An adult case of extra-hepatic portal obstruction with bleeding from esophageal varices

PURPOSE: This study examined the use of a locking reconstruction bone plate/screw system for use in mandibular surgery. PATIENTS AND METHODS: All patients treated with a locking reconstruction bone plate/screw system for fractures of the mandible or continuity defects in an 18-month period were prospectively studied. Ease of use of the locking plate/screw system, characteristics of the fractures/defects, and complications were tabulated. RESULTS: One hundred two locking bone plates were placed in 84 patients. Most patients (n=75) were treated for fractures of the mandible; there were eight continuity defects and one case of mandibular narrowing. There were no cases of malocclusion or difficulties encountered in using the plate/screw system. Loss of fixation was encountered in only one patient. CONCLUSIONS: The use of a locking plate/screw system was found to be simple, and it offers advantages over conventional bone plates by not requiring the plate to be compressed to the bone to provide stability.     

Effects of cordocentesis on inferior vena cava velocity waveforms: differences between normally grown and growth-retarded fetuses

PURPOSE: The purpose of this investigation was to evaluate complete denture patients at pretreatment and postinsertion, 6 months and 18 months after denture delivery in order to develop an explanatory model of successful denture therapy to better understand patient acceptance of complete dentures. MATERIALS AND METHODS: Sixty complete-denture patients treated at a dental student clinic were followed through denture therapy and for 18 months thereafter. Subjects were examined and completed pretreatment questionnaires and posttreatment interviews. Three outcome measures of denture success were tested, and factors considered substantive in achieving a successful denture outcome were examined using multivariate analyses. RESULTS: At post-insertion, 76.7% of subjects were satisfied with their dentures, 74.6% said their expectations were met, and 66.7% said they adjusted easily to their new dentures; reports at 6 and 18 months were similarly high. Logistic regression findings suggest that psychological and interpersonal factors are more important determinants of denture satisfaction than anatomic or clinical factors. CONCLUSIONS: Subject characteristics including age, gender, race, income level, education, marital status, and maxillary and mandibular anatomy were not significantly associated with denture success as defined by the three outcome measures used in this study. Although these variables may represent important co-factors in the patient's acceptance of dental services and may affect the way a patient perceives dental care outcomes, statistically significant relationships were not found within our sample. Psychosocial variables, such as pretreatment expectations, satisfaction with the dental care received, and mental health showed a stronger relationship to a successful outcome.     

A randomized clinical trial comparing the efficacy of mandibular implant-supported overdentures and conventional dentures in diabetic patients. Part I: Methodology and clinical outcomes

STATEMENT OF PROBLEM: Scientific evidence is lacking to support the general application of implant-supported mandibular overdentures. PURPOSE: This randomized clinical trial was undertaken to compare the efficacy of conventional mandibular and implant-supported overdentures in diabetic edentulous patients with clinically acceptable metabolic control. METHOD: A total of 102 diabetic patients, treated with or without insulin, were randomized to receive a new maxillary denture and either a conventional or an implant-supported removable mandibular overdenture. Treatment was completed for 89 patients, 37 with the conventional and 52 with implant-supported dentures. Detailed examinations, tests, and questionnaires were given before and at 6- and 24-months after treatment completion. Comparisons between the two treatment groups were made for treatment failures based on prespecifed criteria and the type and amount of maintenance care provided. RESULTS: The insulin and noninsulin treated groups were collapsed because of the lack of significant differences at entry. The conventional denture and implant-supported overdenture groups were similar in terms of general demographics, medical status, quality of their original dentures and denture support, several functional measures, and patient satisfaction. Treatment was judged to be successful in 56.9% of patients with conventional dentures and 72.1% with overdentures. This difference in success rate was not statistically significant (p > 0.05). Patients with treatment failures in both groups required excessive maintenance care. Those with conventional dentures needed frequent denture base adjustments and relines, whereas those with overdentures required frequent clip replacements and repairs. Although significant improvements were seen with both treatment modalities, a higher percentage of patients with implant-supported overdentures than those with conventional dentures reported improvements in chewing comfort and moderate-to-complete overall satisfaction.     

