider the impact of malocclusion and certain demographic characteristics on the psychosocial well-being of an individual when determining the orthodontic treatment need.

Malocclusions and quality of life among adolescents: a systematic review and meta-analysis

BACKGROUND

Malocclusions in adolescents might have a negative impact on oral health-related quality of life (OHRQoL). Potential confounding variables (confounders) such as age, gender, caries, and socioeconomic status may skew the real relationship between malocclusions and OHRQoL.

OBJECTIVES

To analyse the effect of malocclusions in adolescents on OHRQoL, when controlled for potential confounders.

SEARCH METHODS

Five databases (PubMed, Cochrane Library, Cinahl, Scopus, and Web of Science) were searched up to 15 June 2022.

SELECTION CRITERIA

Studies in which OHRQoL in 10-19-year olds with and without malocclusions were compared.

DATA COLLECTION AND ANALYSIS

Screening, data extraction, and quality assessments were performed by four investigators independently. Risk of bias was assessed according to the Swedish Agency for Health Technology Assessment and Assessment of Social Services (SBU) guidelines. To be included, studies had to control for confounders. Certainty of evidence was assessed with GRADE.

RESULTS

Thirteen cross-sectional studies with low and moderate risk of bias were included in the qualitative synthesis. Four of these were also included in the quantitative synthesis (meta-analysis). The 13 studies in the qualitative synthesis displayed a large variation among the indices used for malocclusion ratings, as well as in instruments measuring OHRQoL. There was moderate quality of evidence that malocclusions have a negative effect on OHRQoL. The four articles included in the quantitative synthesis (meta-analysis) measured malocclusions with DAI and OHRQoL with CPQ 11-14 short form. There was moderate quality of evidence that malocclusions have a negative effect on OHRQoL (RR/PR 1.15, 95% CI 1.12-1.18, 3672 participants).

CONCLUSIONS

There is moderate quality of evidence that malocclusions in adolescents have a negative impact on OHRQoL, after taking relevant confounders into consideration. Future studies should ideally use standardized measures for malocclusion ratings and OHRQoL.

REGISTRATION

PROSPERO. CRD42020186152.

Impact of malocclusion treatments on Oral Health-Related Quality of Life: an overview of systematic reviews

OBJECTIVE

To perform an overview of systematic reviews (SR) assessing the impact of malocclusion treatments (Orthodontic Treatment - OT and/or Orthodontic Surgical Treatment - OST) on Oral Health-Related Quality of Life (OHRQoL).

MATERIALS AND METHODS

A search strategy was conducted in electronic databases until June 7th, 2021, followed by a manual search in grey literature and registration databases. Two independent authors applied the eligibility criteria, extracted the data, assessed the risk of bias (AMSTAR-2), and performed the certainty of evidence (GRADE) evaluation. Meta-analysis was planned to be carried out in RevMan 5.3 (with 95% confidence intervals (CI) considering p < 0.05), in case of homogeneous studies considering OHRQoL instrument and time of follow-up.

RESULTS

A total of 126 articles were accessed on the database, 18 registers, 33 records on grey literature and 3 articles by means of citation searching. After duplicates removal and eligibility criteria analyses, 15 SR were included. From that, 13 showed improvement in OHRQoL after OT and/or OST. The methodological quality ranges from high (n = 2), to critically low (n = 9). Meta-analysis was conducted. Improvement on OHRQoL after a 6-month OST using the OQLQ-22 (p < 0.00001; 19.65; CI: 12.60-26.70) and OHIP-14 instruments (p < 0.00001; 10.70; CI: 9.89-11.51); and after a 6-month OT using the CPQ 11-14 instrument (p = 0.010; 3.57; CI: 0.86-6.28) with very low certainty of the evidence for all outcomes was observed.

CONCLUSIONS

Although most SR selected in this overview are characterized by a critically low quality, as well as very low certainty of the evidence, OT and/or OST seem to have a positive impact in improving the OHRQoL.

CLINICAL RELEVANCE

The overview of existing systematic reviews compiled that OT and/or OST seem to have a positive impact on improving the OHRQoL. This information will facilitate clinical decision-making considering the clinical and psychological parameters.

Assessment of masticatory efficiency based on glucose concentration in orthodontic patients - a methodological study

INTRODUCTION

Treatment for malocclusion can cause discomfort and pain in the teeth and periodontium, which may impair masticatory efficiency. The glucose concentration method is widely used to assess masticatory efficiency for its convenience in the clinical situation, although its validity has not been shown.

OBJECTIVE

The aims were to determine the validity of the glucose concentration method and investigate if this method can be applicable to orthodontic patients with braces.

DESIGN

Sixteen healthy individuals (7 men, 9 women, and 26±5 years old) and 16 patients with malocclusions needing orthodontic treatment (5 men, 11 women, and 26±4 years old) participated. Glucose concentration was measured after 5-, 10-, and 15-s mastication of gummy jelly and compared to Hue values obtained from the color-changing gum method (reference method). In addition, all participants were asked to fill out the Oral Health Impact Profile questionnaire (OHIP) to assess differences in perception related to the mouth before and after the placement of braces.

