Influence of different surgical concepts for moderate skeletal class II and III treatment on the nasopharyngeal airway space.

PURPOSE: This study aimed to compare the effects of different orthognathic and camouflage treatments for correcting moderate skeletal class II and III malocclusions on the pharyngeal airway space (PAS). MATERIALS AND METHODS: Lateral cephalograms of 89 patients with moderate skeletal class II and III malocclusion (WITS up to 7 mm, -7 mm respectively) were evaluated before and after treatment. PAS was divided into 6 levels (P1: nasopharynx, P2-4: oropharynx, P5-6: laryngopharynx), and 7 groups were formed depending on the type of treatment: 1) class II, mandibular advancement; 2) class II, maxillary setback/mandibular advancement; 3) class II, upper premolar extraction; 4) class III, mandibular setback; 5) class III, maxillary advancement; 6) class III, maxillary advancement/mandibular setback; and 7) class III, lower premolar extraction. RESULTS: Significant changes occurred only in patients with class II malocclusion (groups 1 and 2) before and after surgery in the nasopharyngeal and oropharyngeal space. Furthermore, significant differences between the patients with class II malocclusion were found when compared to the premolar extraction group: group 1 vs. group 3 (P3: -1.31 mm (SD 1.74 mm) vs. 0.89 mm (SD 1.79 mm); P4: -0.72 mm (SD 2.82 mm) vs. 1.42 mm (SD 2.16 mm); P ≤ 0.05), group 2 vs. group 3 (P2: 0.35 mm (SD 1.96 mm) vs. 2.28 mm (SD 1.88 mm), P3: -1.31 mm (SD 1.74 mm) vs. 0.35 mm (SD 1.96 mm), P4: -0.72 mm (SD 2.82 mm) vs. 2.84 mm (SD 2.16 mm), P ≤ 0.05). CONCLUSIONS: Orthognathic surgery in patients with moderate skeletal class II and III malocclusion seems to affect PAS only slightly. Premolar extractions for compensation (camouflage treatment) can result in a reduction of the oropharynx airway space in both types of skeletal malocclusions. Therefore, in borderline patients with presence of OSAS, orthognathic surgery should be considered.

Bone and soft tissue palatal morphology and potential anchorage sides in cleft palate patients.

AIM: The aim of this study was to evaluate palatal vertical bone thickness and density in relation to soft tissue on the hard palate for better selection of adequate bone regions for the insertion of orthodontic mini-implants (MIs) in cleft palate patients. MATERIALS AND METHODS: Cone beam computed tomography scans (CBCT) were obtained from 60 patients (mean age range 9-12). The study population included patients with isolate right side cleft palate formation (n = 20; 6 females; 14 males), left side cleft palate formation (n = 20; 9 females; 11 males) and without cleft formation as control group (n = 20; 15 females; 5 males). Bone and soft tissue measurements were performed vertical at a 90° angle to the bone surface, on previously defined measurement points (n = 88) on the hard palate. Bone density was measured on ten vertical layers in caudo-cranial direction. RESULTS: In non-cleft patient the highest bone thickness was in the anterior palate and decreased significantly in posterior direction. In patients with right and left cleft palate, the highest vertical bone level could be observed at the palatal premaxillary border opposite to the cleft side. Patients in the control group showed a significantly lower vertical soft tissue thickness than patients with palatal cleft formation. The evaluation of bone density showed no significant differences in all three groups. CONCLUSION: The results suggest that the favorable region for orthodontic MI placement is in the similar anatomical region compared to non-cleft patients, but differs from one side in each group. In unilateral cleft palate patients, the highest bone level was found on the anterior palate side opposite to the cleft side, indicating the most effective region for MIs placement.