Treatment guidelines for temporomandibular joint ankylosis with secondary dentofacial deformities in adults.

Temporomandibular joint (TMJ) ankylosis with secondary dentofacial deformities in adult patients is a severely disfiguring condition and surgical treatment of this disease remains a great clinical challenge. Treatment goals are to restore the joint function, to improve facial appearances and to correct malocclusion, as well as to re-establishing harmony among them. Currently, various surgical techniques, such as arthroplasty with or without interpositional material, orthognathic surgery, distraction osteogenesis, autologous bone or bone replacement materials graft and plastic surgery, have been described in the literature. In most cases these techniques should be used in combination to achieve satisfactory outcomes. The biggest difficulty for most clinicians is to determine the proper sequence of these procedures because no uniform treatment protocol has been established. Based on the published literature and our own clinical experiences, we have prepared this review article to provide some guidelines for the surgical management of TMJ ankylosis with dentofacial deformities in adults, which will be modified and updated periodically to provide the best treatment options to benefit our patients.

How to achieve a balanced and delicate lower third of the face in Orientals by mandibular contouring.

INTRODUCTION: For East Asians, correction of square jaw has become one of the commonly performed procedures in aesthetic surgery. While reviewing unsatisfactory cases of mandibular reduction, the authors discovered that failure was largely due to surgeons generally focussing too much on treatment of the posterior part of the mandible, and ignoring the aesthetic significance of the harmonious and smooth overall curve from the anterior mandible to the inferior margin of the mandible. Thus, our group proposes that a coordinated, balanced and smooth jaw line is considered a key factor in Oriental mandibular contouring. PATIENTS AND METHODS: A total of 128 patients accepted jaw line reshaping by 'V-line' ostectomy, mandibular outer cortex split ostectomy, narrowing and/or sliding genioplasty and porous polyethylene implantation to achieve the desired cosmetic effects. RESULTS: All patients obtained satisfactory cosmetic results, and their square jaw was corrected. After the operation, a natural, harmonised and balanced jaw line was achieved. Lower third of the facial contour was significantly improved. CONCLUSION: Based on different facial features of square jaw deformity, a variety of plastic surgical methods for mandibular contouring were integrated and applied to achieve a balanced and delicate jaw line.

Correction of midface hypoplasia using a novel trapezoidal osteotomy.

BACKGROUND: Currently, investigating an optimal method to deal with midface hypoplasia has become a significant issue in the field of facial aesthetic surgery. Traditional ways to address this problem primarily include segmental osteotomies and using autogenous bone or cartilage grafts or synthetic implants. For the patients with paranasal hypoplasia but without malocclusion, autogenous bone grafts or implants are recommended. However, some of these patients have a flattened nose and protrusive malar, especially in the Eastern Asian; the nose will seem more flattened after augmentation the paranasal area. Hence, osteotomy is necessary in these patients to bring the flattened nose forward to get a more satisfying contour of the midface. METHODS: We propose a novel osteotomy through the application of model surgery to solve the problem of midface hypoplasia combined with flattened nose but without malocclusion. When compared with other techniques, this novel method not only allows the augmentation to be performed on a broader scale composed of different segments of the midface skeleton, but also results in a lower surgical risk and maintenance of the stability of occlusion. RESULTS: This novel osteotomy can bring the premaxilla in combination with the nasal bone forward to solve the problem of midface hypoplasia combined with flattened nose in patients with normal occlusion. CONCLUSIONS: Through simultaneous augmentation of the different segments of the midface through this novel osteotomy, a more pleasing contour of the midface in all 3 dimensions can be achieved.

Total or partial inferior border ostectomy for mandibular contouring: indications and outcomes.

Among the East Asian population, a long or square face produces a characteristic coarse and masculine appearance and is therefore considered undesirable and unattractive. Because of this many Orientals seek to achieve a harmonious contour of their face by undergoing various cosmetic surgical procedures. Mandibular contouring for a long or asymmetrical face with/without square jaw is rarely reported in the literature and the objective of this study was to investigate the effectiveness of total or partial inferior border ostectomy for mandibular contouring and to discuss its indications. From July 2005 to November 2009, 74 patients in this study received mandibular contouring by total or partial inferior border ostectomy procedure to correct a disharmonious facial contour. Postoperatively the appearance of all 74 cases showed that the length of the lower 3rd of the face and the width of the mandible were decreased effectively, and the mandibular contour was improved. The final aesthetic outcomes were satisfactory for both the surgeons and the patients. The results suggest that facial contour could be improved by using total or partial inferior border ostectomy of the mandible thus achieving a harmonious facial outline based on East Asian aesthetics.

