A Modified Technique of Mandibular Ramus Sagittal Split Osteotomy for Prevention of Inferior Alveolar Nerve Injury: A Prospective Cohort Study and Outcome Assessment.

BACKGROUND: Postoperative functional impairment of the inferior alveolar nerve (IAN) has been a common and well-recognized complication. Our study introduced a modified Obwegeser-Dal Pont bilateral sagittal split osteotomy (BSSO) technique and evaluated the subsequent incidence of postoperative neurosensory disturbance of IAN. METHODS: In this prospective cohort study, 57 patients receiving our modified BSSO during orthognathic surgery were enrolled. The technique contained opening the 2 ramus cortices and inserting the osteotome bypassing the IAN to avoid nerve injury. A 5-point scale self-assessment questionnaire was used to evaluate IAN neurosensory disturbance one week, six months and 12 months postoperatively. Differences between groups were analyzed using χ test for categorical and Wilcoxon signed-rank test for pairwise categorical data. RESULTS: Complete ramus splitting could be achieved in 109 (95.6%) sides. Lower lip or chin neurosensory disturbances presented in 72 (63.2%) sides 1 week postoperatively and gradually reduced to 9 (7.9%), and 4 (3.5%) at postoperative months 6 and 12, respectively. CONCLUSIONS: This BSSO technique could be safely performed with low rates of IAN exposure and injury and a low incidence of persistent neurosensory disturbance in 3.5% of patients 12 months postoperatively.

Higher Dose of Dexamethasone Does Not Further Reduce Facial Swelling After Orthognathic Surgery: A Randomized Controlled Trial Using 3-Dimensional Photogrammetry.

PURPOSE: The objective of this prospective, double-blind, randomized clinical trial was to compare the effect of 2 dexamethasone dosages on reducing facial swelling after orthognathic surgery through 3-dimensional (3D) photogrammetry. PATIENTS AND METHODS: Patients were classified into group 1 (control group) and group 2 (study group), depending on the administered dexamethasone dosage (5 and 15 mg, respectively). Three-dimensional images were recorded at 5 time points: preoperative (T0) and postoperative at 48 ± 6 hours (T1), 1 week (T2), 1 month (T3), and 6 months (T4). A preliminary study was performed on 5 patients, in whom 3D images were captured at 24, 36, 48, and 60 hours postoperatively to record serial changes in facial swelling. Facial swelling at T1, T2, and T3 and the reduction in swelling at T2 and T3 compared with that at the baseline (T4) were calculated. Possible complications, namely, adrenal suppression, wound dehiscence, wound infection, and postoperative nausea and vomiting were evaluated. RESULTS: In total, 68 patients were enrolled, of whom 25 patients in group 1 and 31 patients in group 2 were eligible for final evaluation. No significant differences were found between the 2 groups at any period. On average, the swelling subsided by 86% at 1 month after the orthognathic surgery. Facial swelling peaked approximately 48 hours after the surgery. The incidence of nausea and vomiting did not differ significantly between the groups. CONCLUSIONS: The effect of 5 and 15 mg of dexamethasone on facial swelling reduction as well as on nausea and vomiting after orthognathic surgery was not significantly different.

Intraoperative navigation for single-splint two-jaw orthognathic surgery: From model to actual surgery.

OBJECTIVE: This study reported an intraoperative navigation system for single-splint two-jaw orthognathic surgery, and assessed the accuracy of transferring the computer assisted surgical simulation. METHODS: A skull model was used for validation, and twenty patients receiving such procedure were enrolled. The procedure contained five phases, including virtual surgery on three-dimensional images, fabrication of surgical positioning guides, preparation of registration and validation landmarks, confirmation of bony position during surgery, and postoperative assessment. Target registration error (TRE) and differences between simulation (T0) and postoperative images (T1) were measured from landmarks to Frankfort horizontal plane (FHP), mid-sagittal plane (MSP), and coronal plane (COP). RESULTS: For the model experiment, mean TRE was lowest using the hard tissue landmarks (0.60 ± 0.27 mm), and the mean difference (T1-T0) was less than 1 mm to all three planes. For the patients, mean TRE was 1.07 ± 0.18 mm from the hard tissue landmarks. The mean difference was 0.96. ± 0.60 mm from MSP, 1.39 ± 1.11 mm from FHP, and 2.12 ± 1.82 mm from COP. The differences were not significant. Both surgeons and patients were satisfied with the surgical outcome. CONCLUSION: This study showed that the navigation system had acceptable accuracy and was useful for the two-jaw orthognathic surgery using single-splint method.

