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.

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.

[Plate related complication after mandibular reconstruction].

OBJECTIVE: To evaluate the complications and factors associated with titanium plates in mandibular reconstruction with different methods. METHODS: A retrospective analysis of 660 patients who received primary reconstruction of the mandible was conducted. The characters of the mandibular defect and methods of reconstruction were recorded. The complications and factors associated with the reconstruction were analyzed. RESULTS: The majority of mandibular defect was in a shape of L (n = 324 ). The total complication rate was 14.7% (97/660), which included screw loosening 5.8% (38/660), plate fracture 3.3% (22/660), plate exposure 3.8% (25/660), infection 7.4% (49/660) and malunion or ununion 2.9% (19/660). The mandibular defects reconstructed by reconstructive plates had a higher complication rate than that by bone grafts. The complication rate was 10.8% (63/586) in cases reconstructed by bone grafts with miniplates. The complications were associated with radiation therapy and diabetes. Radiation therapy had a significant effect on plate exposure. CONCLUSIONS: Reconstruction with bone grafts can minimize the rate of plate related complication. The complications were associated with radiation therapy and diabetes.

Osteointegração da hidroxiapatita sintética no processo alveolar da mandíbula de cães: aspectos clínicos e radiográficos / Osteointegration of synthetic hydroxyapatite in alveolar process of the jaw of dogs: clinical and radiographic aspects

Avaliou-se o efeito da hidroxiapatita sintética na regeneração do osso alveolar e o efeito no tecido vivo de cães. Em dois grupos de 14 cães adultos hígidos, pesando entre 10 e 15kg, foram criados defeitos de 6 x 5mm na superfície vestibular do processo alveolar mandibular direito até atingir a raiz do quarto pré-molar. Em um grupo (tratado), o defeito foi preenchido com hidroxiapatita sintética; o grupo sem tratamento foi usado como controle. Efetuaram-se avaliações clínicas diárias durante uma semana, avaliações radiográficas após a cirurgia e aos oito, 21, 42, 60, 90 e 120 dias do pós-operatório. Vinte e quatro cães apresentaram inflamação, sendo a recuperação no grupo tratado mais lenta. Todos os animais tiveram sangramento com a hidroxiapatita. No grupo-controle houve aumento crescente da radiopacidade dos defeitos, no entanto, aos 120 dias do pós-operatório, os defeitos ainda eram visíveis. No grupo tratado, inicialmente a radiopacidade foi maior que a do osso normal, com diminuição gradual até se tornar semelhante à do osso vizinho, 60 dias após a cirurgia. A hidroxiapatita T290800-1 acelerou o preenchimento do defeito provocado no processo alveolar e acarretou inflamação e hemorragia gengival, o que, no entanto, não contra-indicou o seu uso.

The effect of the synthetic hydroxyapatite on the regeneration of the alveolar bone of dogs and on the alive tissue were evaluated. In two groups of 14 adult healthy dogs, weighing from 10 to 15kg, some defects around 6 x 5mm were provoked on the vestibular surface of the right jaw alveolar process until reaching the root of the forth premolar. In one group, the defect was infilled with synthetic hydroxyapatite. The no treated group dogs were used as control. Clinical evaluations were daily performed over one week, as well as radiographic evaluations after surgery, and on 8, 21, 42, 60, 90 and 120 days after surgery. Twenty-four dogs showed inflammation and the recovery in the treated group was slower than in the control group. Bleeding at the presence of hydroxyapatite was observed in all the animals. The radiographic examination presented an increasing radiopacity in the control group; however, this defect was still visible on day 120 after operation. Initially, in the treated group, radiopacity was higher than that of the normal bone and a gradual decrease occurred until becoming similar to the adjacent bone on day 60 days after surgery. The hydroxyapatite T290800-1 accelerated the infilling of the defect provoked in the alveolar process and caused gingival inflammation and hemorrhage; however, this does not contraindicate its use.

Management of a patient with a failed transmandibular implant.

