Three-Dimensional Finite Element Analysis of Stress Distribution and Displacement of the Maxilla Following Surgically Assisted Rapid Maxillary Expansion with Tooth- and Bone-Borne Devices.

OBJECTIVES: The aim of this study was to investigate the displacement and stress distribution during surgically assisted rapid maxillary expansion under different surgical conditions with tooth- and bone-borne devices. MATERIALS AND METHODS: Three-dimensional (3D) finite element model of a maxilla was constructed and an expansion force of 100 N was applied to the left and right molars and premolars with tooth-borne devices and the left and right of mid-palatal sutures at the first molar level with bone-borne devices. Five computer-aided design (CAD) models were simulated as follows and surgical procedures were used: G1: control group (without surgery); G2: Le Fort I osteotomy; G3: Le Fort I osteotomy and para-median osteotomy; G4: Le Fort I osteotomy and pterygomaxillary separation; and G5: Le Fort I osteotomy, para-median osteotomy, and pterygomaxillary separation. RESULTS: Maxillary displacement showed a gradual increase from G1 to G5 in all three planes of space, indicating that Le Fort I osteotomy combined with para-median osteotomy and pterygomaxillary separation produced the greatest displacement of the maxilla with both bone- and tooth-borne devices. Surgical relief and bone-borne devices resulted in significantly reduced stress on anchored teeth. CONCLUSION: Combination of Le Fort I and para-median osteotomy with pterygomaxillary separation seems to be an effective procedure for increasing maxillary expansion, and excessive stress side effects are lowered around the anchored teeth with the use of bone-borne devices.

Comparing Viability of Periodontal Ligament Stem Cells Isolated From Erupted and Impacted Tooth Root.

PURPOSE: The aim of the study was to compare the viability of periodontal ligament-derived stem/progenitor cells (PDLSCs) from 2 different sources. MATERIALS AND METHODS: Periodontal ligament (PDL) tissue was obtained from 20 surgically extracted human third molars and 20 healthy premolars extracted for orthodontic reasons. Periodontal ligament-derived stem/progenitor cells were isolated from 2 different PDL tissue sources and characterized by colony forming unit assay, cell surface marker characterizations, and their osteogenic differentiation potential. To determine cell viability within 2 groups, the colorimetric 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) metabolic activity assay was used. Data were statistically analyzed using independent t-test by SPSS 16 software (SPSS Inc, Chicago, IL). RESULTS: According to the MTT assay, the mean viability rate ± standard deviation of PDLSCs in the impacted third molar sample cells was 0.355 ± 0.411 and for erupted premolar sample cells was 0.331 ± 0.556. Based on One-Sample Kolmogorov-Smirnov test, P value for impacted and erupted teeth was 0.954 and 0.863, respectively. No statistical difference was seen between 2 groups. (P value > 0.05) CONCLUSIONS: Our results demonstrated that if surgical aseptic technique is a method employed to maintain asepsis, PDLSCs obtained from impacted and erupted tooth root would have the same viability rate.

Full mouth implant rehabilitation of a patient with ectodermal dysplasia after orthognathic surgery, sinus and ridge augmentation: a clinical report.

An 18-year-old male presented severe hypodontia due to hypohidrotic ectodermal dysplasia was treated with Le Fort I maxillary osteotomy with simultaneous sinus floor augmentation using the mixture of cortical autogenous bone graft harvested from iliac crest and organic Bio-Oss to position the maxilla in a right occlusal plane with respect to the mandible, and to construct adequate bone volume at posterior maxilla allowing proper implant placement. Due to the poor bone quality at other sites, ridge augmentation with onlay graft was done to construct adequate bone volume allowing proper implant placement, using tissue harvested from the iliac bone. Seven implants were placed in the maxilla and 7 implants were inserted in the mandible and screw-retained metal ceramic FPDs were fabricated. The two year follow up data showed that dental implants should be considered as a good treatment modality for patients with ectodermal dysplasia.

Trigeminocardiac reflex, bilateral sagittal split ramus osteotomy, Gow-Gates block: a randomized controlled clinical trial.

PURPOSE: The behavior of trigeminocardiac reflex (TCR) during maxillofacial surgeries has not yet been sufficiently studied and knowledge of its behavior is limited to some case reports. The present study aimed to assess the occurrence of TCR in bilateral sagittal split ramus osteotomy and to determine the possible effect of Gow-Gates block on its incidence. MATERIALS AND METHODS: Twenty candidates for bilateral sagittal split ramus osteotomy (included were American Society of Anesthesiologists I Class III patients with a prognathism of 3 to 5 mm) were given routine general anesthesia after at least 12 hours of fasting. All patients received Gow-Gates mandibular nerve block on 1 random side (case ramus; the other side was used as the control) after induction of general anesthesia before surgery. Pulse rate was recorded at baseline, soft tissue cutting, bone cutting, sagittal splitting, setback manipulation, and recovery. Mean pulse rate values were compared statistically using t test for the 2 sides in patients. RESULTS: No statistically significant differences were found between the blocked and control sides except during ramus sagittal splitting and setback manipulation (P < .0001), when a significantly decreased pulse rate was recorded for the control ramus compared with the blocked ramus. CONCLUSIONS: The present study provides further evidence for the complex neurophysiologic mechanism and probable prevention of peripheral TCR. The results of the present study should be further validated through future studies but already provide strong evidence that peripheral and central TCR may act differently based on slightly different pathways.

Bilateral temporomandibular joint pain as the first and only symptom of ischemic cardiac disease: a case report.

Pain of ischemic and non-ischemic cardiac disease can be referred to the craniofacial region. Also, in 6% of patients, craniofacial pain can be the first and only and symptom of cardiac ischemia. Missed diagnoses of these cases may lead to unnecessary dental treatment and a significant number of deaths in patients with atypical symptoms of coronary disease. Therefore the aim of this report, was to present a 48-year-old man with a chief compliant of severe bilateral pain in the temporomandibular joint who was referred to us for evaluation of a suspected temporomandibular disorder. Clinical and radiological examinations we did not find any origin for his pain. The patient was referred for cardiological evaluation (exercise test, electrocardiography, laboratory tests and coronary angiography) and was diagnosed with angina pectoris. The patient had no previous history of heart disease or chest pain. In conclusion, awareness of this symptomatology can be useful for diagnosis of coronary insufficiency and timely treatment. Therefore, cardiac disease should be considered in the differential diagnosis of orofacial pain.