Risk factors of nerve injury during mandibular sagittal split osteotomy.

There is little objective data about whether surgical technique or mandibular anatomy are a risk for inferior alveolar nerve (IAN) injury during bilateral sagittal split osteotomy (BSSO). Orthodromic sensory nerve action potentials (SNAPs) of the IAN were continuously recorded on both sides in 20 patients with mandibular retrognathia during BSSO operation. Changes in latency, amplitude, and sensory nerve conduction velocity (SNCV) at baseline and at different stages of the operation were analyzed. The SNAP latencies prolonged, the amplitudes diminished, and the SNCVs slowed down during BSSO (P = 0.0000 for all parameters). The most obvious changes occurred during surgical procedures on the medial side of the mandibular ramus. There was a clear tendency towards more disturbed IAN conduction with longer duration of these procedures (right side R = -0.529. P = 0.02; left side R = -0.605, P = 0.006). Exposure or manipulation of the IAN usually had no effect on nerve function, but the IAN conduction tended to be more disturbed in cases with nerve laceration. Low corpus height (R = 0.802, P = 0.001) and the location of the mandibular canal near the inferior border of the mandible (R = 0.52, P = 0.02) may increase the risk of IAN injury. There was no correlation between the age of the patients and the electrophysiological grade of nerve damage.

Intraoperative monitoring of the inferior alveolar nerve during mandibular sagittal-split osteotomy.

In order to evaluate the risk of nerve injury and to prevent iatrogenic damage at different stages of bilateral sagittal-split osteotomy (BSSO) of the mandible, we monitored the function of the inferior alveolar nerve (IAN) continuously on both sides in 13 orthognathic patients undergoing BSSO. The IAN was stimulated at the mental foramen with two monopolar needle electrodes fixed to the dental splint, and the orthodromic sensory nerve action potentials (SNAP) of the IAN were recorded with a silver-wire electrode inserted near the oval foramen on each side. The latencies, amplitudes, and sensory nerve conduction velocities at baseline, after medial opening, sawing, splitting, eventual manipulation, and fixation of the mandible were analyzed. The monitoring method functioned technically well in 25 of 26 nerves. Both the surgical technique and the duration of medial opening had conspicuous effects on the function of the IAN, which led us to modify the medial approach. When finer instruments were used for retraction and the duration of medial opening was shortened to less than 10 min, the SNAP of the IAN was always preserved at this stage. Monitoring of the IAN also prevented nerve injury during splitting and fixation. This technique for intraoperative monitoring of the IAN seems to be a feasible and promising tool for objective evaluation of intraoperative events and for prevention of nerve injury during BSSO.

Tongue-base suspension with a soft tissue-to-bone anchor for obstructive sleep apnea: preliminary clinical results of a new minimally invasive technique.

The Repose system is a new minimally invasive technique for tongue-base suspension in the treatment of sleep-disordered breathing caused by tongue-base collapse. It involves the insertion of a titanium miniscrew with attached suture into the anterior intraoral mandible and passing the suture through the tongue base. The procedure was performed in 16 patients with sleep-disordered breathing. Fourteen patients reported an improvement in daytime sleepiness, and their bed partners reported an improvement in snoring. The mean respiratory distress index before surgery was 35. Two months after surgery, the mean respiratory distress index was 17, an improvement of 51.4% (P = 0.001, 2-tailed t test). These preliminary results show the initial efficacy and safety of this new surgical procedure.

Detailed tomography of periapical and periodontal lesions. Diagnostic accuracy compared with periapical radiography.

