The effects of hypnosis dental pain threshold

1058 ICOMS 2011—Abstracts: Oral Papers was not compromised by immunosuppression. Conflict of interest: None declared. doi:10.1016/j.ijom.2011.07.109

109 Photoelastic analysis of two protocols for zygomatic implants L.S. Pozzer ∗ , P.H. de Moraes, S. Olate, J.R. Albergaria-Barbosa Piracicaba Dental School, University of Campinas, UNICAMP, Piracicaba, Brazil

Purpose: The objective of this study was to analyse in vitro the stress distribution in craniofacial structures around zygomatic osseointegrated implants. Materials and methods: Synthetic polyurethane skulls replicas were used as templates for installation of standard and zygomatic implants performing two techniques using rehabilitation with zygomatic implants. These models were used as templates for the manufacture of photoelastic models keeping the same arrangement of implants. Were performed using variations of 1 zygomatic implants in each one zygomatic bone in combination with 2 and 4 standard implants in the anterior maxilla (Models 1 and 2). The skulls replicas of photoelastic resin were subjected to photoelastic analysis after linear loading using an Instron 4411 servohydraulic mechanical testing unit with a 2-mm displacement. Results: The stress distribution in the photoelastic analysis, the fringes were concentrated body and frontal process zygomatic bone. In the case of the model 1, higher concentrations of stress were found around the standard and zygomatic implants and surrounding bone. Conclusions: Under the conditions tested, the rehabilitation with 2 zygomatics implants with 4 standard implants (Model2) provided the most favorable behavior. Conflict of interest: None declared. doi:10.1016/j.ijom.2011.07.110

Topic: Miscellaneous 110 Validation of visual analogue scale for anxiety (VAS-A) in dentistry E. Facco 1,2,∗ , G. Zanette 1 , C. Bacci 3 , S. Sivolella 3 , F. Cavallin 1 , G. Manani 1 1 Department of Medico Surgical Specialties, Chair of Dental Anesthesia, University of Padua, Padua, Italy 2 Italian Centre of Clinical and Experimental Hypnosis, Turin, Italy 3 Department of Medico Surgical Specialties, Section Dentistry, University of Padua, Padua, Italy

Objectives: The Visual Analogue Scale for Anxiety (VAS-A) has shown a significant correlation with Corah’s Dental Anxiety Scale (DAS), but a discordance of 28% has been found between the two tests, yielding some uncertainties about their reliability.1 The aim of this study is to check VASA and DAS effectiveness comparing them to Spielberger’s State Trait Anxiety Inventory (STAI) and Beck depression inventory (BDI). Subjects and methods: 100 patients (38 males and 62 females, age 46.3 ± 13.3) filled out the DAS, VAS-A, STAI forms Y1 and Y2, and BDI at preoperative examination; the order of administration of tests was randomized. The statistical analysis was conducted with Shapiro test for gaussianity, multiple regression analysis and X2 test. Results: A significant correlation between all tests was found was found (R2 = 0.40; F = 18.58, p < 0.001), but 20 patients showed discordant values of VAS-A and DAS (STAI Y-1 ≤ 40 in 7 and more than 40 in 13); none of the tests showed a better correlation with STAI. In 7 out of 8 cases with BDI > 16 both VAS-A and DAS were elevated. Conclusions: Our study confirms that VAS-A and DAS are reliable indicators of anxiety and may detect depressed patients also. Their comparison to STAI and BDI fails to show a superiority of any test; rather, our result confirm that the combined use of VAS-A and DAS allows to improve the detection of anxious patients in comparison to the use one test only. Conflict of interest: None declared.