Surgical outcomes using bioabsorbable plating systems in pediatric craniofacial surgery

The purpose of this study was to evaluate the surgical outcomes of the 1.5-mm LactoSorb plating system (Walter Lorenz Surgical, Inc., Jacksonville, FL, U.S.A.) used to stabilize the osteotomized calvarial bone in pediatric patients who have undergone craniofacial surgery. The records of 33 consecutive pediatric patients who underwent craniofacial surgery from January 1997 through December 1997 were reviewed. There were 18 male and 15 female patients, and the age ranged from 4 months to 12 years. Patients were followed-up at 1 week, 1 month, 3 months, 6 months, and 12 months after surgery. For those patients reviewed, the following information is included: age, sex, diagnosis, surgical procedures, number and size of LactoSorb plates and screws used in each patient, operative difficulty of the screws and the heat pack, and postoperative complications, including wound healing, palpability, and infection. The LactoSorb plating system was used to stabilize the osteotomized calvarial bones in 33 patients who were diagnosed with: 1) craniosynostosis, 2) hydrocephalus, 3) fibrous dysplasia, or 4) cranial deformation. Orbital rim advancement and anterior cranial vault reshaping were performed in 17 patients. Posterior cranial vault reshaping, orbital rim advancement, and anterior cranial vault reshaping were performed in eight patients. Posterior cranial vault reshaping only was performed in seven patients. Excision of fibrous dysplasia from temporal bone was performed in one patient. One patient had a postoperative wound infection, and LactoSorb plates were palpable postoperatively in four patients. The LactoSorb plating system provided adequate rigidity for stabilizing the osteotomized calvarial bone during surgery and maintained adequate rigidity after surgery during the bone healing period before absorption. This plating system showed satisfactory results in pediatric craniofacial surgery patients.     

A follow-up study on changes in mastication after insertion of mandibular bilateral free end saddle denture by EMG]

The purpose of this study was to investigate changes in the mandibular shortened arch, whose occlusal deficit had been reconstructed by removable partial denture, during mastication by using the EMG analyzing system. A total of 5 shortened dental arch patients was provided with RPDs, and observed by a sophisticated masticatory analyzing system using EMG, before and one day, about 2 weeks, 3 months, after denture insertion. The conclusions were as follows: i) The elements of the shortened arch during mastication, that is, the duration, interval, and cycletime, were prolonged at the time of insertion of RPD, but 3 months after denture insertion, they were shortened to almost the same state as before treatment. ii) Prosthetic treatment for shortened dental arch improved revitalization of functional musculatures, and their rhythmicity of functional procedure. iii) The functional tongue room for optimal bolus position in mastication was provided by insertion of mandibular bilateral free end saddle removable partial denture.     

Use of a mandibular fracture score to predict the development of complications

PURPOSE: Mandibular fractures are common facial injuries. Classifications are diverse and sometimes correlated with specific treatment modalities. Osteosynthesis using plate and screws is the standard method of fracture treatment. To evaluate the outcome of such fracture management in our clinic, we developed a numeric scoring system for mandibular fractures and investigated the relationship between the scoring of the fracture being treated and the incidence of complications after surgical treatment. PATIENTS AND METHODS: Seventy-six adult patients treated over a 2-year period were evaluated, and the fractures were classified using the mandibular trauma score. This score was based on clinical and radiologic evaluation of each fracture line and ranks from 0 to 15 points. Osteosynthesis was performed using the AO plate systems. Patients were followed-up postoperatively for the presence of complications. RESULTS: During the 2-year period, 76 patients with 134 fractures underwent plate osteosynthesis. Fracture scoring indicated a homogeneous distribution between uncomplicated and severe fractures. The incidence of complications increased with the fracture severity, assessed by the fracture score index. Severe fractures showed fewer complications when treated with a rigid plate system, whereas low-score fractures showed better results when treated with less rigid systems. CONCLUSIONS: The numeric scoring system for mandibular fractures allows an objective and standardized assessment of the degree of severity of a fracture and may facilitate decisions about the use of specific treatment modalities.     