OBJECTIVE: To compare the diagnostic accuracy of detailed tomography using the Scanora system with that of conventional periapical radiography for detecting periapical and periodontal lesions. METHODS: We selected for comparison 243 periapical and 322 periodontal sites in 177 patients. Five observers independently assessed radiographs for the presence or absence of the following lesions: periapical bone changes, widening of apical and marginal ligament space, crestal erosion, vertical bone loss, furcation involvement and calculus. RESULTS: ROC analysis demonstrated no significant differences in the overall interpretation of either disease. Periapical radiography was superior (p < 0.05) to tomography for the detection of calculus. The sensitivity of tomography for periapical pathology was 87%, and 70% for periapical radiography. Sensitivities for periodontal diseases were 84% and 77%. Specificities were 81%, 90%, 77% and 79%, respectively. Differences for sensitivity and specificity were significant (p < 0.05) in relation to periapical pathology. The energy imparted during tomography was 0.92 mJ. CONCLUSION: Detailed tomography and periapical radiography performed equally well for the overall diagnosis of periapical and periodontal lesions. Tomograms differed substantially from periapical radiographs in both sensitivity and specificity for detecting periapical lesions in posterior regions. The energy imparted during detailed tomography is similar to that from two D-speed films.

Radiographic detectability of periodontal diseases. A comparison of perapical radiography with detailed zonography.

OBJECTIVE: To compare the diagnostic accuracy of conventional periapical radiography with detailed zonography using the Scanora system for the detection of periodontal disease. METHODS: We selected for comparison 311 periodontal sites in 165 patients. Five observers independently assessed the periapical radiographs and detailed zonograms for marginal widening of periodontal ligament space, crestal erosion, vertical bone loss, furcation involvement and calculus. RESULTS: ROC analysis revealed no significant differences between the two imaging techniques for either overall or lesion-specific interpretation of periodontal pathology. The sensitivity of periapical radiography was 79%, and of detailed zonography 91% (multiview) and 89% (stereoscopic). Specificities were 82%, 77% and 83%, respectively. CONCLUSION: Detailed zonography performs as well as periapical radiography in the detection of periodontal disease.

A comparison of detailed zonography with periapical radiography for the detection of periapical lesions.

The diagnostic accuracy of detailed zonography using the Scanora multimodal X-ray system was compared with that of periapical radiography. The study was based on the detection of periapical bone lesions at 259 dental sites distributed evenly throughout the dentitions of 164 patients. Each site was examined by periapical radiography and zonography, in parallel. The zonograms consisted of four detailed images that could also be read as stereopairs, in either the horizontal or vertical direction. Five observers evaluated the sites for the presence or absence of periapical osteolysis or sclerosis and apical widening of the periodontal ligament space for the whole dentition, and for three dental regions. ROC analysis revealed no significant overall or regional differences between the diagnostic accuracies of the periapical and zonographic techniques, regardless of whether the zonograms were read as sets of four images (multiview) or stereoscopic images. The sensitivity of periapical radiography was 72%, that of multiview zonography 88%, and that of stereoscopic zonography 85%. Specificities were 93%, 84% and 89%, respectively. The energy imparted during detailed zonography was 0.98 mJ. It is concluded that zonography is as good as periapical radiography for the detection of periapical pathology.

Evaluating function of the inferior alveolar nerve with repeated nerve conduction tests during mandibular sagittal split osteotomy.

PURPOSE: This article evaluates a new intraoperative recording technique for measuring the sensory nerve conduction velocity (SNCV) of the human inferior alveolar nerve (IAN) during orthognathic surgery of the mandible to assess the effects of intraoperative strain on function of the IAN. MATERIALS AND METHODS: The new test was successfully applied in 10 patients during bilateral sagittal split osteotomy of the mandible (20 IANs). The recordings were made with active wire electrodes at foramen ovale and stimulation was done at the mental foramen with two monopolar needle electrodes. The sensory nerve action potentials (SNAP) were recorded intraoperatively at three stages: 1) before the split, 2) after splitting of the mandible and possible mobilization of the IAN from the proximal bone fragment, and 3) at the end of the operation after fixation of the proximal and distal fragments with screws. RESULTS: The SNCV values (mean 64.1 m/sec) were obtained in all 20 nerves at stage 1, with no significant differences between the sides in latency or amplitude of the SNAPs. The sNAPs remained stable in the IANs not exposed during the operation. In the remaining nerves, the most obvious and statistically significant changes indicating nerve injury occurred between stages and 1 and 2. Partial transsection and mobilization of the IAN were equally potent in bringing about abnormal results in objective neurophysiologic tests as well as subjective sensory disturbances. The results of the intraoperative SNCV recordings correlated well with the findings of the mental nerve blink reflex tests conducted 2 weeks after the operation, whereas comparison of the results of clinical neurosensory testing with the intraoperative events and SNCVs were more inconsistent. CONCLUSIONS: Recording of the SNCV offers a useful objective tool for the examination of the IAN both intraoperatively and in clinical diagnosis.