Reference Facco, E., et al. (2011). Anesth Prog, 58(1), 8–13.

doi:10.1016/j.ijom.2011.07.111

111 The effects of hypnosis dental pain threshold E. Facco 1,2,∗ , E. Casiglia 2,3 , G. Zanette 1,4 , C. Bacci 5 , F. Cavallin 1 , G. Manani 1 1 Department of Medico Surgical Specialties, Chair of Dental Anesthesia, University of Padua, Padua, Italy 2 Italian Centre of Clinical and Experimental Hypnosis (CIICS), Turin, Italy 3 Department of Clinical and Experimental Medicine, University of Padua, Padua, Italy 4 Italian Centre of Clinical and Experimental Hypnosis (CIICS), Italy 5 Department of Medico Surgical Specialties, Section Dentistry, University of Padua, Padua, Italy

Introduction: The use of hypnosis has been increasingly advocated in oral surgery to obtain sedation and decrease pain perception, but no data are so far available on dental pain threshold. The aim of this study was to check at which extent hypnosis and hypnotic focused analgesia (HFA) may increase dental pain threshold in healthy volunteers. Subjects and methods: 31 healthy subjects (12 males and 19 females, age range 23–50 years) were submitted to hypnosis; HFA was obtained with suggestions of eminattention and analgesia of the right low arch (suggestion of inferior alveolar nerve block). A posthypnotic suggestion of persisting analgesia was also delivered. The pain threshold of the right and left first premolars (RFP and LFP, respectively) was bilaterally measured, using a Digitest (Parker, Farmingdale, USA). The statistical analysis was conducted with Freedman test and Wilcoxon test according to Bonferroni. Results: The basal pain threshold was 14.6 ± 7.0 mA in the RFP and 13.4 ± 6.6 in the LFP. During hypnosis it increased to 46.7 ± 19.7 (+220%; p < 0.0001) and 31.1 ± 19.9 mA (+132%; p < 0.0001) in RFP and LFP, respectively with a significant difference between the two (p < 0.001), showing the effectiveness of HFA. The posthypnotic pain threshold was 26.3 ± 17.7 (p = 0.0015) in RFP and 20.1 ± 16.2 (p = 0.054) in LFP. Conclusions: Hypnosis is a powerful non-pharmacologic analgesic tool; its effects on pain threshold are related to both relaxation and distraction, and specific effects of HFA in the target area. The analgesic effect partially persists in the post-hypnotic phase, suggesting that hypnosis might improve postoperative pain as well.

ICOMS 2011—Abstracts: Oral Papers Conflict of interest: None declared. doi:10.1016/j.ijom.2011.07.112

112 Alendronate and pamidronate induce cytotoxicity and apoptosis in cultured human gingival fibroblasts S.S. Soydan 1,∗ , K. Araz 1 , F.V. Senel 1 , E. Yutcu 2 , F. Sahin 3 , F. Helvacioglu 4 , A. Dagdeviren 4 1 Oral and Maxillofacial Surgery, Baskent University, Faculty of Dentistry, Turkey 2 Medical Biology, Baskent University, School of Medicine, Ankara, Turkey 3 Medical Genetics, Baskent University, School of Medicine, Ankara, Turkey 4 Histology and Embryology, Baskent University, School of Medicine, Ankara, Turkey

Objectives: Bisphosphonate related osteonecrosis of the jaw (BRONJ) has become one of the most obstinate and complicated pathology in oral and maxillofacial surgery. Defective or delayed epithelization of soft tissue has been observed in almost every case. Whether BRONJ starts from bone or soft tissue is still controversial. It has been hypothesized that the soft tissue of the oral mucosa could play a significant role in BRONJ. Our study was planned to investigate and compare the in vitro effects of alendronate and pamidronate on human gingival fibroblasts. Materials and methods: Primary fibroblast cultures were set up from 6 healthy volunteers’ oral mucosa biopsy under standard cell culture conditions. The cytotoxic concentrations of alendronate and pamidronate were determined by MTT assay. Alendronate and pamidronate were added to culture medium at concentrations of 10−4 to 10−7 M for at 6, 12, 24, 48 and 72 h. Characterization of the cultured cells was assessed by vimentin and pan-cytokeratin immunostaining. Cell proliferation and induction of apoptosis were evaluated and compared with indirect immunofluorescence using anti-Ki67 and anti-caspase-3 monoclonal antibodies, respectively. Results: Both pamidronate and alendronate induced apoptosis and inhibited cell proliferation in a dose and time dependent manner compared to untreated control cells. Although cell proliferation ratios were similar for both drugs, caspase3 activation in all application time and dose groups was significantly higher in pamidronate than alendronate (p < 0.05).

