Hemispheric control of motor function: a whole brain echo planar fMRI study

A sample of 130 patients with vertical maxillary hyperplasia; mandibular hypoplasia with a high mandibular plane angle; narrow, tapered maxillary dental arch form; and anterior vertical open bite were collected from three different institutions to evaluate the stability of transverse maxillary arch dimensions after correction of the open bite. Surgical treatment consisted of Le Fort I or bimaxillary osteotomies. Intermolar, interpremolar, and anterior arch widths were measured three-dimensionally on dental casts using a Reflex microscope, and transverse stability after orthodontic or surgical maxillary expansion was analyzed. Orthodontic expansion followed by a one-piece Le Fort I intrusion osteotomy was performed in 77 patients, and surgical maxillary expansion by a multisegment Le Fort I intrusion osteotomy was performed in 53 patients. The increase of transverse arch width and the relapse after orthodontic or surgical expansion were not significantly different. The transverse arch width in these two groups did not relapse in 20% of the patients after a mean follow-up of 69 months. An additional bilateral sagittal split osteotomy had no detectable effect on stability. Patients who underwent a multisegment Le Fort I osteotomy stabilized with rigid internal fixation showed better transverse stability than those with intraosseous wire fixation and maxillomandibular fixation. Maxillary intermolar and interpremolar arch width relapses were not correlated with tongue interposition or loss of interdigitation. The relapse of these arch widths showed significant correlations with clockwise rotation of the mandible but not with changes of overbite or overjet.     

Open bite deformity in amelogenesis imperfecta. Part 2: Le Fort I osteotomies and treatment results

Functional conditions, skeletal and dento-alveolar stability and condylar changes in 15 patients with mandibular hypoplasia, anterior open bite (AOB) and amelogenesis imperfecta (AI), who had undergone a Le Fort I osteotomy, were analysed after a mean follow-up of 5 years. Two patients underwent a one-piece Le Fort I intrusion osteotomy and 13 patients a multi-segment Le Fort I osteotomy. In three of these patients, an additional bilateral sagittal split osteotomy was performed. Thirteen patients underwent a genioplasty. Surgery was followed by prosthetic rehabilitation in 10 patients. Skeletal and dento-alveolar stability were analysed on lateral cephalometric radiographs and condylar changes on orthopantomographic radiographs. Transverse stability of the dental arches was analysed on dental casts. The treatment results in this group were compared with patients with similar skeletal features but without amelogenesis imperfecta. The harmony of the long faces was restored and a reasonable vertical stability of the maxilla was achieved, however, a slight open bite and tongue interposition was still present. The transverse stability of dental arches (60%) was disappointing. Rigid internal fixation produced better transverse stability. Progressive condylar resorption was seen in two patients (13%). Less occlusal stability could be achieved in patients with AI, but resulted neither in less skeletal stability nor in more susceptibility to morphological condylar changes.     

Treatment of condylar hyperplasia of the mandible using unilateral ramus osteotomies

PURPOSE: The long-term outcome of bilateral and unilateral ramus osteotomies used for the treatment of unilateral condylar hyperplasia of the mandible are evaluated and compared. MATERIALS AND METHODS: Thirteen cases of unilateral condylar hyperplasia of the mandible were surgically treated during a 10-year period from 1985 to 1995. Seven of the patients were treated by bilateral ramus osteotomies alone; six were treated by unilateral ramus osteotomies of the affected side. Unilateral ramus osteotomy was combined with a maxillary Le Fort I procedure in two of the six cases. Preoperative analysis of patients, indications for case selection, and postoperative results relating to facial symmetry, temporomandibular joint (TMJ) pain, occlusion, and stability were compared in the two groups. RESULTS: The postoperative findings and long-term results in both groups of patients were favorable. Symmetry, arch coordination, and occlusion remained stable. TMJ pain and dysfunction were invariably cured postoperatively. Unilateral ramus osteotomies alone, or in combination with maxillary surgery when deemed feasible and applicable by preoperative clinical analysis, was sufficient to restore symmetry and occlusion in dentally compensated cases. CONCLUSIONS: This study shows that patients with unilateral condylar hyperplasia of the mandible and deviation can be treated favorably by unilateral ramus osteotomy of the affected side; bilateral ramus osteotomy did not have any advantage in such cases. In addition, this procedure, combined with a Le Fort I osteotomy of the maxilla, was also effective in restoring occlusal canting and facial symmetry in dentally compensated cases. However, bilateral ramus osteotomy was required in prognathic cases and in cases in which a unilateral procedure would cause excessive rotation of the contralateral condyle.     