RESULTS

Glucose concentrations were strongly correlated to measures of the two-color chewing gum methods (R² =0.965). Both the glucose extraction and chewing gum hue value were the smallest for 5 s chewing cycles and increased as the number of chewing strokes increased for the 15 s chewing cycles. (Hue: R² = 0.510, P < 0.001; glucose: R² = 0.711, P < 0.001) Masticatory efficiency assessed by both methods was significantly lower in orthodontic patients compared to controls (P<0.05), even though it was not affected by bonding (P>0.09). In addition, OHIP scores in physical pain dimension and psychological disability were higher in orthodontic patients than in the control group (P<0.005).

CONCLUSION

Measurement of glucose concentration was confirmed as a reliable and convenient method for assessing masticatory efficiency. Furthermore, it appears that this method is applicable to patients with braces whose perception in the oral cavity could change.

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.

Systemic Disorders Closely Associated with Malocclusion in Late Adolescence: A Review and Perspective

Oral diseases such as dental caries and periodontal disease are reported to be associated with various systemic diseases such as heart disease, respiratory disease, diabetes, rheumatism, and metabolic syndrome, thus increasing the importance of prevention and early treatment [...].

Taxonomic Analysis of Oral Microbiome during Orthodontic Treatment

Background

Orthodontic appliances induce significant changes in the oral microbiome, but this shift in microbial composition has not been well established by the available evidence yet.

Objectives

To perform a systematic review of existing literature in order to assess the taxonomic microbial changes in orthodontic patients during Fixed Appliance Treatment (FAT) and Clear Aligner Treatment (CAT), using next-generation sequencing (NGS) technique of the bacterial 16S rRNA gene. Search Methods and Selection Criteria. The search for articles was carried out in PubMed, including articles published in English until May 2021. They included every human study report potentially relevant to the review. Data Collection and Analysis. After duplicate study selection and data extraction procedures according to the PICOS scheme, the methodological quality of the included papers was assessed by the Swedish Council on Technology Assessment in Health Care Criteria for Grading Assessed Studies (SBU) method.

Results

The initial search identified 393 articles, 74 of which were selected by title and abstract. After full-text reading, six articles were selected according to inclusion criteria. The evidence quality for all the studies was moderate.

Conclusions

Orthodontic treatment seems to transiently affect the composition of subgingival microbiome, although not salivary, maintaining a stable microbial diversity. Different results were found in the shift of microbiome between plaque and saliva, depending on the type of orthodontic treatment. This review should be interpreted with some caution because of the number, quality, and heterogeneity of the included studies.

[Health relevance of malocclusions and their treatment]

Zahn- und Kieferfehlstellungen gehören zu den häufigsten Mundgesundheitsbeeinträchtigungen beim Menschen. Der vorliegende Beitrag gibt eine Übersicht zu deren Ursachen, Häufigkeit und Folgen. Er zeigt die präventiven und kurativen Möglichkeiten kieferorthopädischer Behandlungen auf und gibt Informationen zu deren rechtlichen Rahmenbedingungen in Deutschland. Inanspruchnahme und Qualität der kieferorthopädischen Versorgung werden im internationalen Vergleich dargestellt.

Bei den Ursachen für Zahn- und Kieferfehlstellungen spielen genetische, epigenetische, funktionelle und umweltbedingte Faktoren eine Rolle, die individuell meist nicht eindeutig feststellbar sind. Bisher zeigen nur kleinere Querschnittsstudien, dass bis zu 80 % der Kinder in Deutschland betroffen sind. Essen, Trinken, Kauen, Sprechen und Atmen können beeinträchtigt sein, die Neigung zu Parodontalerkrankungen sowie Überlastungsschäden von Kiefergelenk und Kaumuskulatur sind erhöht. Bei einer Proklination der oberen Schneidezähne steigt die Gefahr von Frontzahntraumata. Fehlstellungen können zudem negative psychosoziale Folgen oder Einschränkungen der Lebensqualität zur Folge haben. Kieferorthopädische Behandlungen leisten in Kooperation mit anderen (zahn-)medizinischen Fachdisziplinen einen wichtigen präventiven bzw. kurativen Beitrag zur Verbesserung der Mundgesundheit, der Allgemeingesundheit und der Lebensqualität.

Die Kieferorthopädie bietet ein erhebliches Potenzial für die Stärkung der zahnärztlichen Prävention im Gesundheitswesen, zumal die gesetzliche Krankenversicherung (GKV) eine breitflächige Versorgung der Bevölkerung mit kieferorthopädischen Leistungen auf international anerkanntem, hohem Niveau ermöglicht. Um die Prävention weiter zu verbessern, wird die Einführung eines kieferorthopädischen Screenings im 7.–8. Lebensjahr als systematische Vorsorge empfohlen.

