18F-FDG PET: early postoperative period of oro-maxillo-facial flaps

Aim: We addressed the feasibility of FDG-PET to differentiate between viability and non-viability in the immediate postoperative assessment of flaps (autologous microvascular anastomosed pedicled flaps) in oro-maxillo-facial surgery. Methods: 3-7 days after surgery, FDG-PET was done in 38 patients who had received flaps for reconstruction of the mandible after partial resection. The studies were done on a dedicated full ring PET-scanner (ECAT EXACT HR+, Siemens/CTI). Acquisition started between 60 and 80 min post injection. The findings of the soft tissue component of the flaps were grouped using a three point scale: (I) no defect, (II) small defects, (III) one large defect. The results of PET were compared with the clinical course for at least 3 months. Results: “No defect” on the FDG-PET study identified viability of the flap and predicted normal clinical follow-up (22/38 patients). “Small defects” visualized areas of decreased perfusion and decreased glucose metabolism indicating risk of non-viability (13/38 patients); adapting the postsurgical management led to delayed but uncomplicated healing of the flaps in these patients. “One large defect” demonstrated early necrosis of the flap (3/38 patients). After removal and replacement of this necrotic portion of the flap the second FDG-PET scan of these 3 patients demonstrated the uncomplicated post-operative healing. Conclusion: FDG-PET facilitated the assessment of viability and non viability of flaps in the immediate postsurgical period, and demonstrated the usefulness of FDG-PET for postoperative care and prognosis.

Assessment of Bone Resorption after Secondary Alveolar Bone Grafting Using Three-Dimensional Computed Tomography: A Three-Year Study

Objective:

Secondary bone grafting plays an important role in the dental rehabilitation of patients with clefts of the lip, alveolus, and palate. A major complication of this surgical technique is resorption of the grafted bone transplant. Conventional two-dimensional radiographs are often inconclusive and do not demonstrate the true deficit. The main objective of this study was to evaluate the amount and exact location of bone loss on the basis of three-dimensional models over a period of 3 years.

Design:

Twenty-four patients with unilateral cleft palate were included in this prospective study. Axial computed tomography scans of all patients were taken immediately preoperatively, and 1, 2, and 3 years postoperatively. Volumetric analysis was performed on three-dimensional models of the cleft defects and the bone bridges using three-dimensional computed tomography.

Interventions:

All patients were treated by secondary alveolar bone grafting prior to eruption of the permanent canine.

Results:

Extensive bone resorption was found in the bucco-palatal dimension of the alveolar portion of the transplant. The success rate of secondary bone grafting was high in cases of rapid orthodontic gap closures. The mean bone loss in the first year after surgery was 49.5%. The transplants remained almost constant in the following 2 years.

Conclusions:

Radiographic scales based on orthopantomography only evaluate the vertical dimension of the transplants. This study, however, showed that bone resorption in the transversal dimension is clearly underestimated with conventional two-dimensional radiographs.

The mandibular symphysis as a starting point for the occlusal-level reconstruction of panfacial fractures with bicondylar fractures and interruption of the maxillary and mandibular arches: report of two cases

Panfacial fractures represent a challenge, even for experienced maxillofacial surgeons, because all references for reconstructing the facial skeleton are missing. Logical reconstructive sequencing based on a clear understanding of the correlation between projection and the widths and lengths of facial subunits should enable the surgeon to achieve correct realignment of the bony framework of the face and to prevent late deformity and functional impairment. Reconstruction is particularly challenging in patients presenting with concomitant fractures at the Le Fort I level and affecting the palate, condyles, and mandibular symphysis. In cases without bony loss and sufficient dentition, we believe that accurate fixation of the mandibular symphysis can represent the starting point of a reconstructive sequence that allows successful reconstruction at the Le Fort I level. Two patients were treated in our department by reconstruction starting in the occlusal area through repair of the mandibular symphysis. Both patients considered the postoperative facial shape and profile to be satisfactory and comparable to the pre-injury situation.

