Korean J Orthod.  2016 May;46(3):137-145. 10.4041/kjod.2016.46.3.137.

Five-year investigation of a large orthodontic patient population at a dental hospital in South Korea

• Piao Y
• Kim SJ
• Yu HS
• Cha JY
• Baik HS

• KMID: 2164257
• DOI: http://doi.org/10.4041/kjod.2016.46.3.137

Abstract

OBJECTIVE
The purpose of this study was to investigate the characteristics of orthodontic patients at Yonsei Dental Hospital from 2008 to 2012.
METHODS
We evaluated Angle's classification from molar relationships, classification of skeletal malocclusion from the A point-nasion-B point angle, facial asymmetry, and temporomandibular joint disorders (TMDs) from the records of 7,476 patients who received an orthodontic diagnosis. The orthognathic surgery rate, extraction rate, and extraction sites were determined from the records of 4,861 treated patients.
RESULTS
The patient number increased until 2010 and gradually decreased thereafter. Most patients were aged 19-39 years, with a gradual increase in patients aged ≥ 40 years. Angle's Class I, Class II divisions 1 and 2, and Class III malocclusions were observed in 27.7%, 25.6%, 10.6%, and 36.1% patients, respectively, with a gradual decrease in the frequency of Class I malocclusion. The proportion of patients with skeletal Class I, Class II, and Class III malocclusions was 34.3%, 34.3%, and 31.4%, respectively, while the prevalence of facial asymmetry and TMDs was 11.0% and 24.9%, respectively. The orthognathic surgery rate was 18.5%, with 70% surgical patients exhibiting skeletal Class III malocclusion. The overall extraction rate among nonsurgical patients was 35.4%, and the maxillary and mandibular first premolars were the most commonly extracted teeth.
CONCLUSIONS
The most noticeable changes over time included a decrease in the patient number after 2010, an increase in the average patient age, and a decrease in the frequency of Angle's Class I malocclusion. Our results suggest that periodic characterization is necessary to meet the changing demands of orthodontic patients.

Keyword

Epidemiology; Classification

MeSH Terms

Bicuspid
Classification
Diagnosis
Epidemiology
Facial Asymmetry
Humans
Korea*
Malocclusion
Molar
Orthognathic Surgery
Prevalence
Temporomandibular Joint Disorders
Tooth

Figure

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  Figure 1 Patient inclusion flowchart. TMD, Temporomandibular joint disorder. *Five patients were excluded from the analysis of Angle's classification because of bilaterally missing permanent first molars and/or primary second molars.

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