Evaluation of photobiomodulation therapy to accelerate bone formation in the mid palatal suture after rapid palatal expansion: a randomized clinical trial.

To evaluate the efficiency of photobiomodulation therapy (PBMT) in the midpalatal suture (MPS) and pain sensation in patients undergoing rapid palatal expansion (RPE). Thirty-four individuals with the diagnosis of skeletal maxillary hypoplasia were divided in two groups: laser (n = 18) and control (n = 16). Treatment plan consisted of the use of the Hyrax expander in all patients. Subjects in the laser group were irradiated with diode laser (980 nm, 0.3 W) in six spots bilaterally distributed along the MPS for 10 s during the active phase of treatment and after overcorrection (passive phase of RPE). Control group received sham irradiations with the laser in standby mode to characterize the placebo effect. Digital occlusal radiographs were performed at different time-points for bone formation evaluation in both groups. The effects of laser irradiation on pain were assessed by the visual analog scale (Wong-Baker Faces Pain Scale). Bone formation between groups was not significantly different (p = 0.2273). At 3 months, bone formation was not yet complete in both groups. Pain sensation was similar between groups (p = 0.3940). However, pain was significantly higher for the first 7 days of treatment compared with the 14th day. PBMT did not accelerate bone regeneration in the MPS and pain sensation was similar.

Comparative study on the incision healing of the palatal mucosa by using Er:YAG laser or traditional scalpel in the SD rats.

The aim of this study was to compare the histology of wound healing following incisions with the scalpel or the Er:YAG laser in the palatal mucosa of SD rats. Two types of wounds were performed with the stainless steel scalpel or the Er:YAG laser in the palatal mucosa of SD rats, while the adjacent untreated palatal mucosa was chosen as control. Rats were sacrificed on day 1, day 3, day 7, and day 30 post-surgery. Biopsy samples from each wound were examined and the expression of IL-1ß and TGF-ß1 was determined by enzyme-linked immunosorbent assay (ELISA). The early postoperative incision of the scalpel group had obvious bleeding and swelling, while the laser wound mainly covered the surface of white pseudomembrane. The infiltration of neutrophils and lymphocytes in the stroma of the scalpel incision was more than that of the laser group. Compared to the laser group, 1 and 3 days after operation, the TGF-ß1 content of the scalpel group were significantly increased (P = 0.032 and 0.019). Seven days after operation, the TGF-ß1 content of two groups was decreased. TGF-ß1 expression of control group was obviously increased (P > 0.05); 1, 3, and 7 days after operation, the traditional scalpel amount of IL-1ß expression was significantly higher than that of control group (P = 0.000, 0.000, and 0.001). Postoperative day 1, IL-1ß expression of laser group and control group had no significant difference (P = 0.572). Three days after operation, IL-1ß expression of laser incision was increased and was significantly higher than that in control group (P = 0.032), however lower than the scalpel group (P = 0.03). Seven days after operation, the IL-1ß expression of two groups had no significant difference (P = 0.333); however, the IL-1ß expression of two groups were significantly higher than that of the control group (P = 0.02 and 0.001). Compared to the traditional scalpel, the incision of Er:YAG laser has smaller inflammation reaction, more pseudomembrane coverage, and minimal damage of the mucoperiosteal tissue.

Preliminary evaluation of near-infrared vein visualization technology in the screening of palatal blood vessels

Background: Avoidance from palatal blood vessel rupture is a major concern during the palatal soft tissue graft surgery. There is no defined chair-side and case-specific palatal blood vessel detection approach to facilitate the harvesting process. The objective of this pilot study is to assess the feasibility of a near-infrared vein visualization system in the screening process of palatal blood vessels. Material and Methods: An extraoral vein visualization device (AccuVein AV400) was applied to a total of 304 hemi-maxilla of 152 individuals by two blind examiners. The study groups were classified according to their maximum inter-incisal measurements. The distances between the coronal border of the vessel image and the mid-palatal gingival margins of the adjacent teeth were measured and in each group. The correlations among the measurements were evaluated within groups. Results: The blood vessel to the adjacent teeth measurements exhibited no statistical difference between both examiners in all subjects (p<0.001). Correlations between the examiners gradually increased in all groups as the mouth opening rates of the subjects were increased (p<0.001). Conclusions: In the current state, screening of the palatal blood vessels via near-infrared vein visualization technology seems to be not suitable for every individual due to the restrictive effect of mouth opening. However, the promising results of this preliminary study demonstrated increasing consistency between the measurements of the examiners as the inter-incisal distance increase which emphasized the need an intraoral version of the device. Considering the lack of local decision-making technology for the detection of palatal blood vessels, further studies are required for development and optimization of these systems (AU)