Management of posttraumatic malocclusion caused by condylar process fractures

PURPOSE: The aim of the study was to evaluate the results of orthognathic surgery in cases with posttraumatic malocclusion as a long-term complication of condylar process fractures. PATIENTS AND METHODS: A retrospective study on 21 patients with posttraumatic malocclusions attributable to condylar process fractures was performed. In group I, 15 patients were treated for asymmetric malocclusion with unilateral or bilateral mandibular ramus osteotomies. In group II, six patients were treated for anterior open bit with either a Le Fort I osteotomy (n=5) or a bilateral ramus osteotomy (n=1). All patients had clinical and radiographic follow-up for at least 1 year. RESULTS: Stable dental and cephalometric results were obtained in all patients except the one in group II who was treated with bilateral sagittal split osteotomies. In two cases, both in the asymmetric group, minor occlusal interferences had to be treated by equilibration in the early postoperative period. CONCLUSIONS: Orthognathic surgery is a predictable and stable method for the treatment of posttraumatic malocclusion due to condylar process fractures. Maxillary orthognathic surgery is successful in correcting symmetric anterior open bites due to bilateral condylar process fractures. Because posttraumatic malocclusion is a rare complication after closed treatment of condylar process fractures, and it can be treated satisfactorily using orthognathic surgery, routine open reduction and fixation of condylar process fractures is not indicated to prevent posttraumatic malocclusion.     

A new condylar positioning appliance for two-jaw osteotomies (Le Fort I and sagittal split ramus osteotomy)

We have presented a new appliance for easy, rapid, and exact repositioning of the proximal segment of the mandible in two-jaw osteotomies (Le Fort I and sagittal split ramus osteotomy).     

Surgical refinement of the operative procedure for a minor degree of mandibular prognathism

Although sagittal splitting ramus osteotomy is used widely for mandibular prognathism and even for that of a minor degree, a long duration of preoperative and postoperative orthodontic treatment is required. Conversely, mandibular segmental osteotomy has often been used to correct a minor degree of mandibular prognathism without specific orthodontic treatment. Here we describe a surgical refinement accomplishing mandibular segmental osteotomy, reduction genioplasty by double horizontal osteotomies, and decortication of the middle portion of the osteotomies for a minor degree of mandibular prognathism. The amount of setback is limited to 4 to 5 mm, no intermaxillary fixation is required, and no orthodontic treatment, in principle, is needed. This procedure can obtain a rapid aesthetic improvement. We used this procedure in 11 patients (7 females and 4 males) with a minor degree of mandibular prognathism. The amount of setback of the mandibular anterior portion was 4 to 5 mm, and satisfactory results were obtained in all patients.     

Tomographic stability of condyle fossa relationships in 40 treated temporomandibular disorder patients

STATEMENT OF PROBLEM: Condylar position and stability after treatment of 40 temporomandibular disorder patients was studied. PURPOSE: This study determined pretreatment position and posttreatment condylar stability. MATERIAL AND METHODS: Forty temporomandibular disorder patients with symptoms of muscles of mastication pain, temporomandibular joint sounds, attrition, interceptive occlusal contacts, and restricted range of motion were used. Axial corrected midcut sagittal tomograms were made of the 80 temporomandibular joints before treatment. Tracings from the tomograms were used to measure and analyze pretreatment position and posttreatment stability. RESULTS: Pretreatment condyle fossa position was not concentric in 26 of 80 patients (32.5%). Posttreatment condylar position showed no change and was statistically stable. CONCLUSION: In this study of 40 temporomandibular disorder patients, no statistical change in condylar position was detected. Variable condylar positions were found in the 80 pretreatment axial corrected midcut sagittal tomograms. All patients were asymptomatic after 1 year.     

Condylar position with rigid fixation versus wire osteosynthesis of a sagittal split advancement

PURPOSE: In this randomized clinical study, two groups of patients who underwent a bilateral sagittal split osteotomy and either wire osteosynthesis or rigid fixation were compared. PATIENTS AND METHODS: Cephalometric radiographs obtained before surgery, immediately after surgery, and at 8 weeks, 6 months, and 1 and 2 years after surgery were available for 125 of these patients, 63 with wire fixation and 62 with rigid fixation. All were traced by an independent examiner, and vertical and horizontal changes in condylar position were recorded for each period. RESULTS: Condylar movement was slightly different with the two fixation techniques beyond 8 weeks postsurgery, but the ultimate position of the condyle was not different. The condyles in both groups moved posterior and superior. There initially was a correlation between the amount of advancement and the amount the condyle moved inferior in both groups, but this diminished with time. In addition, there was a weak but significant positive relationship between forward rotation of the proximal segment and superior condylar position immediately after surgery, which did not exist at later periods. CONCLUSIONS: Whether wire osteosynthesis or rigid fixation was used, the ultimate condylar position was posterior and superior after a bilateral sagittal split osteotomy to advance the mandible. No single factor could be identified to account for this change. It is suggested that change in mechanical load may have resulted in remodeling and adaptation of the condyles.     

