[Patient-specific joint prothesis for ankylotic temporomandibular joints]. / Individueel vervaardigde prothesen voor ankylotische kaakgewrichten.

A 49-year-old woman who suffered from severe obstructive sleep apnea (OSA) was referred to the department of Oral-, Maxillofacial Surgery department due to progressive limitation of the mouth opening and chronic pain in both temporomandibular joints. Based on clinical and radiological examinations, the patient was diagnosed with recurrent ankylosis of the temporomandibular joints. The patient was treated with 2 patient-specific implants of the temporomandibular joint combined with a Le Fort I osteotomy, and a genioplasty including a genioglossus advancement. This treatment may have advantages for the patient such as a lower recurrence rate of ankylosis, improved maximal mouth opening, pain reduction and improved aesthetic results.

[The dentogenic inflammation, diagnosis, course and treatment]. / De dentogene ontsteking: diagnose, beloop en behandeling.

Inflammation begins as a response of the immune system to an external, harmful stimulus. This stimulus can be chemical, mechanical or bacterial in nature. The inflammatory response is necessary to create optimal conditions for healing. In case of pulpitis, a peri-apical granuloma, peri-coronitis or periodontitis, complaints arise as a result of an inflammatory reaction. With further progression, such as an infiltrate or a submucosal abscess, the bacteria will eventually invade the tissues and develop an infection. Given the high prevalence of dental diseases, oral health care providers are regularly confronted with the consequences of dentogenic inflammation and subsequent infections. Each specific stage of dentogenic inflammation presents symptoms that are important for making the correct diagnosis. This is important in applying the optimal dental, surgical or medical treatment.

Factors related to failure of autologous cranial reconstructions after decompressive craniectomy.

PURPOSE: Cranioplasty is customary after decompressive craniectomy. Many different materials have been developed and used for this procedure. The ideal material does not yet exist, while complication rates in cranioplasties remain high. This study aimed to determine factors related to autologous bone flap failure. MATERIALS AND METHODS: In this two-center retrospective cohort study, 276 patients underwent autologous bone cranioplasty after initial decompressive craniectomy between 2004 and 2014. Medical records were reviewed regarding patient characteristics and factors potentially related to bone flap failure. Data were analyzed using univariable and multivariable regression analysis. RESULTS: Independent factors related to overall bone flap failure were: duration of hospitalization after decompressive craniectomy [OR: 1.012 (95%CI: 1.003-1.022); p = 0.012], time interval between decompressive craniectomy and cranioplasty [OR: 1.018 (95%CI: 1.004-1.032); p = 0.013], and follow-up duration [OR: 1.034 (95%CI: 1.020-1.047); p < 0.001]. In patients with bone flap infection, neoplasm as initial diagnosis occurred significantly more often (29.2% vs. 7.8%; RD 21.3%; 95%CI 8.4 -38.3%; NNH 5; 95%CI 3 -12) and duration of hospitalization after decompressive craniectomy tended to be longer (means 54 vs. 28 days, MD 26.2 days, 95%CI -8.6 to 60.9 days). Patients with bone flap resorption were significantly younger (35 vs. 43 years, MD 7.7 years, 95%CI 0.8-14.6 years) and their cranial defect size tended to be wider than in patients without bone flap resorption (mean circumference 39 vs. 37 cm; MD 2.4 cm, 95% CI -0.43-5.2 cm) and follow-up duration was significantly longer (44 vs. 14 months, MD 29 months, 95%CI 17-42 months). CONCLUSION: A neoplasm as initial diagnosis, longer hospitalization after decompressive craniectomy, larger time interval between decompressive craniectomy and cranioplasty, and longer follow-up duration are associated with a higher risk of failure of autologous bone flaps for cranioplasty. Patients with these risk factors may be better served with an early recovery program after decompressive surgery or an alloplastic material for cranioplasty.

The use of cranial resection templates with 3D virtual planning and PEEK patient-specific implants: A 3 year follow-up.

