Sleep-disordered breathing in children seeking orthodontic care-an Australian perspective.

BACKGROUND: The prevalence of sleep-disordered breathing in children is underestimated due to impediments in detection and diagnosis. Consequently, delayed management may affect the quality of life and the growth and development of a child. Due to their patient demographic, orthodontists are optimally positioned to identify those at risk of sleep-disordered breathing and make referrals for investigation and management. This study aims to determine the prevalence of children at risk of sleep-disordered breathing in an Australian orthodontic population. METHODS: A 1-year retrospective study was conducted in an urban Western Australian private orthodontic practice with two branches in similar socioeconomic demographics. The responses of new patients to a modified paediatric sleep questionnaire and standard medical history form were recorded. RESULTS: In 1209 patients (4-18 years), 7.3% were at risk of sleep-disordered breathing. An association between sex and the potential risk of sleep-disordered breathing was found with 11% of males at risk of sleep-disordered breathing compared to 7% of females (P = 0.012). CONCLUSIONS: The relatively high prevalence of children at risk of sleep-disordered breathing presenting for orthodontic care presents an opportunity to identify at-risk individuals through routine use of the paediatric sleep questionnaire. This would facilitate early referral for diagnosis and management of sleep-disordered breathing.

Accuracy of mandibular proximal segment position using virtual surgical planning and custom osteosynthesis plates.

The purpose of this study was to determine whether the use of custom osteosynthesis plates increased the accuracy of proximal segment position following bilateral sagittal split osteotomy in a cohort of 30 patients when compared to a control group of 25 patients who had surgery with conventional plates. Surgery was performed by a single surgeon between October 2015 and December 2017. Post-surgical cone beam computed tomography scans were segmented using Mimics Innovation Suite (Materialise NV), and surface-based superimposition was achieved using ProPlan CMF (Materialise NV). However, there was a tendency for the rotational error to be smaller in the custom group than in the control group. The root mean square error in both groups and for all variables fell within clinical parameters of 2 mm and 4°. In conclusion, the results of this study indicate that customized mandibular fixation plates do not necessarily improve the accuracy of the proximal segments post-surgically; however they may be of benefit in individual patients.

Accuracy of maxillary repositioning surgery using CAD/CAM customized surgical guides and fixation plates.

The advent of three-dimensional imaging and computer-aided surgical simulation (CASS) have brought about a paradigm shift in surgical planning. The aim of this study was to assess the accuracy of maxillary repositioning surgery using computer-aided design and manufacturing (CAD/CAM) customized titanium surgical guides and fixation plates. Thirty consecutive adult patients, 13 male and 17 female, with a mean age of 29.2 years and 25.5 years, respectively, requiring Le Fort I maxillary osteotomy, with or without simultaneous mandibular surgery, were evaluated retrospectively. All orthognathic surgeries were performed by one experienced surgeon. The pre-surgical and post-surgical volumetric imaging were superimposed to assess the linear and angular differences between the planned and actual positions of the maxilla following surgery. With the use of the CAD/CAM titanium surgical guides and fixation plates, all surgical movements were within 2mm and 4° of the planned movements, which is considered clinically insignificant. The overall root mean square error between the planned and actual surgical movements was 0.38mm in the transverse dimension, 0.64mm in the anteroposterior dimension, and 0.55mm in the vertical dimension. In regard to the centroid of the maxilla, the absolute angular difference of the maxillary centroid was 1.06° in pitch, 0.47° in roll, and 0.49° in yaw. Maxillary repositioning surgery can be performed with high accuracy using CAD/CAM titanium surgical guides and fixation plates.

A novel molecule, SLURP-1, enhances the survival of periodontal ligament fibroblasts.

BACKGROUND AND OBJECTIVE: The mechanism behind the survival of periodontal ligament fibroblasts is critical for the maintenance of periodontal ligament tissue. However, the number of known proteins that are involved in this action is limited. The aim of this study was to examine the role of a novel molecule, secreted mammalian Ly-6/urokinase-type plasminogen activator receptor-related protein 1 (SLURP-1), in periodontal ligament fibroblast survival. MATERIAL AND METHODS: Human periodontal ligament fibroblasts were isolated from eight healthy human donors using established protocols. Gene expression for SLURP-1 was analysed using the reverse transcriptase-polymerase chain reaction, while protein expression was examined by immunoblotting with a SLURP-1 antibody. In addition, the apoptotic effect was examined using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling assay. RESULTS: Messenger RNA for SLURP-1 was expressed in the periodontal ligament, gingival fibroblasts, oral keratinocytes and bone. Moreover, the protein was secreted by both periodontal ligament and gingival fibroblasts. Functional analysis revealed that SLURP-1 substantially enhanced cell survival in periodontal ligament fibroblasts by the anti-apoptotic signal phosphatidylinositol 3-kinase. CONCLUSION: These findings suggest that SLURP-1 may play an important role in the control and maintenance of the periodontal ligament by protecting the periodontal ligament fibroblasts from apoptosis.