The aim of this retrospective cohort study was to evaluate the relative amount of cancellous bone in the mandibular ramus as a predictor of lingual fracture patterns after bilateral sagittal split... Show moreThe aim of this retrospective cohort study was to evaluate the relative amount of cancellous bone in the mandibular ramus as a predictor of lingual fracture patterns after bilateral sagittal split osteotomy (BSSO). The study including 78 consecutive patients (156 osteotomy sites). In preoperative cone-beam computed tomographic (CT) scans, the volumes of cancellous and cortical bone in the BSSO surgical field were estimated. Patients were divided into two groups based on the cancellous:cortical bone ratio. We studied postoperative cone-beam CT scans for lingual fracture lines and subcategorised them according to the lingual split scale (LSS). Generalised linear mixed models (GLMM) were estimated to evaluate the association between the cancellous:cortical bone ratio and the lingual fracture pattern. There was a significant association between the cancellous:cortical bone ratio of the mandibular angle and the lingual fracture pattern after BSSO. Mandibular angles with a relatively small amount of cancellous bone showed significantly more LSS3 fracture lines (OR = 1.990, 95%CI 1.043 to 3.796, p = 0.043). These mandibular angles also showed more unfavourable fractures (LSS4), although this was not significant (OR = 2.352, 95%CI 0.748 to 7.392, p = 0.143). The relative amount of cancellous bone in the mandibular angle is significantly associated with the lingual fracture line after BSSO. (C) 2020 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Show less
Purpose: Three-dimensional (3D) autotransplantation is a technique for surgical transposition of a tooth to another site within one patient, using 3D printed replicas of the donor tooth. In this... Show morePurpose: Three-dimensional (3D) autotransplantation is a technique for surgical transposition of a tooth to another site within one patient, using 3D printed replicas of the donor tooth. In this study, we evaluated intraoperative experiences during 3D autotransplantation of teeth.Materials and Methods: A multicenter prospective clinical study was implemented. All procedures were performed using preoperative cone-beam computed tomography imaging and computer-assisted design with computer-assisted manufacturing resulting in a 3D replica of the donor tooth.Results: The 100 autotransplantation procedures (79 patients) included canines, premolars, molars, and 1 supernumerary tooth. In 82% of the procedures, the transplantation was performed with an extra-alveolar time of less than 1 minute and an immediate good fit of the donor tooth. In 14%, the extra-alveolar time was 1 to 3 minutes or multiple fitting attempts were necessary. In 4%, the extra-alveolar time exceeded 3 minutes. Difficulties during the procedures were caused by movement artifacts on the preoperative cone-beam computed tomography imaging, a long interval between the imaging and the procedure, or insufficient bone volume at the recipient site.Conclusions: The use of a 3D printed donor tooth replica during autotransplantation procedures minimized the extra-alveolar time and intraoperative fitting attempts of transplants. This facilitated a quick and reliable treatment and enabled more difficult procedures. (C) 2019 American Association of Oral and Maxillofacial Surgeons Show less
Westerveld, K.J.H. van; Verweij, J.P.; Toxopeus, E.E.; Fiocco, M.; Mensink, G.; Merkesteyn, J.P.R. van 2019
This systematic review provides an overview of studies on autotransplantation techniques using rapid prototyping for preoperative fabrication of donor tooth replicas for preparation of the neo... Show moreThis systematic review provides an overview of studies on autotransplantation techniques using rapid prototyping for preoperative fabrication of donor tooth replicas for preparation of the neo-alveolus. Different three-dimensional autotransplantation techniques and their treatment outcomes are discussed. The systematic literature search yielded 19 articles that satisfied the criteria for inclusion. These papers described one case-control study, four clinical observational studies, one study with a clinical and in vitro part, four in vitro studies, and nine case reports. The in vitro studies reported high accuracy for the printing and planning processes. The case reports all reported successful transplantation without any pathological signs. The clinical studies reported a short extraoral time of the donor tooth, with subsequent success and survival rates of 80.0-91.1% and 95.5-100%, respectively. The case-control study reported a significant decrease in extraoral time and high success rates with the use of donor tooth replicas. In conclusion, the use of a preoperatively designed surgical guide for autotransplantation enables accurate positional planning, increases the ease of surgery, and decreases the extraoral time. However, the quality of the existing body of evidence is low. Further research is therefore required to investigate the clinical advantages of this innovative autotransplantation technique. Show less
Background: Dentofacial deformities frequently require orthodontic treatment. Understanding of preventable risk factors is essential for reducing treatment need. Upper airway obstruction (for... Show moreBackground: Dentofacial deformities frequently require orthodontic treatment. Understanding of preventable risk factors is essential for reducing treatment need. Upper airway obstruction (for example due to hypertrophic adenoids and/or tonsils) has been hypothesized to be a risk factor.Objectives: This systematic review aimed to reflect the contemporary evidence on the risk of obstruction by hypertrophic adenoids and/or tonsils, by assessing the dentofacial changes after adeno-and/or tonsillectomy.Search methods: A systematic search of electronic databases and manual searches of grey literature and reference lists of relevant studies was performed.Selection criteria: No restrictions were placed on publication