Follow up and maintenance of implant supported prostheses: a comparison of 20 complete mandibular overdentures and 20 complete mandibular fixed cantilever prostheses

Two independently selected groups of 20 patients who were edentulous in te mandible, were followed up on a regular basis over a 5-year period following restoration with a lower implant stabilised prosthesis and conventional upper denture. Significantly more treatment was required by those who received complete mandibular overdentures than those provided with complete fixed mandibular prostheses. In addition to adjustment for the relief of denture trauma to the mucosa, more mechanical problems arose with overdenture implant prostheses.     

Reference values for extremity muscle strength obtained by hand-held dynamometry from adults aged 20 to 79 years

We present an 8-year experience with the Würzburg noncompression titanium miniplate system for the rigid fixation of the mandible during elective head and neck cancer surgery in a consecutive series of 100 patients. One half of the miniplates were used to fix mandibulotomies undertaken for surgical access. The remaining half were in patients undergoing reconstruction of segmental mandibular defects, the vast majority (92%) with vascularised bone grafts. One to four variously shaped miniplates were used per patient (mean = 1.5), plate size ranging from 4 to 40 holes. Fifteen patients (15%) developed complications which included 3 mandibular osteoradionecrosis, 8 broken, 5 infected, and 4 exposed plates. Three of the eight fractured plates were associated with nonunion. In this study, the main advantages of titanium miniplate fixation, namely case of application, decreased fixation time and malleability, were accompanied by a level of morbidity which, while comparing well with alternatives, may necessitate a reappraisal of this technique of fixation.     

Reconstruction of residual alveolar cleft defects with one-stage mandibular bone grafts and osseointegrated implants

PURPOSE: This study evaluates a treatment regimen for reconstruction of residual maxillary alveolar cleft defects consisting of mandibular bone grafting and immediate implant installation. PATIENTS AND METHODS: Sixteen cleft patients (five female and 11 male) had residual cleft defects of the alveolar ridge reconstructed with bone grafts from the mandibular symphyseal region. The bone graft was pretapped at the donor site before fixation in the residual ridge with Br?nemark implants. Twenty implants were installed according to this concept. The period of observation ranged from 36 to 69 months, with a mean of 48 months after implant installation. RESULTS: Five patients developed wound dehiscenses that resulted in total or partial bone graft sequestration. Two implants were lost, one due to sequestration and the other due to mobility at the abutment procedure; 18 implants were still well functioning at the end of the observation period. However, all patients showed significant periimplant bone resorption after this one-stage treatment. CONCLUSION: Because of the observed complication rate, the one-stage procedure may not be optimal for reconstructing residual cleft defects.     

Multi-point contact (MPC) osteosynthesis plate. 1: Animal experiment histomorphologic studies in the G?ttingen minipig

Based on the results of clinical and animal studies as reported in the literature, the subimplant cortex becomes porous underneath conventional osteosynthesis plates with a flat surface. To solve this problem, we developed an implantable plate which creates multiple contact points between plate and bone, called the multi-point contact or MPC plate. In an experimental animal study conducted on 16 G?ttingen minipigs we investigated the bone reaction beneath 2 different types of osteosynthesis plates: the conventional type with a flat interface versus the multi-point contact type. Both epiperiostal and subperiostal plating was performed on pig's intact tibiae. After an implantation period of 16 weeks, the results were documented and compared. It was shown that the osteal remodeling activity of the cortical bone adjacent to the plate increased under both plates up to the twelfth week, but declined towards the end of the study period. Compared to the MPC plate, a conspicuous remodeling front accompanied by porosis of the cortical bone adjacent to the plate was found underneath the conventional osteosynthesis plates with a flat surface-to-bone interface. The different subimplant reactions between the 2 plates can be best explained by the fact that intracortical implant-induced viscoelastic osteocyte diffusion is better under the MPC plate, whereas it is impaired under the conventional flat plate.     

