In this case report the author illustrates a protocol for post-extraction fullarch rehabilitation produced with the use of computerized virtual treatment planning and guided surgery. In a 74-year old man presenting a failed maxillary attachment-retained removable partial denture, a treatment plan focused on the immediate loading of a post-extraction full-arch prosthesis was developed. Starting from prosthetic analysis a modular scan template for CBCT examination was designed, with a 3D simulation software a protocol for guided implants placement and prosthetic rehabilitation was setup. With the support of this procedure, the author performed the extraction of eight teeth, the placement of eight implants (including extraction sites) with flapless approach, and the immediate load of a provisional screw retained prosthesis. At one year follow-up clinical and radiographic results were stable. In selected cases, this protocol may offer significant advantages, including one-day treatment, reduced post-surgical discomfort and immediate improvement in function and aesthetics.
Hydroxyapatites (HAPs), which are synthetic ceramics (complex calcium phosphates), are very similar to bone and tooth minerals in their complex and have a biocompatibility. Recently, HAPs are used as a bone implant material in variety of situations, eg, surgical reconstruction, augmentation of the facial skeleton, also used to fill acquired and congenital bone defects.Autogenous particulate cancellous bone and marrow (PCBM) had been known to have an active osteogenesis. These implant materials produce desirable effects on regeneration in osseous defects.The aim of this investigation was to ascertain experimentally the biocompatibility, osteoinductive and/or conductive ability of a combined implant material with HAP and autogenous bone in an ectopic situation. Mixed type of materials, porous HAP granules and PCBM (volume ratio, HAP: PCBM=2: 1), were implanted into adult dogs using an vessel attached type incubating chamber which enabled to make the circumstances being free from the influences of recipient site. This chamber was attached to bilateral carotid artery, HAP-PCBM mixed group was implanted on one side and HAP alone group on the other side. Periodical (7, 14, 28, 60, 90 days) histopathological examinations were carried out by light and electron microscopies after implantation.The results were as follows:New bone formation was not observed in HAP alone group throughout the experimental period (90 days). Implanted HAP was encapsulated with fibrous tissue and these tissues were infiltrated with a few inflammatory cells. Macrophages and multinuclear giant cells (MGC) were observed on the HAP-tissue interface (MGC, I supposed to be a fusion cell type of macrophage). HAP resorption occurred by the activities of macrophage and MGC.After 28 days, a newly formed calcified bone matrix surrounded by transplanted trabecular bone chips was observed in HAP·PCBM group. These new bones, initially grew toward the HAP granules, were formed along with the HAP's surface. The osteoconductive ability of HAP in an ectopic site was also confirmed with this results. Under the same experimental conditions, a lamellar bone formation, which was a matured type of bone formation, was confirmed after 90 days.MGC have a different ultramicroscopical features depending on the contact materials. Namely, MGC surrounding a newly formed bone matrix had a ruffled border and clear zone, which were characteristic in osteoclast, but N1GC around HAP or transplanted bone chips had not such organelles.
In recent years several basic and clinical researches on new synthetic biomaterials, such as hydroxyapatite (HAP), have been reported. It is well known that HAP is available for bone augmentation and has osteoconductive ability. But the use of HAP is not always free of problems, because it is difficult to be handled, to be shaped and to maintain the implanted site. After implantation of granular HAP, some prognoses are poor due to infection at the implanted site and inflammation occasionally appears. The cause is tought that granular HAP easily spills from the implantation site and then is contaminated by some microorganisms. Above all, the use of HAP is limited by its physical properties. Zinc-oxide eugenol cement (ZOE), which has been used extensively in dentistry, has sedative and antimicrobial properties. HAP and ZOE were mixed (HAP-ZOE complex) in order to overcome the above faults.The pH value and the concentrations Ca2+ and Zn2+ of HAP, ZOE and HAP-ZOE complex, which were sunk in the Ringer's solution, were examined. Their ultrastractures were observed with scanning electron microscope.The results were summarized as follows: HAP-ZOE, complex was a paste like substance with easy handling. The pH value of HAP-ZOE complex was 9.4, that of HAP was 6.4 and that of ZOE was 7.4. The concentration of the Ca2+ of HAP-ZOE complex was 103. 6 ppm, that of HAP was 95.3 ppm and that of ZOE was 101.5 ppm. The concentration of the Zn2+ of HAP-ZOE complex was O.2 ppm, that of HAP was 0.4 ppm and that of ZOE was O.7 ppm. The ultrastracture of HAP-ZOE complex indicated that HAP as core and ZOE as matrix contacted closely, and there was an affinity between them.In conclusion, these results suggested that HAP-ZOE complex markedly improved granular HAP's practical use and HAP-ZOE complex is thus expected as a good implantable material.
