Systemic Effects of Photobiomodulation on the Morphology of the Thyroid and Sublingual Glands: A Study in Rabbits.

Objective: To investigate whether photobiomodulation (PBM) applied in a clinical situation with the purpose of improving the healing process of implants placed in the rabbit mandible would cause any morphological change in the thyroid and sublingual glands as a systemic effect of laser irradiation. Methods: Thirty-two New Zealand rabbits were randomly divided into four groups of eight animals each, one control group (CI, nonirradiated animals) and three experimental groups (EI, EII, and EIII) that received PBM postoperatively with an aluminum/gallium/arsenide laser diode (Theralase®) at a wavelength of 830 nm (infrared) and 50 mW output power applied to two irradiation fields per session, for a total of seven sessions. All rabbits underwent surgical extraction of the mandibular left incisor, followed by immediate placement of an osseointegrated implant in the fresh socket. The experimental groups EI, EII, and EIII received PBM at an energy density of 5, 2.5, and 10 J/cm2, respectively, per irradiation field. Results: There was no histomorphometric change in any of the groups. Conclusions: PBM, based on the irradiation protocol used in this study, does not cause morphological changes in the thyroid and sublingual glands when used to stimulate peri-implant bone healing in the rabbit mandible.

Effect of three different protocols of low-level laser therapy on thyroid hormone production after dental implant placement in an experimental rabbit model.

OBJECTIVE: The purpose of this study was to assess the systemic effects of low-level laser therapy (LLLT) on thyroid gland function and, consequently, calcium regulation - as measured by serum triiodothyronine (T3), thyroxine (T4), and free calcium levels - when administered after dental implant placement in a rabbit model. BACKGROUND DATA: Protocols for the use of laser therapy in several clinical procedures are currently under investigation, as not all of the actions and systemic effects of laser irradiation have been clearly established. MATERIALS AND METHODS: Forty male adult New Zealand rabbits were distributed across five groups of eight animals each: two control groups (C-I and C-II) of unirradiated animals, and three experimental groups (E-5, E-10, and E-20), each exposed to a distinct dose of gallium-aluminum-arsenide (GaAlAs) laser [λ=830 nm, 50 mW, continuous wave (CW)] every 48 h for a total of seven sessions. The total dose per session was 5 J/cm(2) in E-5, 10 J/cm(2) in E-10, and 20 J/cm(2) in E-20. Animals in C-II and all experimental groups underwent surgical extraction of the mandibular left incisor followed by immediate placement of an osseointegrated implant (Nanotite(®), Biomet 3i(™)) into the socket. Animals in group C-I served as an absolute control for T3, T4, and calcium measurements. The level of significance was set at 5% (p≤0.05). RESULTS: ANOVA with Tukey's post-hoc test revealed significant differences in T3 and calcium levels among experimental groups, as well as significant within-group differences in T3, T4, and calcium levels over time. CONCLUSIONS: Although not reaching abnormal values, LLLT applied to the mandible influenced thyroid function in this model.

Effects of low-level laser therapy on distraction osteogenesis: a histological analysis / Efeito do laser de baixa intensidade na distração osteogênica: análise histológica

Objective: The aim of this study was to assess the effect of low-level laser therapy on tissue repair in the rabbit mandible after osteotomy and distraction osteogenesis, through histological analysis of the area of bone neo formation and measurement of the amount of neoformed bone. Methods: Twenty-four male New Zealand white rabbits were randomly allocated into one of two groups: experiment (laser applied directly over the site of fracture and distraction osteogenesis) or control (non-irradiated animals). Distraction osteogenesis was performed according to the following protocol: 3 days of latency, 7 days of activation (0.8 mm/day), and 10 days of consolidation. In the experiment group, irradiation was performed with an infrared laser (AlGaAs; wave-length 830 nm, CW, time 101 seconds, 40mW), at a dose of 10 J/cm2 per session, every 48 hours during the activation period. Twenty days after surgery, all rabbits were sacrificed. Results: The amount of neoformed bone was significantly higher in the laser-treated group (62.68%) than in the control group (43.09%) (p < 0.001). Conclusion: The application of low-level laser therapy following the irradiation protocol used in this study had a positive effect on the tissue repair process in a rabbit model of mandibular fracture and distraction osteogenesis, as shown by histological analysis.

