Cranio-Maxillofacial Surgery

Analysing chin prominence in relation to the lower lip: The lower lip-chin prominence angle Publication date: Available online 9 June 2019 Source: Journal of Cranio-Maxillofacial Surgery Author(s): Farhad B. Naini, Umberto Garagiola, David Wertheim Abstract The purpose of this investigation is to describe a potentially useful analysis in assessing the required extent of sagittal chin augmentation or set-back, by relating chin prominence to lower lip position using the 'lower lip-chin prominence angle'. The secondary aim was to quantitatively evaluate the influence of this angle on perceived attractiveness and desire for surgery. Having described this angular analysis, a quantitative evaluation was undertaken by incrementally altering the angle on an idealised profile image to create a range of images that were rated on a 7-point Likert scale by a pre-selected group of pre-treatment orthognathic patients, clinicians and laypeople. In treatment planning alterations in chin prominence, an 'ideal' sagittal position with soft tissue pogonion on or just behind a true vertical line through the most prominent point of the lower lip may be used. Chin retrusion or prominence up to an angle of 15 degrees retrusion to -5 degrees prominence is deemed acceptable. Surgery is desired from chin prominence of greater than -15 degrees and retrusions greater than 25 degrees. The greater the retrusion or prominence of the chin from an angle of 0 degrees, the less the perceived attractiveness and the greater the desire for surgical correction.

Early Return to Sport Post Maxillofacial Fracture Injury in the Professional Athlete: A Systematic Review Publication date: Available online 8 June 2019 Source: Journal of Cranio-Maxillofacial Surgery Author(s): Umair Ansari, Eugene Wong, John Arvier, Dylan Hyam, Weber Huang Abstract Introduction To summarize the current literature on return to sport times post-maxillofacial fracture injury in the professional athlete. Materials and Methods A literature search on six databases for articles relating to maxillofacial fractures, professional athletes, and return to sport times. Study design, clinical data, and author recommendations were analysed. Results 17 studies were retrieved. One prospective study returned 17 athletes to competitive rugby union and soccer at 3 weeks post injury without complication. Two large retrospective studies (n=278) returned patients to sport at approximately 7 weeks without complication. 64% (n=7) of patients from case based studies returned to sport at 3 to 14 days, 4 of which utilized protective facemasks. Athletes generally returned to competition earlier for lower grade (3 to 10 days) compared to higher grade contact sport (21 days at least). 2 articles recommended a 3 months recovery period for combat sports. 8 articles supported the utility of protective facemasks. Conclusion Early return to sport (<6 weeks) in the professional athlete post maxillofacial fracture injury is achievable. The optimal clinical approach may be to grade the sport according to its impact forces, discuss an early return with reference to the available literature, the potential utility of facemasks, risks of refracture and its operative implications.

Gingival fibroblasts and medication-related osteonecrosis of the jaw: results by real-time and wound healing in vitro assays Publication date: Available online 8 June 2019 Source: Journal of Cranio-Maxillofacial Surgery Author(s): Anna Yuan, Adelheid Munz, Siegmar Reinert, Sebastian Hoefert Abstract Objective This study investigated the effects of bisphosphonates and denosumab on human gingival fibroblasts (HGFs) that could influence inflammation, wound healing, and angiogenesis in medication-related osteonecrosis of the jaw (MRONJ). Methods A real-time in vitro assay was performed on HGFs with and without the addition of bacterial lipopolysaccharide and a mononuclear cell co-culture to observe the effects of zoledronate, ibandronate, alendronate, clodronate, denosumab, and combinations of zoledronate and denosumab at varied concentrations. A wound healing assay was performed, and gene and protein expression was analyzed for inflammatory, angiogenic, and osteoclastogenic cytokines and mediators including interleukin (IL)-1β, IL-6, tumor necrosis factor alpha (TNFα), IL-8, vascular endothelial growth factor (VEGF), RANKL, and osteoprotegerin. Results Higher concentrations of antiresorptives resulted in impaired wound healing and HGF death, which also occurred without mechanical damage. These effects were increased with bacterial lipopolysaccharide and mononuclear cells. Increased levels of IL-1β, TNFα, IL-8, VEGF, osteoprotegerin, and decreased levels of IL-6 were observed. Conclusions Antiresorptive exposure was associated with HGF death and delayed wound healing, which could be attributed to an elevated inflammatory response and immune dysfunction contributing to MRONJ development. There was no evidence of anti-angiogenic effects. Our experiments present the first results of denosumab with HGFs.