Surgical treatment of synovial chondromatosis of the temporomandibular joint with erosion of the skull base: a case report and review of the literature

Synovial chondromatosis (SC) is a rare metaplastic disease of the larger joints. It is rarely observed in smaller joints, especially in the temporomandibular joint (TMJ). This disease is considered to be metaplastic and shows no malignant tendencies, but can become locally aggressive, erode the cranial base, and even spread intracranially. To date, nine cases of spread into the intracranial space have been reported in the literature; however, the disease remained extradural in all cases. The authors present a review of the literature and report the case of a 70-year-old man with SC of the right TMJ that had eroded the cranial base, reaching the dura mater; a large intracranial mass was not present. The disease was considered to be stage 3 according to Milgram's classification. The patient was treated surgically, the tumour mass was removed, reconstruction of the cranial base was performed using titanium mesh, and the joint was reconstructed with a temporal muscle interposition flap. Diagnostic images and intraoperative photographs are also presented.

Surgically assisted rapid maxillary expansion: feasibility of not releasing the nasal septum

Surgically assisted rapid maxillary expansion (SARME) is commonly used to correct maxillary transverse deficiency. The aim of this study was to analyse the need for intraoperative liberation of the nasal septum during the procedure. SARME was performed in 25 patients by combining a lateral osteotomy with an inter-radicular maxillary osteotomy. The deviation of the nasal septum after SARME was evaluated by comparing measurements between radiologically defined landmarks on pre- and postoperative computed tomographic images. Two defined angles (angle I, between crista galli-symphysis mandibulae and crista galli-septum nasi; angle II, between maxillary plane and septum nasi) were measured based on four representative planes and septal movement was analysed. The mean changes in angles I (0.03° ± 0.78°) and II (0.25° ± 1.04°) did not differ significantly from zero (p=0.87 and p=0.24, respectively). Observed variations and displacements were considered to be acceptable because they were insignificant in every respect. Intranasal airway function was also examined pre- and postoperatively to evaluate any loss of ventilation. The described surgical technique is a successful method of maxillary segment distraction. The authors found no compelling reason to release the nasal septum in the context of SARME.

The influence of the Tübingen soft palate plate and early cleft closure on the nasopharyngeal airway for the management of airway obstruction in an infant with Pierre Robin sequence: A case report

INTRODUCTION

A Tübingen palate plate and early cleft closure for successful airway management is described in a newborn with Pierre Robin sequence.

PRESENTATION OF CASE

A three-day-old newborn with an acute airway obstruction underwent primary treatment with a Tübingen soft palate plate.

DISCUSSION

After stabilization of the airway, the cleft soft palate was closed after three months.

CONCLUSION

The Tübingen soft palate plate proved to be a very satisfactory treatment for the infant.

Perforating the polydioxanone sheet: avoiding intraorbital hematoma after open treatment of orbital floor fractures

The surgical treatment of orbital floor fracture, a common facial injury, is not a risk-free procedure. Complications after orbital surgery can include infection, implant migration, mydriasis, epiphora, persistent diplopia, enophthalmos, infraorbital numbness, retrobulbar hemorrhage, and blindness. Blindness has been ascribed to retrobulbar hematoma in almost 50% of cases. In our experience, blood collection above the polydioxanone sheet after the treatment of orbital floor fracture can be caused by the tight adhesion of the sheet to the bony edges of the fracture. Here, we present a simple procedure to avoid this potentially dangerous complication.

Primary osteomyelitis of the mandibular condyle--a rare case

Osteomyelitis is an inflammatory process involving cortical and cancellous bone. In the maxillofacial region, the mandible is the most frequently affected bone. In the vast majority, a bacterial focus can be identified as the origin of the disease. Chronic progress of the disease may lead to destruction of mandibular bony structures, resulting in mild or severe loss of function if no adequate treatment is applied. In some cases, the etiology of osteomyelitis remains unclear. Review of literature revealed two cases of necrosis of the mandibular condyle caused by primary osteomyelitis. We report a case of primary osteomyelitis of the mandibular condyle in a 51-year-old woman. Radiography revealed an almost complete destruction of the right mandibular condyle, resulting in malocclusion. The patient was treated with long-term antibiotics. No surgical intervention had been performed. After remission of the symptoms, the malocclusion had been corrected prosthetically. After a 4-year follow up period, the occlusion is stabile and there are no signs of progression of the disease.