Analysis of the morphology and composition of tooth apices apicectomizedusing three different ablation techniques

Objectives: To investigate apicectomies performed using burs, a CO2 laser or an Er:YAG laser and to evaluate thefollowing aspects: morphology of apicectomized surfaces, presence of failures at the dentin/obturation materialinterface (marginal fit) of the apical portions of the root canals, and the proportions of chemical elements in theapicectomized surfaces.Study design: Twenty-four teeth were divided into three groups of eight and each group underwent apicectomy byone of three different ablation techniques: bur, CO2 laser or Er:YAG laser. The morphology of the apicectomizedsurfaces was then analyzed using scanning electron microscopy and their chemical composition was analyzed byenergy dispersive spectroscopy.Results: Surfaces produced with ablation by bur exhibited less surface irregularities and better marginal fit, whileablation with the CO2 laser caused intense surface carbonization and failures in obturation material fit.Conclusions: Our results suggest that, taking into consideration their clinical application, ablation of tooth apicesusing burs proved to be the best option among those tested here (AU)

Analysis of the morphology and composition of tooth apices apicectomized using three different ablation techniques.

OBJECTIVES: To investigate apicectomies performed using burs, a CO2 laser or an Er:YAG laser and to evaluate the following aspects: morphology of apicectomized surfaces, presence of failures at the dentin/obturation material interface (marginal fit) of the apical portions of the root canals, and the proportions of chemical elements in the apicectomized surfaces. STUDY DESIGN: Twenty-four teeth were divided into three groups of eight and each group underwent apicectomy by one of three different ablation techniques: bur, CO2 laser or Er:YAG laser. The morphology of the apicectomized surfaces was then analyzed using scanning electron microscopy and their chemical composition was analyzed by energy dispersive spectroscopy. RESULTS: Surfaces produced with ablation by bur exhibited less surface irregularities and better marginal fit, while ablation with the CO2 laser caused intense surface carbonization and failures in obturation material fit. CONCLUSIONS: Our results suggest that, taking into consideration their clinical application, ablation of tooth apices using burs proved to be the best option among those tested here.

Histological evaluation of the effect of low-level laser on distraction osteogenesis in rabbit mandibles

Objectives: This study evaluated the action of low level laser therapy (LLLT) on the percentage of newly formed bone in rabbit mandibles that underwent distraction osteogenesis (DO).Study design: Ten rabbits underwent bone lengthening according to the following protocol: Latency – 3 days;Activation – 7 days 0.7 mm/d; and Consolidation – 10 days. The control group was composed of 4 rabbits. The experimental group, composed of 6 rabbits, received infrared GaAlAs LLLT (ë=830 nm, P=40 mW) according to the following protocol: point dose of 10 J/cm2 applied directly on the bone site that underwent DO during boneconsolidation at 48-hour intervals. Results: The percentage of newly formed bone was greater in the LLLT group (57.89%) than in the control group (46.75%) (p=0.006). Conclusion: The results suggest that LLLT had a positive effect on the percentage of newly formed bone. Better quality bone sites may allow early removal of the osteogenic distractors, thus shortening total treatment time (AU)

Analgesic action of laser therapy (LLLT) in an animal model

No disponible

Objectives: To evaluate the analgesic effect of laser therapy on healthy tissue of mice. Study design: Forty-five animals were divided in three groups of 15: A – infrared laser irradiation (830 nm, Kondortech®, São Carlos, SP, Brazil); B – red laser irradiation (660 nm, Kondortech®, São Carlos, SP, Brazil); C – sham irradiation with laser unit off.After laser application, the mice remained immobilized for the injection of 30 μl of 2% formalin in the plantar pad of the irradiated hind paw. The time that the mouse kept the hind paw lifted was measured at 5 min intervals for 30 minutes.Results: Results showed statistically significant differences comparing the control group with the infraredlaser group at 5, 20, 25 and 30 accumulated minutes, and with the red laser group at all time points. The analysis of partial times, at each 5 minutes, showed statistically significant differences between the control and the laser groups up to 20 minutes. Conclusions: Laser therapy had an analgesic effect and red laser had the best results (AU)

Dimensional error in selective laser sintering and 3D-printing of models for craniomaxillary anatomy reconstruction.

