[The effect of orthognathic surgery on speech function in patients with skeletal Class â ¢ malocclusion].

PURPOSE: To investigate the influence of the position of the upper and lower jaws on the anatomical structure of pharynx before and after orthognathic surgery in patients with skeletal Class Ⅲ malocclusion. METHODS: Craniofacial CT scan and speech data were collected from 31 patients with skeletal Class Ⅲ malocclusion before and 3 months after surgery. The collected CT data was imported into Dolphin imaging 11.95 software to establish a digital original model, and the anatomical structure of the pharynx was measured and analyzed. Speech data were analyzed objectively and subjectively by Computerized Speech Lab 4500b and professional speech specialists. Statistical analysis was performed using SPSS 24.0 software package. RESULTS: The distance from the lower edge of the soft palate to the posterior pharyngeal wall, the shortest distance from the posterior margin of the tongue to the posterior pharyngeal wall and its corresponding cross-sectional area were significantly different from those before surgery (P<0.05). The changes of SNA, SNB, ANB, OJ, and OBJ before and after surgery were significant in this series. Importantly, the speech intelligibility of orthognathic patients before and after surgery changed significantly subjectively (P<0.05). Objectively, the postoperative vowels /a/B2, B3, B4, /i/B1,B2, /u/B1,B2 and B4 of the patients were significantly different from those before surgery. There was no significant difference in the lower limit frequency of the consonants /x/, /zh/, /s/, the energy value of /zh/ and the grammatical form of /z/ before and after surgery. The maxillary advancement distance was highly correlated or significantly correlated with △S1, △VOP, and voice changes. CONCLUSIONS: Orthognathic surgery moves the upper and lower jaws to cause changes in the anatomy of the pharyngeal cavity, leading to changes of postoperative speech.

[Distraction osteogenesis for correction of cleft palate in rhesus-histological and fluorescent labeling study].

OBJECTIVE: To investigate the mechanism of new bone formation in the distraction osteogenesis (DO) for correction of cleft palate (CP) in rhesus. METHODS: CP was created by operation in 23 rhesus. The CP was corrected with DO in 21 animals as experimental group. The distraction rate was 0.8 mm per day, two times a day. The bone fragments were fixed after cleft closure, every 3 animals were sacrificed to get specimen after 1, 2, 4, 6, 8, 12, 24 weeks of fixation. 6 days before sacrifice, tetracycline was administrated for labeling (30 mg/kg). RESULTS: The hard and soft tissue def of fixation. At the same time, the bone volume and calcification between the distraction gap increased. The cleft in the control group could not b ect was successfully closed with DO by intramembrane osteogenesis. The new formed bone was remodeling and became maturation during the period e corrected spontaneously. CONCLUSIONS: The DO can successfully correct both the soft and hard tissue defect in CP by intramembrane osteogenesis. The fixation is important for remodeling and maturation of the new formed bone.

[Ultrastructural and element spectrometric analysis of distraction osteogenesis for reconstruction of cleft palate in rhesus macaque model].

OBJECTIVE: To study the ultrastructure and Ca/P element spectrometry of distraction osteogenesis (DO) for reconstruction of cleft palate (CP), so as to explore the osteogenesis and remodeling of new bone in situ. METHODS: 23 rhesus macaques were operated to establish animal models of CP. 2 monkeys didn't received DO as controls. The other 21 monkeys in experimental group underwent DO to correct both bony and soft tissue defects in palate. The distraction was performed at a rate of 0.8 mm/d, twice a day until the cleft was closed. After fixation for 1, 2, 4, 6, 8, 12, 24 weeks, every 3 animals were sacrificed to get the specimens at the distraction gap. The scanning electron microscopic study and Ca, P elements spectrometric analysis were adopted. There were also two unoperated animals as sham group. RESULTS: After fixation for 1-2 weeks, the distraction gap was full of collagen fibers oriented along vector of distraction. Few trabeculae was seen at the margin area. After fixation for 4-6 weeks, active osteogenesis was presented with new formed bone trabeculae and abundant cellular component. After fixation for 8-12 weeks, the new formed bone became mature and couldn't distinguish from the normal bone. 24 weeks later, the bone between the distraction gap had a similar structure to the normal bone. Elements spectrometric analysis results indicated that in early stage of osteogenesis, the P and S peaks were relatively high while the Ca peak was much lower. During the late stage, the S peak was obviously decreased, and Ca/P ratio increased to normal level as in the empty control group. CONCLUSIONS: The CP can be corrected by DO. The new bone between the distraction gap is formed and remodeled through intramembraneous osteogenesis.