Jaw Deformities Research Articles

Volumetric comparison of maxillofacial soft tissue morphology: computed tomography in the supine position versus three-dimensional optical scanning in the sitting position

Three-dimensional (3-D) surgical simulation has become popular, but the accuracy of such simulation is difficult to assess. Because maxillofacial soft tissue profiles vary with posture, we compared such profiles obtained in the supine and sitting positions. In total, 28 patients with skeletal Class III jaw deformities underwent computed tomography in the supine position and 3-D optical scanning in the sitting position. The 2 sets of 3-D data were superimposed, and linear and volumetric differences were calculated. We evaluated the cheeks, the subauricular and infraorbital regions, the nose, the lips, and the chin. Statistical analyses were performed by using paired Student's t tests. Differences with P < .05 were considered significant. Patients were divided into 3 groups based on body mass index. The facial profiles of the cheeks and subauricular areas differed significantly between the sitting and supine positions. The extent of variation increased with body mass index. When a patient moves from the sitting position to the supine position, maxillofacial soft tissue migrates from the cheeks to the subauricular regions. Thus, simulations for surgery based on supine computed tomography alone do not accurately model the cheeks and subauricular areas.

Three-dimensional Analysis and Evaluation in Orthognathic Surgical Cases with Facial Asymmetry.

Two-dimensional cephalometric analysis is commonly used in planning and evaluating the outcome of orthognathic surgery. It is difficult to arrive at an accurate evaluation with this method, however, as the jaw bones overlap in profile. Therefore, the purpose of this study was to use 3-dimensional (3-D) orthognathic treatment planning software for measurement of distances and angles to evaluate change in dentofacial morphology and stability after orthognathic surgery in patients with jaw deformity and facial asymmetry. Computed tomography with SimPlant O&O® (Materialize Dental, Belgium) was used to obtain data at before surgery (T1) and at 1 month (T2) and 1-2 years postoperatively (T3). Reference points, reference planes, and evaluation items were set to measure angles and distances. The average values at T1, T2, and T3 and the standard deviations were obtained. The analyses of change in distance and angle between T1 and T2 in both the maxilla and mandible revealed that the amount of postoperative deviation and change was greatest in the mandible (p<0.05). These findings showed a correlation between postoperative change in position of the chin and symmetry. Only a minimal amount of change was observed between T2 and T3 in both the maxilla and mandible. The results also revealed a correlation between positional change in both the proximal and distal bone segments and stability. It was found to be possible to determine change in horizontal, vertical, and anterior/posterior angle in both the maxilla and mandible by such 3-D analysis. The results suggest that the chin is the most appropriate facial element for evaluation of symmetry after orthognathic surgery.

Comparative Study of Mandible Ramus Morphology Using 3-dimensional CT in Sagittal Split Ramus Osteotomy.

The purpose of the present study was to investigate the relevance of the external morphology of the mandibular ramus, internal bone tissue structure, and maxillofacial morphology at the site for sagittal split ramus osteotomy among different facial skeletal patterns. A total of 80 patients with jaw deformities who underwent sagittal split ramus osteotomy were included in the study. The patients were divided into two groups based on facial skeletal type (skeletal Class II or skeletal Class III). A further 7 patients with no skeletal abnormalities were established as the control group (skeletal Class I). Computed tomography images obtained from these patients were 3-dimensionally reconstructed and the morphology of the mandibular ramus determined. Thickness at the mandibular foramen in Class II was greater than that in Class III, and showed the lowest value at the midpoint of the mandibular foramen and mandibular notch in Class I. Mandibular morphology showed change according to facial skeletal type. Correlations were also observed between the cephalometric analysis values and mandibular morphology.

Bite force and Masticatory efficiency before and after Orthognathic Surgical Correction

Introduction: Correction of Dentofacial deformity or Orthognathic surgery can be described and classified, where the treatment goal is to reposition the maxilla, mandible, or chin for patients who have crossed the age for growth modification and for other dentofacial conditions or orthodontic camouflage. The treatment is projected more from the aesthetic point of view, where patients undergo a dramatic change in the skeletal morphology. However, it is important to consider from the aesthetic and functional point of view for the overall well -being of the patient. Hence, Orthognathic surgery in combination with orthodontic treatment, not only corrects the dentofacial deformity, it also improves occlusal contacts, masticatory efficiency, the electromyographic (EMG) activity of the masticatory muscles and the bite force for the patient. Various studies have identified the problems and changes in occlusal discrepancy following orthognathic surgery. Objective: To compare the bite force and masticatory efficacy before and after orthognathic surgical correction. Selection criteria: All studies and articles that evaluated bite force and masticatory efficiency before and after orthognathic surgical correction were selected for review. Data Collection: The parameters compared in both the groups included, the surgical time was taken, postoperative occlusion, IMF stability, oral -hygiene, intra and postoperative complications. Results: Orthognathic surgery can improve the functional deficits, including those of the bite force, but the improvement may not continue beyond the first year of surgery. Conclusion: An objective analysis of the masticatory efficiency is important in evaluating the success of orthognathic treatment of the jaw deformities.

