Jan M. Hirsch

Bone Formation at the Maxillary Sinus Floor Following Simultaneous Elevation of the Mucosal Lining and Implant Installation Without Graft Material: An Evaluation of 20 Patients Treated With 44 Astra Tech Implants

PURPOSE Restoration of lost dentition in the severely artrophic posterior maxilla has for the last 2 decades been successfully treated with various sinus augmentation techniques and installation of dental implants. The use of graft material is anticipated to be necessary; however, recent studies have demonstrated that the mere lifting of the sinus mucosal lining and simultaneous placement of implants result in bone formation. This study was conducted in order to evaluate simultaneous sinus mucosal lining elevation and installation of dental implants without any graft material. PATIENTS AND METHODS Twenty patients were consecutively included from November 2001 to June 2004. Forty-four Astra ST dental implants (Astra Tech AB, Mölndal, Sweden) with a diameter of 4.5 mm or 5 mm were installed in 27 sinuses. A sinus lift was performed where a cortical window was removed from the maxillary anterior sinus wall. The sinus mucosal lining was elevated and implants installed in the residual subantral bone. The cortical window was thereafter replaced and the incision closed. The remaining bone height was recorded during surgery as well as perforations of the sinus mucosal lining. After 6 months of healing, abutments were connected (the series included 5 1-stage procedures). Clinical and radiological follow-up after loading was performed up to 4 years after implant installation. RESULTS Patients tolerated the procedure well as few complications were observed. Firm primary stability was achieved for all implants at installation with bone levels in residual bone of 2 to 9 mm. Perforations of the maxillary sinus mucosal lining occurred in 11 of the 27 operated sinuses (41%). One implant was lost during a mean follow-up of 27.5 months (range, 14 to 45 months) giving an implant survival rate of 97.7%. The average gain of bone at the sinus floor was 6.51 mm (SD = 2.49, 44 implants) including all measured implants after a minimum of 1 year follow-up. Marked bone formation was observed around long implants and also when the residual bone below the sinus was diminutive. CONCLUSIONS The present study including 20 patients showed consistent bone formation at the maxillary sinus floor following simultaneous mucosal lining elevation and installation of implants. It is suggested that the use of this technique can reduce the risk for morbidity related to harvesting of bone grafts and eliminate costs for grafting materials.

Reactivated herpes simplex virus infection as a possible cause of dry socket after tooth extraction

This study was designed to evaluate a possible association between reactivated herpes simplex virus type 1 (HSV-1) infection after lower third molar extraction and development of dry socket (DS). The HSV-1 antibody response was analyzed before and after tooth removal by enzyme-linked immunosorbent assay and immunoblotting in 208 patients. History of previous possible oral herpes reactivation was evaluated by a questionnaire that was based on self-rated frequency of oral cold sores. Tobacco users were identified. The anatomic proximity of the root apex to the mandibular nerve canal was classified radiographically before extraction. Fifteen patients (7%) developed DS after tooth extraction. Eleven of the 15 DS patients (73%) were HSV seropositive as compared with 7 of 15 (47%) in the matched control group. Seven of the 11 seropositive DS patients have shown HSV-1 reactivation by an increase of specific polypeptides, predominantly gB, gC, gD and ICP 4 and 6, in the immunoblot test. No change in HSV-1 reactivity was observed in control sera. DS patients reported a high frequency of oral cold sores (64%) compared with the controls (33%). Tobacco use was not found to influence the frequency of cold sores or the development of DS. A close radiographic proximity between the mandibular canal and root apex was more common (P < .05) in DS patients. The results indicate that extraction of a mandibular third molar could be a possible cause of reactivation and recurrence of an HSV-1 infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunohistochemical detection of p53 in non-malignant and malignant oral lesions associated with snuff dipping in the Sudan and Sweden

Immunohistochemistry was used to examine the expression of p53 in pre‐malignant oral lesions and oral squamous‐cell carcinomas (SCCs) from Swedish and Sudanese snuff‐dippers, as well as in pre‐malignant oral lesions and oral SCCs from non‐snuff‐dippers from the Sudan, Sweden and Norway. Of the 14 SCCs from Sudanese snuff‐dippers, 21% (3/14) expressed p53. Of the 14, 60 and 41 SCCs from non‐snuff‐dippers from the Sudan, Sweden and Norway, 64% (9/14), 65% (39/60) and 68% (28/41) expressed p53, respectively. A statistically significant difference in expression of p53 was found in SCCs from Sudanese snuff‐dippers compared to those from non‐snuff‐dippers from all/or any of the 3 countries. None of the suspected pre‐malignant oral lesions from Sudanese snuff dippers or non‐snuff‐dippers expressed p53. Only 2 out of the 15 oral fibro‐epithelial hyperplastic lesions from Swedish snuff‐dippers expressed p53. Some of the oral epithelial dysplastic lesions, as well as the carcinoma in situ lesions from Norwegian non‐snuffdippers, expressed p53, while the oral fibro‐epithelial hyperplastic lesions did not. The low relative frequency of p53 expression found in oral SCCs from snuff‐dippers compared to those from non‐snuff‐dippers might suggest differences in mechanisms of oncogenic action induced by snuff. Alternatively, the pathogenesis of malignant oral lesions from snuff‐dippers may follow a p53‐independent pathway. In view of the unusually high levels of the tobacco‐specific nitrosamines (TSNA) found in the type of snuff used in the Sudan, investigations of p53 mutations or oncogenes are needed.