Sagittal maxillary growth in children with unilateral cleft of the lip, alveolus and palate at the age of 10 years: an intercentre comparison

OBJECTIVE

Aim of this intercentre study was to compare sagittal facial growth in children with unilateral cleft lip and palate treated with different surgical protocols. A first evaluation had been carried out at the age of 6 years, now the patients have been re-evaluated at the age of 10 years.

MATERIAL AND METHOD

22 patients had been analyzed in centre 1, 32 patients in centre 2. All patients had presurgical orthopaedics. Centre 1 had lip repair at the age of 3 months and one-stage palatal closure with 1 year. Centre 2 had lip repair with 6 months, soft palate repair at 12 and hard palate repair at the age of 30 months. Sagittal growth was evaluated on lateral cephalograms. As control, data of 35 non-cleft children were used. Statistical analysis was carried out with student's t-test, multiple comparisons with Bonferroni.

RESULTS

There was considerably normal sagittal facial growth in centre 1, with tendency of forward growth of the mandible. In centre 2 there was a slight decrease in sagittal maxillary and mandibular growth with unchanged intergnathic relation. There was no statistically significant difference in sagittal growth between the centres. A re-evaluation has to be carried out after the final growth spurt.

Dentoalveolar changes after surgically assisted maxillary expansion: a three-dimensional evaluation

OBJECTIVES

Surgically assisted rapid palatal expansion (SARPE) is a common procedure to correct maxillary transverse deficiency of >5 mm in patients with closed midpalatal suture. The aim of this study was to three-dimensionally analyze skeletal and dentoalveolar changes after SARPE.

STUDY DESIGN

Eighteen mature patients (mean age 26 years) with a palatal transverse deficiency underwent SARPE. The surgical procedure consisted of a lateral osteotomy combined with an interradicular osteotomy between the roots of the upper central incisors. Measuring points were defined on teeth as well as facial skeleton. Computerized tomography scans were performed preoperatively and immediately after the expansion period.

RESULTS

Changes of the dentoalveolar and maxillofacial complex were analyzed.

CONCLUSIONS

Bilateral osteotomy combined with a sagittal osteotomy between the roots of the upper central incisors is a safe method of surgically assisted maxillary expansion. The amount of dentoalveolar tipping was smaller than reported in literature. The expansion was mostly achieved by maxillary expansion.

Three-dimensional evaluation of secondary alveolar bone grafting using a 3D- navigation system based on computed tomography: a two-year follow-up

Secondary bone grafting is widely used in the closure of oronasal fistulas and reconstruction of maxillary defects. It often fails from lack of physiological stress or inadequate covering of the transplanted bone with surrounding tissue. The aim of this study was to assess the exact bone volume after secondary alveolar bone grafting over a period of two years using a navigation system based on computed tomography (CT). We examined 20 patients with complete unilateral cleft lip and palate (UCLP) who had been treated by secondary bone grafting during late mixed dentition. CT scans of the upper jaw were taken immediately preoperatively, and 1 and 2 years postoperatively. The cleft defects and the bony bridges were marked on the monitor. The software of the navigation system created three-dimensional models showing the amount and site of bone resorption. The mean bone loss after one and two years was 51% and 52%, respectively. There was a significant correlation between the size of the cleft and the success of the alveolar bone grafting (p=0.01). When the teeth adjacent to the cleft were missing the amount of bone lost was 95% after the first year. There was also significant bone loss in the buccopalatine direction. Three-dimensional reconstruction of the bony bridges with a navigation system accurately shows the amount of bone within the cleft site. This method is definitely superior to conventional two-dimensional orthopantomography.

Sagittal growth of the facial skeleton of 6-year-old children with a complete unilateral cleft of lip, alveolus and palate treated with two different protocols

OBJECTIVE

The purpose of the study was to compare sagittal growth of the facial skeleton of 6-year-old children treated in two cleft centres with different surgical protocols.

