Biomedical subjects
Publications and source records attributed to N Samman.
An unusual presentation of a chronic suppurative granuloma on the alar base area originating from a maxillary lateral incisor is reported. Treatment involved adequate endodontic therapy with simultaneous apical surgery and excision of the granuloma and sinus tract. Awareness of the possible dental origin of facial sinuses, despite their unusual location, is emphasized.
AIM: To describe the clinicopathological and immunophenotypical findings of two cases of inflammatory pseudotumour in the oral cavity. METHODS AND RESULTS: The patients presented with a short history of swelling in the cheek and the maxilla respectively. Magnetic resonance imaging or computerised tomography scan showed space occupying lesions with infiltrative margins which were interpreted as aggressive malignant neoplasms. Histological examination showed fascicles of spindle cells in a background of chronic reactive inflammatory cells including plasma cells, typical of inflammatory pseudotumour. The spindle cells were positive for vimentin, smooth muscle actin and CD68, but were negative for follicular dendritic cell markers. The lymphocytes showed no light chain restriction. CONCLUSIONS: Inflammatory pseudotumour in the oral cavity is completely benign and simple excision is curative. However, it may be confused with a malignant tumour on clinical and radiographic grounds, and histologically the appearances can also be misinterpreted as those of a more aggressive lesion. Its correct recognition by the surgical pathologist is important to avoid unnecessarily radical and potentially mutilating surgery.
A clinical dilemma exists regarding the type of bone that should be used to replace diseased or traumatized osseous tissue. Oral, plastic, and orthopedic surgeons normally implant viable mineralized endochondral (EC) autografts or demineralized EC allografts. A few clinicians have recognized the disadvantages of using EC bone in craniofacial surgery and advocated the replacement of intramembranous (IM) bone with healthy IM bone. However, controversy and uncertainty surround our understanding of these matrices to induce bone formation. Recent studies have advocated the use of other materials with osteoinductive properties, such as demineralized bone matrix (DBM). The proposed delivery system used in this study included IM bone grafts, DBM, and fixation of the IM bone graft. The purpose of this work was to gain further insights into the mechanism of healing of IM bone, in both the presence and the absence of DBM, and to compare the healing of IM bone grafts with that of DBM alone. Critical-sized (10 x 5 mm), full-thickness bony defects in rabbit parietal bone, devoid of periosteum, were filled with IM bone graft (mandible) alone, demineralized cortical bone matrix (DBM) alone, or combined DBM-IM bone graft, or were left unfilled. Histologic changes were examined 14 days later. The IM bone graft healed through IM ossification with no intermediate cartilage stage. DBM and composite DBM-IM healed through an EC ossification with an intermediate cartilage stage. It is hypothesized that the role of the IM graft is to induce neovascularization into the defect site, and that the undifferentiated mesenchymal cells in the perivascular region of the new blood vessels are induced by the bone morphogenetic protein(s) in the DBM into bone-forming cells.
This paper reviews the indications for, and the biological basis of, costochondral grafting for mandibular condyle replacement in adults and children. Our approach to costochondral grafting is described and illustrated, and known variations in techniques are reviewed and discussed. Data from our clinical series of 28 grafts is summarized.
This paper describes the surgical reconstruction of the maxilla and mandible after ablative surgery. The methods described are original and recently developed with illustrative clinical data presented. Presurgical planning of the occlusion, titanium mesh design supporting the bone graft, and implant-borne prostheses are integral elements of the concepts described to achieve functional reconstruction of the jaws.
OBJECTIVES: It is desirable that the surfaces of surgical implants be uncontaminated by foreign materials to avoid untoward tissue reactions, and grit blasting is widely assumed to leave clean metal surfaces. SEM examination and X-ray microanalysis of a recovered 'pure' titanium implant casting that was associated with tissue breakdown revealed embedded particles of alumina. The casting had been cleaned of investment by blasting with alumina grit. METHODS: A variety of treatments of cast titanium plates was used: (a) to establish that the observed aluminium was due to the blasting grit, and (b) to determine whether removal of investment could be achieved effectively by other means. SEM examination and X-ray microanalysis were used. RESULTS: The detected aluminium was associated with embedded fragments identified as coming from the blasting grit. Acid-pickling and mechanical (rotary instrument) trimming produced minimally contaminated surfaces. CONCLUSIONS: Whilst unproven, the presence of the alumina is viewed with great concern as a possible causative agent in the observed tissue breakdown and procedures avoiding alumina blasting are recommended as a precautionary measure.
In four patients who had osteotomies of the jaws affected by fibrous dysplasia (FD), screws embedded in bone blocks were removed at a re-entry operation 20 months postoperatively. Morphometric measurement of the bone density and calculation of the bone contact percentage were performed. Both normal and dysplastic bone were found to have some direct bone contact with the titanium screws. Although the bone contact percentage was higher in the normal bone when compared with FD, statistics failed to show any significant difference (P < 0.05). The dysplastic bone healed well around the titanium screws without inflammatory reaction and direct dysplastic bone/screw contact was noted. Longer screws should be used in facial FD in order to compensate for the reduced bone contact percentage.
