Rigid internal fixation with titanium versus bioresorbable miniplates in the repair of mandibular fractures in rabbits

The purpose of this study was to compare by qualitative histology the efficacy of rigid internal fixation with titanium system and the Lacto Sorb system in mandibular fractures in rabbits. Thirty male adult rabbits Oryctolagus cuniculus were used. Unilateral mandibular osteotomies were performed between the canine and first premolar. The animals were divided into two groups: for Group I-rigid internal fixation was performed with titanium system 1.5 mm (Synthes, Oberdorf, Switzerland), with two screws of 6 mm (bicortical) on each side of the osteotomy. For Group II-rigid internal fixation was performed with PLLA/PGA system 1.5 mm (Lacto Sorb, WLorenz, Jacksonville, FL, USA). The histological analysis evaluated the presence of inflammatory reaction, degree of bone healing and degree of resorption of the Lacto Sorb screws. The results of both fixation systems were similar, only with a small difference after 15 and 30 days. In Group I a faster bony healing was noted. But after 60 days, bony healing was similar in both groups. It is concluded that both PLLA/PGA and titanium plates and screws provide sufficient strength to permit mandibular bone healing. The resorption process of PLLA/PGA osteosynthesis material did not cause acute or chronic inflammatory reaction or foreign body reaction during the studied period.

Volumetric upper airway assessment in patients with transverse maxillary deficiency after surgically assisted rapid maxillary expansion

Transverse maxillary deficiency is commonly found in patients with sleep apnea and is also related to abnormal breathing patterns. Maxillary expansion procedures promote widening of the nasal floor and reduce the resistance to airflow, and have a positive influence on nasopharynx function. In order to evaluate volume changes in the upper airway, 15 adult patients with transverse maxillary deficiency underwent surgically assisted rapid maxillary expansion (RME) until a slight overcorrection of the crossbite was obtained. Cone beam computed tomography (CBCT) volumetric images were obtained at three predefined time points. The mean age of the patients was 30.2 (±7.4) years; nine were females and six were males. The area, volume, and the smallest transverse section area of the airway were assessed using Dolphin Imaging 3D software. Statistical comparisons were made of the changes between time periods. No statistically significant differences were found for volume or area. However a significant difference was found between the preoperative and immediate postoperative smallest transverse section area (P<0.05). Maxillary expansion, as an isolated procedure, does not result in a statistically significant improvement in the airway dimensions and results in an inferior relocation of the smallest transverse section area.

Nasal airway evaluation in obstructive sleep apnoea patients: volumetric tomography and endoscopic findings

Obstructive sleep apnoea (OSA) results from the recurrent collapse of the upper airway during sleep. Nasal abnormalities influence the stability of the pharynx. The aim of this study was to evaluate the volumetric and anatomical changes of the nasal cavity in patients with OSA. The Nasal Obstruction Symptom Evaluation (NOSE) scale was used to grade nasal obstruction. Sleep-related breathing disorders were evaluated by polysomnography. The nasal airway volume was obtained from computed tomography scans through volumetric reconstruction of the nasal airway. Alterations to the nasal anatomy were identified by nasal fibre-optic endoscopy. Ninety-four patient charts were analyzed. The final sample comprised 32 patients with severe OSA, 16 with moderate OSA, 23 with mild OSA, and 20 without OSA. Three groups were established based on nasal obstruction and OSA. The groups were compared for nasal airway volume (P=0.464) and body mass index (P=0.001). The presence of nasal septum deviation and inferior turbinate hypertrophy were related to the NOSE score (P=0.05 for both), apnoea-hypopnoea index (P=0.03 and P=0.05, respectively), and nasal airway volume (P=0.71 and P=0.78, respectively). In this nasal airway evaluation of OSA patients, the presence of sites of obstruction was correlated with the severity of OSA; this was not the case for the evaluation of the nasal airway volume dimensions.