Surgical designs and techniques for mandibular contouring based on categorisation of square face with low gonial angle in orientals.

INTRODUCTION: In East Asian population, a square face is considered unappealing as it imparts a coarse and masculine look. Therefore, Oriental women prefer to have an ovoid and slender facial contour, which is thought to be more feminine and attractive. Nowadays, mandibular contouring surgery has become a commonly performed procedure. Clinical data show that majority of patients who have severe form are characterised by a definite square-shaped face with low gonial angle. A square face is usually visualised in frontal view but the lateral view provides additional information regarding gonial angle, mandibular plane steepness, chin deficiency and more importantly, length of the ramus. These factors are the key points for a precise categorisation, design, selection of surgical methods and choosing the ostectomy line for contouring on a square face with low angle. PATIENTS AND METHODS: From 2005 to 2009, 94 women were diagnosed as square face with low angle. Three types of surgical design based on procedures such as mandibular 'V-Line' ostectomy, mandibular outer cortex split ostectomy, sliding genioplasty and inlay bone graft in various combinations were constructed, depending upon the presenting facial features. RESULTS: Precise categorisation, designs and techniques resulted in higher satisfaction as these procedures provided an overall narrowing and harmonising effect on the lower facial contour postoperatively. CONCLUSION: Patients with square face and low gonial angle come with multitude of features so that design and technique applied should be tailored to each individual to achieve perfection.

[Narrowing and sliding genioplasty procedure combined with mandibular outer cortex ostectomy technique to correct square jaw in short face].

OBJECTIVE: To evaluate the the feasibility and effectiveness of narrowing and sliding genioplasty combined with mandibular outer cortex ostectomy technique to reshape a square jaw in short face. METHODS: From July 2005 to October 2009, a total of 57 patients received narrowing and sliding genioplasty combined with mandibular outer cortex ostectomy procedure to correct square jaw in short face. All the patients had standard frontal and lateral cephalometric radiographs, panoramic radiographs, and were photographed preoperatively and postoperatively to assess their face contour. The alteration of mandibular angle, mental contour and width of lower face was observed for 6 to 24 months postoperatively. Questionnaires were used to assess the patients' satisfactory. RESULTS: It showed that the postoperative lower face had narrowed and become softer, slender and oval, with a slick mental region. The final aesthetic outcomes were quite satisfactory in all cases from both the view of surgeons and patients. CONCLUSIONS: Narrowing and sliding genioplasty combined with mandibular outer cortex ostectomy procedure could efficiently adjust the shape and position of chin to obtain a good proportion of the lower face, and to change square and short face to slender oval one by single operation in accordance with the fashionable aesthetics in orientals.

Contouring of a square jaw on a short face by narrowing and sliding genioplasty combined with mandibular outer cortex ostectomy in orientals.

BACKGROUND: A square face is considered unattractive in Orientals; thus, it has become a frequently encountered reason for patients undergoing face contouring surgery. While reviewing the unsatisfactory cases of mandibular reduction, the authors discovered that some failed cases were related to a square jaw on a short face. The conventional procedures fix only the posterior region of the mandible, resulting in increased prominence of the stunted or square chin and short face. Thus, the authors applied a narrowing and sliding genioplasty procedure combined with a mandibular outer cortex ostectomy technique to reshape a wide, weak chin, and a square jaw on a short lower facial contour into a slender and attractive oval face. METHODS: From July of 2005 to October of 2009, there were a total of 57 patients in this study who underwent a narrowing and sliding genioplasty combined with a mandibular outer cortex ostectomy procedure to correct a square jaw on a short face. RESULTS: The postoperative appearance of all 57 cases showed that the lower face had narrowed and had become softer, slender, and oval, with a slick mental region. CONCLUSION: Narrowing and sliding genioplasty combined with a mandibular outer cortex ostectomy procedure could efficiently adjust the shape and position of the chin to obtain a good proportion of the lower face and change a square, short face to a slender, oval one in a single operation in accordance with fashionable aesthetics in Orientals.

Correction of zygoma and zygomatic arch protrusion in East Asian individuals.