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Conclusion: Bisphosphonates induce apoptosis via caspase-3 pathway on human gingival fibroblasts in a dose and time dependent manner emphasizing the importance of soft tissue in BRONJ. Conflict of interest: None declared.

descriptive analysis done. Suitable surgical techniques discussed and recommended to avoid injuries to the above mentioned nerves during Oral Maxillofacial surgical procedures in routine practice. Conflict of interest: None declared.

doi:10.1016/j.ijom.2011.07.113

doi:10.1016/j.ijom.2011.07.114

113 Location of post – parotid branches of facial nerve

114 Finite element analysis of dental stress distribution after sarpe

P. Mehra Oral Maxillofacial Surgery, Lady Hardinge Medical College, New Delhi, India

E. Gonc¸ales 1,∗ , A.G.B. Gonc¸ales 1 , D.S. Ferreira Rubim de Assis 2 , P. Yoshito Noritomi 3 1 Stomatology, Sao Paulo University, Brazil 2 Oral and Maxillofacial Surgery, Sacred Heart University, Bauru, Brazil 3 Center for Information Technology Renato Archer, Campinas, Brazil

The facial nerve is basically a motor nerve, which supplies the muscles of facial expression. Injury to this nerve causes functional, social and psychological disability. Aims and objectives: 1. To take into account the points of emergence and arborization, the anatomic planes of distribution and the relationship of the post parotid portion of Facial Nerve. 2. Identification of danger free area and important anatomic pathways of marginal mandibular, temporal and frontal nerves pertaining to TMJ, inferior border of mandible and submandibular region. 3. To provide comparative anatomical surgical appraisal in cadavers and human patients for considering surgical manoeuver to the Oral maxillofacial Surgeons. Materials and methods: This study is based on identification and exposure of the post parotid portion of Facial Nerve, emergence in the face at the anterior border of the parotid gland. The sample consisted of 30 hemifaces of 15 cadavers, irrespective of age, sex and race. Cadavers with any facial alterations were not included in the study. The emergence points of these branches of the Facial Nerve from the superior, anterior and apex of the parotid gland were measured in relation to 1. 2. 3. 4.

Intertragal notch. Palpebral lateral commissure. labial commissure. Midline of Philtrum of upper lip at the red margin.

The aim of this study was investigate by the finite element method the distribution of stress in the maxillar undergoing subtotal Le Fort I osteotomies to surgically assisted maxillary expansion. Five maxillary models were built virtually: M1-no surgery, M2-Le Fort I with a step on zygomatic buttress; M3-Le Fort I with step on zygomatic and pterygoid disruption, M4Conventional Le Fort I M5-Conventional Le Fort I with pterygoid disruption. According to the coherence analysis larger displacements were observed in the region of alveolar anterior ridge and first premolar decreasing the in the posterior region, as a “V” form in surgery models. Comparing the displacement of the models, M4 and M5 had a higher dental displacement in relation to bone displacement, than recorded in M2 and M3. The maximum principal stress showed areas of tension spreading to the jaw and the region between alveolar ridge and the palate, and a critical point in the median suture for M2, M3, M4 and M5. In models M2 and M4, MPS has spread further in the direction and the pterygoid process. The analysis of von Mises stress showed large stress concentration in the appliance and metal poles in the region of orthodontic bands and wire junction for all models. Conclusion: M3 had better performance than other models because it showed less dental displacement in relation to bone displacement, and the tensile stress was interrupted by posterior osteotomy. Conflict of interest: None declared. doi:10.1016/j.ijom.2011.07.115

Result and conclusion: The pathway of the Facial Nerve and the anatomical relations of the branches are outlined and