Three-dimensional computer-assisted orthognathic surgery: experience of 37 patients.

PURPOSE: Three-dimensional computer-assisted orthognathic surgery has been applied to improve planning and outcome. This study presents our experience with this promising modality for simulation of surgery, prefabrication of positioning guides, and navigation of the surgery. METHODS: Thirty-seven patients who received surgical simulation and intraoperative navigation for 2-jaw orthognathic surgery were recruited. Preoperative 3-dimensional cone-beam computed tomographic images were used for surgical simulation and design of intraoperative guidance. An initial surgical plan was developed and transferred for 3-dimensional virtual surgery. Modification of the surgical plan was made if facial symmetry and skeletal harmony or collision of ramus segments were concerned. The result of virtual surgery was used to design and manufacture positioning guides and perform preoperative navigation planning. During the operation, the positioning guides were used to transfer the virtual planning to actual surgery, and a real-time navigation system was used to confirm the predetermined position of the maxillomandibular complex. For assessment of the computer-assisted surgical system, the simulation image was superimposed to the postoperative image for comparison. RESULTS: The computer-assisted orthognathic surgery was successfully carried out in all patients. The initial surgical plan was modified in 17 patients in whom the position of maxillomandibular complex was changed. The positioning guides were helpful in controlling the spatial position of the maxillomandibular complex. The BrainLabTR navigation system was useful to further confirm the position of the facial bone. Superimposition of the simulation and postoperative images revealed satisfactory result with acceptable errors. The difference ranged from 0.05 to 1.46 mm, with a mean value of 0.66 mm, for patients using the positioning guides; and the difference ranged from 0.07 to 2.30 mm, with a mean value of 1.20 mm, for patients using the navigation system. Overall, patient and doctor satisfaction was high. CONCLUSION: This computer-assisted orthognathic surgery system helps to improve surgical planning, reduce surgical difficulty, facilitate positioning and fixation of the maxillomandibular complex, and improve outcome.

Jaw deviation and ankylosis caused by condylar osteochondroma: long-term treatment outcome.

PURPOSE: To evaluate outcomes of total subcondylar excision of mandibular condylar osteochondroma. PATIENTS AND METHODS: Two adult patients presented with progressive facial asymmetry, jaw deviation, and limited mouth opening. Computed tomogram (CT) showed a large osseous tumor arising from the right condyle occupying the subtemporal space in these patients. Complete surgical excision was performed without condyle reconstruction. The pathology report indicated osteochondroma. Patients were followed for an average of 5 years. RESULTS: Long-term evaluation showed restoration of dento-occlusal function and facial appearance. Follow-up CT showed a partly regenerated and remodeled condyle. Patients' chewing function was acceptable, but predominantly on the lesion side. CONCLUSIONS: Condylar osteochondroma caused jaw deviation and joint dysfunction. Complete surgical excision achieved an adequate long-term outcome, but condylar reconstruction is advisable.

The Efficacy and Safety of Ablative Fractional Resurfacing Using a 2,940-Nm Er:YAG Laser for Traumatic Scars in the Early Posttraumatic Period.

BACKGROUND: Skin injuries, such as lacerations due to trauma, are relatively common, and patients are very concerned about the resulting scars. Recently, the use of ablative and non-ablative lasers based on the fractional approach has been used to treat scars. In this study, the authors demonstrated the efficacy and safety of ablative fractional resurfacing (AFR) for traumatic scars using a 2,940-nm erbium: yttrium-aluminum-garnet (Er:YAG) laser for traumatic scars after primary repair during the early posttraumatic period. METHODS: Twelve patients with fifteen scars were enrolled. All had a history of facial laceration and primary repair by suturing on the day of trauma. Laser therapy was initiated at least 4 weeks after the primary repair. Each patient was treated four times at 1-month intervals with a fractional ablative 2,940-nm Er:YAG laser using the same parameters. Post-treatment evaluations were performed 1 month after the fourth treatment session. RESULTS: All 12 patients completed the study. After ablative fractional laser treatment, all treated portions of the scars showed improvements, as demonstrated by the Vancouver Scar Scale and the overall cosmetic scale as evaluated by 10 independent physicians, 10 independent non-physicians, and the patients themselves. CONCLUSIONS: This study shows that ablative fractional Er:YAG laser treatment of scars reduces scars fairly according to both objective results and patient satisfaction rates. The authors suggest that early scar treatment using AFR can be one adjuvant scar management method for improving the quality of life of patients with traumatic scars.