OBJECTIVE: Prominent zygoma is commonly seen in the East Asian population with the clinical characteristics of anteriorly and/or laterally projected zygoma and zygomatic arch resulting in an increased midfacial width. The esthetic surgical modification of zygoma is one of the major aspects of facial-contouring surgery in certain parts of the world. This article aims to evaluate the effectiveness of various surgical methods for reducing the prominent zygoma so as to obtain a harmonious and natural facial contour. METHODS: Surgical approaches, such as zygomatic complex shaving, I-shaped osteotomy, L-shaped osteotomy, and C-shaped osteotomy were used according to the clinical characteristics of zygoma and zygomatic arch protrusion. The corrective effectiveness was then evaluated through cephalometric radiographs, 3D-CT, and pre- and postsurgical standard facial photographs. RESULTS: The zygoma and zygomatic arch protrusion was effectively corrected resulting in improved facial contours in all cases postoperatively. The postoperative period was uneventful except for the slight limitation in mouth opening, which recovered fully after mouth-opening exercises. Serious complications, such as facial nerve injury, were not witnessed in our study. CONCLUSIONS: Malar reduction is an effective and a safe method for the treatment of prominent zygoma. The selection of surgical procedure should be based on different presenting characteristics of zygoma and zygomatic arch protrusion. The correction of prominent zygoma should be designed well, performed precisely, and observed carefully to avoid severe complications so as to achieve a harmonious facial contour.

[Correction of low angel-square jaw with mandibular "V-Line" ostectomy combined with mandibular outer cortex ostectomy].

OBJECTIVE: To evaluate the feasibility of mandibular "V-Line" osteotomy combined with mandibular outer cortex osteotomy for correction of low angle-square jaw. METHODS: From Jul. 2005 to Nov. 2007, 31 patients with low angle-square jaw were corrected with mandibular "V-Line" osteotomy combined with mandibular outer cortex osteotomy. The patients were followed up for 6-24 months. Pre- and Post-operative standard images and X-ray cephalometric examination were used to assess the therapeutic effect. RESULTS: The wounds were healed primarily in all the 31 cases with no severe complication. The lower labial numbness was happened in 13 cases, which was recovered within 4 months. All the patients achieved esthetic improvement at the frontal and lateral view. The mandibular angle and the mandibular plane angle reached 110 degrees - 120 degrees and 25 degrees - 30 degrees after operation. The distance between the angles was decreased. CONCLUSIONS: The low angle-square jaw can be corrected satisfactorily with mandibular "V-Line" osteotomy combined with mandibular outer cortex osteotomy.

The effect of hydrofluoric acid treatment on titanium implant osseointegration in ovariectomized rats.

This study aimed to investigate the effects of hydrofluoric acid (HF) treatment of grit-blasted Ti implants on osseointegration in ovariectomized (OVX) rats. After blasting with aluminium oxide particles, half implants were treated with 0.2 vol.% HF, and the other half were kept non-modified as control. The topographical and chemical changes of implant surface were determined by Scanning Electron Microscope, Atomic Force Microscope, and X-ray Photoemission Spectroscopy. 12 Weeks after bilateral ovariectomy, each rat accepted two implants in distal femora, with the control implant on the left and the fluoride-modified on the right. As a result, fluoride modification induced markedly changed surface topography and chemical composition. 12 Weeks after implant insertion, the fluoride-modified implants showed improved osseointegration compared to control, with the bone area ratio and bone-to-implant contact increased by 0.9- and 1.4-fold in histomorphometry, the bone volume ratio and percent osseointegration by 0.8- and 1.3-fold in micro-CT evaluation, and the maximal push-out force and ultimate shear strength by 1.2- and 2.0-fold in biomechanical test. These promising results indicated that HF treatment of Ti surface improved implant osseointegration in OVX rats, and suggested the feasibility of using fluoride modification to improve Ti implant osseointegration in osteoporotic bone.

Matrix metalloproteinase and its inhibitor in temporomandibular joint osteoarthrosis after indirect trauma in young goats.

Our aim was to examine the change in expression of matrix metalloproteinases (MMP-13), matrix metalloproteinases-3 (MMP-3), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in the articular cartilage of goats with experimentally-induced osteoarthrosis of the temporomandibular joint (TMJ) at various times. Osteoarthrosis was induced in 20 goats in the bilateral TMJ and 5 goats acted as controls. There were 5 goats in each group, and a group was killed at 7 days, and 1, 3, and 6 months postoperatively. The samples were collected, and the joints evaluated histologically. Immunofluorescence was used to detect the presence of MMPs and TIMP-1 in the articular disc and condylar cartilage. The ultrastructure of the articular disc and condylar surface at 1 month was examined with scanning electron microscopy (SEM). Osteoarthrosis of the TMJ progressed gradually over time. MMP-13, MMP-3, and TIMP-1 were expressed strongly in the TMJ soon after injury; MMP-13 became gradually weakened, and MMP-3 strengthened later. None of these were expressed in the normal condyle. After a month the surface of the arthrotic condyle was uneven, and the underlying collagen fibrils were exposed in irregular fissures on the surface. The secretion of TIMP-1 was related closely to the changes of MMPs during osteoarthrosis of the TMJ. The unbalanced ratio between them caused degradation of the matrix of the cartilage and might be the cause of osteoarthrosis of the TMJ.