Final discussion and result of public comment for the certified physician system of Japanese Society for Jaw Deformities

Final discussion and result of public comment for the certified physician system of Japanese Society for Jaw Deformities

Mechanical stress promotes matrix synthesis of mandibular condylar cartilage via the RKIP-ERK pathway.

Mandibular hypoplasia is a common jaw deformity that affects breathing, occlusal function and facial aesthetics. Stimulating mandibular condylar growing with functional appliances is an ordinary but controversial treatment method in orthodontics. Therefore, it is vital to clarify how functional appliances affect condylar growing. Raf-1 kinase inhibitor protein (RKIP), as an endogenous inhibitory molecule of the ERK signaling, is postulated to involve in stress-induced response to articular cartilage. This study was to reveal the role of RKIP in regulating cartilage matrix synthesis with functional appliance treatment. Here, position rat mandibular forward simulating functional appliance effect to examine the stress-induced modification of mandibular condylar in vivo, meanwhile rat mandibular condylar chondrocytes (Mccs) were subjected to cyclic tensile stress (CTS, 16%, 1HZ). The results showed that mandibular forward therapy enhanced condylar cartilage growth. The thicknesses of all layers of condylar cartilage were increased significantly. RKIP expression was also increased in the mature cartilage layer. In addition, CTS could enhance extracellular matrix formation and cartilage marker expression (aggrecan and collagen II), which shared a similar expression pattern with RKIP in Mccs. However, CTS induced up-regulation of collagen II and aggrecan was blocked by RKIP knockdown. Nuclear p-ERK, targeting downstream of RKIP, showed a decrease after CTS,which was disappeared in RKIP-knockdown Mccs. Taken together, physiological mechanical stimulation promotes cartilage growth modification by up-regulating RKIP through inhibiting ERK signaling pathway.

Anaphylaxis with delayed appearance of skin manifestations during general anesthesia: two case reports

BackgroundAnaphylaxis is difficult to diagnose in the absence of skin or mucosal signs and symptoms. We report two cases of anaphylaxis under general anesthesia, in which the initial presentation was in the form of respiratory signs, followed by skin manifestations 10–15 min later. Diagnosis of anaphylaxis was delayed because skin symptoms were absent early on in the presentation.Case presentationIn the first case, a 23-year-old male patient with jaw deformity was scheduled to undergo maxillary alveolar osteotomy. After intubation, auscultation indicated a sudden decrease in breath sounds, together with severe hypotension. Approximately 10 min later, flushing of the skin and urticaria on the thigh appeared and spread widely throughout the body. In the second case, a 21-year-old female patient with jaw deformity was scheduled to undergo maxillomandibular osteotomy. Twenty minutes after the start of dextran infusion, her lungs suddenly became difficult to ventilate, and oxygen saturation decreased to 90%. Approximately 15 min later, flushing of the skin and urticaria were observed.ConclusionIn both cases, there was a time lag between the appearance of respiratory and skin symptoms, which resulted in a delay in the diagnosis, and hence, treatment of anaphylaxis. Our experience highlights the fact that it is difficult to diagnose anaphylaxis under general anesthesia.