BACKGROUND: Selective laser sintering (SLS) and three-dimensional printing (3DPtrade mark) are rapid prototyping (RP) techniques to fabricate prototypes from biomedical images. To be used in maxillofacial surgery, these models must accurately reproduce the craniofacial skeleton. PURPOSE: To analyze the capacity of SLS and 3DPtrade mark models to reproduce craniomaxillary anatomy and their dimensional error. MATERIAL: Dry skull, helical computed-tomography images, SLS and 3DPtrade mark prototypes, and electronic calliper. METHODS: Tomographic images of a dry skull were manipulated with the InVesalius biomedical software. Prototypes were fabricated using SLS and 3DPtrade mark techniques. Ten linear measurements were made on the models and compared with corresponding dry skull measurements (criterion standard) carried out with an electronic calliper. RESULTS: We observed a dimensional error of 2.10 and 2.67% for SLS and 3DPtrade mark models, respectively. The models satisfactorily reproduced anatomic details, except for thin bones, small foramina and acute bone projections. The SLS prototypes showed greater dimensional precision and reproduced craniomaxillary anatomy more accurately than the 3DPtrade mark models. CONCLUSION: Both SLS and 3DPtrade mark models provided acceptable precision and may be useful aids in most maxillofacial surgeries.

Estudo comparativo das avaliações cefalométrica do perfil dentoesquélito maxilar e perfil mole nasolabial de indivíduos de diferentes etnias / Comparative study of variations cephalometrics of the tooth skeleton maxilar profile and soft nasolabial profile of individuals of differents ethinics

Objetivo: Partindo do pressuposto que o padrão cefalométricodeve ser étnico-específico, esta pesquisa realizou um estudocomparativo entre dimensões cefalométricas lineares eangulares de pontos anatômicos relacionados com o perfildentoesquelético maxilar e perfil mole nasolabial. Método: Asamostras que compuseram o estudo foram obtidas a partir detelerradiografias, em norma lateral, e agrupadas de acordo comas etnias branca e negra, cada uma com 20 indivíduos. Asradiografias foram submetidas à análise cefalométricacomputadorizada de Ricketts, utilizando o Programa Radiocef2.0®. Os valores alcançados tiveram tratamento estatístico,utilizando o teste paramétrico Anova, considerando p=0,05.Resultados: As dimensões cefalométricas que expressamdistância do ponto A ao ponto subnasal, comprimento do lábiosuperior, inclinação dos dentes incisivos superiores e o ângulonasolabial são as mais representativas das diferenças entre asetnias estudadas. Conclusão: Existem diferençasestatisticamente significativas entre as dimensõescefalométricas lineares e angulares entre os indivíduosleucodermos e melanodermos, indicando que a estrutura facialdo negro é maior que a dos indivíduos brancos, econseqüentemente atribui-se um perfil convexo, decorrentesdo posicionamento maxilar, dentário e labial nestes indivíduos.Este estudo reforça a hipótese de que as normascefalométricas devem ser elaboradas para cada grupo racial, individualmente.

Submandibular gland sialolith in a renal transplant recipient: a case report.

Salivary dysfunction may be due to systemic diseases and medications. The development of sialoliths is a multifactorial event in which disturbances in secretion, microliths, and bacteria may play a major role. A case of sialolith in the submandibular gland of a 58-year old woman, with a medical history of renal failure end kidney transplant, is reported.

Displasia fibrosa monostótica. Relato de un caso clínico / Monostotic fibrous dysplasia. A clinical case report

La displasia fibrosa (DF) es una patología benigna rara, generalmente asintomática, que afecta el tejido óseo. Debido al remplazo gradual del tejido óseo por tejido fibroso se producen alteraciones óseas estéticas y funcionales. En este artículo se realiza una revisión de la literatura sobre la DF y se relata un caso clínico de un hombre de 33 años de edad que presenta deformidad facial debida al crecimiento lento y progresivo del maxilar(AU)

Fibrous dysplasia (FD) is a rare bening pathology, generally asymptomatic affecting the bone tissue. Due to the gradual replacement of the bone tissue by fibrous tissue, aesthetic and functional bone alterations are produced. A review of the literature on FD is made and it is reported a clinical case of a 33-year-old man presenting facial deformity as a result of the slow and progressive growth.of the jaw(AU)

Displasia fibrosa monostótica. Relato de un caso clínico / Monostotic fibrous dysplasia. A clinical case report

La displasia fibrosa (DF) es una patología benigna rara, generalmente asintomática, que afecta el tejido óseo. Debido al remplazo gradual del tejido óseo por tejido fibroso se producen alteraciones óseas estéticas y funcionales. En este artículo se realiza una revisión de la literatura sobre la DF y se relata un caso clínico de un hombre de 33 años de edad que presenta deformidad facial debida al crecimiento lento y progresivo del maxilar(AU)