A comprehensive classification of mandibular fractures : a preliminary agreement validation study

This study evaluates a comprehensive classification system for mandibular fractures based on imaging analysis. The AO/ASIF scheme, defining three fracture types (A, B, C), three groups within each type (e.g. A1, A2, A3) and three subgroups within each group (e.g. A1.1, A1.2, A1.3) with increasing severity from A1.1 (lowest) to C3.3 (highest) was used. The mandible is divided into two vertical units (I and V), two lateral horizontal units (II and IV) and one central unit (III) comprising the symphyseal and parasymphyseal region. Type A fractures are non-displaced, type B are displaced and type C are multifragmentary/defect injuries. Groups and subgroups are further defined in the classification system. Two classification sessions using semi-automatic software with 7 and 9 surgeons were performed to evaluate 100 fracture cases in the first session and 50 in the second. Inter-observer reliability and individual raters accuracy were evaluated by kappa coefficient and latent class analysis, respectively. The analysis of inter-observer agreement for the detailed coding showed kappa coefficients around 0.50 with higher agreement among raters in the vertical units. This system allows standardization of documentation of mandibular fractures, although improvement in the definition of categories and their application is required.

Skull base and maxillofacial fractures : two centre study with correlation of clinical findings with a comprehensive craniofacial classification system

PURPOSE A comprehensive classification based on high resolution computed tomography (CT) of the whole craniofacial region was correlated with clinical findings of combined skull base and maxillofacial fractures. MATERIAL AND METHODS In a study of two clinical centres, 70 patients with such injuries were admitted at the Universities of Basel (n=29) and Uppsala (n=41). Clinical signs (rhinorrhoea, periorbital haematoma and pneumencephalus) and surgical versus conservative treatment were correlated with a cranio-maxillofacial injury severity score (CMF-ISS) calculated from the classification system. Fracture classifications were decided in consensus on the basis of CT and semiautomatic classification software. The classification system defined 3 fracture types (A, B, C), 3 groups (A1, A2, A3), and 3 subgroups (A1.1, A1.2, A1.3) with increasing severity from A1.1 (lowest) to C3.3 (highest). RESULTS Of 70 patients, 43 were operated upon and 27 conservatively treated. The operated patients had significantly higher severity scores than non-operated. Patients with or without periorbital haematoma do not differ significantly in the severity score. The severity of the CMF-ISS score was significantly associated (two sample T-test P<0.01) with the occurrence of pneumencephalus, rhinorrhoea and treatment approach. CONCLUSION Based on our present results, this system seems to be clinical useful for operative decisions and interventions.

Ways of understanding the encounter with head and neck cancer patients in the hospital dental team – a phenomenographic study.

IntroductionHead and neck cancer is the sixth most common malignancy in the world. Fifty percent of the patients can be cured by surgery, radiotherapy or a combination approach. Head and neck cancer is life-threatening, and treatment may leave the patient with visible facial disfigurements and impairment of functions such as speech and eating. This affects not only the patient, but may arouse difficult feelings in the treatment staff. Dental personnel are involved in all facets of treatment, yet they have no specific training in cancer care.BackgroundThe aim of this study was to describe the variation in ways dental personnel understand and experience the encounter with head and neck cancer patients, as the way of understanding a certain phenomenon is judged to be fundamental to the way we act and form our beliefs.MethodsTwenty members of hospital dental teams were interviewed. The interviews focused on experiences of the encounter with head and neck cancer patients. A qualitative research approach, phenomenography, was used in analysing the interviews. The encounter was perceived in three qualitatively different ways: as an act of caring, as a serious and responsible task and as an overwhelming emotional situation. The results indicate that hospital dental personnel are not able to lean on education and professional training in finding ways of dealing with situations with strong emotional impact. This has implications for the treatment of patients with head and neck cancer, as well as education of dental personnel.