Mats Sjöström

Simultaneous or delayed placement of titanium implants in free autogenous iliac bone grafts

Abstract The aim of the present study was to histologically analyse the bone graft-titanium implant interface after six and twelve months of healing for a simultaneous approach and after six months for a delayed approach. For this purpose, screw-shaped c.p. titanium microimplants, 2 mm in diameter and 5 mm long, were placed and retrieved at different time intervals in ten consecutive patients with severely resorbed maxillae and treated with iliac cortico-cancellous bone grafts and titanium implants in a two-stage procedure. The histomorphometrical analyses of ground sections of the specimens showed a higher degree of bone-implant contact and more bone filling the implant threads in the delayed approach microimplants. This was probably due to the partly revascularized grafted bone in the delayed approach being able to respond to the surgical trauma, resulting in interfacial bone formation. It is concluded that the results from the present study favour the use of a delayed approach when using free autogenous bone grafts and titanium implants for reconstruction of the severely atrophied maxilla.

Strategies in reconstruction of the atrophic maxilla with autogenous bone grafts and endosseous implants

Strategies in reconstruction of the atrophic maxilla with autogenous bone grafts and endosseous implants.

Bone Graft Healing in Reconstruction of Maxillary Atrophy

PURPOSE Evaluate correlations between volume change for iliac crest bone grafts in maxillary reconstruction (graft volume change [GVC]) and bone mineral density (BMD), bone volume fraction (BVF), hematologic bone metabolic factors (I), and identify indicators of implant failure (II). MATERIAL AND METHODS Forty-six consecutive patients had their edentulous atrophic maxilla reconstructed with free autogenous bone grafts from anterior iliac crest. Endosteal implants were placed 6 months after graft healing. Computer tomography was performed after 3 weeks and 6 months after grafting. Bone biopsies were taken from the internal table of donor site for calculation (BVF), and blood samples were collected. Implant stability was measured at placement with resonance frequency analysis and expressed as implant stability quotient (ISQ). Implant failure was registered. RESULTS GVC in onlay bone graft was 37%. The BVF in iliac crest biopsies was 32%. Serum-IGFBP3 differed with 79% of the samples over normal range. Fifteen patients had one or more implant failures prior to loading (early failures). Forty-two patients were followed for a minimum of 3 years after implant loading and, in addition, 6/42 patients had one or more implants removed during the follow-up (late failures). GVC correlated to decreased BMD of lumbar vertebrae L2-L4 (Kruskal-Wallis test, p=.017). No correlation was found between GVC and hematologic factors (Pearson correlation test) or between GVC and BVF (Kruskal-Wallis test). No correlation was found between ISQ and GVC (Pearson correlation test, p=.865). The association between implant failures and the described factors were evaluated, and no significant correlations were found (unconditional logistic regression). CONCLUSION Onlay bone grafts decrease 37% during initial healing period, which correlate to BMD of lumbar vertebrae L2-L4. No other evaluated parameters could explain GVC. The evaluated factors could not explain implant failure.

What Factors Are Associated With Impacted Canines in Cleft Patients

PURPOSE It is important to predict and prevent the impaction of canines. The aim of this study was to estimate the prevalence of impacted canines in patients with unilateral cleft lip and palate (UCLP) and to identify factors associated with impaction. MATERIALS AND METHODS This retrospective cohort study included patients with nonsyndromic UCLP. The predictors were pre-eruptive inclination angle, deviation in tooth number (agenesis or supernumerary lateral incisors), and reoperation of bone transplant. The outcome variable was impacted and surgically exposed canines. RESULTS The prevalence of impacted and surgically exposed canines in the 68 consecutive patients with UCLP was 20.6%. The pre-eruptive inclination angle was significantly larger (34.4°) for the impacted canines on the cleft side compared with the spontaneously erupted canines on the cleft and non-cleft sides (25.5° vs 15.4; P < .05). Reoperation of the bone transplant significantly increased canine impaction (50%; P < .05). CONCLUSION The eruption of maxillary canines needs to be supervised carefully in patients with UCLP, because the prevalence of impaction is 10 times higher compared with the general population. Factors associated with canine impaction are a pre-eruptive inclination larger than 30° and reoperation of the bone transplant.