Orthognathic surgery: a hierarchy of stability

The stability and predictability of orthognathic surgical procedures varies by the direction of surgical movement, the type of fixation, and the surgical technique employed, largely in that order of importance. The most stable orthognathic procedure is superior repositioning of the maxilla, closely followed by mandibular advancement in patients in whom anterior facial height is maintained or increased. (If facial height is decreased by upward rotation of the chin, stability is compromised). The combination of moving the maxilla upward and the mandible forward is significantly more stable when rigid internal fixation is used in the mandible. Forward movement of the maxilla is reasonably stable, with or without rigid internal fixation, but mandibular setback often is not stable, and downward movement of the maxilla that creates downward rotation of the mandible is unstable. For mandibular setback, the inclination of the ramus at surgery appears to be an important influence on stability. It has been suggested that both interpositional synthetic hydroxyapatite grafting and simultaneous ramus osteotomy improve the stability of downward movement of the maxilla, but this has not been well documented. In two-jaw Class III surgery, the stability of each jaw appears to be quite similar to that of isolated maxillary advancement or mandibular setback. The least stable orthognathic procedure is transverse expansion of the maxilla. Although surgically assisted rapid palatal expansion has been suggested as a more stable alternative to segmental Le Fort I osteotomy, the patterns of movement resulting from the two procedures are different, and differences in stability have not been established.     

Midfacial advancement by bone distraction for treatment of craniofacial deformities

Craniofaciostenosis is often associated with midfacial hypoplasia and has been treated traditionally using Le Fort advancement osteotomies and bone grafts. The surgical procedure requires a prolonged operating time, several osteotomies with a significant blood loss, and wide surgical exposure. According to the principles of bone lengthening, we performed midfacial advancement by bone distraction in 4 patients with midfacial hypoplasia to reduce the operative time and complication rate. In 2 patients with Crouzon's syndrome we performed a Le Fort III osteotomy and placed the distraction device behind the malar eminence and screwed it on the temporal bone bilaterally. In the other 2 children, with Apert's syndrome, we performed frontal advancement and remodeling before placing the device during the same surgery behind the malar bone without any midfacial osteotomy. It appears to us that patients with more severe deformities will need surgical procedures to offer more satisfactory results. In these patients, distraction is an initial therapy to reduce the severity of the deformity, making it possible to effect a better treatment afterward.     

Surgical maxillofacial treatment of obstructive sleep apnea

Obstructive sleep apnea is the most common sleep-related breathing disorder, with a surprisingly high prevalence. The treatment of choice is nasal continuous positive airway pressure (CPAP) ventilation during sleep, which has to be applied throughout the patient's whole life. Because of various underlying pathomechanisms in patients with certain craniofacial disorders--narrow posterior airway space and maxillary-mandibular deficiency--surgical therapy by craniofacial osteotomies seems possible. A series of 38 consecutive patients were treated by 10-mm maxillomandibular advancement by retromolar sagittal split osteotomy and Le Fort I osteotomy, respectively. Obstructive sleep apnea syndrome was improved considerably in all patients; there was no significant difference compared to the results under nasal CPAP. In 37 of 38 patients, the postoperative apnea-hypopnea index was reduced clearly to under 10 per hour, oxygen saturation rose, and sleep quality improved. This was achieved by maxillomandibular advancement of 10 mm without secondary refinements in all but 2 patients. In one patient, the apnea-hypopnea index could only be reduced to 20 per hour, probably because of insufficient maxillary advancement. These results indicate that successful surgical treatment is possible in a high percentage of selected patients with certain craniofacial characteristics. In addition to cardiorespiratory polysomnography, there should be routine cephalometric evaluation of all patients. Maxillomandibular advancement should be offered as an alternative therapy to all patients with maxillary and/or mandibular deficiency or dolichofacial type in combination with narrow posterior airway space.     

