Mandibular Rami Implant: A New Approach in Mandibular Reconstruction.

PURPOSE: The mandible is an essential esthetic and functional component of the lower third of the face and its reconstruction has always been a challenge, especially after severe post-traumatic injuries. The purpose of the present report was to introduce a new approach of mandibular reconstruction in a patient who had lost the entire mandible except for the rami after being severely injured in a blast. MATERIALS AND METHODS: A new approach using a titanium mandibular rami implant technique was applied using computer-aided 3-dimensional virtual planning and rapid prototyping technology. A prosthetic component was supported by the mandibular implant, which achieved occlusion and dedicated function for the patient. RESULTS: This method offered precise adaptation of the implant and prosthesis and an easier surgical procedure, providing a shortened operation time, no donor site morbidity, and more predictable outcomes. CONCLUSION: This new technique allows reconstruction of large-scale mandibular defects that is not possible by conventional surgical methods.

Antibacterial Effect of Bacteriocin Isolated From Lactobacillus Plantarum ATCC 8014 on Postoperative Infection of Mandibular Fracture In Vivo.

OBJECTIVE: The primary objective of this study was to verify the effects of bacteriocin in treatment of postoperative infection of mandibular fracture in vivo. METHODS: Eighty-two mice were inoculated intravenously with staphylococcal suspensions. Bacterial cultures were obtained from implants. Blood samples were collected at 1, 2, 4, 6, and 8 hours after the injection of bacteriocins. RESULTS: Bacteriocins have significant inhibitory effects on Staphylococcus aureus (P < 0.05) and there are significant differences interleukin (IL)-8 and IL-10 in serum (P < 0.05). CONCLUSIONS: Bacteriocin isolated from L plantarum may be one of promising ways to control postoperative infection of mandibular fracture in vivo.

Prosthetic rehabilitation of a patient with a resected right temporomandibular joint.

This case report presents the prosthodontic rehabilitation of a patient with a resected right mandible, caused by an accident. Right condyle, ramus, and the posterior part of ramus were affected by the accident. These structures were resected, and the mandible was positioned toward the surgical area and a facial asymmetry was occurred. The patient was treated with a bar-retained maxillar denture with a guide ramp and an implant-supported fixed mandibular prosthesis.

Is 2 mm a safe distance from the inferior alveolar canal to avoid neurosensory complications in implant surgery?

AIM: The aim of the present study was to compare the neurosensory complications related to implants inserted closer than 2 mm to the inferior alveolar canal (IAC) with those inserted further than 2 mm. MATERIALS AND METHODS: A total of 474 implants in 314 patients placed posterior to mental foramen area were evaluated retrospectively on panoramic radiographs. Patients were divided into two groups regarding implant proximity to the IAC (Group 1, distance ≤2 mm, Group 2, distance >2 mm). Postoperative neurosensory complications (pain and paresthesia) were recorded. Chi-square test was used for statistical comparison and P ≤ 0.05 was considered significant. RESULTS: One hundred and fifty-three implants (32.2%) were inserted closer than 2 mm to the IAC whereas 321 implants (67.8%) were inserted further than 2 mm. Three implants which had a distance of 0 mm to the IAC (0.63%) caused paresthesia after surgery. Implant distance to IAC did not show a significant difference regarding pain and paresthesia (P = 0.06 and P = 0.08, respectively). CONCLUSION: When 2 mm is considered as a safety distance, the distance of the implants to the IAC did not yield any statistical difference regarding postoperative neurosensory complications.

Simple prosthesis for a cancer patient with a segmental mandibulectomy and free fibula flap reconstruction: a clinical report.

Tumors of the mandible often necessitate the resection of a major portion of the body of the mandible as well as tissue from the tongue. Resection of the body of the mandible often leads to discontinuity of the mandible, affecting function to a large extent. While the rehabilitation of such defects with free fibula flaps may provide a certain level of stability to the mandible and aid in the prosthetic rehabilitation of these patients, the bulk of these flaps may create difficulties during prosthetic rehabilitation. The economic constraints of patients and/or their fear of implant surgery may also rule out prosthetic rehabilitation with implant-retained prostheses. This case report describes a simple and cost-effective method of prosthetic rehabilitation for a cancer patient who had undergone a segmental mandibulectomy followed by reconstruction with a free fibula flap.

Management of severe mandibular deviation following partial mandibular resection: a case report.