Osteoblastoma of the temporal articular tubercle misdiagnosed as a temporomandibular joint disorder

The case of a 17-year-old female with a benign osteoblastoma in the temporomandibular joint (TMJ) is reported. The patient had a 2.5-year history of reduced mouth opening accompanied by tenderness and swelling in the left TMJ. Initial treatment included stabilization of the occlusion with a splint, jaw exercises, and analgesics. At first the patients symptoms decreased, but they then increased 18 months later, prompting a cone beam computed tomography (CBCT) evaluation of the joint. The radiographic findings showed a somewhat ill-defined, radiolucent, expansile lesion containing small scattered calcifications located in the temporal articular tubercle. The lesion was removed under general anaesthesia and sent for histopathological examination. At the 12-month follow-up, the patient had normal TMJ function without clinical symptoms. CBCT examination showed a small recurrence of 3mm. Another 12 months later, CBCT showed a 1-mm increase in the recurrence. Her function was normal, with slight tenderness lateral to the left TMJ. The decision from a multidisciplinary meeting was further annual follow-up. The present case illustrates the importance of initial radiographic examination together with clinical examination in patients with TMJ dysfunction.

Clear cell variant of intraosseous calcifying epithelial odontogenic tumor: a case report and review of the literature

CEOT is a rare benign, but locally aggressive odontogenic tumor, and some authors have claimed that the biologic behavior of the clear cell variant is even more aggressive, with greater propensity to recur. We report a rare case of clear cell calcifying epithelial odontogenic tumor (CEOT) and discuss its possibly aggressive behavior. A 40-year-old woman experienced an asymptomatic expansion of the left posterior mandible. After radiographic examination and biopsy, a block resection was performed. Histologic examination included analysis of Ki-67 reactivity as a marker of tumor growth activity. Ki-67 labeling was pronounced in the non-clear cell population in the tumor periphery but low in the central and clear cell portions. Clinical and radiographic follow-up 6 years after resection has not revealed any signs of recurrence. On the basis of a review of the literature and our own findings, there is no clear data to suggest that clear cell CEOT exhibits more aggressive behavior compared with conventional CEOT.

Epstein-Barr virus is not detected in mucosal lichen planus

Background Lichen planus (LP) is a chronic inflammatory, immunological, mucocutaneous disease can affect skin, genital and oral mucosa. Oral lichen planus (OLP) is the most common noninfectious, chronic inflammatory oral disease affecting 1-2% of the general adult population. World Health Organization (WHO) classifies OLP as a potentially malignant disorder. Epstein Barr virus or human herpesvirus-4, is a member of the herpes virus family and one of the most ubiquitous viruses known to human, infecting approximately 90% of the world’s adult population. The virus often infects B lymphocytes resulting in a wide spectrum of mucocutaneous and systemic diseases, ranging from mild lesions to aggressive malignancies. The aim of this study was to investigate expression of the EBV encoded RNAs EBER1 and EBER2 in oral and genital lichen planus and compare results with normal tissues in situ hybridization which is considered the golden standard for detection of EBER. Material and Methods A total of 68 biopsies, 25 oral LP, 26 genital LP, 10 oral controls and finally 7 genital controls were analysed using situ hybridization. Results All samples had RNA as shown by the control slide, whereas no case contained neither EBER1 nor EBER2. Conclusions Based on results from our study EBV is not involved in aetiology of lichen planus. Key words:Mucosal lichen planus, Epstein - Barr virus.

Indications and Frequency of Orthognathic Surgery in Sweden – A Questionnaire Survey

Orthognathic surgery, a standard procedure used to improve intermaxillary relationship, surgically moves either one or both jaws. However, statistics for frequency and indications for orthognathic ...