MATERIAL AND METHODS

Each group consisted of 20 consecutive non-syndromic children with complete unilateral cleft lip, alveolus and palate. They all had presurgical orthopaedics with a passive plate and external strapping until lip repair. Centre 1 had lip repair at the age of 3 months and one stage palatal closure at the age of 1 year. Closure of the alveolar cleft was planned at 9 years with bone grafting. In centre 2 lip repair was performed at the age of 6 months, soft palate repair at 12 months and hard palate repair together with mucoperiosteal closure of the alveolar cleft at the age of 30 months. At the time of investigation, the children from both centres had not received any postoperative orthodontic treatment. Sagittal growth was evaluated on lateral cephalograms using the angles SNA, SNB, ANB and SNPg. For control, Droschl standards were used. The Mann-Whitney U test was used for statistical analysis.

RESULTS

There was no statistically significant difference in SNA, SNB, ANB and SNPg between the centres at the age of 6 years. There were no children with a class III jaw relationship. The sagittal dimensions were close to the values of non-cleft control persons (Droschl standards).

CONCLUSION

There was considerable similar sagittal growth of the facial skeleton in both centres which has not been affected by the different surgical protocols so far. A final evaluation should be delayed until the growth of the facial skeleton is complete.

Case Report: Fusion of positron emission tomography (PET) and computed tomography (CT) images for image-guided endoscopic navigation in maxillofacial surgery: Clinical application of a new technique

INTRODUCTION

Surgery based on computed tomography (CT) data is becoming increasingly important in the head and neck region. The technique for hardware fusion between positron emission tomography (PET) and computed tomography (CT) has only been established commercially in the last 4 years. The advantages over CT alone are obvious. The surgeon is simultaneously provided with a map of anatomical as well as of functional (metabolic) details. The fused images offer improved localization of malignant lesions and improved targeting of biopsy, especially for small lesions.

PURPOSE

A new technique for image-guided tumour localization for maxillofacial surgery based on PET/CT-image fusion is described.

PATIENT AND METHOD

A 78-year-old woman was admitted to this department with a tumour of the skull base. Three dimensional fusion of computed CT with positron PET images on a commercially available navigation system is described. After patient-to-image registration, a high-resolution endoscope was calibrated intraoperatively. Image-guided biopsy specimens were taken under direct visual control.

CONCLUSION

PET/CT-image fusion proved extremely helpful to navigate the endoscope to the target lesion and to identify the tumour.

Removal of a pellet from the left orbital cavity by image-guided endoscopic navigation

In the cranio-maxillofacial field, computer-aided surgery based on computed tomography data is becoming increasingly important. Complex surgical procedures can be performed utilizing preoperative imaging to provide real-time localization of surgical instruments in the surgical field. Image-data-based navigation plays an ever-increasing role in cases of minimal invasive surgery. The case is presented here of a 58-year-old male patient referred after a hunting accident with a pellet in the left orbit. After transferring the preoperatively acquired computed tomography data to a commercially available navigation system, the bullet was removed through the original wound canal using an intraoperatively calibrated high-resolution endoscope.

Cervicofacial and mediastinal emphysema after crown preparation: a rare complication

Cervicofacial emphysema is a well-known complication associated with the use of a high-speed air turbine. However, retropharyngeal emphysema or pneumomediastinum in the absence of severe trauma is rare. Immediate recognition of this phenomenon is essential to avoid life-threatening complications such as potential airway obstruction or venous air embolism. This article reports a case of gas diffusion into the mediastinum after dental preparatory treatment for a single-tooth crown. Pneumomediastinum should be considered whenever there are anamnestic data for retrosternal chest pain accompanied by dysphagia, dysphonia, or dyspnea caused by cervicofacial emphysema after dental treatment.

Extensive ameloblastoma of the jaws: surgical management and immediate reconstruction using microvascular flaps

OBJECTIVE

Ameloblastoma is a rare histological benign but locally aggressive tumor with a marked tendency for recurrence. Especially larger, aggressive lesions require a more radical surgical approach resulting in large jaw defects. The purpose of this study is to analyze the long-term functional and esthetic results after immediate reconstruction of large jaw defects using microvascular flaps.

