Intact Margins Research Articles

Ureibacillus aquaedulcis sp. nov., isolated from freshwater well and reclassification of Lysinibacillus yapensis and Lysinibacillus antri as Ureibacillus yapensis comb. nov. and Ureibacillus antri comb. Nov.

A Gram-stain-positive aerobic, rod-shaped, spore-producing bacterium forming colonies with convex elevation and a smooth, intact margin was isolated from a freshwater sample collected from a well situated in an agricultural field. The 16S rRNA gene sequence of the isolated strain BA0131T showed the highest sequence similarity to Lysinibacillus yapensis ylb-03T (99.25%) followed by Ureibacillus chungkukjangi 2RL3-2T (98.91%) and U. sinduriensis BLB-1T (98.65%). The strain BA0131T was oxidase and catalase positive and urease negative. It also tested positive for esculin hydrolysis and reduction of potassium nitrate, unlike its phylogenetically closest relatives. The predominant fatty acids in strain BA0131T included were anteiso-C15:0, iso-C16:0, iso-C15:0, iso-C14:0 and the major polar lipids comprised were phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine. The respiratory quinones identified in strain BA0131T were MK8 (H2) (major) and MK8 (minor). The strain BA0131T shared the lowest dDDH values with L. yapensis ylb-03T (21%) followed by U. chungkukjangi 2RL3-2T (24.2%) and U. sinduriensis BLB-1T (26.4%) suggesting a closer genetic relationship U. sinduriensis BLB-1T. The ANI percentage supported the close relatedness with U. sinduriensis BLB-1T (83.61%) followed by U. chungkukjangi 2RL3-2T (82.03%) and U. yapensis ylb-03T (79.57%). The core genome-based phylogeny constructed using over 13,704 amino acid positions and 92 core genes revealed the distinct phylogenetic position of strain BA0131T among the genus Ureibacillus. The distinct physiological, biochemical characteristics and genotypic relatedness data indicate the strain BA0131T represents a novel species of the genus Ureibacillus for which the name Ureibacillus aquaedulcis sp. nov. (Type strain, BA0131T = MCC 5284 = JCM 36475) is proposed. Additionally, based on extensive genomic and phylogenetic analyses, we propose reclassification of two species, L. yapensis and L. antri, as U. yapensis comb. nov. (Type strain, ylb-03T = JCM 32871T = MCCC 1A12698T) and U. antri (Type strain, SYSU K30002T = CGMCC 1.13504T = KCTC 33955T).

Comparison of conventional preparation with modified access preparation on fracture resistance of primary molars - A finite element analysis

ObjectiveTo investigate the influence of Conventional Straight (CS) line and Modified Straight (MS) line access preparations with various restorative materials on the fracture resistance of primary molars using Finite Element Analysis (FEA). MethodologyThree FEA models for each of the primary molars were divided into Group I- Intact tooth model; Group II- Model with CS outline and Group III- Model with MS outline. Based on the restorative material used, Group II and III were further subdivided into subgroup 1- GIC restoration, subgroup 2 – composite resin with GIC base and subgroup 3- Stainless Steel Crown (SSC). Each model was subjected to 5 different force loads directed at the occlusal surface. Maximal von Mises (VM) stresses calculated from stress distribution patterns. ResultThe maximum displacement, in all the models of primary molars were seen in GIC restored models in molars with both CS and MS access whereas the minimal displacement was seen in the SSC restored molars of MS group. ConclusionIn primary maxillary second molar and mandibular first and second molar with intact marginal ridges, the fracture resistance of tooth with MS outline restored with GIC base followed by Composite resin was comparable with the tooth restored with SSC and CS outline. Clinical outcomeBased on the results of this FEA analysis, composite restorations with MS outline would be appropriate for endodontically treated primary molars that have intact margins.

12 Month's Assessment Of Clinical Efficacy Of Resin Modified Glass Ionomer Cement And Flowable Composites In Restoration Of Non-Carious Cervical Lesions, A Randomized Clinical Trial.