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Laser and LED phototherapy on midpalatal suture after rapid maxilla expansion: Raman and histological analysis.

The aim of this study was to analyze the effect of laser or LED phototherapy on the acceleration of bone formation at the midpalatal suture after rapid maxilla expansion. Forty-five rats were divided into groups at 7 days (control, expansion, expansion and laser irradiation, and expansion and LED irradiation) and into 14 days (expansion, expansion and laser in the 1st week, expansion and LED in the 1st week, expansion and laser in the 1st and 2nd weeks, expansion and LED in the 1st and 2nd weeks). Laser/LED irradiation occurred every 48 h. Expansion was accomplished with a spatula and maintained with a triple helicoid of 0.020-in stainless steel orthodontic wire. A diode laser (λ780 nm, 70 mW, spot of 0.04 cm2, t = 257 s, SAEF of 18 J/cm2) or a LED (λ850 ± 10 nm, 150 ± 10 mW, spot of 0.5 cm2, t = 120 s, SAEF of 18 J/cm2) was applied in one point in the midpalatal suture immediately behind the upper incisors. Raman spectroscopy and histological analyses of the suture region were carried and data was submitted to statistical analyses (p ≤ 0.05). Raman spectrum analysis demonstrated that irradiation increases hydroxyapatite in the midpalatal suture after expansion. In the histological analysis of various inflammation, there was a higher production of collagen and osteoblastic activity and less osteoclastic activity. The results showed that LED irradiation associated to rapid maxillary expansion improves bone repair and could be an alternative to the use of laser in accelerating bone formation in the midpalatal suture.

Effect of low-level laser therapy after rapid maxillary expansion: a clinical investigation.

To evaluate the effectiveness low-level laser therapy (LLLT) on the repair of the mid palatal suture, after rapid maxillary expansion (RME). A single-operator, randomized single-blind placebo-controlled study was performed at the Orthodontic Department at the Dental Hospital of Bellvitge. Barcelona University, Hospitalet de Llobregat, Spain. Thirty-nine children (range 6-12 years old), completed RME and were randomized to receive active LLLT (n = 20) or placebo (n = 19). The laser parameters and dose were 660 nm, 100 mW, CW, InGaAlP laser, illuminated area 0.26 cm(2), 332 mW/cm(2), 60 s to four points along midpalatal suture, and 30 s to a point each side of the suture. A total of seven applications were made on days 1, 7, 14, 28, 42, 56, and 70 of the retention phase RME. A cone beam computed tomography (CBCT) scan was carried out on the day of the first laser treatment, and at day 75, a second CBCT scan was performed. Two radiologists synchronized the slices of two scans to be assessed. P = 0.05 was considered to be statistically significant. At day 75 of the suture, the irradiated patients presented a greater percentage of approximate zones in the anterior (p = 0.008) and posterior (p = 0.001) superior suture-and less approximation in the posterior superior suture (p = 0.040)-than the placebo group. LLLT appears to stimulate the repair process during retention phase after RME.

Effects of low-level laser therapy on bone regeneration of the midpalatal suture after rapid maxillary expansion.

