Evaluation of Upper Airway Width and Facial Height Cephalometric Parameters in Adult Caucasians with Skeletal Class I and Class III Malocclusion.

Background and

Objectives

The main objectives of our study were to assess sexual dimorphism and to compare the facial height, as well as the anteroposterior width of the upper airway, within adult Caucasians diagnosed with skeletal Class I and skeletal Class III malocclusion, based on a number of angular and linear cephalometric parameters. Materials and

Methods

One hundred lateral cephalograms were selected from orthodontic adult Caucasian patients from western Romania. Several angular parameters (SNA, SNB, ANB, FMA, Y-FH, Ba-S-PNS and NL-ML angles) and linear parameters (total, upper and lower anterior facial height-TAFH, UAFH, LAFH; total posterior facial height-TPFH) were analysed for each case. The upper airway width parameters included the width of the nasopharynx, as well as the upper, middle and lower pharyngeal airway width (UPAW, MPAW and LPAW).

Results

Distinct sexual dimorphism was observed regarding the vertical cephalometric parameters within both Class I and Class III groups, with males exhibiting significantly larger facial height parameters, while females demonstrated larger nasopharyngeal depth angles (Ba-S-PNS). The Y-FH angle had significantly higher values in Class I than in Class III subjects, regardless of sex. Upper airway dimensions showed sexual dimorphism specifically in Class III subjects, with females exhibiting larger UPAW values than males. The inter-class comparisons showed larger values for LPAW, especially in females. Correlation analyses revealed no statistically significant relationships between the vertical and the upper airway parameters in Class I subjects. UPAW showed a tendency to decrease in Class III subjects as TAFH and LAFH increased. Ba-S-PNS showed consistent negative correlations with the vertical dimensions in both groups.

Conclusions

These findings suggest that skeletal Class I and Class III malocclusions exhibit not only different sagittal relationships, but also distinctive, sex-related vertical skeletal patterns within each group, and therefore it would be advised that male and female patients should be diagnosed and treated according to separate protocols. In our population, Class III males are more likely to require orthognathic surgery, in addition to orthodontic treatment, with a more reserved prognosis and they might have a higher risk of OSA or other respiratory disorders in comparison with Class III females.