Small extra ring chromosome derived from chromosome 10p: clinical report and characterisation by FISH

We report our experience with a modified Le Fort I osteotomy developed to avoid nasal tip upturning, alar base widening, and upper lip flattening in anterosuperior repositioning of the maxilla. We compare the aesthetic results obtained with this variation of the surgical technique to those obtained using the more traditional Le Fort I osteotomy combined with the alar cinch suture and the anterior nasal spine reduction procedures on a sample of 20 patients.     

P2u purinoceptor modulation of intracellular Ca2+ in a human lung adenocarcinoma cell line: down-regulation of Ca2+ influx by protein kinase C

The aim of the present investigation was to study the functional alterations in the stomatognathic system following orthodontic-surgical management of skeletal vertical excess problems. The sample comprised 43 patients who received combined orthodontic-surgical treatment including bilateral vertical ramus osteotomy for posterior repositioning and counterclockwise rotation of the mandible (n = 26) or Le Fort I osteotomy for maxillary impaction (n = 17). All subjects were examined within 1 week before operation and 6 months postsurgery. Methods of examination included: (a) evaluation of dysfunction by means of a clinical index, (b) measurement of mandibular range of motion, (c) assessment of the number and intensity of occlusal contacts, and (d) tomographic evaluation of condyle-fossa relationships. The results of the study indicated that postoperatively (a) there was an increase of patients with dysfunction in the mandibular osteotomy group and a decrease of patients with dysfunction in the maxillary osteotomy group; (b) the maximum interincisal opening decreased significantly in the mandibular osteotomy group; (c) there was a significant increase in the number and intensity of occlusal contacts in both groups; and (d) the shortest posterior and anterior interarticular distances increased significantly in the mandibular osteotomy group.     

Bunionette correction by metatarsal osteotomy: preliminary report

A preliminary report is presented of 17 patients who underwent 27 fifth metatarsal osteotomies. Oblique osteotomy without internal fixation was used. Union of the osteotomy without external immobilization occurred in 16 of the patients. Correction was effected in a case of delayed union in one foot because it was symptomatic. Improvement and normal function were the result in 26 of the 27 osteotomies. Delayed union did not seem to mean failure of relief. No painful scars occurred.     

Risk of long-term disability among patients with back pain

This follow-up study was designed to identify the differences between the TMJ movements of individuals undergoing orthognathic surgery, with and without positioning of the mandibular proximal segment. A further aim was to assess the location of the terminal hinge axis before and after surgery regarding variations due to mandibular advancement or set back, respectively combined two jaw osteotomy. Mechanical axiographic tracings were documented in 14 patients undergoing orthognatic surgery without positioning of the mandibular proximal segment. The terminal hinge axis position was marked by a tattoo. After surgery two more axiographic tracings were recorded over a follow-up period of 24 months. Changes to the terminal hinge axis position were also documented. Condylar guidance angles showed no differences, whereas Bennett angles decreased by an average of 25%. Subjective or objective TMJ symptoms after surgery could be observed in 64% of the patients, compared to 50% before surgery. Considerable variations in the position of the terminal hinge axis were observed nine months after surgery, especially in the two jaw group. In Class II individuals the terminal hinge axis was found in a cranial position both after 9 and 24 months. Class III individuals with two jaw surgery also gained a long term cranial localisation, whereas Class III patients with mandibular setback only demonstrated a hinge axis position inferior and anterior compared to the preoperative reference. No statistically significant differences were apparent between the axiographic condylar movement parameters in the present group as compared to data published employing condylar positioning.     

Wound healing after multisegmental Le Fort I osteotomy and transection of the descending palatine vessels

PURPOSE: Vascular ischemia has been associated with improper soft tissue flap design, stretching of the palatal vascular pedicle, bony segmentation, transection of the descending palatal vessels, or hypotension. This study examined Le Fort I osteotomy wound healing after some of these surgical maneuvers. MATERIALS AND METHODS: Clinically analogous four-segment Le Fort I osteotomies were accomplished through circumvestibular incisions in nine adult rhesus monkeys and the animals were killed at 0, 3, 7, 14, and 28 days after surgery. Revascularization and bone healing were studied by microangiographic and histologic techniques. RESULTS: The findings indicated that the palatal mucosa or labial-buccal gingiva and mucosa provide adequate nutrient pedicles for Le Fort I osteotomies accomplished through a circumvestibular type incision. CONCLUSIONS: It was concluded that segmentalization, stretching of the vascular pedicles, or transection of the descending palatine vessels have only transitory discernible effects on revascularization and bone healing.     