The objective of this study was to compare the clinical efficacy of Resin modified glass ionomer cement and Flowable composite in terms of retention, marginal adaptation and surface texture using United States Public Health Service criteria in non-carious cervical lesions measured over a period of one year. A Randomized Clinical Trial is conducted with Informed consent on 60 patients who are randomly allocated into 2 groups with at least 2 Non Carious Cervical Lesions in each. Group 1 is used for Flowable Composite while group 2 is used for resin modified glass ionomer cement. A recall is maintained to draw conclusions between two materials in terms of occurrence of marginal adaptation, retention and surface texture, to show which material is superior to other. Out of 30 restorations in 12 months follow up, only 19 found to be present in flowable composite group while in resin modified glass ionomer cement group, 28 are retained. Regarding margin integrity, Group 1 showed 21 intact margins whereas 23 margins were intact in group 2, while 18 and 25 showed smooth surface in flowable composite and Resin modified glass ionomer cement group respectively, on exploration. It can be concluded from our study that Resin modified glass ionomer cement is superior to Flowable composite in terms of retention (p=0.005) and surface texture (p=0.045) in restoration of non carious cervical lesion.

Evaluation of histopathological margin and other recurrence parameters in basal cell carcinoma: A retrospective analysis of 8821 lesions

Basal cell carcinoma (BCC) is the most common skin cancer. Removing the lesion with wide surgical margins and obtaining a microscopically intact margin is considered sufficient in the treatment of BCC. However, it may not always be possible to provide wide and intact margins in cosmetically and functionally important areas. Although recurrence rates after BCC excision vary among studies, the recurrence rate at 5 years is considered to be 2%. BCC subtype, perineural invasion, and close margin are important factors in recurrence. The aims of this study are to investigate the other factors associated with recurrence in BCC treatment and reveal the value of the "histopathological surgical margin" which can help in making the decision for re-excision. A statistically significant correlation is observed between the increase in tumour size and recurrence(p<0.05). The recurrence rate after excision with a histopathologic margin of 1mm or less is 19%. This rate is found to be 8% in patients with a histopathological margin greater than 1mm and 3mm or less. Reticular dermis and deeper tissue invasion statistically increase the recurrence rate. Multiple excision and the presence of residual tumour in the re-excision sample also increase the recurrence rate. In conclusion, recurrence in BCC patients is affected by more than one parameter. We highly recommend re-excision in patients with a histopathological margin of 1mm or less. In tumours with histopathological margins between 1mm and 3mm, the decision for re-excision or "wait-and-see" approach should be made according to the characteristics of the tumours and patients.

The "hump" a new arthroscopic phenomenon guiding for reliable therapy of osteochondritis dissecans of variable stability status.

Despite 150years of research, there are currently no reliable morphological characteristics that can be used to differentiate between stable and unstable juvenile osteochondritis dissecans (JOCD) lesions in the knee joint. Arthroscopic probing is still the gold standard. In arthroscopic evaluation, a previously undescribed pattern of a cartilaginous convex elevation ("hump") was identified as a new feature and potential sign of JOCD in transition to instability. The aim of the study was to evaluate the clinical outcomes after surgical intervention (drilling) on the "hump". In a retrospective case series of sixteen patients with an arthroscopically detectable "hump", the analysis of clinical function scores (Lysholm, Tegner) and morphological MRI monitoring of radiological healing were performed. The assessment of lesion healing was based on pre- and postoperative MRI examinations. The "hump" was defined as an arthroscopically impressive protrusion of the femoral articular surface with a minimally softened, discolored, but intact cartilage margin that, is not mobile upon in the arthroscopic palpation hook test. The primary therapy of choice was drilling of all "humps". The "hump" could be detected arthroscopically in 16 of 59 JOCD lesions. Specific MRI correlations with the "hump" or arthroscopic unstable lesions could not be detected. Not all "humps" showed signs of MRI-based healing after the drilling, and in some a dissection of the osteochondral flap occurred within the first postoperative year. As a result, secondary refixation became necessary. In the present study, the "hump" was identified as an important differential diagnostic arthroscopic feature of an arthroscopically primarily stable JOCD lesion, potentially placing the lesion at risk of secondary loosening over time. Therefore, drilling alone may not be appropriate in the event of arthroscopic "hump" discovery, but additional fixation may be required to achieve the healing of the lesion. III.