Previous clinical studies and animal experiments have demonstrated that the placement of expanded polytetrafluoroethylene (e-PTFE) membranes (GORE-TEX) may be valuable for bone regeneration in nonosteogenic areas. This study aimed to explore the application of this technique to bone grafting of wide alveolopalatal clefts. Ten patients with bilateral clefts were selected and during a 2-week period, all received autogenic cancellous iliac bone bilaterally. The membrane was placed nasally and orally on the larger cleft side and removed after 3-6 months. All patients have been followed for 14 months. Bone graft incorporation was successful except for one patient (membrane side), who was regrafted 1 year later. However, soft-tissue problems with membrane exposure occurred in the majority of patients, while on the nonmembrane side, healing was uneventful in all cases. Further research in membrane technology is necessary before this method can be accepted for cleft grafting.
This paper is the first report of overgrowth of a costochondral graft in an adult male. The case supports the notion that this graft partly exhibits features of a primary growth center with inherent potential for growth.
OBJECTIVES: To evaluate the stability of maxillary osteotomies in cleft palate patients using miniplate fixation. DESIGN: A prospective clinical study. SUBJECTS: 46 consecutive cleft palate patients with residual alveolar clefts and maxillary hypoplasia in one or more dimensions. These patients underwent standardised maxillary osteotomies and simultaneous bone grafting of the alveolar cleft over 44 months during 1988-1992. Titanium mini-plate fixation was used for the maxilla in all patients. Follow-up ranged from 6 to 51 months with a mean of 28 months. MAIN OUTCOME MEASURES: The 3-dimensional stability of maxillary osteotomies in cleft palate patients in the long term. RESULTS: In the unilateral clefts, relapse in the horizontal plane was 22% and in the vertical plane 22.5%; in bilateral clefts, the relapse was 17.5% and 7% respectively, with no statistically significant difference between the two groups. Longitudinal analysis of the repositioned maxilla over a 3-year period showed that most of the relapse occurred in the first 6 months and stabilised at 2 years postoperatively. Relapse in the transverse plane, based on analysis of the study models of 26 cases, ranged from 13.4% to 33.6%. A clockwise rotational relapse of the maxilla was noted in bilateral cases. Postoperative orthodontics compensated for the horizontal relapse by increasing incisor proclination to maintain positive overjet. There was no significant difference between the relapse of bimaxillary cases and that of maxillary osteotomies alone. CONCLUSION: The long-term 3-dimensional surgical stability, using miniplate fixation, has decreased the relapse of cleft maxillary osteotomies with simultaneous alveolar bone grafting to a level comparable to that of maxillary osteotomies in non-cleft patients.
A retrospective study was made of 22 consecutive patients who underwent mandibular reconstruction with a Dacron (Osteo-mesh, Xomed Inc, Jacksonville, FL) tray technique from September 1988 to April 1992. Free autogenous iliac bone, in the form of particulate cancellous chips and marrow, was densely packed into the Dacron tray, that was adapted to bridge the mandibular segmental defect. Sixteen cases underwent uneventful healing with the formation of a continuous bony bridge and union with the remaining mandible. The pattern of bone remodeling and rate of resorption in these cases were assessed by sequential panoramic radiographs taken up to 3 years postoperatively. The mean horizontal dimension of the mandibular defects was 75 mm and the mean vertical reconstructed height was 25 mm. When the grafted bone was radiographically of uniform density, it progressed into a mature trabecular pattern matching that of the normal mandible. However, when there were areas of radiolucency, most likely from inadequate condensation of the graft, such areas were not replaced by bone in the long term. The bony height at both ends and the middle of the reconstructed segment underwent reasonably even resorption and retained about 80% of the bony height over a 3-year period. The rate of resorption was highest in the first 6 months and stabilized at about 2 years. There were six failures, all showing significant irregular bony resorption prior to tray removal.
A detailed cephalometric analysis of the soft and hard tissues of the upper airway was conducted with lateral cephalographs from 116 normal Chinese, aged between 18 and 25 years. Normal values and deviation range were preliminarily established for the size of the tongue, soft palate, nasopharynx, oropharynx, and hypopharynx, and for the relative position of the hyoid bone and vallecula in both sexes. Statistical findings showed that there were significant differences between the sexes. Significant relationships (P < 0.001) were observed 1) between the hypopharyngeal depth and the position of the hyoid bone and the vallecula, in which the horizontal position of vallecula appears to be the best predictor of the hypopharyngeal depth, as confirmed by the multiple regression equation; 2) between the upper airway depths at four different levels; and 3) between the naso-oropharyngeal area and tongue, soft palate, and oral area. The present data can be used to investigate further the upper airway in abnormal states.