Dynamic magnetic resonance of the temporomandibular joint. Observations and findings

Condylar movements can be executed only if the TMJ morphology can satisfy functional needs of the masticatory apparatus. Articular components have to be in good relation with dento-skeletal functional anatomy: if this does not occur, mandibular dynamics may establish some functional stresses on the condylar head and the articular eminence. These overloaded structures and particularly their functional surfaces react to this situation to be remodelling and deformation of the articular cavity. In our work we have used a new method to analyse condylar dynamics using MRI. The reconstruction of mandibular movements, using this instrumentation, permits to make some useful observations on the functional capability of TMJ to adjust itself to different maxillofacial morphologies and, consequently, how this joint can fall in a dysfunctional and pathological condition.     

Distraction osteogenesis and its application to the midface and bony orbit in craniosynostosis syndromes

The purpose of this study was to demonstrate the potential advantages of applying distraction osteogenesis techniques to the correction of orbital and midfacial hypoplasia in craniosynostosis syndromes. Fifteen children with various craniosynostosis syndromes underwent Le Fort III advancement assisted by gradual distraction utilizing a pair of internal distraction devices custom-fabricated for each child. The surgical procedure consisted of a Le Fort III osteotomy, implantation of internal devices with initiation of distraction intraoperatively, and an accelerated rate of midfacial advancement over the next 3 to 5 days. Activation of the distraction hardware was accomplished by a percutaneous pin, which was removed at the end of the distraction protocol, allowing the internal devices to fixate the fragment for a minimum of 6 months during the period of consolidation. With follow-up ranging between 3 to 38 months, the average orbital and midfacial advancement was 19.7 mm (range, 12.0-30.0 mm). Proptosis was lessened and facial proportions significantly improved in all patients. Serious complications were not encountered. The modified distraction protocol utilized in this group of patients was aimed at addressing the unique requirements of pediatric craniofacial surgery, and resulted in almost twice the amount of correction previously reported for traditional rigid fixation techniques.     

Aged median eminence glial cell cultures promote survival and neurite outgrowth of cocultured neurons

The purposes of this investigation were to compare functional performance between controls and a sample of patients with skeletal anterior open bite prior to surgical correction and to examine how the patients' oral motor function adapted after treatment. Five female patients with skeletal open bite malocclusion were treated with Le Fort I osteotomy and compared to sex-, size-, and age-matched controls. Measurements of skeletal morphology, mandibular range of motion, occlusal force, and muscle efficiency were taken on all subjects over time. Prior to surgery, all patients had lower occlusal forces than did controls at all bite positions. After surgery, occlusal forces at several occlusal positions increased significantly from the presurgical recordings but remained below the level of controls. The mechanical advantages of the muscles of mastication were not significantly different between controls and patients either before or after surgery. The results of this study suggest that correction of skeletal open bite malocclusion may improve occlusal force, but a larger sample is needed to confirm this finding.     

Six year's experience with the zygomatic "sandwich" osteotomy for correction of malar deficiency

PURPOSE: This study discusses the rationale, modifications, and complications of an osteotomy technique used to increase malar projection. PATIENTS AND METHODS: Seventy "sandwich" zygomatic osteotomies were performed in a 6-year period. Hydroxyapatite (HA) blocks were used to stabilize the anterolateral rotation of the zygomatic body in 44 osteotomies, calcium carbonate blocks were used in 23, calvarial bone grafts in three, a piece of bovine cartilage in one, and a bone graft from a chin ostectomy procedure combined with mesh osteosynthesis in one procedure. Fifty-six zygomatic osteotomies were combined with Le Fort I-type osteotomies (eight with a midline split). Nineteen zygomatic osteotomies were performed simultaneously with a Le Fort I-type osteotomy and a rhinoplasty with lateral osteotomies. RESULTS: The increase of malar projection and the stability of the procedure could not be measured on conventional three-plane cephalograms. However, patient's and surgeon's satisfaction were high and remained so during the follow-up period (maximum, 6.5 years; minimum, 6 months). Three patients developed maxillary sinusitis. In two of them, this was clearly related to fragmentation of an HA block. A Treacher-Collins patient developed a chronic fistula in the upper vestibule, caused by leakage of infraorbitally placed HA granules. In two cases, a fracture of the zygomatic arch occurred. Osteosynthesis was performed in one of them. CONCLUSION: With proper technique and care not to fracture the interpositional HA block, complications are rare. The procedure is expedient and provides predictable and stable correction of malar deficiency.