PURPOSE: The aim of this study was to evaluate the accuracy of resection templates in cranioplasties in order to facilitate a one-stage resection and cranial reconstruction. PATIENTS AND METHODS: In three cases, cranial resections were combined with direct reconstructions using the principles of computer-aided design, manufacturing, and surgery. The precision of the resection template was evaluated through a distance map, comparing the planned and final result. RESULTS: The mean absolute difference between the planned and actual reconstructed contour was less than 1.0 mm. After 3 years, no clinical signs of infection or rejection of the implants were present. The computed tomography scans showed no irregularities, and the aesthetic results remained satisfactory. CONCLUSION: One-stage resection and cranial reconstruction using a resection template, control template, and a prefabricated patient-specific implant of poly(ether-ether-ketone) (PEEK) proved to be a viable and safe method.

Effects of sterilization on the mechanical properties of poly(methyl methacrylate) based personalized medical devices.

BACKGROUND: Nowadays, personalized medical devices are frequently used for patients. Due to the manufacturing procedure sterilization is required. How different sterilization methods affect the mechanical behavior of these devices is largely unknown. MATERIALS AND METHODS: Three poly(methyl methacrylate) (PMMA) based materials (Vertex Self-Curing, Palacos R+G, and NextDent C&B MFH) were sterilized with different sterilization methods: ethylene oxide, hydrogen peroxide gas plasma, autoclavation, and γ-irradiation. Mechanical properties were determined by testing the flexural strength, flexural modulus, fracture toughness, and impact strength. RESULTS: The flexural strength of all materials was significantly higher after γ-irradiation compared to the control and other sterilization methods, as tested in a wet environment. NextDent C&B MFH showed the highest flexural and impact strength, Palacos R+G showed the highest maximum stress intensity factor and total fracture work. CONCLUSION: Autoclave sterilization is not suitable for the sterilization of PMMA-based materials. Ethylene oxide, hydrogen peroxide gas plasma, and γ-irradiation appear to be suitable techniques to sterilize PMMA-based personalized medical devices.

Outcome in patient-specific PEEK cranioplasty: A two-center cohort study of 40 implants.

OBJECTIVE: The best material choice for cranioplasty following craniectomy remains a subject to discussion. Complication rates after cranioplasty tend to be high. Computer-assisted 3-dimensional modelling of polyetheretherketone (PEEK) was recently introduced for cranial reconstruction. The aim of this study was to evaluate patient- and surgery-related characteristics and risk factors that predispose patients to cranioplasty complications. MATERIAL AND METHODS: This retrospective study included a total of 40 cranial PEEK implants in 38 patients, performed at two reference centers in the Netherlands from 2011 to 2014. Complications were registered and patient- and surgery-related data were carefully analysed. RESULTS: The overall complication rate of PEEK cranioplasty was 28%. Complications included infection (13 %), postoperative haematoma (10 %), cerebrospinal fluid leak (2.5 %) and wound-related problems (2.5 %). All postoperative infections required removal of the implant. Nonetheless removed implants could be successfully re-used after re-sterilization. CONCLUSION: Although overall complication rates after PEEK cranioplasty remain high, outcomes are satisfactory, as our results compare favourably to recent literature reports on cranial vault reconstruction.

Complications of mandibular distraction osteogenesis for acquired deformities: a systematic review of the literature.