Extensive mandibular resection commonly leads to a deviation of the mandible, facial disfigurement, and difficulty with speech and mastication. The rehabilitation of these patients is a prosthodontic challenge. This article presents the case of a 60-year-old man who sought prosthetic rehabilitation after a right segmental mandibulectomy. The prosthetic rehabilitation was planned in 2 phases. A palatal ramp was constructed, followed by a mandibular guiding flange. After 4 months, the patient's chewing ability, tongue movement, and facial esthetics were improved.

Mandibular reconstruction with a prefabricated free vascularized fibula and implant-supported prosthesis based on fully three-dimensional virtual planning.

Because optimal reconstruction of maxillofacial defects requires functional rehabilitation, the current study demonstrates the successful secondary reconstruction of a large mandibular continuity defect using a fully digitally planned prefabricated free vascularized fibula with immediate implant-supported prosthodontic restoration. A 56-year-old man presented with a large mandibular continuity defect after resection of an enlarged squamous cell carcinoma arising from the floor of the mouth. For secondary reconstruction, the shape of the neomandible and implant position for support of the lower prosthesis were planned virtually. The combined cutting and drilling guide was printed in 3 dimensions. In a 2-step surgical approach, first, the implants were inserted into the fibula and covered with a split-thickness skin graft to form a neogingiva. In a second operation, the fibula was harvested, osteotomized, and fixed with the denture on the preinserted implants. The fibula was placed to its final position guided by the occlusion. Using three-dimensional virtual backward planning, it was feasible to perform a mandibular reconstruction with immediate prosthetic rehabilitation.

Keratocystic odontogenic tumor: treatment modalities: study of 3 cases.

Management of the keratocystic odontogenic tumor has been one of the most controversial entities of the maxillofacial surgery. It can become quite large because of its ability for significant expansion, extension into adjacent tissues and rapid growth and also has high reccurence rate as it shows a thin, friable wall, which is often difficult to enucleate from the bone in toto, and have small satellite cysts within the fibrous wall. There are various treatment modalities suggested from conservative to radical approach, but studies have shown even with conservative approach good results are achieved. In this paper we are presenting various treatment modalities and 3 cases have been discussed.

[Complex treatment approach in patients with lower jaw defects].

The aim of the study was to evaluate the clinical efficiency of modern materials in complex treatment of patients with lower jaw defects. The study demonstrates the advantages of biologically inert materials (carbon composite material "Uglekon-M" and titanium alloys) for lower jaw defect restoration.

[A comparative evaluation of bone tissue formation by tissue scaffold and osteoplastic material «Bio-Oss¼ transplantation in the maxillary sinus floor].

The effectiveness of bone tissue formation by transplantation of tissue-engineering scaffold and frequently used osteoplastic material «Bio-Oss¼ combined construction in maxillary sinus floor was evaluated and marked differences in regeneration terms by this treatment mode were found out.

[Therapy-resistant aggressive cystic lesion of the mandible]. / Therapieresistente aggressive zystische Läsion des Unterkiefers.

Several extensive surgical interventions of a cystic lesion in the left mandible were followed by recurrences. The lesion extended from the primary mandibular region into the area of pterygopalatine fossa finally infiltrating the orbital region and the skull base. Histological results could never demonstrate a malignancy with certainty. Due to the patient's poor general condition, the refusal for further surgical inventions and due to the malignoma-like growth pattern radiation treatment was performed. However, this had no effect on tumor progression.

Mandibular guidance prosthesis: Conventional and innovative approach: A case series.

Surgical resection of the lower jaw due to the presence of a benign or malignant tumor is the most frequent cause of mandibular deviation. Location and extent of the tumor decide the surgical modality of mandibulectomy to be performed. The clinician must wait for an adequate span of time for completion of the healing and acceptance of the osseous graft before considering a definitive prosthesis. During the inceptive healing period, prosthodontic intervention is of utmost priority for preventing the mandibular deviation. A corrective appliance termed "guide flange prosthesis (GFP)" is indicated to limit this clinical manifestation. The basic intention of rehabilitation is to train the mandibular muscles and to re-establish an acceptable occlusal relationship so that the patient can adequately control the opening and closing movements. This case series describes early prosthodontic management of three patients who had undergone hemimandibulectomy, with different techniques of fabrication of a GFP. The three techniques described consist of two conventional methods of fabrication while the third technique is a new innovative approach.

Replacement of the condyle and ascending ramus by a modular endoprosthesis in Macaca fascicularis--part 4: evaluation of the temporomandibular joints.

