Gender differences in the upper airway, craniofacial morphological and polysomnographic parameters in patients with obstructive sleep apnoea.

BACKGROUND: Obstructive sleep apnoea (OSA) is a common sleep disorder characterized by repetitive episodes of upper airway collapse during sleep associated with arousals with or without oxygen desaturation. OBJECTIVE: This study aims to assess and analyse the morphological and neurological factors associated with obstructive sleep apnoea using polysomnography study data and two-dimensional cephalometric analysis of airway and skeletal parameters and their correlation in the patients with varying severities of obstructive sleep apnoea. METHODS: This study included 892 patients who underwent a complete work up, including a thorough history, clinical examination, standard polysomnography study and 2D cephalometric analysis to diagnose obstructive sleep apnoea. This study divided the participants into two groups based on the AHI score from the PSG study: AHI < 15 and AHI > 15 groups. The groups were further divided into male and female groups to study the prevalence of OSA. The analysis involved 13 cephalometric parameters: Seven linear and six angular measurements. The airway parameters measured in this study were minimum posterior airway space (PAS_min), hyoid bone to the mandibular plane (H_MNP) and soft palate length (SPL). All the subjects in this study underwent a standard overnight polysomnography study at the sleep centre in Samsung Medical Center. RESULTS: A total of 892 adult participants (M: F = 727:165, mean age: 50.6 ± 13.2 years and age range: 18-85 years). AHI >15 group was significantly older with higher BMI, NC and WC compared to the AHI < 15 groups in both male and female groups. There was statistical significance observed in N1, N3, AI, ODI, lowest saturation (%) and apnoea max length between the groups (p < .001). The arousal index (AI), especially the respiratory arousal index was considerably higher in the male group. There were significantly higher values in all the PSG parameters in the male group. In the airway parameters, hyoid bone position and soft palate length showed significant differences (p < .001), whereas the PAS did not show any differences (p = .225) between the AHI <15 and AHI >15 groups. The overall skeletal cephalometric parameters showed no significant differences between the groups, whereas the gonial angle and AB to mandibular plane angle showed significant differences in the female group (p = .028, p = .041 respectively). CONCLUSION: The partial correlation of cephalometric parameters with AHI showed a stronger correlation between the H_MNP and AHI in both men and women. The position of the hyoid bone and the soft palate length influences the progression of OSA, especially in male patients. This study found no direct association between the minimum PAS and varying severities of OSA in men and women. We speculate that more than the craniofacial morphological factors such as the sagittal and vertical position of the maxilla and the mandible, the position of the hyoid bone might be more responsible for the severity of OSA.

3D simulation of interosseous interference in sagittal split ramus osteotomy for mandibular asymmetry.

BACKGROUND: The purpose of this study was to evaluate the pattern of predicted interosseous interference and to determine the influencing factor to volume of bony interference using a computer-assisted simulation system. This retrospective study recruited 116 patients with mandibular prognathism who had undergone sagittal split ramus osteotomy (SSRO) with or without maxillary osteotomy. The patients were divided into 3 groups according to the amount of menton (Me) deviation: less than 2 mm (Group 1), 2-4 mm (Group 2), and more than 4 mm (Group 3). Changes in the distal segments following BSSRO and the volume of the interosseous interference between the proximal and distal segments were simulated after matching preoperative occlusion and postoperative expected occlusion with the cone-beam computed tomography data. Ramal inclinations and other skeletal measurements were analyzed before surgery, immediately after surgery, and at least 6 months after surgery. RESULTS: The anticipated interosseous interference was more frequently noted on the contralateral side of chin deviation (long side) than the deviated site (short side) in Groups 2 and 3. More interference volume was predicted at the long side (186 ± 343.9 mm3) rather than the short side (54.4 ± 124.4 mm3) in Group 3 (p = 0.033). The bilateral difference in the volume of the interosseous interference of the osteotomized mandible was significantly correlated with the Me deviation (r = - 0.257, p = 0.009) and bilateral ramal inclination (r = 0.361, p < 0.001). The predictor variable that affected the volume of the osseous interference at each side was the amount of Me deviation (p = 0.010). CONCLUSION: By using the 3D simulation system, the potential site of bony collision could be visualized and successfully reduced intraoperatively. Since the osseous interference can be existed on any side, unilaterally or bilaterally, 3D surgical simulation is necessary before surgery to predict the osseous interference and improve the ramal inclination.

Secondary healing property using Neoveil®, a polyglycolic acid bioabsorbable sheet on the oral mucosal defects.

Neoveil® is a wound surface-covering agent composed of polyglycolic acid(PGA) effective for secondary healing. This study evaluated the secondary healing property of oral cavity mucosal defects using the PGA sheet. Thirty-four patients who underwent surgical excision of oral benign and malignant lesions, precancerous lesions, and tumors were evaluated. The PGA sheet was placed over the open wound to aid secondary healing. The defects were reviewed post-operatively for secondary healing, contracture, and secondary deformity. Male to female ratio was 20:14, and the mean age was 63.5 years. In all cases, the oral mucosal defect was present after the wide excision of the mucosal lesion. The PGA sheet was used as a surface covering agent which was found to be effective in secondary healing of the wound. Any side effects and adverse reactions which were caused by the PGA sheet was not evident. It can be used to avoid skin graft or free flap reconstruction or deformity from the direct closure in moderate size oral mucosal defect.

Orthognathic surgery for patients with fibrous dysplasia involved with dentition.

BACKGROUND: Fibrous dysplasia (FD) is characterized by the replacement of normal bone by abnormal fibro-osseous connective tissue and typically treated with surgical contouring of the dysplastic bone. When dysplastic lesions involve occlusion, not only is surgical debulking needed, orthognathic surgery for correction of dentofacial deformity is mandatory. However, the long-term stability of osteotomized, dysplastic bone segments is a major concern because of insufficient screw-to-bone engagement during surgery and the risk of FD lesion re-growth. CASE PRESENTATION: This case report reviewed two patients with non-syndromic FD that presented with maxillary occlusal canting and facial asymmetry. Le Fort I osteotomy with recontouring of the dysplastic zygomaticomaxillary region had been performed. The stability of osseous segments were favorable. However, dysplastic, newly formed bone covered the previous plate fixation site and mild bony expansion was observed, which did not influence the facial profile. Including the current cases, 15 cases of orthognathic surgery for FD with dentition have been reported in the literature. CONCLUSION: The results showed that osteotomy did not appear to significantly reduce the long-term stability of the initial fixation insufficiency of the screw to the dysplastic bone. However, based on our results and those of the others, long-term follow-up and monitoring are needed, even in cases where the osteotomized segment shows stable results.