Cross sectional analysis of positional and numerical variations of mental foramina in dry human mandibles

Introduction: During lower jaw surgeries, mental nerve block is given at mental foramen level. However, mental foramen is prone for variations in its location and number, which could lead to iatrogenic injuries to neurovascular structures in this region. Aim and Objective: The aim of this study is to provide precise information of variations of site and number of mental foramen for helping dental surgeons to avoid injuries to mental nerve and vessels. Hence, the objective of the study is to analyze changes in site and number of mental foramen in the form of accessory foramina osteologically in Gujarat’s population. Materials and Methods: Three hundred dry mandibles of unknown sexes, and bearing all teeth or intact alveolar margin were included in the study. In 37.33% of mandibular sides, mental foramens were found between 2nd premolar and the 1st molar teeth. Numerical variations in the form of accessory foramina were found in 16.66% mandibles, more on the left side, showing statistically significant difference in laterality distribution. Conclusion: Iatrogenic injuries of mental neurovascular structures could better be avoided with precise idea of variations in site and numbers of mental foramen, which may ease the work of dental surgeon. Keywords: Dry mandibles, Mental foramen, Anaesthesia, Anatomical variation.

Why Do Parotid Pleomorphic Adenomas Recur? A Systematic Review of Pathological and Surgical Variables.

The recurrence of pleomorphic adenoma (PA) has been extensively debated, mostly in relation to the extent of parotidectomy. A systematic review was undertaken to clarify the surgical and pathological variables related to PA recurrence. Inclusion criteria were as follows: English literature, and prospective or retrospective studies. Exclusion criteria were as follows: single case reports, reviews, and lack of PA recurrence data. Pathology-related variables associated with recurrence include the histological subtype, the thickness and incompleteness of the tumor capsule, pseudopodia, and satellite nodules. Surgery-related variables associated with recurrence are the presence of intact margins and tumor puncture or spillage. Other factors are the size of the tumor and the age of patient. Myxoid subtypes of PA tend to have incomplete and thinner capsules and to recur more frequently. Surgical variables related to recurrence include positive margins and tumor spillage. Myxoid and/or large PA, especially in young patients, should be approached more cautiously to avoid recurrences.

