Preferred and actual retirement age of oral and maxillofacial surgeons aged 55 and older in the Netherlands: a longitudinal study from 2003 to 2016.

BACKGROUND: In workforce planning for oral and maxillofacial surgeons in the Netherlands, it is important to plan timely, as these dental specialists are required to earn both medical and dental degrees. An important factor to take into account in workforce planning is the outflow of the profession through retirement. In the workforce planning in the Netherlands, it was assumed that retirement plans are a predictor for the actual moment of retirement. The purpose of this study was to investigate this assumption. METHODS: A standardised survey to investigate the work activity and retirement plans of oral and maxillofacial surgeons was conducted seven times between 2003 and 2016. With some minor variations, in every edition, all oral and maxillofacial surgeons aged 55 years and older who did not indicate to be retired in an earlier edition were invited to participate. The data of all seven editions was analysed to investigate what factors influence the actual retirement age. For the analyses of the data, ANOVA and linear regression were employed. RESULTS: The response rate was at least 80% in all editions. For all editions combined, 185 surgeons were invited one or more times, of whom 170 responded at least once. Between 2003 and 2016, the mean preferred retirement age increased from 63.7 to 66.7. Two thirds of the respondents who participated in more than one edition had revised their preferred retirement age upwards. Regarding the difference between preferred and actual retirement age, 45% of the oral and maxillofacial surgeons retired at a higher age than originally preferred and another 14% was still working at the age the originally preferred to retire. Linear regression shows that preferred retirement age is associated with sex and the number of working hours and that actual retirement age is associated with preferred retirement age, earlier preference to decrease working hours and working in non-academic hospitals. CONCLUSION: Altogether, it seems that in this group the preferred retirement age has some predictive value, but the oral and maxillofacial surgeons tend to retire at a higher age than they originally preferred to.

Long-term changes in graft height after maxillary sinus floor elevation with different grafting materials: radiographic evaluation with a minimum follow-up of 4.5 years.

OBJECTIVE: To compare the vertical dimensional changes with regard to graft height in a long-term follow-up in patients treated with two different grafting materials used in maxillary sinus floor elevation procedures. MATERIAL AND METHODS: Twenty consecutive patients were included. One group was grafted with autogenous bone from the mandible (chin area), and the other group was augmented with a 100% beta-tricalcium phosphate (beta-TCP). During a 4- to 5-year period, in each patient, at least five panoramic radiographs were made. These panoramic radiographs were used for morphometric measurements, at three different locations. The three locations were the first bone to implant contact at the distal side of the second most posterior implant (L1), halfway between this implant and the most posterior implant (L2) and the site 5 mm distal to the most posterior implant (L3). The measured vertical bone heights were evaluated to assess whether there was loss of height and, if so, whether the reduction in graft height occurred in an initial healing period or whether it was an ongoing process during the whole study period. RESULTS: There is a statistically significant reduction of vertical bone height in time at all locations (P<0.001). The mean decrease of the total vertical height during the whole study period at the three different locations did not differ significantly for and between both grafting groups. Repeated measures analysis of variance showed that at location L1, the reduction in millimeters per month decreased in time (P=0.001). There was no difference between the grafting groups (P=0.958). Similar results were found on L2 (P=0.005). For L3, there also appeared to be a statistically significant difference in reduction in time in millimeters per month (P=0.004). There was no statistically significant difference in height reduction between locations L1, L2 and L3 for vertical bone height and graft height, respectively. CONCLUSIONS: Both beta-TCP and mandibular bone grafts resulted in radiographic reduction of the vertical height over the 5-year period following maxillary sinus floor elevation. After an initial height reduction in the first 1.5 year, subsequent changes were minimal. No significant differences were observed between the two types of grafting material. There was no statistically significant difference in reduction between the three locations for vertical bone height and graft height, respectively.

Anatomical and surgical findings and complications in 100 consecutive maxillary sinus floor elevation procedures.

PURPOSE: To investigate the prevalence of anatomical and surgical findings and complications in maxillary sinus floor elevation surgery, and to describe the clinical implications. PATIENTS AND METHODS: One hundred consecutive patients scheduled for maxillary sinus floor elevation were included. The patients consisted of 36 men (36%) and 64 women (64%), with a mean age of 50 years (range, 17 to 73 years). In 18 patients, a bilateral procedure was performed. Patients were treated with a top hinge door in the lateral maxillary sinus wall, as described by Tatum (Dent Clin North Am 30:207, 1986). In bilateral cases, only the first site treated was evaluated. RESULTS: In most cases, an anatomical or surgical finding forced a deviation from Tatum's standard procedure. A thin or thick lateral maxillary sinus wall was found in 78% and 4% of patients, respectively. In 6%, a strong convexity of the lateral sinus wall called for an alternative method of releasing the trapdoor. The same method was used in 4% of cases involving a narrow sinus. The sinus floor elevation procedure was hindered by septa in 48%. In regard to complications, the most common complication, a perforation of the Schneiderian membrane, occurred in 11% of patients. In 2%, visualization of the trapdoor preparation was compromised because of hemorrhages. The initial incision design, ie, slightly palatal, was responsible for a local dehiscence in 3%. CONCLUSION: To avoid unnecessary surgical complications, detailed knowledge and timely identification of the anatomic structures inherent to the maxillary sinus are required.