[Influence of thermochemotherapy on the activity of cytotoxic T lymphocyte in oral maxillofacial cancer patients].

OBJECTIVE: To study the influence of thermochemotherapy on the activity of cytotoxic T lymphocyte (CTL) in peripheral blood of patients with oral maxillofacial cancer. METHODS: Twenty-one subjects with oral maxillofacial cancer were treated by thermochemotherapy, and the activity of CTL in peripheral blood was analyzed. RESULTS: Thermochemotherapy can obviously enhance the activity of CTL (P<0.01). CONCLUSION: Thermochemotherapy can enhance the activity of CTL, thus enhance the patient's immune function. Therefore, it can enhance the antitumor response in whole body.

[Induction of drug resistance in Tca8113 cell line by exposing to chemotherapy drug].

OBJECTIVE: To study the drug resistance changes in Tca8113 cell lines by exposing to carboplatin. METHODS: The concentration of carboplatin added to Tca8113 cells was increased gradually and continually, which was to induce the carhoplatin-resistance in Tca8113 cells. The sensibility to drugs of the cells was analyzed by MTT method. Immunocytochemistry and RT-PCR were utilized to examine the expression of multidrug resistance proteins and genes. RESULTS: After exposing to carboplatin, the Tca8113/CBP cells had higher drug-resistance to CBP, MTX, PYM, VCR and higher expression of MRP, GST-pi than Tca8113 cells. CONCLUSION: Multidrug resistance of Tca8113/CBP is associated with over expression of MRP, GST-pi and MDR. Tca8113/CBP can provide an ideal model for multidrug resistance research.

[Expression of inducible nitric oxide synthase in cartilage in progression of temporomandibular joint osteoarthritis].

OBJECTIVE: To study the expression of inducible nitric oxide synthase (iNOS) in cartilage of temporomandibular joint osteoarthriti (TMJOA), and to evaluate the role of iNOS in the progression of TMJOA. METHODS: The goats were used and TMJOA was induced by injection of collagenase in upper joint space. The joints were obtained and were investigated by using immunohistochemistry at 2, 4, 12, 24 weeks after injection. RESULTS: Almost no expression of iNOS in normal cartilage of TMJ. In the diseased joints, strong or definite iNOS reactivity was expressed. CONCLUSION: iNOS plays an important role in the progression of TMJOA.

Changes in the temporomandibular joint after mandibular setback surgery in monkeys: intraoral vertical versus sagittal split ramus osteotomy.

OBJECTIVE: This study was to investigate the changes in condylar position and structure of the temporomandibular joint (TMJ) after mandibular setback using 2 forms of the ramus osteotomy. STUDY DESIGN: Twelve adult male rhesus monkeys were randomly divided into groups A (n = 6) and B (n = 6) for mandibular setback surgical procedure. An intraoral vertical ramus osteotomy (IVRO) was performed in group A, whereas a sagittal split ramus osteotomy (SSRO) was performed in group B. Changes in condylar position were quantified by computed tomography (CT) preoperatively and postoperatively. All animals in groups A and B were killed at 12 weeks after surgical procedure. The TMJ specimens were harvested and processed for histological examination. RESULTS: In group A, the CT examinations showed a significant anteroinferior displacement of the condyle after surgical procedure. In group B, slight posterior displacement and lateral tilting of the condyle were noted after surgical procedure. Thickened cartilage layer and endochondral ossification were seen in the condyles of group A, but only minimal alteration in articular cartilage was found in group B. CONCLUSIONS: Both SSRO and IVRO can be biologically sound procedures for correction of mandibular prognathism. Intraoral vertical ramus osteotomy procedure leads to condylar adaptive remodeling, which may have favorable effects on TMJ, and it could be considered as a preferred surgical treatment for those patients with preoperative TMJ disorders.

[Study of reconstruction of mandibular condyle by transport distraction osteogenesis in monkeys].