A Rare Complication Associated with Distraction Osteogenesis in Correction of Maxillary Hypoplasia

Aim: Distraction osteogenesis (DO) is an alternative to orthognathic surgery that appears to have some advantages for advancement in the maxilla and mandible, but relatively high complication rates have been reported in the maxillofacial region.&#x0D; Methodology: A 22-year-old female with the chief complaint of maxillary hypoplasia was referred to our clinic. A two-stage procedure combining maxillary advancement by distraction technique with mandibular setback surgery was performed to correct jaw deformity. At the sixth day of the distraction breakage of the device occurred. The distractors were removed and the patient was treated using conventional osteotomy techniques to achieve good occlusion and improve the facial profile&#x0D; Results: Besides there are a number of studies about complications of DO, breakage of distractor has been really rare reported. In our case this unexpected and a very rarely reported complication occurred.&#x0D; Conclusions: The purpose of the present case report is to present an undesirable and very rare complication associated with the maxillary distraction device and an alternative treatment method for managing this undesirable failure.&#x0D; How to cite this article: Apaydın A, Yenigün S, Can T. A Rare Complication Associated with Distraction Osteogenesis in Correction of Maxillary Hypoplasia. Int Dent Res 2012;2:23-26.&#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Change in lip closing force in Classes II and III malocclusion before and after sagittal split ramus osteotomy with Le Fort I osteotomy

PurposeThe purpose of this study was to examine lip closing force in Class II and III patients before and after orthognathic surgery. Subject and methodsThe subjects were 45 patients (15 Class II women, 15 Class III men and 15 Class III women) diagnosed with jaw deformity who underwent sagittal split ramus osteotomy with Le Fort I osteotomy and 30 controls with normal skeleton and occlusion (15 men, 15 women). Maximum and minimum lip closing forces were measured using Lip De Cum® before and after surgery, and compared statistically. ResultsIn the Class II women, maximum and minimum lip closing forces did not change after surgery. However, maximum and minimum lip pressure increased significantly in the Class III men (P = 0.0116, P = 0.0295) and maximum lip closing force increased significantly in the Class III women (P = 0.0082). After 6 months, maximum lip closing force was significantly lower in both Classes II and III women than in the control women (P = 0.0002, P = 0.0045). ConclusionsThis study suggested that maximum postoperative lip pressure did not improve in the Class II women, although maximum lip closing force increased in the Class III men and women after sagittal split ramus osteotomy with Le Fort I osteotomy.

Intraoral vertico-sagittal ramus osteotomy: modification of the L-shaped osteotomy

The sagittal split ramus osteotomy and intraoral vertical ramus osteotomy carry the potential risk of postoperative nerve paralysis, bleeding, and fracture and dislocation of the condyle. In 1992, Choung first described the intraoral vertico-sagittal ramus osteotomy for the purpose of avoiding postoperative dislocation of the condyle. However, there is still potential for damaging the inferior alveolar nerve and maxillary artery with this technique. The authors have developed a modified technique to minimize these risks. An evaluation of surgical experience and patient outcomes with the use of this technique is presented herein. One hundred twenty-two sides in 97 Japanese patients diagnosed with a jaw deformity were analyzed. This technique includes a horizontal osteotomy that is performed at a higher position than in the original Choung procedure. Intraoperatively, there was no unexpected bleeding from the operative site. Proximal segment dislocation from the glenoid fossa was observed on one side (0.82%). Non-union of the osteotomy was not observed in any patient. Intraoperative fracture of the coronoid process occurred in 2.46%, but none necessitated treatment of the fracture. Nerve dysfunction was found in 2.46% at the 12-month postoperative follow-up. The modified technique presented herein was developed to reduce postoperative nerve dysfunction and intraoperative hemorrhage.

Circulatory CNP Rescues Craniofacial Hypoplasia in Achondroplasia

Achondroplasia is the most common genetic form of human dwarfism, characterized by midfacial hypoplasia resulting in occlusal abnormality and foramen magnum stenosis, leading to serious neurologic complications and hydrocephalus. Currently, surgery is the only way to manage jaw deformity, neurologic complications, and hydrocephalus in patients with achondroplasia. We previously showed that C-type natriuretic peptide (CNP) is a potent stimulator of endochondral bone growth of long bones and vertebrae and is also a potent stimulator in the craniofacial region, which is crucial for midfacial skeletogenesis. In this study, we analyzed craniofacial morphology in a mouse model of achondroplasia, in which fibroblast growth factor receptor 3 (FGFR3) is specifically activated in cartilage (Fgfr3ach mice), and investigated the mechanisms of jaw deformities caused by this mutation. Furthermore, we analyzed the effect of CNP on the maxillofacial area in these animals. Fgfr3ach mice exhibited midfacial hypoplasia, especially in the sagittal direction, caused by impaired endochondral ossification in craniofacial cartilage and by premature closure of the spheno-occipital synchondrosis, an important growth center in craniomaxillofacial skeletogenesis. We crossed Fgfr3ach mice with transgenic mice in which CNP is expressed in the liver under the control of the human serum amyloid-P component promoter, resulting in elevated levels of circulatory CNP (Fgfr3ach/SAP-Nppc-Tg mice). In the progeny, midfacial hypoplasia in the sagittal direction observed in Fgfr3ach mice was improved significantly by restoring the thickness of synchondrosis and promoting proliferation of chondrocytes in the craniofacial cartilage. In addition, the foramen magnum stenosis observed in Fgfr3ach mice was significantly ameliorated in Fgfr3ach/SAP-Nppc-Tg mice due to enhanced endochondral bone growth of the anterior intraoccipital synchondrosis. These results clearly demonstrate the therapeutic potential of CNP for treatment of midfacial hypoplasia and foramen magnum stenosis in achondroplasia.