This study evaluated the effect of low-level laser therapy (LLLT) on bone regeneration at the midpalatal suture (MPS) after rapid maxillary expansion (RME), using cone beam computed tomography. Fourteen 8-14-year-old patients with transverse maxillary deficiency underwent RME with a Hyrax-type expander activated with one full turn after installation and two half turn daily activations until achieving overcorrection. Patients were randomly assigned to either a control group (RME alone, n = 4) or an experimental group (n = 10) in which RME was followed by 12 LLLT sessions (GaAlAs, p = 70 mW, λ = 780 nm, Ø = 0.04 cm(2)). Two tomographic images of the MPS were obtained-T0, after disjunction and T1, after 4 months. Bone regeneration was evaluated by measuring the optical density (OD) on the tomographic images using InVivo Dental 5.0 software. Data were analyzed by the paired Student's t test (α = 0.05 %). A statistically significant difference between T0 and T1 OD values was observed in the laser-treated group (p = 0.00), but this difference was not significant in the control group (p = 0.20). Intergroup comparison of OD values at T1 revealed higher OD in the laser-treated group (p = 0.05). In conclusion, LLLT had a positive influence on bone regeneration of the midpalatal suture by accelerating the repair process.

Effect of GaAIAs low-level laser therapy on the healing of human palate mucosa after connective tissue graft harvesting: randomized clinical trial.

Among the available techniques to treat gingival recession, connective tissue graft (CTG) presents more foreseeability and better results in the long term. However, this technique causes morbidity and discomfort in the palatine region due to graft removal at that site. The aim of this clinical trial was to evaluate the influence of low-level laser therapy (LLLT) on the healing of the donor palatine area after CTG. Thirty-two patients presenting buccal gingival recession were selected and randomly assigned to receive LLLT irradiation (test group) or LLLT sham (control group) in the palatine area after connective graft removal. A diode laser (AsGaAl, 660 nm) was applied to test the sites immediately after surgery and every other day for 7 days. The evaluated parameters were wound remaining area (WRA), scar and tissue colorimetry (TC), tissue thickness (TT), and postoperative discomfort (D). These parameters were evaluated at baseline and 7, 14, 45, 60, and 90 days after surgery. Two-way repeated measures ANOVA was used for analysis. The test group presented statistically significant smaller wounds at days 14 and 45. None of the patients presented a scar at the operated area, and colorimetry analysis revealed that there was no statistically significant difference between groups (p > 0.05). Patients reported mild to moderate discomfort, with low consumption of analgesic pills. We concluded that LLLT irradiation can accelerate wound healing on palatine mucosa after connective tissue removal for root coverage techniques (ClinicalTrial.org NCT02239042).

The effects of low-level laser therapy on palatal mucoperiosteal wound healing and oxidative stress status in experimental diabetic rats.

OBJECTIVE: The biostimulation effects of low-level laser therapy (LLLT) have recently been demonstrated. In this study, we aimed to investigate the effects of LLLT on palatal mucoperiostal wound healing and oxidative stress status in experimental diabetic rats. MATERIALS AND METHODS: Forty-two male Wistar rats that weighed 250-300 g were used in this study. Experimental diabetes was induced in all of the rats using streptozotocin. A standardized full thickness wound was made in the mucoperiosteum of the hard palates of the rats using a 3 mm biopsy punch. The rats were divided into groups: 1 (control group, non- irradiated), and 2 (experimental group, irradiated). Treatment using a GaAlAs laser at a wavelength of 940 nm and at dose of 10 J/cm(2) began after surgery, and was repeated on the 2nd, 4th, and 6th days post-surgery. Seven animals from each group were killed on the 7th, 14th, and 21st day after surgery. Biopsies were performed for the histological analysis and blood samples were collected by cardiac puncture for biochemical analysis. RESULTS: The histopathological findings revealed reduced numbers of inflammatory cells, and increased mitotic activity of fibroblasts, collagen synthesis, and vascularization in rats in group 2. The total oxidative status was significantly decreased in the laser-treated group on the 21st day. CONCLUSIONS: LLLT elicits a positive healing effect on palatal mucoperiostal wounds, and modulates the oxidative status in experimental diabetic rats.

Risks of radiation versus risks from injury: a clinical decision analysis for the management of penetrating palatal trauma in children.