Passive and active intracranial translocation of osteosynthesis plates in adolescent minipigs

On the basis of the clinical and experimental proof that intracranial translocation of osteosynthesis plates occurs in infants after fixation on frontal bone, we conducted an animal study on four adolescent G?ttingen minipigs. Our aim was to study the effects on intracranial translocation of two different types of osteosynthesis plates by comparing the plate-bone interface on the intact frontal bone treated with a multiple-point contact plate versus a conventional smooth one, paying special emphasis to the periosteum. Within a few weeks of implantation, osseous regeneration products surrounded the plate. Total invagination of plates with initial intracranial translocation occurred 12 to 16 weeks postimplantation, regardless of plate design. In epiperiosteal fixation, intracranial translocation was delayed. The results revealed two mechanisms at play here: cranial growth-related passive intracranial translocation, which occurs regardless of plate design, and plate-dependent active intracranial translocation. In conclusion, we recommend that all metal osteosynthesis materials implanted in the infant cranium be removed as early as possible (within 3 months).     

Evaluation of titanium in oral conditions and its electrochemical corrosion behaviour

Due to its excellent biocompatibility and good mechanical properties, titanium has been used successfully in dentistry for many years. In this study, complete dentures with titanium palatal plates were applied to 10 patients who were in need of upper dentures. The clinical performance of cast titanium palatal plates was determined over a period of 6 months. No increase in accumulation of denture plaque nor mucosa irritation was observed. After the above period, the electrochemical corrosion behaviour of cast titanium and chromium-cobalt palatal plates were compared with the titanium plates that were not left in an oral environment after casting. For the electrochemical corrosion tests, a corrosion cell was designed and artificial saliva with lactic acid was used, with the temperature during the tests being about 37 degrees C. The potential difference between the test sample and the saturated calomel electrode was measured, and after the determination of the rest potentials, the anodic potentiodynamic polarization curves were traced at a rate of 1 mV/s. From the standpoint of corrosion, the titanium plates used by the patients for a 6-month period corroded more than the titanium not used by the patients. This may be due to the casting and processing conditions and the effect of the oral environment.     

Fixation of facial and auricular prosthesis with osseous implants in cranial bone

OBJECTIVE: To evaluate the use of osseointegrated implants to fix facial and auricular prostheses. DESIGN: Retrospective. SETTING: University Hospital Groningen, the Netherlands. METHODS: Thirty patients were treated with Br?nemark implants for fixation of auricular (21 patients) and orbital (9 patients) prostheses during May 1988-December 1995. The complications during the procedure, the success rate of the implants, skin reactions around the implants and patient satisfaction were recorded. RESULTS: A total of 97 implants were placed. One implant had to be removed after the healing period because it was loose. No other implants were lost during the follow-up period (mean 36 months; range: 12-91). The skin around the implants sometimes showed a mild reaction which could be adequately treated. In most of the cases no inflammation of the skin was observed. Retention, ease of handling and wearing comfort of the facial prostheses were excellent. CONCLUSION: Fixation of facial and auricular prostheses can be improved by osseointegrated implants resulting in high patient satisfaction.     

Treatment of tibial plateau fractures by limited internal fixation

Seventy-five adults who sustained 76 tibial plateau fractures were treated according to a prospective protocol using instability in extension as the principal indication for operative fixation. Patients showing instability underwent closed manipulative reduction under fluoroscopic guidance. If significant joint depression persisted after reduction, elevation of the fracture was performed either from below using bone punches through a cortical window or via limited arthrotomy. Iliac crest bone graft was used to buttress depressed fractures. Fixation was then secured using 7-mm cannulated screws with washers or buttress plates and screws. Postoperatively, 58 of 76 knees were managed in a hinged knee brace, allowing the patient early range of motion and protected weightbearing for 8 weeks. Patients who were found to have a stable knee were treated with Bledsoe braces according to the postoperative protocol. In the 75 patients, 18 of the 76 knees were unsuitable for percutaneous screw fixation because of fracture complexity requiring plates, severe open injuries, or inadequate reductions with limited fixation had been done. A minimum followup of 12 months was obtained in 55 patients (range, 12-59 months). All fractures had healed at the time of followup. Eighty-seven percent of the patients at followup had a successful outcome using Rasmussen's criteria. Fourteen of these patients had arthroscopic assisted reduction or evaluation. All seven patients who had poor outcomes had AO Type C3 fracture patterns. Severely depressed or comminuted fractures or fractures with significant metaphyseal diaphyseal extension may not be suitable for this technique and require the addition of an external fixation device or buttress plate to maintain the reduction and allow for early range of motion.     