A systematic review on complications in all forms of mandibular distraction osteogenesis (MDO) for acquired deformities was performed. Search terms expressing distraction osteogenesis were used in 'AND' combination with search terms comprising 'mandible' and terms for complication, failure, and morbidity. A search using PubMed (National Library of Medicine, NCBI), EMBASE, and the Cochrane Controlled Trials Register yielded 644 articles published between 1966 and mid October 2013. Three hundred and twenty-one eligible articles were screened in detail. Complications related to MDO in acquired deformities were reported in 105 clinical articles, involving 1332 patients. Treatments included alveolar distraction osteogenesis (ADO), mandibular lengthening, DO in bone grafts, and bi-/trifocal transport disc DO (TDDO) for segmental mandibular defects. A high incidence of complications was seen in MDO for acquired deformities (ADO 44.4%; residual group 43.9%). An index for classifying complications in MDO, based on the impact and further treatment or final results, was used. In the ADO group, soft tissue complications (8.0%), insufficient vector control (7.6%), temporary inferior alveolar nerve (IAN) neurosensory disturbances (6.5%), device-related problems (3.5%), mandible fractures (2.8%), insufficient bone formation (2.5%), and fracture of the transport disc (1.3%) were seen. In the residual group, temporary IAN neurosensory disturbances (13.4%), minor infection (5.3%), DO failure (4.0%), and device-related problems (3.8%) were reported.

Complications of mandibular distraction osteogenesis for developmental deformities: a systematic review of the literature.

A systematic review of English and non-English articles on the complications of mandibular distraction osteogenesis (MDO) for patients with developmental deformities was performed, in accordance with the PRISMA statement. Search terms expressing distraction osteogenesis were used in 'AND' combination with search terms comprising 'mandible' and terms for complication, failure, and morbidity. A search using PubMed (National Library of Medicine, NCBI), EMBASE, and Cochrane Controlled Trials Register yielded 644 articles published between 1966 and mid October 2013. Clinical articles that reported complications related to MDO in developmental deformities were included. Two hundred and fifty articles were eligible and were screened in detail. A total of 32 articles reporting the cases of 565 patients were finally included. Patients underwent mandibular lengthening and transverse widening. A total of 211 complications were reported (37.4%); these were classified according to an index that indicates the clinical impact. Inferior alveolar nerve (IAN) neurosensory disturbances, minor infection, device failure, anterior open bite, permanent dental damage, and skeletal relapse were most represented. Complications that resolved spontaneously (type I) were seen in 11.0%, medically or technically manageable complications, without hospitalization, were seen in 10.8% (type II), and permanent complications (type VI) were seen in 9.6%.

Complications of mandibular distraction osteogenesis for congenital deformities: a systematic review of the literature and proposal of a new classification for complications.

A systematic review of English and non-English language articles on the complications of mandibular distraction osteogenesis (MDO) for patients with congenital deformities was performed, in accordance with the PRISMA statement. Search terms expressing distraction osteogenesis were used in 'AND' combination with search terms comprising 'mandible' and terms for complication, failure, and morbidity. A search using PubMed (National Library of Medicine, NCBI), EMBASE, and the Cochrane Central Register of Controlled Trials yielded 644 articles published between 1966 and mid October 2013. Clinical articles that reported complications related to MDO were included. Finally 81 articles on MDO in congenital deformities were eligible and were screened in detail. Complications including minor infection (6.0%), device-related problems (7.3%), skeletal open bite (2.4%), hypertrophic scar formation (2.1%), facial nerve palsy (1.8%), neurosensory disturbances of the inferior alveolar nerve (1.9%), and (fibrous) non-union (0.7%) were seen. A new index for more detailed classification of complications in MDO is proposed based on six categories that indicate the impact of the complication and its further treatment or final results. The proposed complication index may be a useful tool to classify complications related to MDO.

[Osteoradionecrosis of the jaw, presumably caused by a removable partial denture]. / Osteoradionecrose van de mandibula, vermoedelijk veroorzaakt door een frameprothese.

An 81-years-old man developed a severe osteoradionecrosis of the mandible following surgery and radiotherapy in the head and neck area as a result of a carcinoma at the front ofthe floor of the mouth. Presumably, the osteoradionecrosis had been developed by an injury of the oral mucosa due to a removable partial denture. There are no uniform guidelines for the treatment of osteoradionecrosis of the jaw bones. Treatment modalities vary from removal of sequesters, sometimes long-term use of antibiotics, treatment with hyperbaric oxygen and wide surgical resection with or without reconstruction of the jaw.