OBJECTIVES/HYPOTHESIS: Penetrating palatal trauma in children presents a diagnostic dilemma regarding the small but severe risk of injury to carotid vessels. Decisions regarding which children require computed tomography with angiography must be balanced against the risk of radiation-induced malignancy. Our objectives were to compare outcomes between children with and without computed tomography with angiography in the evaluation of palatal trauma and to identify thresholds where the ideal strategy changes in the management of children with palatal trauma through sensitivity analyses. STUDY DESIGN: Decision analytic techniques were used to compare management strategies for penetrating palatal trauma. METHODS: We assigned utilities to the following outcomes: 1) perfect health, 2) future malignancy, 3) carotid injury diagnosed by computed tomography with angiography, and 4) delayed diagnosis of stroke. We calculated outcomes when the risk of stroke ranged from 0.01% to 5.0% for a hypothetical cohort of 10,000 injured children. RESULTS: Not obtaining computed tomography with angiography is the optimal strategy when the stroke risk is less than 4.5%. In two-way sensitivity analyses that consider a range of probabilities of radiation-induced malignancy and stroke, not obtaining computed tomography with angiography on all patients dominates as a strategy until the risk of stroke exceeds 2.3%, and the risk of malignancy is under 0.24%. Routine imaging would introduce 20 additional malignancies for each additional stroke diagnosed. CONCLUSIONS: Routine use of computed tomography with angiography for well-appearing children with palatal trauma should be reconsidered, as the risk of radiation-induced malignancy may outweigh the benefit of identifying the rare carotid injury. LEVEL OF EVIDENCE: 2b.

Denture stomatitis treated with photodynamic therapy: five cases.

OBJECTIVE: Photodynamic therapy (PDT) is an effective method for Candida spp. inactivation in vitro and in vivo, but as yet, no clinical trial has been conducted. This report describes 5 cases of denture stomatitis (DS) treated with PDT. STUDY DESIGN: Five subjects with clinical and microbiologic diagnosis of DS were submitted to 6 sessions of PDT 3 times a week for 15 days. In each session, patients' dentures and palates were sprayed with 500 mg/L Photogem, and, after 30 minutes of incubation, irradiated by light-emitting diode light source at 455 nm (37.5 and 122 J/cm(2), respectively). Cultures of Candida spp. from dentures and palates and standard photographs of the palates were taken at baseline (day 0), at the end of the treatment (day 15), and at follow-up time intervals (days 30 and 60). RESULTS: Four patients showed clinical resolution of DS (no inflammation) after PDT sessions, and only 1 subject demonstrated reduction in palatal inflammation. Recurrence of DS was observed in 2 patients during the follow-up period. CONCLUSIONS: PDT appears to be an alternative treatment for DS.

Infrared laser therapy after surgically assisted rapid palatal expansion to diminish pain and accelerate bone healing.

The aim of this study was to illustrate how gallium arsenite aluminum diode laser (824 nm) irradiation can reduce postsurgical edema and discomfort and accelerate sutural osseous regeneration after surgically assisted rapid palatal expansion (SARPE). An adult patient with an 8-mm transverse maxillary discrepancy was treated with SARPE. Infrared laser therapy was started on the 7th postoperative day, with a total of eight sessions at intervals of 48 hours. The laser probe spot had a size of 0.2827 cm2 and was positioned in contact with the following (bilateral) points: infraorbital foramen, nasal alar, nasopalatine foramen, median palatal suture at the height of the molars, and transverse palatine suture distal to the second molars. The laser was run in continuous mode with a power of 100 mW and a fluency of 1.5 J/cm2 for 20 seconds at each point. Subsequently, an absence of edema and pain was observed. Further, fast bone regeneration in the median palatal suture could be demonstrated by occlusal radiographs. These findings suggest that laser therapy can accelerate bone regeneration of the median palatal suture in patients who have undergone SARPE.

Oral Hodgkin lymphoma: a wolf in wolf's clothing.