OBJECTIVE: To evaluate the applicability and effectiveness of reconstruction of mandibular condyle by transport distraction osteogenesis in an animal model of rhesus monkeys. METHODS: Six adult rhesus monkeys were used in this study. Bilateral condyles and articular discs were extirpated, and the technique of transport distraction osteogenesis was performed to reconstruct the condyle. X-ray and CT scanning films were taken at various intervals. Two monkeys selected at random were sacrificed respectively at 4, 12 and 24 weeks after completion of distraction, and the newly formed condyles resulted from bony transport disc were harvested and processed for histologic examination. The removed condyles at surgery were used as normal control and prepared in the same manner. RESULTS: Open bite was seen in all animals postoperatively, and disappeared at the end of distraction. The shape and appearance of the bony transport disc was similar to original condyles at sacrifice. The articular cavity was filled with fibrous connective tissue and considerable cartilage cells were observed in the surface of the condyle stump. Bone regeneration was perfect in the distraction gap. CONCLUSION: A neocondyle with functional shape can be created by transport distraction osteogenesis, which suggested that this technique might be an alternative method in reconstruction of the condyle.

The role of bone morphogenetic protein-2 in vivo in regeneration of peripheral nerves.

We investigated the effects of bone morphogenetic protein-2 (BMP-2) and some other BMPs on regeneration of peripheral motor nerves in vivo. The facial nerves of 24 New Zealand rabbits were crushed to examine a series of retrograde changes in the facial nuclei and axons, in what has been called the "axon reaction". The facial nerves of the experimental group were treated with epineurial coaptation and BMP-2 after the injury. Nerves not treated with BMP-2 were regarded as controls. The expression of BMP-2 was investigated by in situ hybridisation in the neurons of facial nuclei. The electrophysiology, image analysis and transmission electron microscopy were used to evaluate the level of the recovery of facial nerves. The results showed that the axons in the experimental group were thicker and denser than those in the control group four weeks later. The expression of BMP-2 in the neurons of facial nuclei increased after injury. The electron microscopic observations showed that the axons' degeneration in the experimental group was less than that in the control group. Despite the morphological difference between the two groups, there was no apparent difference between them in nerve conduction velocity. These findings suggest that BMP-2 might be involved in the regeneration of facial nerves, and might function as a potential neurotrophic factor.

[Effect of hyperthermia on multidrug resistance of tongue squamous cell carcinoma cell line (Tca8113) and its multidrug resistance cell line Tca8113/CBDEA].

OBJECTIVE: To study the effect of hyperthermia on expressions of multidrug resistance (MDR) genes in tongue squamous cell carcinoma cell line Tca8113 and its MDR cell line Tca8113/CBDEA and intracellular ADM concentration. METHODS: Cell lines were hyperthermia-treated (42 degrees C for 0.5 h), 4 h and 24 h later real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) detected expressions of MDR relative genes (MDR1, MRPI, GST-pi) and HTS 7000 Plus Bio Assay Reader measured intracellular ADM concentration. RESULTS: Expressions of MDR1, MRPI, GST-'pi genes in Tca8113/CBDEA significantly descended at 4 h and 24 h post-hyperthermia (P < 0.01). Expressions of MDR1, MRP1 genes in Tca8113 significantly descended at 4 h and 24 h post-hyperthermia (P < 0.05), but there was not statistical difference between 4 h and 24 h post-hyperthermia. GST-pi expression had not statistical descent at 4 h, but there was significantly descend at 24 h post-hyperthermia (P < 0.01). Drug tolerance decreased and hyperthermia increased intracellular drug concentration in Tca8113/CBDEA and Tca8113 (P < 0.01). CONCLUSION: Hyperthermia enhance chemotherapy effect and reverse MDR genes expression in tongue squamous cell carcinoma cell line. It is suggested that hyperthermia could be used as a method to overcome MDR, which is worth more investigation.

[Influence of the expression of heat shock protein 70 in maxillofacial squamous cell carcinoma by thermochemotherapy].

OBJECTIVE: To study the influence of thermochemotheraphy on the expression of HSP70 in maxillofacial squamous cell carcinoma. METHODS: 12 patients were treated with thermochemotheraphy twice a week, altogether 10 times. After 8 mg of Pingyangmycin infused, the patients were treated with microwave hyperthermia at 43 degrees C for 40 min. The part of carcinoma tissue was removed with surgical operations at before treatment and aftre five times of treatment. The expression of HSP70 in tumor cells was determined by SP immunohistochemcial method. RESULTS: The expression of HSP70 in tumor cells was enhanced obviously by thermochemotherapy. CONCLUSION: Special high expression of HSP70 in the tumor cells was induced by thermochemotherapy. With the antigen presenting action and other action, HSP70 have special antitumor effect.