Shape and innervation of popliteus muscle.

The aim of this study was to delineate the shape of the popliteus muscle and determine the correct motor point site for treating spasticity. A total of 22 legs from 13 fresh Korean cadavers were evaluated. The x-axis was set as a transverse line across the lateral and medial epicondyle of the femur and the y-axis as a vertical line at the midpoint of the medial malleolus of the tibia and lateral malleolus of the fibula. The popliteus muscle is an obtuse triangle in shape. Superior, medial, and inferior angles were 27.2±4.3°, 114.8±19.8°, and 38.0±18.8° respectively. The lengths of the superior, medial, and lateral sides of the triangle were 7.6±1.0 cm, 6.2±1.0 cm, and 11.9±1.5 cm respectively. Nerve branches ran superficially on the periosteum of the tibia and entered the popliteus on its superficial surface. The diverging point of the nerve branch entered the popliteus from the tibial nerve located at the midline of the popliteal fossa and 17% of the leg length above the intercondylar line. Most nerve entry points (83.3%) were within a 2.0×3.0 cm rectangle with the center located at -1.0 cm (-7%) on the x-axis and -3.3 cm (-9%) on the y-axis.

Hypoglossal-facial nerve anastomosis in the rabbits using laser welding.

The aim of this study is to compare laser nerve welding of hypoglossal-facial nerve to microsurgical suturing and a result of immediate and delayed repair, and to evaluate the effectiveness of laser nerve welding in reanimation of facial paralysis of the rabbit models. The first group of 5 rabbits underwent immediate hypoglossal-facial anastomosis (HFA) by microsurgical suturing and the second group of 5 rabbits by CO2 laser welding. The third group of 5 rabbits underwent delayed HFA by microsurgical suturing and the fourth group of 5 rabbits by laser nerve welding. The fifth group of 5 rabbits sustained intact hypoglossal and facial nerve as control. In all rabbits of the 4 different groups, cholera toxin subunit B (CTb) was injected in the epineurium distal to the anastomosis site on the postoperative sixth week and in normal hypoglossal nerve in the 5 rabbits of control group. Neurons labeled CTb of hypoglossal nuclei were positive immunohistochemically and the numbers were counted. In the immediate HFA groups, CTb positive neurons were 1416 +/- 118 in the laser welding group (n = 5) and 1429 +/- 90 in the microsurgical suturing group (n = 5). There was no significant difference (P = 0.75). In the delayed HFA groups, CTb positive neurons were 1503 +/- 66 in the laser welding group (n = 5) and 1207 +/- 68 in the microsurgical suturing group (n = 5). Difference was significant (P = 0.009). There was no significant difference between immediate and delayed anastomosis in the laser welding group (P = 0.208), but some significant difference was observed between immediate and delayed anastomosis in the microsurgical suturing group (P = 0.016). Injected CTb in intact hypoglossal neurons (n = 5) were labeled 1970 +/- 165. No dehiscence was seen on the laser welding site of nerve anastomosis in all the rabbits as re-exploration was done for injection of CTb. This study shows that regeneration of the anastomosed hypoglossal-facial nerve was affected similarly by either laser welding or microsurgical suturing in immediate repair; however, the welding was more effective especially in delayed repair.

Electrophysiologic change and facial contour following botulinum toxin A injection in square faces.

BACKGROUND: This study was proposed to evaluate the facial contour and electrophysiologic changes of the masseter and temporalis muscles before and after botulinum toxin A injection in the wide lower face (square face). METHODS: The botulinum toxin A injections were performed on 10 patients for the treatment of square face with masseter hypertrophy. To obtain an objective evaluation of the change in the facial contour, physical measurements, cephalometry, and clinical photographs were taken; and for evaluation of the function of the masseter and temporalis muscles, electromyographic studies were performed before and 1, 3, 5, 7, 9, and 12 months after treatment. RESULTS: By physical measurements and cephalometry, the maximal reduction in lower facial contour (mean reduction, 6.6 mm by physical measurements and 7.5 mm by cephalometry) was observed 3 months after the injection, and increased slowly until 12 months after treatment. The maximal amplitude of the right and left masseter muscles decreased to the lowest value 1 month after treatment, with continuous increase being observed thereafter. There were statistically significant differences at all of the follow-up time points in reduction of lower facial contour by physical measurements and in electromyographic studies of the left masseter muscles. There was no hypertrophy of the temporalis muscle to compensate for the atrophy of the masseter muscles. CONCLUSIONS: In this study, there was a 2-month interval between the lowest value of the maximal amplitude of the surface electromyography and the maximal clinical effects following botulinum toxin A injection, and there was similarity between the recovery of the masseter function and the diminution of the clinical effect. The clinical effect of botulinum toxin A persisted for 12 months after treatment on physical measurements, and the authors felt that this long-lasting effect of botulinum toxin A beyond expectation could be explained by incomplete recovery of muscle function.