Mandibular anterior ridge extension: a modification of the Kazanjian vestibuloplasty technique

PURPOSE: A modification of the secondary epithelization vestibuloplasty technique described by Kazanjian that eliminates the sharp V in the depth of the extended vestibule and counteracts shallowing of the sulcus is presented. PATIENTS AND METHODS: Ten consecutive patients indicated for anterior mandibular secondary epithelization vestibuloplasty were treated. A bipedicled mucosal flap was developed in the labioalveolar mucosa for lining the extended vestibular depth. A comparison was made of the vestibular depth measured from the crest of the ridge to the junction of the attached mucosa both preoperatively and postoperatively. RESULTS: Healing of raw surfaces was uneventful. The mean preoperative anterior mandibular vestibular depth was 3.5+/-1.1 mm. After 6 months, the mean anterior mandibular vestibular depth was 9.2+/-1.7 mm, a statistically significant difference (P < .05). The mean gain in vestibular depth was 5.7+/-2.2 mm. CONCLUSION: Overcorrection is unnecessary with this modification. Elimination of the sharp V in the extended vestibular depth enables denture fabrication with better flange extension and improved oral hygiene.     

Microsurgical anterior decompression and internal fixation with iliac bone graft and titanium plates for treatment of cervical intervertebral disc herniation

42 cervical interbody fusions with iliac bone graft and titanium plate fixation were performed between October 1991 and March 1994. The mean follow up period in this study was 10.7 months. In 32 cases fusion was done for 1 and in 10 cases for 2 segments. 2 different types of plates were used. In 25 cases micro-osteosynthesis plates and screws with 2.7 mm diameter were used, and in 17 cases cervical H-plates and screws with 3.5 mm diameter. A favourable outcome was achieved in 31 of 42 cases (74%). Satisfactory pain relief was achieved in 90%. For radicular motor deficit good results were obtained in 84% and for cervical myelopathy in 54%. The 2 different types of plates showed a remarkable difference in the clinical outcome. The results were regarded favourable in 15 of 25 microplate fusions (60%) and in 16 of 17 H-plate fusions (94%). Compression of the bone graft was seen in 5 patients of the micro plate group, however, radiological signs for fusion were present in all 42 cases at follow up. Major surgical complications, damage to neural structures or neurological deterioration did not occur in this study. Plate fixation in cervical interbody fusions seems to be a safe procedure and may reduce graft related complications at the fusion site if the plates and screws are sufficiently well proportioned. A favourable impact upon the results for cervical interbody fusion might be expected and should be further investigated in a long term follow up study.     

Analysis of reconstruction procedures for defects of the mouth floor. Report of 96 cases

The aim of this study was to assess the reconstruction of floor of the mouth defects after cancer surgery. The medical records of 140 patients treated between January 1st, 1987 and December 31st, 1995 were reviewed. Ninety-six patients had primary reconstruction: there were 82 cutaneous or osteomyocutaneous flaps and 14 microsurgical transfers. Among these patients 15 had titanium mandibular reconstruction plates. The reconstruction procedures and postoperative follow-up were evaluated. Healing by first intention is appropriate for superficial soft tissue defects. The nasolabial flap is used only for small mucosal defects. A forearm flap should be the first choice treatment for large soft tissue defects owing to its plasticity and reliable vessels. Segmental mandibular resections often imply mandibular reconstruction. Titanium plates may be used alone or with a cutaneous flap. Tolerance of plates after radiotherapy is very good and they are an effective method of reconstruction for fragile patients.     