3-D computed tomography measurement of mandibular growth after costochondral grafting in growing children with temporomandibular joint ankylosis and jaw deformity

The aim of this study was to evaluate the long-term results after costochondral grafting (CCG) in growing children with temporomandibular joint ankylosis and jaw deformity by 3-dimensional computed tomography (CT) measurement. Patients with unilateral TMJ ankylosis and jaw deformity treated by CCG from 2010 to 2014 were evaluated. Their CT data within 1week after operation and after at least 2years of follow-up were analyzed using ProPlan CMF 1.4 software. Maximal incisal opening (MIO), condyle-ramus heights, chin deviation, and growth of CCG were measured and compared before and after the operation and at the last follow-up. SPSS 17.0 software was used for statistical analysis. Seven patients were included in the study. The mean follow-up period was 46.4months. Five of 7 patients treated with this protocol experienced good mouth opening and symmetric mandibular growth. One patient achieved good mouth opening but not symmetric growth, and 1 patient experienced ankylosis again. CCG can be a reliable method to treat temporomandibular joint ankylosis with jaw deformity in growing children. Continued growth occurs in the children, but long-term outcomes require further investigation.

The effect of bone mass and architecture on mandibular condyle after mandibular distraction

Mandibular distraction surgery is a critical treatment for jaw deformity. However, abnormal mandibular condylar bone resorption is often seen as complication after surgery. Our previous study using a rat mandibular distraction model suggested that overloading leads to mandibular condylar resorption. Host factors are also believed to influence the resorption. To understand the relationship between host factors and resorption, we investigated the effect of changing bone mass and architecture on the mandibular condyle using FK506. FK506, an immunosuppressant, was used to compromise bone mass and architecture in this study. Animals were divided into 4 groups: distraction surgery (Dist), FK506 administration (FK), distraction surgery with FK506 administration (FK+Dist), and no surgery or FK506 administration (Cont). The FK group showed reduced bone mass and impaired bone architecture. The Dist group exhibited abnormal bone resorption on the surface of the condyles, which was slightly exacerbated in the FK+Dist group. Bone defect length decreased over time as a result of bone apposition in the Dist group. However, in the FK+Dist group, the bone defect length remained the same. These results suggest that bone mass and architecture strongly affect the tolerance to the overloading and adaptation with bone apposition in condylar resorption site.

自動心理診断システム(MINI)による顎変形症患者の男女間における性格傾向の検討

自動心理診断システム(MINI)による顎変形症患者の男女間における性格傾向の検討

The different effects of intraoral vertical ramus osteotomy (IVRO) and sagittal split ramus osteotomy (SSRO) on mandibular border movement

Objectives: This study investigated the different effects of intraoral vertical ramus osteotomy (IVRO) and sagittal split ramus osteotomy (SSRO) on mandibular border movement.Methods: The participants included 22 patients receiving IVRO and 22 patients receiving SSRO who were treated at Okayama University Hospital. Their mandibular border movement was evaluated in three dimensions with 6° of freedom using an optical recording system.Results: A strong correlation between condylar and lower incisor movement was observed during maximum jaw protrusion and laterotrusion. Significant improvements in condylar and lower incisor movement were detected after orthognathic surgery during maximum jaw protrusion and laterotrusion in the IVRO group and during maximum jaw protrusion in the SSRO group.Discussion: IVRO likely achieves greater improvement in jaw movement than SSRO. Therefore, the application of IVRO could be considered in the treatment of patients with jaw deformities featuring temporomandibular joint problems.

