Comparative effects of photobiomodulation therapy at wavelengths of 660 and 808 nm on regeneration of inferior alveolar nerve in rats following crush injury.

The aim of the present study was to investigate the therapeutic effects of 660-nm and 880-nm photobiomodulation therapy (PBMT) following inferior alveolar nerve (IAN) crush injury. Following the nerve crush injuries of IAN, 36 Wistar rats were randomly divided into three groups as follows: (1) control, (2) 660-nm PBMT, and (3) 808-nm PBMT (GaAlAs laser, 100 J/cm2, 70 mW, 0.028-cm2 beam). PBMT was started immediately after surgery and performed once every 3 days during the postoperative period. At the end of the 30-day treatment period, histopathological and histomorphometric evaluations of tissue sections were made under a light and electron microscope. The ratio of the inner axonal diameter to the total outer axonal diameter (g-ratio) and the number of axons per square micrometer were evaluated. In the 808-nm PBMT group, the number of nerve fibers with suboptimal g-ratio ranges of 0-0.49 (p < 0.001) is significantly lower than expected, which indicates better rate of myelinization in the 808-nm PBMT group. The number of axons per square micrometer was significantly higher in the 808-nm PBMT group when compared with the control (p < 0.001) and 660-nm PBMT group (p = 0.010). The data and the histopathological investigations suggest that the PBMT with the 808-nm wavelength along with its settings was able to enhance IAN regeneration after nerve crush injury.

Evaluation of the Effects of Low-Level Laser Therapy on Diabetic Bone Healing.

The aim of the present study was to evaluate the effects of low-level laser therapy (LLLT) and biphasic alloplastic bone graft material on diabetic bone healing. Induction of diabetes was performed in 14 male Sprague-Dawley rats by intraperitoneal injection of a 50 mg/kg dose of streptozotocin. Two bilaterally symmetrical non-critical-sized bone defects were created in the parietal bones in each rat. Right defects were filled with biphasic alloplastic bone graft. Rats were randomly divided into 2 groups, with 1 group receiving 10 sessions of LLLT (GaAlAs, 78.5 J/cm, 100mW, 0.028 cm beam). The LLLT was started immediately after surgery and once every 3 days during postoperative period. At the end of treatment period, new bone formation and osteoblast density were determined using histomorphometry. Empty (control), graft-filled, LLLT-treated and both graft-filled and LLLT-treated bone defects were compared. New bone formation was higher in the graft treatment samples compared with the control (P = 0.009) and laser samples (P = 0.029). In addition, graft-laser combination treatment samples revealed higher bone formation than control (P = 0.008) and laser (P = 0.026) samples. Osteoblast density was significantly higher in the laser treatment (P <0.001), graft treatment (P = 0.001) and graft-laser combination treatment (P <0.001) samples than control samples. In addition, significantly higher osteoblast density was observed in the graft-laser combination treatment samples compared to the graft treatment samples (P = 0.005). The LLLT was effective to stimulate osteoblastogenesis but failed to increase bone formation. Graft augmentation for treatment of bone defects seems essential for proper bone healing in diabetes, regeneration may be supported by the LLLT to enhance osteoblastogenesis.

Two-stage treatment of TMJ ankylosis by early surgical approach and distraction osteogenesis.

Temporomandibular joint (TMJ) ankylosis is characterized by the formation of bone or fibrous adhesion of the anatomic joint components, which replaces the normal articulation and limitation of mouth opening. Early surgical intervention is considered as a treatment procedure to release the joint ankylosis and to maintain the function of the joint. Longstanding temporomandibular joint ankylosis which starts during the active growth period in early childhood resulting in facial asymmetry. Thus, the importance of the evaluation for the facial asymmetries and unfavorable remodeling of the mandible has to be considered during the initial treatment planning. Further operations, either osteotomies or distraction osteogenesis, are required for the treatment of maxillofacial deformities. The present study reports a case of unilateral TMJ ankylosis treated by interpositional arthroplasty prior to distraction osteogenesis for the treatment of mandibular secondary deformity. Various treatment procedures and timing protocols are reviewed and discussed.

Surgically assisted rapid maxillary expansion compared with orthopedic rapid maxillary expansion.

The objective of this study is to evaluate and compare the dental and skeletal changes occurring during orthopedic rapid maxillary expansion (RME) and surgically assisted RME during the active phase of treatment. The study was divided into two groups. The first group of 10 patients (six males, four females; mean age, 15.51 years) received orthopedic RME. The second group of 10 patients (seven males, three females; average age: 19.01 years) received surgically assisted RME (SARME). All patients underwent maxillary expansion with occlusal-coverage Hyrax-type expanders activated two turns a day (0.25 mm per turn). Preexpansion and postexpansion lateral and posteroanterior cephalograms were obtained for each patient. Statistically significant differences between the SARME and RME groups were found in the N-ANS, SN/ PP (P < .01) and SNA, SNB, mandibular dentoalveolar, and maxillary bony base (P < .05) measurements. Clinically, there is no difference in patient response between the RME and SARME groups. The only difference between the groups was their indication for RME or SARME, which is based on the age and skeletal maturation of the patient.