The Ovary-Sparing Laparoscopic Excision of a Benign Teratoma

Purpose: We demonstrate complete excision of a benign ovarian teratoma and combine the benefits of laparoscopy with ovary preservation and avoidance of tumor spillage. Case History: A 9-year-old female presented with 2 months of intermittent right lower quadrant abdominal pain. Physical examination was unremarkable with no palpable abdominal mass. Pelvic ultrasonography revealed an enlarged right ovary with no evidence of torsion on duplex scan. MRI revealed a calcified, 3.5 cm mass within the right ovary, consistent with a teratoma. Tumor marker blood studies, including beta-HCG, alpha-fetoprotein, and CA-125, were negative. Procedure: General anesthesia was administered. The patient was placed in Trendelenburg position with the monitor at the foot of the bed. Three 5-mm laparoscopic ports were placed, one for the 5-mm, 30° camera at the umbilicus and one each in the lower quadrants for dissection instruments. A 12-mm port was placed in the skin crease, directly above the ovary, for the endocatch bag. The abdomen was insufflated with carbon dioxide to 13-mm Hg pressure. Initial inspection revealed a normal-appearing abdomen, a normal contralateral ovary, and the serosa of the enlarged right ovary appeared intact. The dissection began at the pelvic edge by dividing the peritoneal attachments between the adnexal structures and the pelvic side wall with the harmonic scalpel. It proceeded toward the point between the bladder and the epigastric vessels. The ovarian and iliac vessels and ureter were avoided. The dissection extended under the adnexa. The ovary reached the 12-mm port without tension. It was placed in an endocatch bag to prevent spillage in case of rupture and carefully pulled through the 12-mm port site. The hydroplane technique of saline injection with a 30-gauge needle under the ovary serosa allowed dissection of the teratoma from normal ovarian tissue. The serosa was opened and the teratoma circumferentially excised.1,2 The preserved ovary serosa was closed with running suture of 3–0 chromic catgut. The adnexa were replaced in the abdominal cavity in the correct orientation. The abdomen was desufflated and port sites were closed. Results: The pathology analysis revealed a benign 3.0 cm teratoma, completely excised with intact margins and no immature elements. No complications occurred. The operative time was 70 minutes. The patient was discharged on postoperative day 2. Conclusion: We demonstrate complete excision of a benign ovarian teratoma and combine the benefits of laparoscopy with ovary preservation and avoidance of tumor spillage.3 For patients with negative tumor markers, an MRI with a teratoma contained in the ovary and a tumor diameter less than 5 cm are appropriate. The distance between bladder and epigastric vessels may limit the size of lesion that can be brought through the abdominal wall along the suprapubic skin crease. The hydroplane technique reveals a consistent plane between teratoma and normal ovary. However, this technique is also suitable for lesions where malignancy is suspected. The risk of suspicious histology, tumor rupture, and spillage increases with tumor diameter. In general, these risks increase with lesions more than 5 cm in diameter.4 Therefore, we promote the use of the endocatch bag. No competing financial interests exist. Runtime of video: 4 mins 55 secs

An ontogenetic approach to gynecologic malignancies.

Ontogenetic anatomy is the mapping of body compartments established during early embryologic development, particularly well demarcated in the adult pelvis. Traditional cancer surgery is based on wide tumour excision with a safe margin, whereas the ontogenetic theory of local tumour spread claims that local dissemination is facilitated in the ontogenetic compartment of origin, but suppressed at its borders in the early stages of cancer development. Optimal local control of cancer is achieved by whole compartment resection with intact margins following ontogenetic “planes”. The principles embodied in this hypothesis are most convincingly supported by the results of the implementation of total mesorectal excision in rectal cancer, and more recently, by innovative surgical approaches to gynaecologic malignancies. The high resolution contrast of MR, accurately delineating pelvic fascial compartments, makes it the best imaging modality for gynaecologic cancer surgery planning following these principles, but requires interpretation of imaging anatomy from a different perspective.Teaching Points• Ontogenetic anatomy refers to mapping of embryologically determined body compartments.• Ontogenetic theory claims tumour growth is not isometrical, but rather compartment permissive.• Ontogenetic principles are highly supported by the outcome results of total mesorectal excision.• Innovative gynaecologic cancer surgery approaches based on ontogenetic theory show promising results.

A case report of traumatic dislocation of eyeball

Complete dislocation of an intact globe into the maxillary sinus after an extensive blowout fracture is a rare occurrence. We report a case of pure blowout fracture of the floor of the orbit with intact orbital margins due to trauma resulting in complete dislocation of the globe into the maxillary sinus in a 42-year-old male. On ocular examination, the right eyeball was found to be absent from the orbit. Computerized tomography scan with contrast showed: (1) pure orbital blowout fracture; (2) intact eyeball in the right maxillary sinus; and (3) optic nerve seemed to be intact. Surgical exploration of the right maxillary sinus through Caldwell-Luc approach revealed a circular fracture which was just the size of the globe in the middle of the inferior orbital wall. The orbital contents were also found to be dislocated completely into the right maxillary sinus. The dislocated globe was repositioned into the orbit and the orbital floor fracture repaired with bone graft taken from iliac crest. The visual acuity in the right eye after the repositioning was no light perception. We are reporting this case because it is a rare condition and the various operative challenges.