In vivo reactions of Ca,P particle containing surface reactive glasses.

Four Ca,P particle containing surface reactive glass composites and two glasses (in the SiO2-CaO-P2O5-Na2O-Al2O3-B2O3 system) were implanted in the diaphyseal area of goat femora up to 24 weeks. Scanning electron microscopic, energy dispersive x-ray, and histological analysis were performed to evaluate the material-tissue interactions. A new type of integration mechanism was observed. Instead of the bone growing to the material surface, a gel-like silica formation appeared between the cortex bone and the material surface. In time the gel-like formation was replaced by a Ca,P layer. The results provided indirect evidence that pure silica gel formed in the tissues could also achieve an apatite layer formation and bone bonding on its surface.

Comparison of periapical and detailed narrow-beam radiography for diagnosis of periodontal pathology.

The diagnostic performance of the detailed narrow-beam (DNB) technique of the Scanora multimodal X-ray system was compared with periapical radiography for detecting periodontal pathology. In total, 253 sites in 133 patients were examined. Receiver operating characteristics (ROC) of both imaging modalities were analyzed in relation to the ratings of five observers for the whole dentition, three dental regions and five types of periodontal lesion. ROC analysis demonstrated that the overall diagnostic performance of DNB radiography was better (P < 0.05) than that of periapical radiography. DNB radiography was significantly superior (P < 0.01) for detecting marginal widening of periodontal membrane space, but there was no significant difference between the two techniques for crestal erosion, vertical bone loss, furcation involvement or calculus. The regional differences found in overall diagnostic performance of the two imaging modalities were not significant. The sensitivity for periapical radiography was 71% and for DNB radiography 85%, and the specificities 82% and 81% respectively. It is concluded that DNB radiography is a good radiographic examination for periodontal disease, and an acceptable alternative to periapical radiography.

Comparison of periapical and detailed narrow-beam radiography for diagnosis of periapical bone lesions.

The diagnostic performance of the detailed narrow-beam (DNB) technique of the Scanora multimodal radiography system was compared for periapical radiography for the detection of periapical bone lesions at 262 dental sites in 144 patients. Receiver operating characteristics (ROC) of both imaging modalities were analysed in relation to the ratings of five observers for the whole dentition, three dental regions, and two types of periapical lesions. ROC analysis demonstrated no overall or regional significant differences in the diagnostic performance of the two imaging modalities. The sensitivity for periapical radiography was 72% and for DNB radiography 90%, and the specificities 89% and 88%, respectively. It is concluded that DNB radiography performs as well as periapical radiography for detecting periapical bone lesions.

Articaine and lidocaine for maxillary infiltration anesthesia.

This study was undertaken to compare the anesthetic properties of articaine hydrochloride with 1:200,000 epinephrine (Ultracain DS) and lidocaine with 1:80,000 epinephrine (Xylocain-Adrenalin) for maxillary infiltration anesthesia. Twenty healthy dental student volunteers were included in this double-blind study. Each subject received 0.6 mL of each test solution at different times. Infiltration anesthesia was performed on the upper lateral incisor. The onset and duration of anesthesia were monitored using an electric pulp tester. No statistically significant differences were seen in the onset and duration of anesthesia between the articaine and lidocaine solutions.