Interrelation of sagittal cephalometric parameters with the severity of transverse deficit in patients with skeletal forms of malocclusion

Abstract

Summary. Transverse deficiency (TD) of the maxilla (TM) is often combined with sagittal malocclusion, but its influence on orthognathic treatment planning is not well understood. Modern studies show a link between transverse and sagittal anomalies, which requires an integrated approach to diagnosis and treatment.

The aim of the study – to analyze the relationship between transverse maxillary deficiency and sagittal facial parameters in adult patients requiring orthognathic surgery due to skeletal malocclusion. It is assumed that the severity of the transverse deficit has a significant relationship with the type and degree of sagittal anomalies.

Materials and Methods. This study is based on the analysis of multislice computed tomography data of patients with skeletal forms of jaw anomalies that required surgical treatment. Inclusion in the study was determined by the presence of skeletal forms of cranial anomalies with a sagittal component, exclusion - by age less than 16 years, previous surgical interventions, and other criteria. The technique of multislice CT of the facial skull was used, and the data were analyzed using specialized software. We measured 12 angles and 4 distances characterizing the sagittal and vertical parameters of the jaw, as well as 11 distances characterizing the transverse parameters of the face. Patients were divided into 2 groups according to the ANB angle: Skeletal class II (ANB ≥ 4°) and skeletal class III (ANB ≤ 0°). Reference points and planes were determined for further cephalometric analysis. Statistical analysis was performed using SPSS Statistics v.22.

Results and Discussion. This study included 100 patients with skeletal malocclusion, including 38 % of men, with an age range of 18 to 40 years. Among them, 32 % belonged to skeletal class III, and 68 % to class II. The analysis showed that the vertical type of growth was more typical for class III, and the horizontal type – for class II. The prevalence of different types of bite, including open and deep bite, also varied by class. Transverse measurements showed a relationship between jaw width and type of sagittal anomaly, and statistical analysis confirmed these relationships. The study highlights the importance of assessing facial growth, development, and occlusion parameters in orthodontics. The analysis shows that sagittal abnormalities can be associated with the size of the TD. In addition, it was found that the assessment of transverse parameters requires a comprehensive approach that includes different levels of measurement, and correlations between different facial parameters were found.

Conclusions. The introduction of CT diagnostic methods and 3-D cephalometry has significantly increased the possibilities of a comprehensive assessment of complex types of malocclusion anomalies and deformities. In adults with skeletal sagittal malocclusion requiring surgical treatment, crossbite was found in 21 % of cases. Indirect signs of transverse deficiency were found in 74 % of cases, regardless of skeletal class. An adequate assessment of the maxillary transverse deficit requires the use of 3-D cephalometry to measure at different levels and compare them with the width of the mandible and midface.