The effect of human amniotic fluid on mandibular distraction osteogenesis.

The aim of this study was to evaluate the effects of local administration of human amniotic fluid (HAF) on newly formed bone obtained by mandibular distraction osteogenesis (DO) with histomorphometry. A unilateral mandibular osteotomy at the left corpus was performed in 32 adult male rabbits. After a 5-day latency period, the left mandibles were lengthened by mandibular DO over 5 days, at a rate of 1mm/day, via a custom-made distractor. After the distraction, the rabbits were divided randomly into four groups: 0.3 ml HAF was injected into the distraction gap followed by 21 (group 1) or 45 (group 2) days of consolidation; or 0.3 ml normal saline (NS) was administered followed by 21 (group 3) or 45 (group 4) days of consolidation. Mandibles were removed at the end of the consolidation period and investigated histomorphometrically. The newly formed bone area (NFBA) and number of fibroblasts increased significantly in the HAF groups compared to the NS groups (NFBA: group 1 vs. group 3, P<0.05; group 2 vs. group 4, P<0.01; fibroblasts: group 1 vs. group 3, and group 2 vs. group 4, P<0.05), and also in both 45-day consolidation groups compared to the 21-day consolidation groups (NFBA: group 1 vs. group 2, and group 3 vs. group 4, P<0.001; fibroblasts: group 1 vs. group 2, and group 3 vs. group 4, P<0.01). Additionally, the numbers of osteoblasts and capillaries were increased significantly at 45 days of consolidation compared to 21 days in both the HAF and NS groups (osteoblasts: group 1 vs. group 2, P<0.01; group 3 vs. group 4, P<0.05; capillaries: group 1 vs. group 2, and group 3 vs. group 4, P<0.01). Histomorphometric analysis demonstrated that local HAF administration effectively accelerated bone formation. Thus, a HAF injection procedure could improve new bone formation around the bone in maxillofacial operations such as DO.

Three-dimensional evaluation of nasal and pharyngeal airway after Le Fort I maxillary distraction osteogenesis.

The aims of this study were to evaluate volumetric changes in the nasal cavity (NC) and pharyngeal airway space (PAS) after Le Fort I maxillary distraction osteogenesis (MDO) using a three-dimensional (3D) simulation program, and to determine the effects of MDO on respiratory function during sleep with polysomnography (PSG). 3D computed tomography images were obtained and analyzed before surgery (T0) and at a mean 8.2 ± 1.2 months postsurgery (T1) (SimPlant-OMS software) for 11 male patients (mean age 25.3 ± 5.9 years) with severe skeletal class III anomalies related to maxillary retrognathia. The simulation of osteotomies and placement of distractors were performed on stereolithographic 3D models. NC and PAS were segmented separately on these models for comparison of changes between T0 and T1. PSG including the apnoea-hypopnoea index (AHI), sleep efficiency, sleep stages (weakness, stages 1-4, and rapid eye movement (REM)), and mean lowest arterial O2 saturation were obtained at T0 and T1 to investigate changes in respiratory function during sleep. MDO was successful in all cases as planned on the models; the average forward movement at A point was 10.2mm. Increases in NC and PAS volume after MDO were statistically significant. These increases resulted in significant improvement in sleep quality. PSG parameters changed after MDO; AHI and sleep stages weakness, 1, and 2 decreased, whereas REM, stages 3 and 4, sleep efficiency, and mean O2 saturation increased.

Changes in posterior airway space, pulmonary function and sleep quality, following bimaxillary orthognathic surgery.

Bimaxillary orthognathic surgery (BOS) is commonly used in the correction of severe Class III deformities (mandibular prognathism with maxillary retrognathism). The postural response of the pharyngeal airway after mandibular setback and maxillary advancement procedures is clinically crucial for maintaining optimum respiration. Patients might suffer from obstructive sleep apnoea, postoperatively. The aim of this study was to determine the effects of BOS on pharyngeal airway space, respiratory function during sleep and pulmonary functions. 21 male patients were analysed using cephalometry, spirometry for pulmonary function tests, and a 1 night sleep study for full polysomnography before and 17±5 months after BOS. The data show that the hyoid bone repositioned to the inferior, the tongue and soft palate displaced to the posterior, narrowed at the oropharynx and hypopharynx and widened at the nasopharynx and velopharynx levels significantly (p<0.05). The alterations indicated decreased airway resistance and better airflow. As a consequence of polysomnography evaluation, the sleep quality and efficiency of the patients improved significantly after BOS. Patients who undergo BOS should be monitored with pulmonary function tests and polysomnography pre- and postoperatively to detect any airway obstruction.

Effect of complete denture wearing on deglutition time: a cine-magnetic resonance imaging study.

Purpose of the study was to evaluate the effect of complete denture wearing on deglutition time (DT), hyoid bone and larynx movements in edentulous patients with real-time balanced turbo field echo cine-magnetic resonance imaging. Subjects were examined by cine-magnetic resonance imaging in supine position during swallowing water. Two sets of images for 23 edentulous (with/without wearing complete dentures) and one for 23 dentulous patients were obtained. Radiographic outputs representing three consecutive deglutition stages (oral, pharyngeal and oesophageal) were provided to perform measurements. Deglutition time significantly increased when edentulous patients wore their dentures (mean 0·75 s increased to 1·17 s), whereas dentulous patients' DT was about 0·91 s (P ≤ 0.05). The duration of deglutition is crucial because prolonged pharyngeal transit times increases the risk of aspiration. Within the limitations of the study, complete denture wearing could increase the shortened DT of the edentulous patients.

Anterior segmental distraction of the hypoplastic maxilla by a tooth borne device: a study on the movement of the segment.

The aim of this study is to determine the relative movement of the teeth and bone after premaxillary distraction with a tooth-borne device constructed in the authors' centre. To evaluate the effects of this device on the anterior segment and teeth, the space formed between the anterior and posterior segments of the maxilla was measured on computerized tomography images from 10 patients. The average differences were 3.5mm at the apex level, 5.5 mm at alveolar ridge level and 7.4 mm at crown level on the right side. On the left side, the average differences were 3.2, 5.2 and 7.1 mm, respectively. There were statistically significant differences between all these measurements (p<0.05), but the difference between right and left sides was not statistically significant (p>0.05). The ratio between the movements at apex and crown levels was 46%. These results showed that the tooth-borne distractor was able to distract the anterior segment of the maxilla but it also caused anchorage loss of the maxillary incisors.

Gold weight implantation for rehabilitation of the paralysed eyelid.

Patients with complete facial nerve palsy are at risk of severe eye complications due to corneal exposure. Gold weight implantation improves function, cosmetic appearance and morbidity. Three patients with nerve palsy underwent insertion of precisely prepared gold weights between May 2000 and December 2001. Individual gold weights were implanted into a small pocket between the orbicularis oculi and the tarsal plate of the upper eyelid, fitting the curvature of the eye. According to follow-up examinations (after at least 5 years), none of the gold weights had extruded; all patients experienced marked improvement of their dry-eye symptoms and expressed a high degree of satisfaction. Implantation of gold weights is effective and should be considered in all patients for the management of paralytic lagophthalmos.