PURPOSE: To assess, using cone-beam computed tomography and histologic examination, whether the fixation of a condyle-ascending ramus mandibular modular endoprosthesis results in a physiologic condylar replacement in Macaca fascicularis. MATERIALS AND METHODS: The right condyle and ascending ramus were resected in 8 adult monkeys and replaced with a modular endoprosthesis, fixed with polymethyl methacrylate bone cement (Palacos). Four monkeys were sacrificed at 3 months and another 4 at 6 months postoperatively. The reconstructed and contralateral temporomandibular joints were harvested en bloc and studied using cone-beam computed tomography and descriptive histologic examination. Heterotopic bone formation was quantified using a modified grading scale. The condyle cartilage thickness in the contralateral temporomandibular joint was measured using histomorphometric methods. The results were compared with those of the unoperated control monkeys. RESULTS: Bone resorption in the glenoid fossa and pathologic changes in the articular disc were noted on the reconstructed side in most specimens. Nevertheless, cone-beam computed tomography findings, histologic findings, and condyle cartilage thickness measurements of the contralateral temporomandibular joint were not significantly different from those of the control specimens. CONCLUSION: Replacement of the condyle and ascending ramus using a modular endoprosthesis in Macaca fascicularis resulted in adaptive remodeling of the glenoid fossa at up to 6 months postoperatively. Long-term studies are required to further assess the potential of this mode of reconstruction.

Accurate reconstruction of discontinuous mandible using a reverse engineering/computer-aided design/rapid prototyping technique: a preliminary clinical study.

PURPOSE: To improve the reconstructive surgical outcome of a discontinuous mandibular defect, we used reverse engineering (RE), computer-aided design (CAD), and rapid prototyping (RP) technique to fabricate customized mandibular trays to precisely restore the mandibular defects. Autogenous bone grafting was also used to restore the bony continuity for occlusion rehabilitation. PATIENTS AND METHODS: Six patients who had undergone block resection of the mandible underwent reconstruction using a custom titanium tray combining autogenous iliac grafts. The custom titanium tray was made using a RE/CAD/RP technique. A virtual 3-dimensional model was obtained by spiral computed tomography scanning. The opposite side of the mandible was mirrored to cover the defect area to restore excellent facial symmetry. A bone grafting tray was designed from the mirrored image and manufactured using RP processing and casting. The mandibular defects were restored using the trays in combination of autologous iliac grafting. An implant denture was made for 1 of the 6 patients at 24 weeks postoperatively for occlusion rehabilitation. RESULTS: The trays fabricated using this technique fit well in all 6 patients. The reconstructive procedures were easy and time saving. Satisfactory facial symmetry was restored. No severe complications occurred in the 5 patients without occlusion rehabilitation during a mean 50-month follow-up period. The reconstruction in the patient with occlusion lasted for only 1 year and failed eventually because of bone resorption and infection. CONCLUSIONS: Mandibular reconstruction was facilitated using the RE/CAD/RP technique. Satisfactory esthetic results were achieved. However, the rigidity of the cast tray could cause severe stress shielding to the grafts, which could lead to disuse atrophy. Therefore, some modification is needed for functional reconstruction.

Clinical application of a custom-made bioresorbable raw particulate hydroxyapatite/poly-L-lactide mesh tray for mandibular reconstruction.

Mandibular reconstruction using particulate cancellous bone and marrow (PCBM) allows functional oral reconstruction. Although ready-made titanium trays are the most common material used in this method, they have some disadvantages such as difficulty in making them form a suitable contour for the defect, and the need for removal. A forged composite of raw particulate hydroxyapatite (HA)/poly-L-lactide (PLLA) is a bioresorbable material that is stronger than pure PLLA and induces bone formation more rapidly. We present two cases successfully treated with custom-made bioresorbable HA/PLLA mesh trays for mandibular reconstruction. A 29-year-old woman with recurrent ameloblastoma and a 66-year-old man with a recurrent keratinized odontogenic tumor of the mandible gave informed consent for this reconstruction technique. Mesh sheets of HA/PLLA were customized by a rapid prototyping method based on computed tomography (CT) data. Marginal resection of the tumor was carried out, and PCBM was harvested from the bilateral posterior iliac crests. PCBM and platelet-rich plasma were transferred to the tray, and the tray was fixed rigidly with HA/PLLA screws. In the second case, dental implants were inserted. There has been no bone resorption for over 2 years since reconstruction in these two cases, and the inserted dental implants have been free from any complications 1 year after loading. The average CT value in Hounsfield units (HU) of the implant sites of two cases was 790. In conclusion, the customized HA/PLLA tray was easily adapted to the mandible, and fine bone quality was obtained. These cases show that this tray system contributed to functional oral rehabilitation with dental implants.

Modular endoprosthesis for mandibular body reconstruction: a clinical, micro-CT and histologic evaluation in eight Macaca fascicularis.