Facial-hypoglossal nerve anastomosis using laser nerve welding.

The aim of this study is to compare laser nerve welding to microsurgical suturing of hypoglossal-facial nerve anastomosis (HFA), and a result of immediate to delayed repair, and to evaluate the effect of laser nerve welding on HFA for reanimation of facial palsy. The first group of five rats underwent immediate HFA by microsurgical suturing and the second group of five rats by CO2 laser welding. The third group of five rats underwent delayed HFA by microsurgical suturing, and the fourth group of five rats by laser nerve welding. The fifth group of five rats served as controls, with intact hypoglossal and facial nerve. In all rats of the four different treatment groups, cholera toxin B subunit (CTb) was injected in the epineurium distal to the anastomosis site on the postoperative 6th week and in the normal hypoglossal nerve in the five rats of the control group. Neurons labeled CTb of hypoglossal nuclei were positive immunohistochemically, and the numbers were counted. In the immediate HFA groups, CTb-positive neurons were 751 +/- 247 in the laser welding group (n = 5) and 888 +/- 60 in the microsurgical suturing group (n = 5). There was no significant difference (P = 0.117). In the delayed HFA groups, CTb-positive neurons were 749 +/- 54 in the laser welding group (n = 5) and 590 +/- 169 in the microsurgical suturing group (n = 5). The difference was not significant (P = 0.116). There was no significant difference between immediate and delayed anastomosis in the laser welding group (P = 0.600), but there was significance between immediate and delayed anastomosis in the microsurgical suturing group (P = 0.009). Injected CTb in intact hypoglossal neurons (n = 5) were labeled 1,003 +/- 52. No dehiscence in the laser welding site of nerve anastomosis was seen at the time of re-exploration for injection of CTb in all 10 rats. This study shows that the regeneration of anastomosed hypoglossal-facial nerve was affected similarly by laser welding and microsurgical suturing, and more effective, especially in delayed repair.

Analysis of nasal bone fractures; a six-year study of 503 patients.

The aim of this study is to classify the nasal bone fractures based on computed tomography (CT) analysis and patterns of the nasal bone fractures, and review 503 cases treated between 1998-2004 at the Department of Plastic Surgery, Inha University Hospital, Incheon, South Korea. The age, sex, etiology, associated injuries, pattern of fractures and treatments were reviewed and a radiographic study was analyzed. Plain simple radiographs of lateral and Waters view of the nasal bones combined with computed tomography scans were done. Nasal bone fractures were classified into six types: Type I) Simple without displacement; Type II) Simple with displacement/without telescoping; IIA; Unilateral; IIAs) Unilateral with septal fracture; IIB) Bilateral; IIBs) Bilateral with septal fracture; Type III) Comminuted with telescoping or depression. Diagnosis of nasal bone fractures were made positively by plain x-ray films in 82% of cases, negative finding was 9.5% and 8.5% of cases were suspicious of the fractures. Reliability of the plain film radiographs of the nasal bone fracture was 82% in this study. In the most of the fractured nasal bones (93%) the closed reduction was done, open reduction in 4% and no surgical intervention in 3%. Nasal reduction was carried out in average 6.5 days post the injury. The patterns of the nasal bones fractures classified by CT findings were type IIA (182 cases, 36%), IIBs (105 cases, 21%), IIB (90 cases, 18%), IIAs (66 cases, 13%), I (39 cases, 8%) and III (21 cases, 4.3%). We think the CT is necessary for diagnosing nasal bone fracture because the reliability of the plain film was only 82%.

The results of periorbital rejuvenation with botulinum toxin A using two different protocols.