It's feared that morphologic changes of face and abnormal occlusion may occur after surgical intervention in growing mandibles. So the author experimentally studied the influence of 4 types of bony resections on rat mandible growth.Sixty 4-week-old WKA rats were used in the study. They were divided into 6 groups as follows: Group 1. Periosteal elevation and bone resection at the inferior border of the mandibular body were performed in the left mandible. The resected bone size was φ 2.3mm. The operation procedure before bone resection in groups 2-5 was the same as in group 1. Group 2. Bone resection was performed at the same site as in group 1, but the size was φ 4.0mm. Group 3. The bone was resected at the center of the ramus; the size was φ 2.3mm. Group 4. The bone was resected at the mandibular foramen. At the same time, the inferior alveolar artery and nerve were cut. Group 5. Only periosteal elevation was performed. Group 6 (Control). These rats were sacrifiecl at 15 weeks of age and decapitated, the specimens were measured and analyzed statistically.The resection at the inferior border of the mandibular body led to mandible growth of inhibition, mainly at the site of the mandibular angle. This inhibition was great in proportion to the size of the bone resection. The bone resection at the inferior border of the mandibular body led to greater growth inhibition than the bone resection at the center of the ramus. The bone resection at the mandibular foramen led to great mandibular growth inhibition.
Vascularization of grafted bones has been the title of a number of morphological studies. However, there are few published papers following up dynamic changes of blood flow in process of vascularization. In view of these facts, I investigated a morphological study concerning vascularization of grafted bones and also diurnal dynamic changes of blood flow in grafted bones using the microsphere technique.MethodsUsing male wister rats as test animals, autologous tibia (about 1 cm) was grafted into the bipedicle tubed abdominal flap (4×2cm) established on the abdominal wall. The animals were sacrificed at 3 days, 1, 2, 3 and 4 weeks after the bone graft, and pathological preparations and transparent preparations were prepared. Then, microsphere 125I was injected into the left venticle immediately and at 3 days, 1, 2, 3 and 4 weeks after the operation, and radioactivities were counted by Beckman Ganma Radiation Counter. By using a Mutoh Desitizer, the bone reconstruction rate was determined.Group A...Tibia without periosteumGroup B...Longitudinally-cut tibia without periosteum and marrowResults1. Vascularization in the bone grafted into the flap1) In both Groups A and B vascularity appeared at day 3 after the operation.2) Vascularization in the cortical bone of the grafted bone appeared earlier in Group B as compared to Grooup A.3) In Group A, the medullary vascularization almost completed in about 3 weeks, at which period vascularization in the cortical bone exceeded that observed in Group B.4) Changes in blood flow determined by the microsphere technique showed almost similar patterns for both Groups A and B: Namely, the blood flow showed an increasing tendency to reach its peak at week 2, followed by a decrease at week 3 and slight increase at week 4.2. Bone reconstruction associated with vascularization1) Bone reconstruction appeared at week 1 after the operation and it occurred in the region where accelerated vascularization was seen.2) In Group B, bone reconstruction started in the earlier stage and progressed gradually in the entire grafted bone. Until week 2, the bone reconstruction in Group B was superior to that in Group A.3) In Group A, the bone reconstruction exceeded that of Group B from week 2. In particular active bone reconstruction was seen in the medullary cavity where pronounced vascularization was observed.