STUDY DESIGN

A review of 7 cases of giant ameloblastoma (2 in the maxillary and 5 in the mandibular region) is presented. The lesions were between 4 and 8 cm in diameter. All patients were treated by a radical surgical protocol. All cases were immediately reconstructed using microvascular grafts from either the scapula or the iliac crest bone. Dental implants were inserted in all patients after removal of the osteosynthesis material.

RESULTS

All patients were prosthetically rehabilitated. All implants survived throughout the observation time. The esthetic and functional outcomes were satisfying in all patients. No case of recurrence of the tumor could be observed so far.

CONCLUSION

According to our opinion, immediate reconstruction is the treatment of choice after radical surgical excision of ameloblastoma. This 1-step procedure decreases the number of surgeries and allows earlier prosthetic rehabilitation.

Extraosseous schwannoma of the mental nerve clinically simulating intraosseous

We report a case of a benign neurilemmoma arising from the right mental nerve. Schwannomas are rare neurogenic tumours that originate from Schwann cells of the peripheral nervous system. Frequent locations are the head and neck region. Most of the tumours occur in the soft tissue whereas intraosseous schwannomas are rare. This case report deals with a young patient who was referred to our hospital with an unidentified fast-growing tumour located mainly in the premolar region of the right mandible. The tumour presented as an expansive, unilocular, well defined, radiolucent lesion on orthopantomography. No expansion of the mandibular canal could be seen. Computerized tomography scans of the mandible helped to identify the solid nature of the tumour. A biopsy was necessary to make the final diagnosis and the tumour was then excised surgically. Postoperative magnetic resonance imaging scans and a histological examination of the surgical specimen showed no signs of neurofibromatosis type 2.

Veränderung der Nasalanz nach Le Fort-I Osteotomie

BACKGROUND

Nasalance represents a measure of the relative amount of oral and nasal acoustic energy produced by a speaker. Literature shows changes in nasalance after surgery of the oropharynx. The aim of this prospective study was to evaluate the outcome of speech and nasalance scores after Le-Fort-I-Osteotomy.

PATIENTS AND METHODS

A total of 20 individuals with normal speech development were examined preoperatively and 6 weeks postoperatively with the Nasometer 6200 (Kay-Elemetrics, USA) after bimaxillary surgery. The tone materials used comprised the standardized text passage: "Ein Kindergeburtstag", the vowels: /a/, /e/, /i/, /o/, /u/ and a syllable repetition subtest.

RESULTS

All patients showed changes in nasalance scores 6 weeks postoperatively. There were no significant changes reading the standard text. The syllable repetition test showed significant changes for repetition of "ma ma ma" and "na na na" (p=0,003, respectively p=0,033). Intonation of the vowel /a/1 also revealed significant changes regarding the pre- and postoperative values (p=0,006). However, the obtained values had no significant impact on the nasality characteristics of speech.

CONCLUSION

This study confirms that maxillary osteotomies can result in significant changes of nasalance scores. However these changes do not have any impact on normal speech and voice.

Evaluation of bone volume following bone grafting in patients with unilateral clefts of lip, alveolus and palate using a CT-guided three-dimensional navigation system

PURPOSE

In cleft patients the eruption of the permanent canine depends very much on the amount of bone available following bone grafting. The purpose of this study was to evaluate the initial defect in alveolar clefts and the volume of bone bridging found in unilateral clefts which had undergone bone grafting.

PATIENTS AND METHODS

To determine the fate of the bone graft in cleft palate patients a three-dimensional CT-based Navigation System (Zeiss, Aalen, Germany) was used. CT scans of 16 patients with unilateral clefts were taken immediately preoperatively and 1 year postoperatively. The patients underwent surgery between the age of 9 and 14 years using iliac crest bone grafts. The data was transferred to the work station of the navigation system. Using the STN software, the defect at the alveolar clefts and volume of the bone grafts were determined in each case. Three-dimensional models were created showing the amount of bone immediately preoperatively and 1 year postoperatively.