A new method for cranial vault reconstruction: augmented reality in synostotic plagiocephaly surgery Publication date: Available online 4 June 2019 Source: Journal of Cranio-Maxillofacial Surgery Author(s): Wenqing Han, Xianxian Yang, Shuihua Wu, Shuangshi Fan, Xiaojun Chen, Mar Aung Zin, Tianjia Liu, Yan Zhang, Shuo Gu, Gang Chai Summary Purpose Augmented reality (AR) is considered to be a valuable tool in craniofacial surgery for preoperative design, intraoperative navigation, and postoperative assessment. Corrective surgery is necessary synostotic plagiocephaly for functional and aesthetic outcomes. Open calvarial reconstruction is a difficult classic surgical procedure with a high accuracy requirement. The purpose of this study was to introduce an AR system application in synostotic plagiocephaly surgery. Materials and Methods Seven plagiocephaly patients (ages 6 months to 24 months, average 16.7 months) were enrolled. Preoperative design was accomplished based on three-dimensional computed tomography (CT) data for patients with synostotic plagiocephaly. We completed the registration with the predefined markers through an image registration process preoperatively. Then, we overlaid the registration results into the surgical field to assist surgeons intraoperatively. CT scans were performed postoperatively. Intracranial volume was measured to judge the surgical outcomes. We performed a quantitative craniometric analysis between the planning of the reconstruction and post-operative results, and the main evaluation indicator was the intracranial volume asymmetry. Results We successfully applied the AR system in patients undergoing synostotic plagiocephaly, providing real-time navigational images of position and orientation information during open calvarial reconstruction surgery in 7 plagiocephaly patients within a span of 5 years. Good appearances were observed after the surgery. Cranial volume asymmetry was decreased from 27.87% to 16.57%, achieving precise intra-operative goals. No significant differences were found between planning and post-operative results. Conclusions The AR system can be applied to plagiocephaly procedures guiding to obtain reliable and accurate results via a precise osteotomy.

Scaffold implantation in the omentum majus of rabbits for new bone formation Publication date: Available online 3 June 2019 Source: Journal of Cranio-Maxillofacial Surgery Author(s): Falk Birkenfeld, Andre Sengebusch, Chiara Völschow, Björn Möller, Hendrik Naujokat, Jörg Wiltfang Abstract Restoration of the mandible after defects caused by ablative surgery remains challenging. Microvascular free flaps from the scapula, fibula or iliac crest remain the 'gold standard'. A drawback of these methods is donor-side morbidity, availability and the shape of the bone. Former cases have shown that prefabrication of a customized bone flap in the latissimus dorsi muscle may be successful; however, this method is still associated with high donor-side morbidity. Osteogenesis in the omentum majus of rabbits by wrapping the periosteum into it was confirmed recently and is particularly interesting for bone endocultivation. Twelve adult male New Zealand white rabbits were used. In each, two hydroxyapatite blocks were implanted in the greater omentum with autologous bone or autologous bone+rhBMP-2. Bone density measurements were performed by CT scans. Fluorochrome labelling was used for new bone formation detection. The animals were sacrificed at week 10, and the specimens were harvested for histological and histomorphometric analysis. In histological and fluorescence microscopic analysis, new bone formation could be found, as well as new blood vessels and connective tissue. No significant differences were found regarding the histological analysis and bone density measurements between the groups. It could be demonstrated that the omentum majus is a practical way to use one's own body as a bioreactor for prefabrication of tissue-engineered bony constructs. Regarding the influence and exact dose of rhBMP-2, further research is necessary. To establish and improve this method, further large-animal experimental studies are also necessary.

Patient-specific, printed titanium implants for reconstruction of mandibular continuity defects: A systematic review of the evidence Publication date: June 2019 Source: Journal of Cranio-Maxillofacial Surgery, Volume 47, Issue 6 Author(s): Alexander MC. Goodson, Madhav A. Kittur, Peter L. Evans, E. Mark Williams

Three-dimensional orbital wall modeling using paranasal sinus segmentation Publication date: June 2019 Source: Journal of Cranio-Maxillofacial Surgery, Volume 47, Issue 6 Author(s): Hannah Kim, Tae-geun Son, Jeonghwan Lee, Hyeun A. Kim, Hyunchul Cho, Woo Shik Jeong, Jong Woo Choi, Youngjun Kim Abstract Purpose Three-dimensional orbital wall modeling is a time-consuming process because of the presence of pseudoforamina. We developed an automated three-dimensional modeling software to characterize the orbital wall, and evaluated it using data from fracture patients. Methods We first characterized the air and face regions using multiphase segmentation; the sinuses were segmented by applying morphological operations to air regions. Pseudoforamina of the orbital wall were offset with the segmented sinuses. Finally, the three-dimensional facial bone model, with orbital wall, was reconstructed from the segmented images. Results Ten computed tomography data sets were used to evaluate the proposed method. Results were compared with those obtained using the active contour model and manual segmentation. The process took 31.7 ± 8.0 s, which was 30–60 times faster than other methods. The average distances between surfaces obtained with the proposed method and those obtained with manual segmentation (normal side: 0.20 ± 0.06 mm; fractured side: 0.28 ± 0.10 mm) were approximately half those obtained using the active contour model. Conclusions Three-dimensional orbital wall models, which were very similar to the manually segmented models, were archived within 1 min using the developed software, regardless of fracture presence. The proposed method might improve the safety and accuracy of surgical procedures.