Nineteen unilateral and 19 bilateral alveolar clefts (group A) were grafted with cancellous iliac bone by a standard method, and 21 unilateral and 15 bilateral clefts (group B) underwent simultaneous maxillary osteotomies and alveolar bone grafting with cancellous iliac bone. The two groups were retrospectively evaluated clinically and radiographically for alveolar bone level (ABL), attached keratinized gingiva (AKG), sulcus depth (SD), and persistence of oronasal fistulae (ONF). The follow-up ranged from 6 to 54 months with a mean of 23 months for group A and 26 months for group B. In group A, AKG ranged from 1 to 10 mm (mean 5 mm), most patients having deep or normal SD and type I ABL as measured according to the Oslo method. No persistent ONF was noted. In group B, AKG ranged from 0 to 8 mm (mean 3 mm), half the patients showing a shallow sulcus, most with type II or III ABL. In this group, a 4% failure rate of the bone grafting was noted and 6% fistula persistence. It is concluded that the overall results of standard alveolar bone grafting are better in this series than those of simultaneous osteotomy cases, results which are still quite acceptable because they are comparable with published results of standard alveolar bone grafting. The results of this study indicate that simultaneous osteotomy with alveolar bone grafting in cleft patients does not compromise the outcome of bone grafting; therefore, they support the one-stage surgical management of patients with ungrafted clefts and maxillary hypoplasia.
Despite the wide popularity of the pedicled temporalis myofascial flap, aesthetic management of the temporalis donor site has received little attention. A technique for immediate camouflage of the temporalis flap donor site with cold-cure methyl methacrylate, either alone or in combination with residual muscle in the temporal fossa, is presented. A retrospective evaluation of this technique in 34 consecutive patients was undertaken, with particular reference to the aesthetic results and morbidity associated with the use of cold-cure acrylic for this form of reconstruction. Apart from transient postoperative swelling and neuropraxia, no major or lasting complications associated with the use of cold-cure acrylic were recorded. The aesthetics of the camouflaged temporalis donor site by acrylic alone, or when combined with part of the temporalis muscle, was judged objectively to be excellent in 25 patients, satisfactory in 3 patients, and poor in 2 patients. 4 patients who did not have acrylic reconstruction, but had part of the temporalis muscle transposed to conceal the anterior fossa depression, leaving the posterior fossa unreconstructed, were judged mostly as satisfactory. Histology of the soft tissues around an acrylic implant after nearly 2 years confirmed the good biocompatibility of this material. It is concluded that this technique is a safe and reliable method for immediate camouflaging of the temporal fossa after harvesting a temporalis muscle flap.
Reconstruction of the maxilla should aim to restore appearance, speech and occlusion. With modern reconstructive techniques and availability of an increasing variety of reliable tissue flaps, many of the traditional problems of treatment have been overcome. This paper reviews local and distant tissue flaps useful in rehabilitating an acquired maxillary defect of various dimensions. The local flaps discussed include flaps from the palate, cheek, tongue and the buccal fat pad. The distant flaps considered are the temporalis myofascial flap, pedicled cutaneous and myocutaneous flaps, and vascularized free flaps. Bony reconstruction of the maxilla with particular emphasis on restoring an anatomical alveolar ridge for occlusal rehabilitation by dental implants is presented.
The use of the buccal fat pad (BFP) as an uncovered pedicled graft to close oral defects is relatively recent. A series of 29 consecutive cases of reconstruction utilizing the BFP is presented, showing excellent results and without added surgical morbidity. Indications include defects after benign or malignant tumour resection, and the combined BFP/temporalis myofascial pedicled flap is reported as an additional option in reconstruction. Histologic findings in healed reconstruction sites indicate fibrous replacement of the fat tissue, and epithelialization of its oral surface. From the results of this series, we conclude that the use of the BFP for the reconstruction of appropriate surgical defects in the mouth is worthy of consideration.
A new method for immediate reconstruction of the maxilla after resection is described. The ipsilateral pedicled temporalis muscle is tunneled into the defect and sagittaly split into two layers. The inner layer is used to line the nasal side. An individually shaped titanium mesh, tightly filled with free autogenous corticocancellous bone, is fixed by titanium screws to the remnant of the zygoma and contralateral maxilla. The outer layer of the split muscle covers the reconstruction, the temporalis fascia forming the oral side. The method resulted in good cosmetic appearance and permitted the re-creation of a maxillary alveolar ridge suitable for endosseous implants or a simple prosthesis.
We report an extremely rare case of bilateral transverse facial clefts and accessory maxillae with severe mandibular hypoplasia in a 7-year-old Chinese boy. The transverse facial clefts had been repaired in infancy. The accessory maxillae were excised via a combined temporal and oral approach. Functional orthodontic appliance therapy was not feasible due to restricted protrusive movements of the mandible. Bimaxillary osteotomies were performed one year later due to failure mandibular catch-up growth to occur. The pathogenesis of the accessory maxillae in the presence of lateral facial clefting is postulated to be compensatory mesenchymal growth from the temporal region, and a case is made for this condition to be considered as a possible syndrome rather than a variant of the transverse facial cleft.