Hodgkin lymphoma typically presents as a nodal lesion and infrequently involves extranodal sites. The English language literature contains only 7 reports of primary Hodgkin lymphoma arising in the oral mucosa in the absence of nodal disease. We report a case of primary, extranodal Hodgkin lymphoma in the palatal mucosa of a 79-year-old white female. An incisional biopsy revealed a diffuse, mixed cellular infiltrate, consisting of benign lymphocytes, plasma cells, histiocytes, and foci rich in eosinophils. Within this background was a scattering of large, atypical cells, including Reed-Sternberg forms that exhibited immunoreactivity for CD30 and CD20 and nonreactivity for CD15 and CD45RO, supporting a diagnosis of classical Hodgkin lymphoma. Positron emission tomography exhibited a single focal area of abnormal hypermetabolic activity involving the left palate area, without involvement of any other site. The clinical stage was Ann Arbor I-A. The primary tumor and submandibular and upper neck lymph nodes were treated with a 6-MV photon beam to a total dose of 4000 cGy. There was no evidence of disease at 15-month follow-up.

[Diagnosis, treatment and prognostic factors of adenoid cystic carcinoma of the palate].

OBJECTIVE: To explore the clinical characteristics, diagnosis, treatment and prognosis of adenoid cystic carcinoma of the palate. METHODS: A retrospective review was conducted in 42 patients with adenoid cystic carcinoma of the palate treated in our hospital from 1967 to 1998. Statistical analysis was performed using the Kaplan-Meier method. Prognostic factors were analyzed by Log Rank test. RESULTS: The overall 5-, 10-, 15-year accumulative survival rates were 85.0%, 61.8% and 28.1%, and the 5-, 10-, 15-year accumulative disease-free survival rates were 52.4%, 32.7% and 22.4%, respectively. The 5-, 10-, 15-year accumulative local recurrence rates were 25.2%, 50.9% and 73.1%, and the 5-, 10-, 15-year accumulative distant metastasis rates were 28.5%, 50.4% and 66.0% respectively. T stage, bone invasion, extent of tumor, local recurrence and distant metastasis were significant prognostic factors. Treatment method, dose and area covered by radiotherapy were related to the prognosis. CONCLUSION: Surgery alone can be done for early lesions, and combination of surgery with radiotherapy should be adopted for advanced lesions in adenoid cystic carcinoma of the palate. Radiotherapic salvage could prolong the survival of the locally recurrent patients.

Intraoral melanoma: long-term follow-up and implication for dental clinicians. A case report and literature review.

Primary intraoral melanoma is a rare neoplasm with a poor prognosis, accounting for 1% to 8% of all melanoma in Europe and the United States. The incidence (12%) and 5-year survival rate (17.4%) are higher in Japan. We report a case of oral lentiginous melanoma in a Japanese-American man who survived disease-free for more than 5 years after surgery, radiation therapy, and chemotherapy but developed chronic mucositis of the palate under the denture in the primary radiated field. This lesion responded to antifungal therapy. Subsequent multiple biopsies ruled out the recurrence of melanoma but demonstrated prolonged melanocytic hyperplasia and focal epithelial atypia. We reviewed clinical differences in oral melanoma reported in the United States and Japanese literature, and describe the wide variety of oral clinical features of postoperative radiation and chemotherapy, as well as the oral tissue changes caused by denture-induced mucositis and candidiasis in such patients. Dental clinicians should conduct a thorough head, neck, and oral follow-up with increased vigilance in patients with a history of prior cancer.

Radiation-induced craniofacial bone growth inhibition: development of an animal model.

Craniofacial deformities caused by therapeutic radiation-induced bone growth inhibition can occur in up to 100% of survivors of childhood head and neck cancers. The mechanism of radiation-induced craniofacial bone growth inhibition is poorly understood. The objective of this study is to establish a model of radiation-induced craniofacial bone growth inhibition to study the pathophysiology of radiation on growing membranous bone. Seven-week-old male New Zealand white rabbits were randomized into 4 groups (n = 10/group) and received a single dose of orthovoltage radiation (0, 15, 25, or 35 Gy) to the right orbital-zygomatic complex. Serial radiographs and computed tomography scans were performed for cephalometric analysis, bone volume, and bone density measurements until skeletal maturity at 21 weeks. Statistically significant ( P < 0.05) reductions in orbital-zygomatic complex linear bone growth, bone volume, and bone density were found after radiation with 25 or 35 Gy compared with nonirradiated control animals. A significant ( P < 0.05) decrease in orbital-zygomatic complex volume was noted after 15-Gy radiation but there were no significant effects on linear bone growth as assessed by cephalometric analysis at this dose. This study establishes the rabbit orbital-zygomatic complex as a suitable model for the study of radiation-induced craniofacial bone growth inhibition and will permit investigation into the underlying cellular and molecular basis of this injury.