UNLABELLED: The Transmandibular Implant System (TMI) had been developed in order to provide a patient with a severely resorbed mandible with a stable and retensive implant-supported overdenture. Failure of the transmucosal posts may necessitate removal of the transmandibular implant in total and treatment with an implant-supported prosthesis. The purpose of this paper is to describe overcoming failure of a transmandibular implant without removal and synchronous placement of endosseous dental implants in the interforaminal region, providing an implant-retained overdenture to the patient. CLINICAL RELEVANCE: Transmandibular implants are rarely used nowadays and management of a failed transmandibular implant is reported even less often. Where bone height is adequate, dental implants may be placed in the anterior mandible, even when the failed transmandibular implant is not completely removed.

Sagittal split osteotomy of a vascularised iliac crest free flap to correct residual asymmetry and malocclusion in the reconstructed mandible.

Reconstruction of the mandible with a vascularised bone graft from the iliac crest based on the deep circumflex iliac artery is an established and reliable technique. We report two cases in which mandibular asymmetry followed reconstruction with such grafts and was corrected by sagittal split osteotomies.

Diagnostic and prognostic value of 99mTc-tetrofosmin scintigraphy in maxillofacial flaps.

In oro-maxillofacial malignancies, new therapeutic approaches are placing changing demands on the diverse diagnostic modalities. In contradistinction to mandibular reconstruction of former years, the transplants (microvascular anastomosed pedicled flaps, "flaps") now consist of one or more arteries feeding a soft tissue component attached to a piece of bone suitably fitted to fill the defect. We addressed the diagnostic value of technetium-99m tetrofosmin scintigraphy in differentiating between viability and non-viability of the soft tissue portion of flaps in the immediate postoperative assessment. A total of 60 patients who had received flaps for reconstruction of the mandible after partial resection were investigated with (99m)Tc-tetrofosmin 3-5 days after surgery. Scintigraphy consisted of (a) radionuclide angiography, (b) static planar imaging in four projections starting at 10 min post injection, and (c) single-photon emission tomography (SPET) performed immediately after the planar imaging. Normal perfusion associated with no defects throughout the soft tissue portion of the transplant was observed in 46/60 patients. This scintigraphic pattern was identical to viability and normal postoperative follow-up. Hypoperfusion and small defects on planar and SPET images indicated viability and uncomplicated postoperative healing in 6/60 patients, but non-viability/inadequate healing of the flap in 4/60 patients. Absence of perfusion combined with a large defect on static planar and SPET images definitively showed the non-viability of the flap (4/60 patients). It is concluded that (99m)Tc-tetrofosmin scintigraphy is a sensitive diagnostic tool for the immediate postoperative assessment of the viability and the adequacy of implantation of the soft tissue portion of flaps. Therefore tetrofosmin scintigraphy is an important modality in order (a) to define the optimal therapeutic regimen in the immediate postoperative period and (b) to provide better prognosis.

[Displacement of the titanium endoprosthesis of the mandibular condyle process towards the middle cranial fossa and method for its repair]. / Smeshchenie titanovogo éndoproteza myshchelkovogo otrostka nizhnei cheliusti v storonu srednei cherepnoi iamki i sposob ego ustraneniia.

A clinical case is presented: endoprosthesis of the articular depression of the temporomandibular joint (TMJ) was used in the treatment of a patient with a complication which developed several years after insertion of an isolated endoprosthesis of the mandibular condylar process. This case is presented as a proof of the efficiency of a complete TMJ endoprosthesis.

Alloplastic and microvascular restoration of the mandible: a comparison study.

The evolution of mandibular reconstruction following composite resection is advanced by improved alloplastic prosthesis and reliable microvascular free tissue transfers. A 42-case, 6-year experience is presented using both methods at the University of California, San Francisco. The advantages and complications of both are discussed. The authors conclude that the success rate for lateral defect restoration is equivalent with either technique, and that the anterior defects are more reliably reconstructed with free tissue transfer. The advantage of microvascular flaps in the anterior defect must be gauged against the physical status of the patient, disease extent, and likelihood of dental rehabilitation by interosseous fixation.