BACKGROUND: This study was proposed to analyze the changes in shape and position of the eyebrow before and after botulinum toxin A injection using two different protocols for a periorbital rejuvenation. METHODS: The botulinum toxin A treatment was performed for brow-lift and effacement of crow's feet (group A), and for brow-lift and effacement of glabellar frown lines in addition to crow' feet (group B). To evaluate the change in brow shape and height, measurements of five points around the brow were taken before and after treatment. RESULTS: In groups A and B, the brow positions were elevated, and the interbrow distance was increased. The central brow showed the largest elevation, followed by the lateral brow and the medial brow. The difference in the interbrow distance between groups A and B was statistically significant (p < 0.001). CONCLUSION: Elevation of the eyebrow with the desired aesthetically pleasing curvature was obtained after botulinum toxin A treatment in both groups using two different protocols for periorbital rejuvenation. The effect on the muscular dynamics after treatment can be changed according to the amount and the injection points. Therefore, in determining the injection protocols for periorbital rejuvenation, consideration should be given to the change in brow position and shape according to the change in the muscular dynamics after treatment.

Laser welding of rat's facial nerve.

The aim of this study is to compare regeneration of the severed nerves that were repaired by laser welding with those repaired by microsurgical suturing and evaluate the value in use of laser nerve welding in the head and neck area. In 12 rats the buccal branches of the facial nerves on the both sides were transected, and CO2 laser welding of the epineurium was performed on the right side and microsurgical suture technique was applied on the left side. In six rats Cholera Toxin B Subunit (CTb) was injected in the epineurium distal to the nerve anastomosis site at postoperative week 4. Another six rats were treated exactly in the same way in postoperative week 8. Six normal rats were used as controls. Intact facial nerve was observed after injection of CTb as well. Neurons of facial nuclei labeled positively by CTb were detected immunohistochemically, and the numbers were counted. CTb-positive neurons in the control group were 1311 +/- 258 (n = 6). CTb-positive neurons in the group (n = 6) with laser nerve welding were 1174 +/- 122 in postoperative week 4 and 1562 +/- 565 in postoperative week 8. CTb-positive neurons in the group (n = 6) with microsurgical suture were 1066 +/- 89 in postoperative week 4 and 1443 +/- 531 in postoperative week 8. CTb-positive neurons were seen significantly more in the group with laser welding than in the group with microsurgical suture in postoperative week (P = 0.028), but there was not much difference in postoperative week 8 (P = 0.463). None of 12 rats showed dehiscence at the nerve anastomosis done by laser welding. This study shows that nerve regeneration is more apparent in the nerve repaired by laser welding than in that repaired by microsurgical suture.

Neurilemmoma of the tongue.

The authors report a case of uncommon neurilemmoma on the tip of the tongue. A 23-year-old Korean man presented with a mass on the tip of the tongue, which was noted first 3 years before, when it was a small nodule. The mass had been growing slowly. Physical examination revealed a firm, not-tender, oval, elevated, protruded, red mass on the right side tip of the tongue. It measured 2 x 2 cm. The lesion was well capsulated and separated easily. A complete excision was done, and the wound was closed primarily. Histopathologic examination revealed an encapsulated spindle cell tumor, of which two types of the tissue were clear. A small and slow-growing mass in the tongue with positive history of tongue bite is first suggestive of neurilemmoma, as well as neurofibroma, lingual cyst, and minor salivary gland tumor.

Blepharoptosis caused from compression of levator muscle by fractured orbital roof fragment.

The authors report two cases of blepharoptosis caused by compression of the levator muscle by fractured orbital roof fragment; both were improved by surgical treatments. In one case, because neurosurgeons were concerned with the contusional hemorrhage of the right frontal lobe during the early admission period, they missed the orbital roof fracture. The patient underwent surgery on the 18th post-trauma day. In the other case, the early diagnosis was made, and the surgical treatment were performed on the 10th post-trauma day. The authors think if the blepharoptosis is not improved in several days and the fractured fragment is suspected to compress the levator in computed tomography scan, surgical decompression is necessary and should be performed as soon as possible.

Mode of parotid involvement in external auditory canal carcinoma.

Until now, little was known about the mode of parotid involvement in external auditory canal (EAC) carcinoma. The incidence of parotid node metastasis and direct parotid invasion was examined in patients with EAC carcinoma. The study comprised 11 patients with squamous cell carcinomas (SCC) and 10 patients with adenoid cystic carcinomas (ACC). A retrospective review of the surgical specimens was undertaken with specific reference to parotid node metastasis and parotid invasion. Parotid node metastasis was noted only in two cases of advanced staged SCC, whereas none of the ACC patients showed parotid node metastasis. Direct parotid invasion occurred only in advanced staged SCC, however, it did occur in early stage ACC. Our data indicated that elective parotidectomy for control of occult parotid node metastasis is necessary only in advanced SCC carcinoma, whereas parotid management to secure adequate safety margins is mandatory for advanced SCC and all cases of ACC.