Closure of an oronasal fistula in an irradiated palate by tissue and bone distraction osteogenesis.

Uses for distraction osteogenesis in the craniofacial skeleton have expanded during the last decade. It has become an important rung in the reconstructive ladder for correction of difficult defects. Distraction of irradiated bone has been successfully performed in an animal model but has not been reported in human subjects. We present a case of distraction osteogenesis in a patient with multiple failed reconstructive attempts to close an irradiated palatal defect. An additional benefit included improvement in support of the upper lip from bone transported and the potential for placing dental implants.

Effect of X irradiation on secondary palate development in mice.

The mechanisms whereby X irradiation induces palatal clefting were investigated in vivo and in an in vitro organ culture system. When pregnant mice at day 12.5 of gestation were exposed to a 4-Gy dose of whole-body X radiation, the incidence of palatal clefting in their offspring was 91%. The volume of the irradiated palatal shelves was too low for them to make contact with each other. On gestational day 13.5 after labeling, bromodeoxyuridine-positive cells were sparse and apoptotic cells were abundant in the irradiated shelves. To prevent secondary effects of irradiation from the injured maternal body, fetal palatal explants were immediately transferred to an organ culture system after X irradiation in utero. The incidence of palatal clefting was 24%, much lower than the incidence in vivo. The addition of 10(-4) M of dexamethasone to the culture medium increased the incidence of palatal clefting to 56%. These findings indicated that X irradiation inhibited cell proliferation and induced apoptosis, resulting in small-volume palatal shelves that could not fuse with each other. The organ culture data also indicated that 4 Gy of irradiation appears to produce its effects both by a direct action on the fetus and indirectly by affecting the metabolism of the pregnant dam.

[Adenoid cystic carcinoma. Presentation of three clinical cases]. / Carcinoma adenoide quístico. Presentación de tres casos clínicos.

Adenoid cystic carcinomas are malignant epithelial tumors that originate in body regions containing exocrine and eccrine glands. Their most common location is the salivary glands. These tumors have specific, highly individualized histopathological and clinical features. Three cases of adenoid cystic carcinoma in different sites, palate, sublingual gland, and nasal cavity, are reported. The literature is reviewed for information about the fundamental clinical, diagnostic, and therapeutic aspects of these tumors.

Stimulatory effects of low-power laser irradiation on bone regeneration in midpalatal suture during expansion in the rat.

The purpose of this study was to investigate the effects of low-power laser irradiation on bone regeneration during expansion of a midpalatal suture in rats. Gallium-aluminum-arsenide diode laser 100 mW irradiation was applied to the midpalatal suture during expansion carried out over 7 days (3 or 10 minutes per day), 3 days (7 minutes per day for day 0-2 or 4-6), and 1 day (21 uninterrupted minutes on day 0). The bone regeneration in the midpalatal suture estimated by histomorphometric method in the 7-day irradiation group showed significant acceleration at 1.2- to 1.4-fold compared with that in the nonirradiated rats, and this increased rate was irradiation dose-dependent. Irradiation during the early period of expansion (days 0 to 2) was most effective, whereas neither the later period (days 4 to 6) nor the one-time irradiation had any effect on bone regeneration. These findings suggest that low-power laser irradiation can accelerate bone regeneration in a midpalatal suture during rapid palatal expansion and that this effect is dependent not only on the total laser irradiation dosage but also on the timing and frequency of irradiation. We suggest laser therapy may be of therapeutic benefit in inhibiting relapse and shortening the retention period through acceleration of bone regeneration in the midpalatal suture.