The effect of immediate dentures on maxillomandibular relations

Immediate mandibular and maxillary dentures were made for six patients to determine the relative changes in the vertical dimension of occlusion and rest position over a 3-month test period. The dentures were mounted on the articular in centric occlusion (habitual). Pilkington-Turner anatomic teeth were used on the maxillary denture, which was set against a flat, noninterfering acrylic resin occlusion rim instead of mandibular posterior teeth. Positional cephalometric measurements in centric occlusion and rest position were made before extraction and at 1-week, 1-month, 2-month, and 3-month intervals. The dentures were relined after 2 months. The results were as follows: 1. In the centric occlusion position the mandible moved forward after 1 week and remained forward for the 3-month test period. 2. The rest position showed no significant change in the anteroposterior position of the mandible with time. 3. The vertical dimension of occlusion and rest showed a gradual decrease over the entire test period. 4. The reline procedure did not affect the trend of the dimensional changes. 5. A noninterfering occlusal scheme is advantageous for immediate dentures.     

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.     

Bony healing of large cranial and mandibular defects protected from soft-tissue interposition: A comparative study of spontaneous bone regeneration, osteoconduction, and cancellous autografting in dogs

The purpose of this study was to compare spontaneous bone regeneration, osteoconduction, and bone autografting in critical size calvarial and mandibular defects (defects which do not heal spontaneously during the lifetime of the animal) that were protected from soft-tissue interposition. Eighteen adult mongrel dogs underwent osteotomies to create a unilateral 30-mm segmental defect in the midbody of the edentulated right mandible and bilateral 15-mm x 20-mm full-thickness window defects in the parietal bones. The defects were either left empty, implanted with coralline hydroxyapatite (HA) blocks, or autografted with iliac cancellous bone. All defects were protected with a macroporous titanium mesh and the segmental mandibular defects were additionally stabilized by internal plate fixation. Specimens were retrieved after 2 and 4 months and three undecalcified longitudinal central sections including the osteotomy interfaces were prepared from each specimen for histometry and histology. Sections were analyzed for volume fractions of bone, soft tissue, and implant using scanning electron microscopy, backscatter electron imaging and histometric computer software. In the mandibular model, the empty defects exhibited the greatest amount of bone formation after 4 months (47.3 percent), which was greater than the amount of bone in the autografted group (34.8 percent) and significantly greater than the amount of bone within the hydroxyapatite implants (19.0 percent, p < 0.05). In the cranial defects, the autografted specimens demonstrated the greatest volume fraction of bone after 4 months (27.3 percent), which was significantly greater than within both the empty defects (18.2 percent, p < 0.05) and the hydroxyapatite implants (18.2 percent, p < 0.05). New bone formation in the mandibular defects united the cut ends at 4 months regardless of treatment and originated predominantly from the periosteum which remained present only along the alveolar border after surgical closure. In the calvarial defects, periosteum was not preserved and bone regenerated centripetally, originating from the diplo? without any evidence of dural osteogenesis. Bone bridging was incomplete in the empty cranial defects at 4 months. In both the mandibular and cranial specimens, new bone at 2 months was a mixture of woven and parallel fibered bone. At 4 months, the new bone had remodeled almost entirely into mature Haversian bone. This study demonstrated a remarkable ability of defect protection with a macroporous protective sheet to facilitate bone regeneration in critical size mandibular and cranial bone defects. When active osteogenic periosteum was present, as in our mandibular model, we concluded that defect protection alone was sufficient to allow for healing even of critical size defects. When periosteum was absent as in our cranial defects, the limited spontaneous bone formation benefited from the added contributions of cancellous grafting and osteoconductive implants, both of which promoted bone bridging across the defects. We suggest that in the future a resorbable macroporous protective sheet would be advantageous in comparison to a titanium mesh to facilitate bone regeneration by preventing soft-tissue prolapse and allowing the migration of mesenchymal cells and the proliferation of blood vessels from the adjacent soft tissues into the bone defect. Finally, this study identified the need to differentiate critical size defects into those with and without defect protection and periosteum.