Analysis of the accuracy of a novel preformed osteosynthesis plate for the reduction and fixation of zygomaticomaxillary complex fractures Publication date: June 2019 Source: Journal of Cranio-Maxillofacial Surgery, Volume 47, Issue 6 Author(s): Philipp Poxleitner, David Steybe, Britta Bublitz, Stefan Schlager, Marc Anton Fuessinger, Pit Jacob Voss, Rainer Schmelzeisen, Carl-Peter Cornelius, Marc Metzger Abstract Introduction There has been a shift toward surgical treatment of ZMC (zygomaticomaxillary complex) fractures with open reduction and subsequent fixation in the past decades. Anatomically preformed osteosynthesis plates, already used in the field of craniomaxillofacial surgery for the treatment of fractures of the mandible and the orbit, might be a suitable option for ZMC fractures as well. Material and methods A statistical shape model was created from 179 cranial CT scans. Based on this surface model, an anatomically preformed plate for the reduction and fixation of ZMC fractures was developed in 3 sizes (S, M, L). Virtual analysis of the accuracy of the plate was performed on a dataset consisting of 120 CT scans. Results Within a determined tolerance range of 0–1.5 mm, analysis revealed a high accuracy of the plate in 70–87 % of the CT scans. The S-sized plate has the highest overall accuracy, whereas the L-sized plate has highest accuracy at the "base" region which is essential for the placement of the plate. Discussion The newly developed plate can be placed via an intraoral approach and analysis of the plate has confirmed its accuracy to be sufficient to ensure an adequate fracture reduction and fixation. It thus might allow for a less extensive approach and less approaches/incisions necessary overall to reduce and fixate ZMC fractures.

Nearthrosis in true long-standing temporomandibular joint dislocation; a report on pathogenesis and clinical features with review of literature Publication date: June 2019 Source: Journal of Cranio-Maxillofacial Surgery, Volume 47, Issue 6 Author(s): Orhan Güven Abstract The behavior and function of the condyle are not the same in every type of temporomandibular joint (TMJ) dislocation. Acute displacement or dislocation of the condyle is not a rare incident, and the treatment modalities have been well known by physicians for a long time. Chronic dislocation of the condyle is considered a relatively common entity for which treatment may indispensably be surgical intervention. Type of dislocation, duration and the number of episodes are taken into account while constructing the treatment plan. Chronic dislocation that has been left untreated for a long time is a relatively less often encountered type exhibiting difficult clinical conditions for treatment. This type of dislocation is usually seen in elderly patients with poor general health conditions and can be classified as "long-standing dislocation." In this clinical condition, after having some chronic dislocation episodes, the condyle leaves the original fossa, sits in the anterior part of the eminence permanently, creates a new fossa and never gets back to the original place again. Duration is the most important criterion in classifying long-standing dislocations and has a great effect on decisions regarding the type of management. The relevant literature includes few reports, most of which speculate upon "duration," which varies on a large scale ranging from 5 weeks to 33 years. There has been neither an agreement on time span within which long-standing dislocation develops, nor a universally accepted definition for what "long-standing" is indeed meant to be. On the other hand, in some cases, the condition has been named "true long-standing dislocation" due to some permanent pathological changes that the TMJ undergoes, such as pseudoarticulation/nearthrosis/false joint/neo-joint. In this paper, management of true long-standing/permanent dislocation in two patients, whose conditions lasted more than 1 year and resulted in permanent changes in TMJ anatomy, is presented. Due to the poor general health condition of the two elderly patients, they were treated in the most conservative way possible. In one of the patients, eminectomy and head-gear application were used to attain gradual relocation of the condyles. Rehabilitation of masticatory function of the other patient was improved prosthetically.

The relationship between temporomandibular joint effusion and pain in patients with internal derangement Publication date: June 2019 Source: Journal of Cranio-Maxillofacial Surgery, Volume 47, Issue 6 Author(s): Hatice Hosgor Abstract Objectives The purpose of this study was to evaluate the relationship between temporomandibular joint (TMJ) effusion and joint pain in patients with internal derangement based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Methods A total of 240 TMJs from 120 patients with unilateral painful joints (103 females and 17 males, mean age 29.9 ± 12 years) were evaluated. Clinical assessments were carried out according to the DC/TMD guidelines. Magnetic resonance imaging (MRI) was used to evaluate the degree of effusion in each joint. The radiological and clinical findings were analysed for statistically significant correlations. Results Although the results indicated a statistically significant association between moderate joint effusion and disc displacement (p < 0,05), there was no statistically significant association between moderate effusion and joint pain (p > 0,05). There were, however, statistically significant associations between marked effusion and both disc displacement and joint pain (p < 0,05). Conclusion TMJ effusion is associated with both disc displacement and joint pain: the effusion increased in direct proportion to the severity of pain and disc displacement. The possibility that there are various aetiologies for the condition should also be considered.

Alexandros Sfakianakis
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