RESULTS

The size of the cleft defect did not correlate with the success rate of the alveolar bone grafting. The form of the transplant remained almost constant when the permanent canine erupted spontaneously into the graft. In cases of absence of the permanent tooth or when the permanent canine required orthodontic treatment, significant bone loss could be observed in the buccopalatal direction.

CONCLUSION

Three-dimensional reconstruction of bone grafts using a navigation system enables a valuable objective assessment of graft volume. Bone formation can be assessed in all three dimensions showing a high grade of resorption in patients lacking physiological load.

18F-FDG PET: early postoperative period of oro-maxillo-facial flaps

AIM

We addressed the feasibility of FDG-PET to differentiate between viability and non-viability in the immediate postoperative assessment of flaps (autologous microvascular anastomosed pedicled flaps) in oro-maxillo-facial surgery.

METHODS

3-7 days after surgery, FDG-PET was done in 38 patients who had received flaps for re-construction of the mandible after partial resection. The studies were done on a dedicated full ring PET-scanner (ECAT EXACT HR+, Siemens/CTI). Acquisition started between 60 and 80 min post injection. The findings of the soft tissue component of the flaps were grouped using a three point scale: (I) no defect, (II) small defects, (III) one large defect. The results of PET were compared with the clinical course for at least 3 months.

RESULTS

"No defect" on the FDG-PET study identified vi-ability of the flap and predicted normal clinical follow-up (22/38 patients). "Small defects" visualized areas of decreased perfusion and decreased glucose metabolism indicating risk of non-viability (13/38 patients); adapt-ing the postsurgical management led to delayed but uncomplicated healing of the flaps in these patients. "One large defect" demonstrated early necrosis of the flap (3/38 patients). After removal and replacement of this necrotic portion of the flap the second FDG-PET scan of these 3 patients demonstrated the uncomplicated post-operative healing.

CONCLUSION

FDG-PET facilitated the assessment of viability and non viability of flaps in the immediate postsurgical period, and demonstrated the usefulness of FDG-PET for postoperative care and prognosis.

Simultaneous orbital expansion and intraoral distraction osteogenesis of upper and lower jaws in a patient with hemifacial microsomia

BACKGROUND

Correction of a micro-orbit, caused by clinical anophthalmia is a very challenging task. In hemifacial microsomia a micro-orbit may be combined with hypoplasia of the malar and the ascending mandibular ramus.

MATERIAL

A 5-year-old patient with hemifacial microsomia is described. Hypoplasia of the malar bone and the tilted occlusal plane were corrected by means of intraoral distraction osteogenesis in the upper jaw following precise simulation surgery on a 3D-model. At the same time, the ascending mandibular ramus was lengthened with a second distraction device and a spherical tissue expander was inserted into the hypoplastic orbit.

RESULTS

The malar as well as upper and lower jaws were lengthened and positioned symmetrically. The orbital cavity was expanded to 79% of that of the healthy side. Following removal of the distraction devices, the expander was exchanged for a larger one and orbital expansion was continued until overcorrection of the orbit up to 118 percent was achieved.

CONCLUSION

Orbital expansion is a minimally invasive method of enlarging the volume of the eye socket three-dimensionally. Intraorally activated buried distraction devices enable "growth" of the jaws making bone transplants avoidable in many cases. By combining both methods, complex malformations can be corrected simultaneously in children.

Cephalometric and occlusal outcome in adults with unilateral cleft lip, palate, and alveolus after two different surgical techniques

OBJECTIVE

To assess differences in the aesthetic and functional long-term results of one-stage and two-stage surgical and orthodontic treatment in patients with cleft lip, palate, and alveolus.

DESIGN

Sixty adult patients who were operated on as children for unilateral cleft lip, palate, and alveolus were examined. In every patient the lip was closed using Tennison's technique. Thirty patients had soft and hard palate closure in two stages and 30 patients in a single stage. Lateral cephalometric and model analyses were conducted at a mean age of 18.4 years.

