Angle’s Classification Versus Dental Aesthetic Index in Evaluation of Malocclusion among Turkish Orthodontic Patients

Research Article

J Dent App. 2015;2(3): 168-173.

Angle’s Classification Versus Dental Aesthetic Index in Evaluation of Malocclusion among Turkish Orthodontic Patients

F Deniz Uzuner1*, E Kaygisiz1, L Taner1, K Güngör2 and Z Gençtürk3

1Department of Orthodontics, Gazi University Faculty of Dentistry, Ankara, Turkey

2Department of Dento Maxillofacial Radiology, Gazi University Faculty of Dentistry, Ankara, Turkey

3Department of Biostatistics, Ankara University Faculty of Medicine, Ankara, Turkey

*Corresponding author: F Deniz Uzuner, Department of Orthodontics, Gazi University Faculty of Dentistry, Biskek Cd, (8.Cd) 82, Sk. No: 406510; Emek, Ankara, Turkey

Received: September 09, 2014; Accepted: December 27,2015;Published: January 21, 2015


Objective: To evaluate Angle’s classification and dental aesthetic index (DAI) in interpretation of malocclusion among orthodontic patients.

Methods: A total of 457 orthodontic patients (284 female, 173 male) between 9 to 17 years old who referred to the orthodontic clinic were included in this study. Malocclusion prevalence, the severity of malocclusion and treatment requisite were evaluated as was the association between DAI and Angle’s classification. Pearson Chi-square test was used for the comparison of categorical data. p<0.05 was considered as significant.

Results: The percentage of patients with DAI =25 indicating little or no need for treatment was 20.8% and 52.7% (DAI =31) had highly desirable or mandatory need for treatment. Among patients with DAI =25, a significantly high percentage of patients were in Class I (37.0%) (p<0.001). Significantly higher percentage of patients were having DAI score of =35 in Class II/1(42.6%) and Class II/2 (36.5%) than Class I (18.8%) and Class III (31.3%) groups (p<0.001). Only 50.1% of patients with Class III malocclusion were associated with appropriate DAI scores (=31) of severity and treatment need category.

Conclusion: Only 52.7% of patients referring to orthodontic clinic revealed DAI score of =31 suggesting severe, very severe or disabling malocclusion with highly desirable or mandatory orthodontic treatment requisite. Although DAI seems sensitive to detect the presence of Angle’s classification based malocclusion, it may be improved in terms of severity and treatment requisite criteria. While the complementary use of the two methods seems to be feasible and is suggested in all-inclusive evaluation and care for patients with malocclusion in clinical practice.

Keywords: Malocclusion; Prevalence; Angle’s classification; Dental aesthetic index; Treatment requisite


Malocclusion, defined as an irregularity of the teeth or a mal relationship of the dental arches beyond the ideal range, is one of the most common dental problems ranking third among worldwide dental public health priorities [1-3], while associated also with oral dysfunction, increased susceptibility to trauma and periodontal disease as well as psychosocial problems related to impaired dento facial aesthetics and disturbed quality-of-life [1,4-8]. In this regard, gathering epidemiological data on the prevalence and distribution of malocclusions as well as orthodontic treatment need become of special interest for screening treatment priority and resource planning for orthodontic treatments within a public health system [2,9-12].

Since its publication in 1899, the Angle’s classification become a milestone in orthodontics as the most widely used instrument for evaluation of malocclusions [13,14].

The Dental Aesthetic Index (DAI) was developed in the USA and integrated into the International Collaboration Study of Oral Health Outcomes by the World Health Organization (WHO) [15] as an

objective, simple and easy to use universally accepted cross-cultural index that links clinical and aesthetic components mathematically to produce a single score [14,16,17]. Being recommended to be used in epidemiologic research to establish the orthodontic treatment need and the priority of orthodontic care in public programs, DAI has been a widely used index of assessing malocclusion with high reliability and validity that was shown to compare favorably with other indices in the population-based studies of malocclusion [11,12,18-20].

Verification of Angle’s classification and DAI in comparative and complementary terms as two widely used indexes in the assessment of malocclusions is important in the dental clinical practice. Most of the published data on treatment requisite has been based on screening of general population, while limited data are available on actual treatment need in patients diagnosed with orthodontic disorders and thereby referred to orthodontics clinics for treatment [14,21]. The present study was designed to evaluate Angle’s classification and dental aesthetic index in assessment of malocclusion and treatment need among orthodontic patients who referred to the orthodontic clinic after the initial diagnosis made in oral diagnostic clinics.


Study population

A total of 523 randomly selected orthodontic patients who consecutively admitted to the orthodontics clinic at Gazi University Faculty of Dentistry between May 2011 and April 2012 were included in this study. Patients with cleft lip and palate, having previous orthodontic and/or prosthetic treatment, having great restorations/ crown were excluded from the study. Remaining 457 (284 female, 173 male) patients between 9 to 17 years old were clinically examined in reference to the DAI and Angle malocclusion.

Study parameters

Data on demographic characteristics, Angle’s classification and DAI scores were recorded. Malocclusion prevalence was identified according to both methods, while the severity and treatment requisite were evaluated according to DAI. The association between DAI and Angle classification was also evaluated.

Angle’s classification

Patients were considered to have Class I (neutral occlusion), Class II (distocclusion; Class II/1: increased overjet > 4 mm, Class II/2: retroclined upper central incisors with increased overbite) and Class III (mesiocclusion) malocclusion according to Angle’s classification [13].


DAI was based on evaluation of criteria including dentition (absence of incisor, canine and premolar), space (crowding in the incisor region, spacing in the region of incisors, diastema , anterior jaw misalignment, anterior mandibular misalignment) and occlusion (anterior maxillary overjet, anterior mandibular overjet, vertical anterior open bite) and anteroposterior molar relationship. DAI score was calculated using the regression equation of 10 occlusal traits: “(visible missing teeth x 6) + (crowding) + (space) + (diastema x 3) + (anterior maxillary misalignment) + (anterior mandibular misalignment) + (anterior maxillary overjet x 4) + (anterior mandibular overjet x 4) + (anterior vertical open bite x 4) + (anteroposterior molar relationship x 3) + 13” [14-16].

To determine the treatment need based on the DAI score, patients were categorized into four groups including those with score of =25 (normal or mild occlusion with little or no need for treatment), scores of 26-30 (defined malocclusion with elective need for treatment), 31- 35 (severe malocclusion with highly desirable need for treatment) and =36 (very severe or disabling malocclusion with mandatory treatment) [22,23].


One specialist was previously calibrated using re-examination of dental students. To ascertain intraexaminer reliability in the use of the DAI, 60 students were re-examined after a period of 2-3 weeks by the same examiner. The intrarater correlation coefficient for repeated measurements was 0.98 ( P < 0.001), indicating high reliability.

Statistical Analysis

Statistical analysis was made using computer software (SPSS version 15.0, SPSS Inc. Chicago, IL, USA). Pearson Chi-square (χ2) test for the comparison of categorical data. Data were expressed as “mean (standard deviation; SD)”, minimum-maximum and percent (%) where appropriate. p<0.05 was considered statistically significant.


Malocclusion according to Angle’s classification and DAI scores

Angle fs classification revealed Class I, Class II/1, Class II/2 and Class III malocclusion in 33.7%, 33.9%, 11.4% and 21.0% of patients respectively. According to DAI scores 20.8% of patients (DAI . 25), 26.5% (DAI 26-30), and 52.7% (DAI .31) (Table 1).