language. Experimental, cohort, and case-control studies were eligible for inclusion. Studies reporting associations between treatment of adenoid and/or tonsil hypertrophy and dentofacial deformities in children were included. Adenoidectomy and/or tonsillectomy were performed in all patients; outcomes were assessed before and after surgery.Data collection and analysis: Data were extracted by two independent reviewers in duplicate. The Cochrane Risk of Bias tool was used to assess the methodological quality of the included papers.Results: The initial search yielded 1196 papers, of which 16 articles could be included. All papers described controlled prospective cohort studies, reporting on a total of 461 patients and controls (mean age, 4.1-13.9 years). A descriptive and quantitative synthesis of dentofacial change postoperatively is presented. Consistent findings across studies were the normalisation towards labial inclination of the upper and lower incisors and towards a more horizontal mandibular growth pattern. No change in vertical or sagittal maxillary growth was reported after surgical treatment. Post-surgical increase in maxillary archwidth and decrease in lateral crossbite-frequency were consistently reported. Findings on overjet, overbite and angle from S to N to B (SNB-angle), mandibular arch width, and gonial angle were inconsistent.Conclusion: The available literature suggests that treatment of hypertrophic adenoids and/or tonsils affects dentofacial deformity. This could indicate a relationship between nasopharyngeal obstruction (i.e. upper airway obstruction) and the dentofacial growth pattern. However, the high risk of bias and considerable diversity between studies impedes a clear conclusion regarding this effect. Show less
Bilateral sagittal split osteotomy (BSSO) is a widely used surgical technique that is used to treat mandibular deformity. This thesis investigated BSSO with splitter and separators. The... Show moreBilateral sagittal split osteotomy (BSSO) is a widely used surgical technique that is used to treat mandibular deformity. This thesis investigated BSSO with splitter and separators. The occurrences of common complications and their risk factors are assessed. BSSO was performed according to the Hunsuck modification with splitter and separator without the use of chisels. Retrospective analysis of more than 250 patients was performed. BSSO performed with the splitter-separator technique was found to be associated with a low mean incidence of permanent hypoaesthesia of 9.9% per patient. Age was a significant risk factor for hypoaesthesia with marked differences between age groups (<19 years: 4.8%; 19-30 years: 7.9%; >30 years 15.2%). The incidence of bad split was 4.0% per patient. The intra-operative presence of third molars significantly increased the risk of bad split. Infection occurred in 15.1% of patients. Removal of bicortical screw osteosynthesis material because of symptoms was indicated in 4.9% of patients. Relevant risk factors for complications are age (hypoaesthesia) and the presence of third molars during surgery (bad split). Show less
Verweij, J.P.; Moin, D.A.; Wismeijer, D.; Merkesteyn, J.P.R. van 2017
This article describes the autotransplantation of third molars to replace heavily damaged premolars and molars. Specifically, this article reports on the use of preoperative cone-beam computed... Show moreThis article describes the autotransplantation of third molars to replace heavily damaged premolars and molars. Specifically, this article reports on the use of preoperative cone-beam computed tomographic planning and 3-dimensional (3D) printed replicas of donor teeth to prepare artificial tooth sockets. In the present case, an 18-year-old patient underwent autotransplantation of 3 third molars to replace 1 premolar and 2 molars that were heavily damaged after trauma. Approximately 1 year after the traumatic incident, autotransplantation with the help of 3D planning and rapid prototyping was performed. The right maxillary third molar replaced the right maxillary first premolar. The 2 mandibular wisdom teeth replaced the left mandibular first and second molars. During the surgical procedure, artificial tooth sockets were prepared with the help of 3D printed donor tooth copies to prevent iatrogenic damage to the actual donor teeth. These replicas of the donor teeth were designed based on the preoperative cone-beam computed tomogram and manufactured with the help of 3D printing techniques. The use of a replica of the donor tooth resulted in a predictable and straightforward procedure, with extra-alveolar times shorter than 2 minutes for all transplantations. The transplanted teeth were placed in infraocclusion and fixed with a suture splint. Postoperative follow-up showed physiologic integration of the transplanted teeth and a successful outcome for all transplants. In conclusion, this technique facilitates a straightforward and predictable procedure for autotransplantation of third molars. The use of printed analogues of the donor teeth decreases the risk of iatrogenic damage and the extra-alveolar time of the transplanted tooth is minimized. This facilitates a successful outcome. (C) 2017 American Association of Oral and Maxillofacial Surgeons Show less
Verweij, J.P.; Hof, K.S. van; Malessy, M.J.A.; Merkesteyn, R. van 2017