RESULTS

In the model analysis, transverse narrowing was seen in all patients after two-stage operations and in three patients after one-stage operations. The deficit was more severe in the molar region in the two-stage group and nearly similar in the premolar and molar region in the one-stage group. A sagittal deficiency in the anterior maxilla was found in 26 patients after two-stage operations and in 16 patients after one-stage operations. In the lateral cephalometric analysis, the mean sella-nasion-point A angle in the one- and two-stage group was 78.2 degrees and 76.8 degrees, respectively. The ANB angle was normal in both groups. In both groups the inclination of the midface was low. There was a low posterior facial height. Minor scarring was seen in the single-stage group.

CONCLUSION

A more severe impairment of growth of the maxilla in the sagittal and frontal plane was observed after two-stage operations on the cleft palate.

Differences in cephalometric and occlusal outcome of cleft palate patients regarding different surgical techniques

INTRODUCTION

The purpose of this study was to assess differences of the long-term results following surgical treatment in patients with cleft palate treated by two different surgical concepts.

PATIENTS

Fifty-nine adult patients operated on for cleft palate were examined. Thirty palates were closed by a two stage (Widmaier and Veau) and 29 by a single-stage procedure (Veau's pedicled flap).

METHODS

Lateral cephalometric and model analysis was performed. In the cephalometric analysis, the vertical and horizontal parameters of the position of maxilla and midface and transverse and sagittal dimensions of the models were compared between the two groups.

RESULTS

Model analysis: According to the Bolton analysis the maxillary dental arch was too large in 22 patients in each group. The other patients had mandibular arches that were too large. In 18 patients with two-stage closure and in 9 patients with one-stage closure, a space deficit in the lateral part of the maxilla was observed. Persisting transverse deficits were seen in all patients with two-stage repairs and in 11 patients with one-stage repairs. The deficit was more severe in the molar area in the first group and almost equally severe in the premolar and the molar regions of the second group. A sagittal deficiency was found more often in patients with two-stage repairs while Angle's class I occlusion was seen more often in patients with one-stage surgery. Lateral cephalometry: Similar SNA-angles were seen in both groups whereas the ANB-angle was greater following two-stage repair. In both patient groups a low inclination of the midface was seen. The vertical dimension of the midface in comparison with the lower face was normal in the one-stage group; in the other group a deficiency of the anterior midface height was registered.

CONCLUSION

There was a more severe growth impairment of the midface in patients with this type of two-stage palatal repair. The horizontal deficiency was similar in both groups. The long-term occlusal result revealed smaller sagittal and transverse deficiencies in patients with this type of single-stage closure.

Evaluation of distraction implants for prosthetic treatment after vertical alveolar ridge distraction: a clinical investigation

PURPOSE

The purpose of this study was to clinically evaluate the mucosal condition and the esthetic and functional results of distraction implants loaded with fixed or removable implant-supported restorations.

MATERIALS AND METHODS

A total of 35 patients were treated with 62 distraction implants for correction of alveolar ridge deficiency. The distraction implants were loaded with prosthetic superstructures 4 to 6 months after distraction. Nine patients were provided with single-crown restorations, 16 received metal-ceramic fixed partial dentures, and 10 received removable overdentures. Recall was scheduled before and 3, 6, and 9 months after implant loading. Periotest values, periimplant probing depths, and radiographic marginal bone levels were recorded, along with any biologic or mechanical complications.

RESULTS

Patients were followed for 9 months after implant loading. Two distraction implants were lost before abutment connection. After fabrication and placement of individual abutments, all implants were loaded with prosthetic superstructures. The results showed a decrease of the Periotest values, and thus an increase of implant stability, during the following 9 months. Periimplant probing depths also decreased in the first months after implant loading. Soft tissue around the superstructures and adjacent teeth was healthy.

CONCLUSION

The distraction implant system has a high potential for osseointegration. Because of the gentle distraction technique and the possibility of using individual abutments at almost any angulation, satisfying esthetic and functional results are possible. The rate of complications was low in this short-term study.