The surgical management of post-traumatic malocclusion.

Facial skeleton fractures should be reduced as early as possible to restore optimal function and minimize skeletal and soft-tissue deformity. With unsatisfactory outcome from delayed treatment because of comorbidity, or despite optimal management, late reconstruction can succeed with conventional orthognathic surgical procedures. Management follows well-established principles of correcting dentofacial deformities, coordinated with orthodontic and prosthodontic support. Planning should include dental records when available, and clinical photographs. The late deformity of midfacial fractures can be corrected by following initial fracture lines; condylar fracture patients can be treated by remote osteotomies. Before surgical intervention, diminished temporomandibular joint (TMJ) mobility should be managed with aggressive physiotherapy to maximize stomal opening. Additionally, successful outcome will depend on a stable TMJ relation without ongoing remodeling.

Maxillary sinus floor augmentation using a beta-tricalcium phosphate (Cerasorb) alone compared to autogenous bone grafts.

PURPOSE: A prospective human clinical study was conducted to determine the clinical and histologic bone formation ability of 2 graft materials, a beta-tricalcium phosphate (Cerasorb; Curasan, Kleinostheim, Germany) and autogenous chin bone, in maxillary sinus floor elevation surgery. MATERIALS AND METHODS: Ten healthy patients underwent a bilateral (n = 6) or unilateral (n = 4) maxillary sinus floor elevation procedure under local anesthesia. In each case, residual posterior maxillary bone height was between 4 and 8 mm. In cases of bilateral sinus floor elevation, the original bone was augmented with a split-mouth design with 100% beta-tricalcium phosphate on the test side and 100% chin bone on the contralateral control side. The unilateral cases were augmented with 100% beta-tricalcium phosphate. After a healing period of 6 months, ITI full body screw-type implants (Straumann, Waldenburg, Switzerland) were placed. At the time of implant surgery, biopsy samples were removed with a 3.5-mm trephine drill. RESULTS: Sixteen sinus floor elevations were performed. Forty-one implants were placed, 26 on the test side and 15 on the control side. The clinical characteristics at the time of implantation differed, especially regarding clinical appearance and drilling resistance. The increase in height was examined radiographically prior to implantation and was found to be sufficient in all cases. After a mean of nearly 1 year of follow-up, no implant losses or failures had occurred. DISCUSSION: The promising clinical results of the present study and the lack of implant failures are probably mainly the result of requiring an original bone height of at least 4 mm at the implant location. CONCLUSION: Although autogenous bone grafting is still the gold standard, according to the clinical results, the preimplantation sinus floor elevation procedure used, which involved a limited volume of beta-tricalcium phosphate, appeared to be a clinically reliable procedure in this patient population.

Histomorphometry of human sinus floor augmentation using a porous beta-tricalcium phosphate: a prospective study.

Tricalcium phosphate (TCP) has been historically a well-accepted material for bone augmentation. We examined the use of a porous beta-TCP (100%) in a split mouth model for sinus floor augmentation. Five patients were treated bilaterally, receiving 1-2 mm-sized beta-TCP particles (Cerasorb) on one side (test side) and autologous chin bone particles on the other (control) side. Four other patients were treated with a unilateral sinus floor augmentation using 100% beta-TCP (no controls). Biopsies of the augmented sites were taken at 6 months. Histomorphometry measurements were carried out in order to quantify bone augmentation at test and control sides. The average bone volume (BV) formed in the augmented sinus at the control side was 41% (32-56%) and 17% (9-27%) in the test side when all nine patients were included (statistically significant, P=0.04). When only the five bilateral patients were included, mean BV of the test side was 19% (13-27%), which was also significantly different from the control side (P=0.009). Osteoid formation tended to be higher in the test side biopsies (1.3%) than in the controls (0.3%) (marginally significant, P=0.1), indicating ongoing bone formation in the TCP material. The amount of lamellar bone at the test side was less than half the amount in the control side, indicating that remodelling had only recently started in the TCP-augmented side. The resorption surface, however, did not differ significantly between the two sides. These histological results indicate that Cerasorb is an acceptable bone substitute material for augmentation of the maxillary sinus. Due to the osteoconductive, but not osteoinductive properties of this material, the rate of bone formation is somewhat delayed in comparison to autologous bone.

Fractures of the iliac crest after split-thickness bone grafting for preprosthetic surgery: report of 3 cases and review of the literature.

PURPOSE: In this study fractures of the iliac crest after split-thickness bone grafting in a patient population treated for preprosthetic reasons were evaluated. PATIENTS AND METHODS: In a retrospective patient population of 146 patients, during a 5-year period (1998 to 2002), 3 avulsion fractures of the iliac crest were noticed. All fractures were postsurgical, occurring as late fractures. A review of the literature regarding etiology, clinical characteristics, and results of treatment is given. RESULTS: In all 3 cases treatment was conservative, consisting of a period of bed rest followed by progressive ambulation. Further recovery was uneventful. CONCLUSIONS: According to this patient population and the literature, late fracture of the iliac crest after split-thickness bone grafting is an uncommon complication. We recommend a harvesting and grafting technique at an appropriate distance from the iliac spine with an oscillating saw. Treatment of an iliac crest fracture is almost always conservative.