Purpose: Bone defects of the inferior mandibular border (osseous inferior border defects) can cause unesthetic postoperative outcomes after bilateral sagittal split osteotomy (BSSO). The aim of... Show morePurpose: Bone defects of the inferior mandibular border (osseous inferior border defects) can cause unesthetic postoperative outcomes after bilateral sagittal split osteotomy (BSSO). The aim of this study was to estimate the frequency of osseous inferior border defects after BSSO and to identify risk factors for this complication.Materials and methods: This retrospective study included consecutive patients who underwent BSSO for mandibular retrognathia. The primary outcome was the presence/absence of osseous inferior border defects. Predictors included the mandibular movement, rotation of the occlusal plane, postoperative proximal segment position, pattern of lingual fracture, occurrence of bad split, and presence of third molars.Results: The study sample consisted of 200 patients and had a mean follow-up of 13 months. The mean mandibular advancement and rotation was respectively 5.8 mm and 5.4 degrees clockwise. Osseous inferior border defects were present in 7.0% of splits and in 12.5% of patients. Significant risk factors for inferior border defects included increased advancement, increased clockwise rotation, cranial rotation of the proximal segment, and a split originating in the lingual cortex.Conclusion: In conclusion, osseous inferior border defects occur significantly more often in cases with large mandibular advancement, increased clockwise rotation of the occlusal plane, malpositioning of the proximal segment, and a split originating in the lingual cortex. (C) 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved. Show less
Verweij, J.P.; Hassing, G.J.M.; Fiocco, M.; Houppermans, P.N.W.J.; Merkesteyn, J.P.R. van 2016
Bilateral sagittal split osteotomy (BSSO) is a widely used orthognathic surgery technique. This prospective observational study investigated the correspondence between the planned inferior border... Show moreBilateral sagittal split osteotomy (BSSO) is a widely used orthognathic surgery technique. This prospective observational study investigated the correspondence between the planned inferior border cut and the actually executed inferior border cut during BSSO. The influence of the inferior border cut on lingual fracture patterns was also analyzed.Postoperative cone beam computed tomography (CBCT) scans of 41 patients, representing 82 sagittal split osteotomies, were investigated. The inferior border cut was intended to penetrate completely through the caudal cortex. Descriptive statistics were used to analyze the executed inferior border cuts. Mixed models were used to investigate the influence of independent variables such as the surgeon's experience on the inferior border cut. Secondarily the influence of the inferior border cut on lingual fracture patterns and the incidence of bad splits was assessed.The inferior border cut reached the caudal cortex in all cases, but reached the lingual cortex in only 38% of the splits. There was no significant relationship between the inferior border cut and a specific lingual fracture line.In this study, postoperative CBCT analysis revealed that the bone cuts during BSSO were often not placed exactly as planned. No significant relationship between the inferior border cut and lingual fracture patterns or bad splits was, however, detected. (C) 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved. Show less
The most common complications that are associated with bilateral sagittal split osteotomy are: bad splits, postoperative infection, removal of osteosynthesis material, and neurosensory disturbances... Show moreThe most common complications that are associated with bilateral sagittal split osteotomy are: bad splits, postoperative infection, removal of osteosynthesis material, and neurosensory disturbances of the lower lip. Particularly in elective orthognathic surgery, it is important that surgeons inform their patients about the risk of these complications and attempt to minimize these risks. The purpose of this literature review and meta-analysis is to provide an overview of these common complications and their risk factors.After a systematic electronic database search, 59 studies were identified and included in this review. For each complication, a pooled mean incidence was computed. Both the pooled study group and the pooled 'complication group' were analysed.The mean incidences for bad split (2.3% per SSO), postoperative infection (9.6% per patient), removal of the osteosynthesis material (11.2% per patient), and neurosensory disturbances of the lower lip (33.9% per patient) are reported. Regularly reported risk factors for complications were the patient's age, smoking habits, presence of third molars, the surgical technique and type of osteosynthesis material. This information may help the surgeon to minimize the risk of these complications and inform the patient about the risks of complications associated with bilateral sagittal split osteotomy. (C) 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved. Show less
Verweij, J.P.; Mensink, G.; Fiocco, M.; Merkesteyn, J.P.R. van 2016
Purpose: Autotransplantation of premolars is a good treatment option for young patients who have missing teeth. This study evaluated the use of a preoperatively 3-dimensional (3D)-printed replica... Show morePurpose: Autotransplantation of premolars is a good treatment option for young patients who have missing teeth. This study evaluated the use of a preoperatively 3-dimensional (3D)-printed replica of the donor tooth that functions as a surgical guide during autotransplantation.Materials and Methods: Five consecutive procedures were prospectively observed. Transplantations of maxillary premolars with optimal root development were included in this study. A 3D-printed replica of the donor tooth was used to prepare a precisely fitting new alveolus at the recipient site before extracting the donor tooth. Procedure time, extra-alveolar time, and number of attempts needed to achieve a good fit of the donor tooth in the new alveolus were recorded.Results: For each transplantation procedure, the surgical time was shorter than 30 minutes. An immediate good fit of the donor tooth in the new alveolus was achieved with an extra-alveolar time shorter than 1 minute for all transplantations.Conclusion: These results show that the extra-alveolar time is very short when the surgical guide is used; therefore, the chance of iatrogenic damage to the donor tooth is minimized. The use of a replica of the donor tooth makes the autotransplantation procedure easier for the surgeon and facilitates optimal placement of the transplant. (C) 2016 American Association of Oral and Maxillofacial Surgeons Show less
Verweij, J.P.; Toxopeus, E.E.; Fiocco, M.; Mensink, G.; Merkesteyn, J.P.R. van 2016