Assessment of perfusion of facial microvascular transplants and early detection of ischemia by perfusion-CT scan

OBJECTIVE

Perfusion-computed tomography (CT) is a promising new technique to assess ischemic lesions caused by ischemic brain stroke. In this study, the use of perfusion-CT scans to predict ischemia in microvascular transplants of the face was examined.

STUDY DESIGN

Thirty-eight patients with microvascular latissimus dorsi transplants after tumor surgery were assessed by perfusion-CT scan 34 to 72 hours after surgery. In these cases, clinical examination of the transplant and examination by means of O(2)-probes were either unsuccessful or impossible. An electron beam tomography of the region of interest was performed by using an intravenous nonionic iodine-containing contrast medium (Ultravist 300, Nycomed, Germany) that was applied with an injector at a flow rate of 5 mL/min. Twenty scans with a scanning time of 300 ms and an interscanning time of 3 seconds were carried out. Changes in the Houndsfield units within the transplant as well as the region of the contralateral erector spinae muscle were measured.

RESULTS

Central malperfusion resulting in later complete transplant loss was detected in 2 cases. Peripheral malperfusion was found in 6 cases, resulting in localized resection and secondary wound closure. When no malperfusion was registered, the straightforward healing process took place.

CONCLUSION

Perfusion-CT scans are of great aid in the assessment of microvascular transplant perfusion in the face, when adequate perfusion is not verifiable clinically or by O(2)-probe because of removal or malfunction.

The transgingival approach for placement of distraction implants

PURPOSE

Since 1997, distraction implants have been clinically used for alveolar ridge distraction and, later, for prosthetic treatment. While 63 patients have been treated by the authors by alveolar ridge distraction with distraction implants with an open approach, the aim of this study was to demonstrate a minimally invasive technique of distractor placement via a transgingival approach.

PATIENTS AND METHODS

Twelve patients were treated with a modified surgical incision using distraction implants. A tissue punch was used to remove transgingival mucosa, and a segmental osteotomy was performed using a vestibular incision. The distracted segment was pedicled at the lingual and crestal mucoperiosteum. Distraction was carried out for 0.5 mm per day, divided into 2 to 4 turns per day. A distraction of 5 to 7 mm was performed. At the end of distraction, the distraction insert was changed into a definitive stable implant insert. Prosthetic treatment was performed 4 months after the distraction period with fixed superstructures. The follow-up was performed with the aid of dental radiographs, evaluation of peri-implant probing depths, and Periotest values (Siemans, Bensheim, Germany).

RESULTS

The outcome of this technique showed minimal scarring of the gingiva with good aesthetic results, the clinical and radiologic findings were satisfying, and the Periotest values were negative at every examination. The rate of complications was low.

CONCLUSION

Minimal scarring and good aesthetic and functional outcome resulted in patients with alveolar ridge distraction performed with a transgingival approach.

Analysis of midface asymmetry in patients with cleft lip, alveolus and palate at the age of 3 months using 3D-COSMOS measuring system

INTRODUCTION

Patients suffering from unilateral cleft lip, alveolus and palate exhibit a varying degree of asymmetry of the midface. Evaluation of this asymmetry can be carried out by means of 3D-CT, or a laser surface scanner.

MATERIAL AND METHODS

In this paper, 3D-CT-scan data of 21 patients with unilateral clefts of lip, alveolus and palate were analysed using three-dimensional models. Evaluations of the 3D-models were carried out with the computer-aided 3D-operation simulator 3D-Cosmos.

RESULTS

Asymmetry was found in the orbital, nasal and maxillary regions. The infraorbital rims were displaced craniocaudally and horizontally as well as laterally of the cleft-sided piriform aperture. This asymmetry corresponded to a dislocation of the maxillary segment on the cleft side. A deficit in volume was not reliably found.

The Graz implant supported pendulum, a technical note

A new, immediately loadable palatal implant with rotational stability and an implant-supported pendulum for patients with dental class II dysgnathia and dental crowding is presented. In seven cases, the treatment goal of distalization of all upper molars without extraction of a single tooth was achieved within 8 months.