A-8 顎変形症に対する上下顎同時移動術の臨床的検討

A-8 顎変形症に対する上下顎同時移動術の臨床的検討

Simultaneous treatment of temporomandibular joint ankylosis with severe mandibular deficiency by standard TMJ prosthesis

Temporomandibular joint (TMJ) ankylosis is a refractory disease that is difficult to predictably treat. This study evaluated the prognosis of using standard alloplastic TMJ prostheses for the treatment of TMJ ankylosis in Chinese patients with severe mandibular deficiency. Patients treated from 2013 to 2015 were reviewed. The computer-aided design and manufacture (CAD/CAM) technique was used to guide bony mass removal and locate the TMJ prosthesis (Biomet, USA). Eleven patients were included in this study. All prostheses were successfully installed and stabilized intraoperatively. In 4 patients with severe mandibular deficiency, their mandibular ramus was elongated by the TMJ prosthesis and 2 patients were combined with Le Fort I osteotomy guided by digital templates. Their mean chin advancement was 10.19 mm. Their SNB and ramus heights were also significantly improved after operation (P < 0.05). There was no prosthesis loosening, breakage, or infection leading to removal after a mean follow-up period of 22 months (range, 12-31mos.). Mouth opening was significantly improved from 5.5 mm preoperatively to 31.5 mm postoperatively. TMJ reconstruction with standard alloplastic prosthesis is a reliable treatment for ankylosis, especially in recurrent cases. By CAD/CAM technique, it can correct jaw deformities simultaneously and produce stable results.

Qualitative analysis of cartilaginous jaw element malformation in cultured yellowtail kingfish (Seriola lalandi) larvae

A central problem facing worldwide culture of yellowtail kingfish (Seriola lalandi) is the presence of skeletal malformations, including jaw deformities. This study presents a morphological characterization of normal and abnormal cartilage jaw structures during early larval development. Samples of 70–150 larvae were collected from three cohorts from 2 to 9 days post hatching, anaesthetized and fixed for cartilage staining. Cartilaginous components were defined clearly at four days post hatch (dph) (4.65 ± 0.05 mm total length), and abnormal jaw structures were detectable at this time. Jaw deformities observed included extension of Meckel's cartilage with or without ventral bending of the anterior tip, displacement of ceratohyal and hypohyal cartilage ventrally and below Meckel's cartilage, and shortening and dorsal flexion of the lower jaw. At 4 dph, between 44% and 47% of all larvae examined had jaw abnormalities. The contribution of each deformity to the total number of deformities was variable among the three cohorts examined. To compare shape difference accurately we performed an exploratory, landmark-based geometric morphometric analysis using seven homologous landmarks. Larvae were classified into three jaw morphology groups. The geometric morphometric approach provides a useful tool to standardize classification of cartilage jaw abnormalities at early developmental larval stages. Early recognition of developing abnormalities is of importance for fish farmers in both improving fish selection efficiency and for evaluating effects of rearing parameters.

Evaluation of the condyle remodeling after costochondral graft in growing children with temporomandibular joint ankylosis and jaw deformity

Evaluation of the condyle remodeling after costochondral graft in growing children with temporomandibular joint ankylosis and jaw deformity

Management of dentofacial deformities and facial asymmetry with orthognathic surgery concomitant alloplastic temporomandibular joint replacement whit stock prosthesis

Temporomandibular joint (TMJ) disorders or pathology and dentofacial deformities (DFD) commonly coexist. The TMJ pathology may be the causative factor of the jaw deformity or develop as a result of the jaw deformity. Total alloplastic replacement is indicated in TMJ ankylosis, congenital deformation or absence of the TMJ, other end-stage TMJ pathologies, etc. Studies have shown that both custom and stock alloplastic TMJ replacements resulted in statistically significant improvement in pain level, jaw function, and incisal opening. The TMJ stock prosthesis has the advantage of having a more flexible adjustment and lower cost compared to custom made prosthesis, also has immediate placement availability. Objective: The aim of this study is to describe stock alloplastic TMJ total replacement with orthognathic surgery in patients with DFD and concomitant facial asymmetry. Methods: Two patients presenting with congenital and acquired disease DFD and facial asymmetry underwent orthognathic surgery with TMJ alloplastic replacement with stock prosthesis. All patients were planned by traditional model surgery. Conclusions: The TMJ is the basis of the mandibular position, the function, occlusion and facial balance. Several authors have described the performance of orthognathic surgery in conjunction with TMJ alloplastic replacement with custom-made prosthesis, however, there is little literature on performing orthognathic surgery concomitant with stock prosthetic.