This paper presents the results of an animal experiment, in which a modular endoprosthesis is tested to replace a resected part of the mandible. The prostheses were fixed with polymethacrylate (PMMA) cement into the medullar space of the stumps. Clinical, radiologic, micro-computed tomographic and histologic evaluations were made after 3 and 6 months on four Macaca fascicularis for each implantation time. The prosthesis had not loosened but there were some loose screws that had caused fistulas in three animals. The stems of the modules were stably fixed with PMMA cement, surrounded by a fibrous capsule with inflammatory cells. This capsule was thinner in the 6-month group and showed less inflammatory infiltrate compared with the 3-month group; this was not statistically significant. There was an increase in woven bone surrounding the modules after 6 months. After 3 months of implantation, there was a considerable inflammatory reaction in the soft tissues surrounding the module, which subsided over following 3 months. The results are encouraging, but a longer period of follow-up is required to assess its application in a clinical setting, and some design drawbacks need to be addressed.

Masseter muscle reattachment after mandibular angle surgery.

BACKGROUND: Altering the dimensions of the mandibular angle by alloplastic augmentation or skeletal reduction requires elevation of the insertion of the masseter muscle, including the pterygomasseteric sling. Disruption of the pterygomasseteric sling during exposure of the inferior border of the mandible can cause the masseter muscle to retract superiorly, resulting in a loss of soft tissue volume over the angle of the mandible and a skeletonized appearance. Subsequent contraction of the masseter elevates the disinserted edge of the muscle and not only increases the skeletonized area, but also exaggerates the deficiency by causing a soft tissue bulge above it. OBJECTIVE: The authors describe the disinsertion of the masseter and the resulting deformity as a potential complication of mandibular angle surgery and review the technique for repair. METHODS: The records of 60 patients (44 primary, 16 secondary) who presented for alloplastic mandible augmentation between 2003 and 2008 were reviewed. RESULTS: Nine patients presented with clinical signs of disruption of the pterygomasseteric sling after mandibular angle surgery. Five patients had clinical signs consistent with complete disruption. Two of these patients requested reconstruction. The other four had signs consistent with partial disruption. Through a Risdon approach, the masseter was successfully reinserted using drill holes placed at the inferior border of the mandible. CONCLUSIONS: Masseter disinsertion is a previously unreported sequelae after aesthetic surgery for the angle of the mandible. The resultant static and dynamic contour deformity can be corrected by reattaching the muscle to the inferior border of the mandible.

[Reverse engineering and rapid prototyping technique for restoration of mandibular bone defect].

The application principle and procedure of reverse engineering and rapid prototyping techniques are introduced in this paper. The description is concentrated on the applications of the above techniques in medical field, especially in reconstructive surgery of mandibular bone defect.

Modular endoprosthesis for mandibular reconstruction: a preliminary animal study.

The use of a mandibular modular endoprosthesis after segmental resection of part of the body of the mandible was studied. This preliminary study was carried out on four pigs and four monkeys. The devices were made of a titanium alloy and were cemented in the prepared medullary spaces with polymethylmetacrylate cement. The prosthesis failed in one pig, but in the other animals the prostheses were stable and firmly fixed to the stumps after 3 months. It was concluded that the endoprosthesis has potential in reconstructive surgery of the mandible, but that further studies are necessary to substantiate this claim. Pigs are not suitable for further studies as the medullary space is too large and filled with fat. They are also too big to handle and the variations in size and shape of the mandibles precludes the use of a modular system.

Malignant fibrous histiocytoma of the mandible in the context of a traumatic Marjolin's ulcer.

We present a rare manifestation of a chronic mandibular wound with a traumatic diathesis. A 38-year-old male patient sought medical consultation because of painless swelling in the mandibular symphysis and mild paresthesia of the lower lip. He mentioned a history of physical trauma to the mandibular symphysis 12 months ago. The radiographic evaluation and CT scan showed gross destruction of bone leading to a well-defined radiolucent lesion without any sclerosing margins. The histological examination revealed numerous spindle-shaped fibroblasts arranged in a fascicular pattern and scattered multinucleated and mononuclear cells with bizarre nuclei throughout the lesion. Moderate nuclear pleomorphism was evident with few mitotic cells. The lesion was diagnosed as a malignant fibrous histiocytoma of storiform-pleomorphic type based on the previous descriptions. After surgical removal of the lesion and the adjacent tissues and reconstruction, the patient was referred to a radiotherapist for continuation of treatment. Despite this therapy, the lesion recurred after a year, and prior to the second operation, the patient died as a result of brain involvement.