A case of bilateral maxillary aneurysmal bone cysts in a 55-year-old woman is described. A brief review of the literature is presented. The diagnosis was based on the characteristic radiographic, macroscopic, and microscopic findings. Both lesions responded well to curettement. Followup showed no recurrence after five years.
Total or posterior mandibular alveolar osteotomy was performed on 12 patients for vertical open bite (2), mandibular alveolar hypoplasia (short-face syndrome) (7), and posterior arch discrepancies (3). Follow-up periods were from nine to 48 months. Most cases showed excellent stability. Permanent damage to the inferior alveolar nerve was found in five of the 21 operated sides (25%). Damage to the tooth pulps was considerable. Two molars had to be removed and apicoectomy or endodontic treatment was carried out on ten others. Although the method is technically difficult, it can be recommended in selected cases because of its excellent stability and predictable end results.
A double-blind clinical evaluation comparing 1% etidocaine with 1/200,000 epinephrine and 2% lidocaine with 1/100,000 epinephrine for third molar surgery was done on 42 patients. Aspects of long-acting and short-acting local anesthesia were compared, including time of onset, potency, regression, duration, and appraisal by the patient. The preference of patients and the experience of postoperative pain are emphasized.
The primary purpose of this study was to determine a measure of selected patients' perceptions of the scope of services provided by the oral and maxillofacial surgeon. Data were collected from 403 patients by a questionnaire and were combined with data from the participating patients' charts. Analysis and interpretation of the data disclosed two trends: patients perceived that problems of odontogenic origin should be treated by dentists or oral surgeons, and patients perceived that problems of nonodontogenic origin should be treated by medical professionals rather than by oral and maxillofacial surgeons. If these patients are representative of the general population, then these trends strongly suggest a need for greater public and professional dental educational opportunities about the scope of services rendered by the oral and maxillofacial surgeon. It is recommended that dental societies and dental schools assume the lead in offering these opportunities.
The carbon dioxide laser is a relatively new mode of therapy in the treatment of oral lesions. In our experience, when the laser has been used, bleeding, scarring, and edema have been minimal. With the development of hand-held instrumentation, this useful tool can be added to the oral surgeon's armamentarium.
An unusual case of ameloblastoma that underwent malignant change and metastasis during recurrence is described. The primary tumor of the mandible and two independent recurrent lesions found in the base of the coronoid process and in the mandibular notch were cystic ameloblastoma of follicular type, with no histological evidence off malignancy. The second recurrence developed in the soft tissues on the medial aspect of the ascending ramus and consisted of a large solid tumor mass with poorly differentiated ameloblastoma cells, which were seen clustered in blood vessels in close apposition to tumor nests. Apparently these metastasized to the temporal bone in five months. The metastatic tumor was composed of atypical follicles packed with undifferentiated hyperchromatic cells with nuclear atypia and abundant mitoses. The histological diagnosis was malignant ameloblastoma. The cerebral lesion that developed in the skull base, possibly by direct extension of the second recurrent tumor, was also regarded as malignant because of its rapidity and aggressive growth and its high sensitivity to radiotherapy.
Eagle's syndrome is the symptomatic elongation of the styloid process of the temporal bone. It is an uncommon clinical entity that often causes vague and seemingly inconsistent symptoms. The pain associated with this syndrome is relieved by amputation of the elongated portion of the styloid process. The regional anatomy and possible causes of the pain were discussed. An improvement in the surgical approach, which aids in visualization and assures the retraction and deflection of significant adjacent anatomical structures, has been suggested. Three cases were presented that had varying symptoms but apparently common etiologies. This syndrome should be considered when considering the differential diagnosis of facial pain.
According to Bell, "the aim of bone grafting is to place a readily vascularizable osteogenic organic structure in intimate contact with a vascular osteogenic cancellous host bed." To accomplish these objectives, a tunneling procedure was developed. This technique provided a circumferentially intact vascular bed, which minimized the edema usually caused by interference with venous and lymphatic drainage. Together with adequate graft stabilization and maxillomandibular fixation, this surgical approach deceased shearing forces, permitted unimpeded capillary ingrowth, minimized hematoma and dead-space formation, and maximized the viability of the graft.
