Comparison of PAS and adenoids in patients with and without maxillary micrognathia before orthodontic treatment.

OBJECTIVE: Craniofacial anomalies are widely discussed as predisposing factors of breathing disorders. Since many more cofactors exist, this study investigated the association between maxillary micrognathia and morphological changes of posterior airway space and adenoids in these patients. MATERIAL AND METHODS: Cephalometric radiographs of n = 73 patients were used for data acquisition. The patients were divided into two groups according to certain skeletal characteristics: maxillary micrognathia (n = 34, 16 female, 18 male; mean age 10.55 ± 3.03 years; defined by a SNA angle < 79°) and maxillary eugnathia (n = 39, 19 female, 20 male; mean age 10.93 ± 3.26 years; defined by a SNA angle > 79°). The evaluation included established procedures for measurements of the maxilla, posterior airway space and adenoids. Statistics included Kolmogorov-Smirnov-, T- and Mann-Whitney-U-Tests for the radiographs. The level of significance was set at p < 0.05. RESULTS: The cephalometric analysis showed differences in the superior posterior face height and the depth of the posterior airway space at palatal level among the two groups. The depth of the posterior airway space at mandibular level was the same for both groups, just as the size of the area taken by adenoids in the nasopharynx. CONCLUSIONS: Skeletal anomalies affect the dimension of the posterior airway space. There were differences among the subjects with maxillary micrognathia and these with a normal maxilla. However, the maxilla was only assessed in the sagittal direction, not in the transverse. This study showed that the morphology of the maxilla relates to the posterior airway space whereas the adenoids seem not to be affected. CLINICAL RELEVANCE: Maxillary micrognathia is significantly associated with a smaller depth of the posterior airway space at the palatal level compared to patients with maxillary eugnathia.

Effects of combined orthodontic-orthognathic treatment for class II and III correction on posterior airway space : Comparison of mono- and bignathic osteotomies.

OBJECTIVES: Comparison of treatment effects on the posterior airway space (PAS) in patients treated with combined orthodontic-orthognathic surgical treatment. METHODS: Pre- and postsurgical lateral cephalograms of 53 (34 females, 19 males) Caucasian patients were analyzed using a customized set of measurements. According to malocclusion (Class II or III) and surgical approach (either monognathic or bignathic), patients were allocated into four groups. PAS was assessed from cranial to caudal at six levels (P1-P6). Paired t tests were used for intragroup and t tests for independent samples for intergroup comparisons. Results were considered statistically significant at p < 0.05. RESULTS: In patients treated for Class II malocclusion, PAS retropalatally (P1 level) almost remained unchanged, whereas measurements at levels P2-P6 showed a mean increase ranging from approximately 2-5.5 mm. Significant changes were most pronounced in monognathic Class II patients (group 1) at levels P2-P4 with mean values ranging from approximately 3.7-5.5 mm. In patients treated for Class III malocclusion (groups 3 and 4), measurements at the P1 level almost remained unchanged in patients who underwent mandibular setback surgery (group 3), whereas the same measurements exhibited significant increase (>6 mm) in patients treated with bignathic surgery (group 4). CONCLUSIONS: Bignathic surgery led to smaller changes of pharyngeal depth in Class II and III patients than monognathic surgery. Alterations of the PAS due to orthognathic surgery should be considered during orthodontic and presurgical treatment planning.