[Correlation between adenoid hypertrophy, maxillary sinus mucosal thickening and dentofacial development in children].

PURPOSE：To investigate the effects of adenoid hypertrophy and maxillary sinus mucosal thickening on dentofacial development. METHODS：The selected subjects were divided into 4 groups according to the inclusion criteria: group A (adenoid hypertrophy with maxillary sinus mucosal thickening), group B (adenoid hypertrophy without maxillary sinus mucosal thickening), group C (normal adenoid with maxillary sinus mucosal thickening), and group D (normal adenoid without maxillary sinus mucosal thickening). There were 20 subjects in each group, aging from 12 to 14 years old. The volume of maxillary sinus was measured by Mimics software. The adenoid, dental arch width, basal bone width and palatal height were measured by Dolphin software and dentofacial measurements were performed in the lateral cephalograms derived from cone-beam CT (CBCT). The data were analyzed with SPSS 24.0 software package. RESULTS： There was no significant difference in dentofacial measurements between group B and group D or group C and group D，except for ANB angle (P<0.05). Compared with group D, SNB, ANB, Wits appraisal, NA-APo, MP-HP, N-Me, S-Go/N-Me, N-ANS (perp HP), sum of three angles, Ar-Go of group A were significantly different (P<0.05). Neither left nor right maxillary sinus bony volume had significant difference between group B and D or group C and D. CONCLUSIONS： Both adenoid hypertrophy and maxillary sinus mucosal thickening have impact on dentofacial development. Moderate or more severe adenoid hypertrophy with maxillary sinus mucosal thickening has greater impact on dentofacial development over adenoid hypertrophy or maxillary sinus mucosal thickening alone.

[Biomechanical effect of 2 anchorages on maxillary protraction with cleft lip and palate: a finite element analysis].

PURPOSE: To establish cranio-maxillary complex finite element models (FEMs) in cleft lip and palate (CLP) patients with miniplate and tooth-borne anchorage, and to investigate the biomechanical effects on maxillary protraction. METHODS: The protracting process was simulated on FEMs established from a male patient's cone beam CT (CBCT) data to analyze the displacement and stress from different appliances. RESULTS: Four FEMs of unilateral cleft lip and palate (UCLP) or bilateral cleft lip and palate (BCLP) patients' cranio-maxillary complex with MA and TA were established. The maxillary arch on both sides of the cleft moved towards the cleft side during protraction, which was more obvious in the miniplate anchorage three-dimensional finite element models(FEM-MA) than the tooth-borne anchorage three-dimensional finite element models (FEM-TA).The amount of forward, downward displacement of the inferior orbital rim, paranasal area and middle maxilla point in the FEM-MA was larger than that in the FEM-TA, while the amount of forward displacement of premaxilla and upper canine in the FEM-TA was larger than that in the FEM-MA. The FEM-MA exhibited an orthopedic effect with more favorable stress distribution on the middle maxilla point while the FEM-TA showed a dentoalveolar effect with prominent stress distribution on the upper canine point. In addition, the FEM-MA showed a larger stress distribution area and sutural stress value than did the FEM-TA. The UCLP models showed an asymmetric pattern in stress distribution and displacement, which was larger on the cleft side than that on the non-cleft side. The amount of displacement of premaxilla in the BCLP models was smaller than that in the UCLP models. CONCLUSIONS: The established models have high geomagic and biomechanical similarities. It would be more advantageous to obtain more aesthetic outcomes and better stability using the miniplate anchorage.