Is the adolescent's esthetic concern associated with anterior occlusal conditions or the malocclusion severity level?

OBJECTIVES

To assess the esthetic impact of anterior occlusal conditions and malocclusion severity levels.

MATERIALS AND METHODS

A population-based cross-sectional study of 700 adolescents aged 15 to 19 years was conducted. The Oral Aesthetic Subjective Impact Scale (OASIS) was used to evaluate the subjective esthetic impact of malocclusion. The Dental Aesthetic Index (DAI) criteria were used to diagnose the anterior occlusal characteristics in isolation and the severity levels of malocclusion. The variables with P < .20 in the individual analyses were tested in multiple logistic regression models, and those with P < .10 remained in the model. The adjusted odds ratio (OR) was estimated with a 95% confidence interval (CI).

RESULTS

Of the adolescents, 42% showed negative self-perception of malocclusion. In addition, 15.4% of adolescents had severe malocclusion (DAI 3) and 18.9% very severe malocclusion (DAI 4). Crowding and spacing were shown to be 2.90 (CI: 2.06-4.09) and 2.53 (CI: 1.65-3.86) times, respectively, more likely to cause a negative esthetic impact in adolescents (P < .05). In addition, adolescents with orthodontic treatment need (DAI 2, 3, and 4) were more likely to report a negative esthetic impact (P < .05).

CONCLUSIONS

Anterior crowding and spacing are the conditions that most influence the esthetic concern of adolescents. Adolescents with very severe malocclusion and higher orthodontic treatment need are more likely to report a negative esthetic impact.

Orthodontic Treatment as a Protective Factor for Dental Caries Experience and Severity: A Population-Based Study

Objective

The aim of this study was to assess the effects of orthodontic treatment on the experience, prevalence, and severity of dental caries later in life in a representative sample of U.S. adults.

Methods

Using a population-based study design, data from 9,486 participants in the third National Health and Nutrition Survey (NHANES), including self-reported information on the history of orthodontic treatment and its timing, were obtained. Caries experience and prevalence was assessed using the decayed (DT) and filled (FT) teeth indices (i.e., DT > 0, FT > 0, and their aggregate DFT > 0). Severe dental caries experience and prevalence was defined as DT > 2, FT > 11, and DFT > 12. Unadjusted and adjusted logistic regression models that accounted for the complex sampling design were used to assess the association between orthodontic treatment and dental caries experience, prevalence, and severity. Statistical significance was set at a P value of less than 0.05.

Results

The history of orthodontic treatment was reported in 19.62% of the adults. Around 94% of participants had at least one decayed or filled tooth (DFT > 0), and 21.09% met the aggregate DFT criterion for severe caries (DFT > 12). After controlling for confounding variables, a reported history of orthodontic treatment was found to significantly decrease the odds of DT > 0, DT > 2, FT > 11, and DFT > 12 (odds ratios (OR) = 0.41, 0.36, 0.74, and 0.60, respectively).

Conclusion

A history of orthodontic treatment was a protective factor for untreated dental caries, in assessments of the severity and prevalence of dental caries experience.

Close Association between Awareness of Teeth-Alignment Disorder and Systemic Disorders in Late Adolescence

Background: Oral diseases are associated with various systemic disorders. Our previous research revealed new insights into the close relationship between occlusal disorder (functional disorder) and systemic disorders (allergic rhinitis, asthma, and arrhythmia) in late adolescence. Here, we investigated whether there was an association between the awareness of teeth-alignment disorder (morphological disorder) and common systemic disorders. Subjects and Methods: We retrospectively reviewed the data of the mandatory medical questionnaire that is required for the freshman medical checkup in Japan. We collected the data of all students who completed the questionnaire between April 2017 and April 2019. The data were analyzed using the χ² test, and a multivariate analysis was performed with a binomial logistic regression model. Results: The subjects were 8903 students aged 17–19 who had no awareness of occlusal disorder. The rate of awareness of teeth-alignment disorder was 20.43% (1819 of 8903 eligible subjects), and the aware students had significantly greater rates of gum bleeding (p < 0.001), pollinosis (n = 0.007), and atopic dermatitis (n = 0.042). The multivariate analysis revealed significant rates of gum bleeding (odds ratio (OR) 1.540, 95% confidence interval (CI): 1.386–1.711, p < 0.001), pollinosis (OR 1.197, 95% CI: 1.040–1.378, p = 0.012), and female gender (OR 1.141, 95% CI: 1.002–1.299, p = 0.046) among the students with awareness of teeth-alignment disorder. Conclusion: We identified close associations between the awareness of teeth-alignment disorder and both gum bleeding and pollinosis in a late-adolescent population. The systemic disorders that are targeted by teeth-alignment disorder were found to be different from those targeted by occlusal disorder.