Recovery of nerve injury after mandibular sagittal split osteotomy. Diagnostic value of clinical and electrophysiologic tests in the follow-up.

The diagnostic value of several clinical, quantitative sensory tests (brush-stroke directional discrimination (BSD), touch detection threshold (TD), warm/cold (W/C) and sharp/blunt discrimination (S/B)), and electrophysiologic tests (mental nerve blink reflex (BR), nerve conduction study (NCS), cold (CDT), and warm (WDT) detection thresholds) in the recovery of inferior alveolar nerve (IAN) injury was evaluated in a prospective 1-year follow-up study of 20 patients after bilateral sagittal split osteotomy (BSSO). The subjective sensory alteration was assessed from patients' drawings. The predictive values of different tests at 2 weeks were determined in relation to the subjective sensory recovery at 12 months. The most pronounced recovery of the nerve damage occurred during the first 3 months according to all measures used. After 3 months, the electrophysiologic tests, especially the NCS, indicated significant further improvement. Except for the TD test, all other clinical test results were normal already at 3 months postoperatively. At early and late controls, the NCS and the thermal quantitative sensory testing could best verify the subjective sensory alteration, and most accurately assess the degree of thick and thin fibre dysfunction. At 1 year, the nerve dysfunction, as revealed by the NCS, corresponded with the figures of sensory alteration reported by the patients (35% R, 40% L). The W/C, BSD, S/B and WDT tests had the best early positive predictive values. Electrophysiologic tests had higher negative predictive values compared to clinical tests.

An evaluation of clinical and electrophysiologic tests in nerve injury diagnosis after mandibular sagittal split osteotomy.

The yield of clinical sensory tests and electrophysiologic tests in the diagnostics of inferior alveolar nerve (IAN) damage after bilateral sagittal split osteotomy (BSSO) was studied. The diagnostic value of these tests was evaluated by comparing the test results to the degree of nerve damage at the end of the operation as documented by means of the intraoperative nerve conduction recording of the IAN. Twenty patients undergoing BSSO were analysed preoperatively and 2 weeks postoperatively. The frequency of the IAN disturbance ranged from 10% to 94% depending on the test method and the test site used. Of the clinical sensory tests, the touch detection threshold (TD) test was the most sensitive and clinically useful test. It also correlated best with the electrophysiologically verified intraoperative nerve damage (R = -0.603, P = 0.017 on the right, R = -0.626, P = 0.01 on the left). The blink reflex and quantitative cold detection threshold tests were almost as often abnormal as the TD-test, but nerve conduction study (NCS) was the most sensitive (88%) of all clinical and electrophysiologic tests. The frequency of abnormal findings in the electrophysiologic tests indicating IAN injury, 75% on the right side and 90% on the left side, corresponded exactly with the figures of subjective sensory alteration. Almost all electrophysiologic tests showed obvious associations with the objectively verified IAN damage. All tests, except the NCS, showed only moderate sensitivity. Specificity of the tests was generally high, the only exceptions being the TD test and the NCS. To increase the diagnostic accuracy of the testing and to detect different types of damage in different nerve fibre populations, a combination of different sensory and electrophysiologic tests is recommended.

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.

Expectations and perceptions regarding treatment: a prospective study of patients undergoing orthognathic surgery.

One hundred consecutive patients undergoing orthognathic surgical treatment were interviewed concerning their problems before surgery, motives for seeking treatment, and the effects of treatment 1 year after surgery. Comparison with other studies was undertaken using questionnaires validated in such studies. Before surgery, problems relating to function were most significant, followed by esthetic concerns and, to a far lesser extent, social interaction-type problems. Motives for seeking treatment also related mostly to functional issues. Such issues were considered best resolved through treatment. The finding that functional issues were of greater significance to patients than esthetic concerns differs from findings in most previous studies. The difference may at least partly be explained by sociocultural differences.

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.

The effect of intermaxillary fixation on leukocyte zinc, serum trace elements and nutritional status of patients undergoing maxillofacial surgery.

Mononuclear cell (MNC), polymorphonuclear cell (PMNC) and serum zinc levels were studied in 17 oral surgical patients with intermaxillary fixation. Serum copper, iron, selenium and bromide concentrations were also measured together with common indices of nutritional status. Nine patients received nutritional counselling. Eight patients had, in addition, oral supplementation with a commercial formula. No changes in intracellular or serum zinc levels were seen during the study period. A statistically significant decrease was seen in mean body weight with subsequent changes in anthropometry. Maximal mean weight loss was 6.0 +/- 3.8% in control group and 3.8 +/- 2.7% in supplemental group. The impaired oral intake due to intermaxillary fixation does not interfere significantly with zinc status as estimated by MNC, PMNC or serum zinc levels. The reduction in body weight and anthropometric indices in the relatively short fixation period may be clinically significant in some patients. Supplementation with a commercial formula helps to maintain the nutritional status of these patients.

Superior repositioning of the maxilla combined with mandibular advancement: mandibular RIF improves stability.

