Dentoskeletal characteristics of orthodontic patients with KIG-grades D4 and D5 - A retrospective cephalometric study

In the statutory health system in Germany, orthodontic treatment is determined through the KIG index system. Category D describes all malocclusions with a positive overjet. Skeletal characteristics are not recorded. The aim of this study was to analyse the dento-skeletal characteristics of patients exhibiting KIG grades D4 and D5. Additionally, the similarities and differences compared to the characteristics of Angle Class II/1 malocclusion should be identified.

N= 225 patients (116 female, 109 male) aged 11.41 ± 1.77 years were included in the study. The patients were classified into KIG-grades D4 or D5, respectively. An analysis of cephalometric parameters took place for both groups, which were then compared with each other.

The cephalometric evaluation always revealed a Class II malocclusion, characterized primarily by mandibular retrognathia. The maxilla was orthognathic. Significant proclination of upper and lower incisors occurred. These characteristics were more pronounced in the D5 group: mandibular retrognathia and proclination of upper incisors were more pronounced, while dental compensation in the lower jaw was reduced. The growth pattern is predominantly horizontal in both groups. Comparison with Angle Class II/1 symptoms shows that the KIG-grade D4 and D5 patients generally fall within the known spectrum of characteristics of the Angle-Class II, division 1, but still exhibited KIG-grade specific properties.

Analysis of the KIG-grades D4 and D5 revealed a complex, multifactorial profile. Patients with KIG-grades D4 and D5 exhibit dentoskeletal characteristics that are comparable to Angle Class II/1, but with specific properties.