Postsurgical changes in 24 patients who had rigid internal fixation (RIF) of the mandible with screws after combined superior repositioning of the maxilla and mandibular advancement were compared with 53 patients who underwent the same surgery but who had intraosseous wire fixation, skeletal suspension wires, and 8 weeks of maxillomandibular fixation (MMF). During the first 8 weeks after surgery, the mean posterior relapse of the mandible was greater in the MMF group than in the RIF group (for example, -1.1 mm versus 0.15 mm at B point), and the percentage of patients with clinically significant vertical and horizontal changes was greater in the MMF group. By 1 year, there had been slight additional mean relapse in the MMF group (-1.5 mm net relapse at B point, with 42% of the patients showing 2 mm or more relapse). In the RIF group, the mandible was more likely to be repositioned forward than posteriorly (net mean change at B point, 0.7 mm forward; 33% had 2 mm or more forward movement). In the RIF group, all but one of the patients (96%) were judged to have an excellent clinical result; in the MMF group, the corresponding figure was 60%.

Oral mucosal soft tissue necrosis caused by superinfection. Report of three cases.

Three patients in whom flap necrosis developed after oral surgeries and antibiotic therapies were studied microbiologically by routine aerobic and anaerobic methods. In all cases the bacteria Enterobacter cloacae, Klebsiella oxytoca, Escherichia coli, and coagulase-negative penicillinase-producing staphylococci were resistant to the antibiotics used. These bacteria are frequent microorganisms of superinfection and were not found after the necrotic tissues had repaired.

Non-Hodgkin's lymphomas presenting through oral symptoms.

Non-Hodgkin's lymphomas (NHL) presenting through oral symptoms are rare. Between 1976 and 1987, a total of 17 cases (7 male, 10 female) were diagnosed in our departments. The first symptom was an intraoral tumour mass in 9 cases, loosening of teeth in 2 cases and paraesthesia in another 2. Most tumours (13/17) were located in the lower jaw. In only 5 cases had the referring physician or dentist suspected malignancy. In 3 cases, the histological diagnosis was Burkitt's lymphoma. The grade of malignancy was classified as low in 4 cases, intermediate in 3 and high in 8. None of the patients was HIV-positive. Nine patients died of their disease within 1-132 months (mean 18.3 months).

A botryoid odontogenic cyst with multiple recurrences.

A botryoid odontogenic cyst (BOC) which recurred 4 times over a period of 9 years is presented. Immunocytochemical comparison of cytokeratin composition of the cyst epithelium with that of the overlying oral epithelium showed distinct differences. The cyst epithelium expressed keratins typical of both simple and nonkeratinizing squamous epithelia. The keratin profile of BOC is in line with previous findings on odontogenic epithelia, thus confirming its odontogenic origin.

Synovial chondromatosis of the temporomandibular joint. Report of a case and review of the literature.

An illustrative case of synovial chondromatosis in the temporomandibular joint (TMJ) region is presented, and 36 cases reported earlier are reviewed. The present patient, a 35-year-old woman, had been suffering from swelling and pain in the TMJ area as well as limited mandibular movements for 7 years. The condition had been treated with various conservative methods without any relief of the symptoms. Finally, radiological examination revealed calcified nodules within the joint space and a surgical exploration was performed. In all, 27 loose particles were removed from the joint in connection with the extirpation of the perforated and deformed disk. The result of surgical therapy has been favourable during the follow-up period of 18 months. Although synovial chondromatosis is rare in the TMJ, it should be kept in mind as one possible disease when treating patients suffering from symptoms similar to those of mandibular dysfunction syndrome.

Recurrence of keratocysts. A long-term follow-up study.

The aim of the study was to investigate the recurrence rate of keratocysts based on a material with a follow-up of at least 5 years, and to evaluate the relationship between different features of these cysts and their recurrence. It was found that of 75 keratocysts with follow-up times ranging from 5 to 17 years (mean 8.3), 32 (43%) recurred. The cumulative recurrence rate of the 67 annually examined cysts increased from 3% after the 1st year following the operation to 37% after the 3rd year. Thereafter, no new recurrences were noted. Recurrence of keratocysts in patients with basal cell nevus syndrome occurred more frequently than that of patients without the syndrome. Keratocysts enucleated in one piece recurred significantly less often than cysts enucleated in several pieces. The recurrence rate of keratocysts with a clinically observable infection, with fistula or with a perforated bony wall was higher than that of keratocysts without these features. Recurrence was also found more frequently in cysts with multilocular radiographic appearance than in unilocular cysts. The size or the location of the keratocysts did not have an influence on the recurrence rate.

Simple bone cyst. Review of the literature and analysis of 23 cases.

A retrospective study of 23 simple bone cysts including analysis of clinical, radiographical, histopathological features and follow-up information was made. The age of the patients varied from 8 to 59 years (mean 21.4 years). All lesions were found in the mandible, and 2 of them were radiologically multilocular. A loose connective tissue lining was found histologically in 8 out of 17 cysts with the biopsy specimens available. At follow-up, 2 failures of the primary surgical treatment were noted. The results emphasize that a proper follow-up is required after the treatment of simple bone cyst.

Osteochondroma of the mandibular condyle. Report of a case and review of the literature.

Osteochondroma (osteocartilaginous exostosis) is a rare tumour in the region of the mandibular condyle. Much confusion seems to exist in the literature in differentiating these tumours from condylar chondromas as well as from condylar hyperplasias. A case of condylar osteochondroma with a review of the literature is presented.