MÉTODOS RECONSTRUTIVOS DA PÁLPEBRA INFERIOR – APLICAÇÃO NA PRÁTICA DERMATOLÓGICA

Introdução: A ressecção de neoplasias cutâneas é a principal causa de defeitos palpebrais. Os princípios de reconstrução da pálpebra encontram-se bem definidos. No entanto, permanece um desafio conseguir um bom resultado funcional e estético. Material e Métodos: Conhecer as diversas técnicas cirúrgicas e os conceitos anatómicos é fundamental na abordagem de lesões palpebrais. Anatomicamente a pálpebra pode ser dividida em duas lamelas: a lamela anterior (pele e músculo orbicular) e a lamela posterior (tarso e conjuntiva).Resultados: Para efeitos reconstrutivos, os defeitos da pálpebra inferior podem ser divididos em dois principais grupos: (1) defeitos de espessura parcial, com a margem palpebral intacta e (2) defeitos de espessura total envolvendo a margem palpebral. As técnicas cirúrgicas de reconstrução da lamela anterior incluem retalhos miocutâneos de rotação ou de deslizamento e enxertos cutâneos. Para reconstruir a lamela posterior são necessários enxertos compostos (condrocutâneos ou condromucosos). Nos defeitos de espessura total ambas as lamelas têm de ser reparadas, para restaurar a função. Nos algoritmos de reconstrução, os defeitos palpebrais de espessura total são classificados em: pequenos (até 30% do tamanho horizontal da margem palpebral), médios (30-50%) e grandes (acima de 50%). Um pequeno defeito pode ser encerrado com sutura directa. Se necessário mobiliza-se a margem palpebral lateral 3 a 5 mm (cantólise lateral). Num defeito de tamanho médio pode ser aplicado um retalho. Para os defeitos de grandes dimensões, o cirurgião deve reconstruir a lamela posterior e planear a reconstrução da lamela anterior com uma combinação das técnicas anteriores. Os autores reviram a metodologia de reconstrução de defeitos da pálpebra inferior e exemplificam com casos da sua prática clínica. Conclusões: Existem inúmeras abordagens possíveis para restaurar a anatomia palpebral. O método reconstrutivo de eleição é individualizado caso a caso, com particular atenção à localização e dimensões do defeito.

Behavioral plasticity of a grass-feeding caterpillar in response to spiny- or smooth-edged leaf blades

Ontogenetic changes in feeding behavior of armyworms, Pseudaletia unipucta (Haworth), were compared on tall fescue [Schedonorus arundinaceus (Schreb.) Dumort] cultivars with spiny-, intermediate-, or smooth-edged leaf blades to clarify whether the edge spines deter caterpillars, in which case release of modified, smooth-edged forage grasses for improved livestock performance might aggravate armyworm damage to pastures. Edge biting, success initiating edge-feeding, and propensity to window- or edge-feed were observed for individual 2nd, 3rd, or 4th instars on grass leaf blades with intact margins. Early second instars bit smooth and spiny leaf edges with equal frequency but were unable to initiate edge-feeding. They fed on leaf edges after margins were cut away, but not when leaf juice was applied to intact edges, indicating the leaf margin is a barrier. Third and 4th instars mostly edge-fed on smooth leaves, but on the grasses with spiny margins they compensated for the difficulty of edge-feeding by prolonging their window-feeding. There was no developmental cost to window-feeding by 3rd instars, but 4th instars suffered reduced weight gain on spiny grass apparently because, unlike earlier instars, their mandibles are too large and not well shaped for efficient window-feeding between the parallel vascular bundles. Armyworms display behavioral plasticity in feeding mode in response to spiny- versus smooth-edged grasses. Greater use of smooth-bladed pasture grasses may result in proportionately more edge-feeding by armyworms but is unlikely to result in markedly greater pasture losses because this grass-feeding specialist so effectively exploits conventional tall fescue despite its structural characteristics.

Otolith retrieval from faeces and reconstruction of prey-fish size for Great Cormorant (Phalacrocorax carbo) wintering at the East Dongting Lake National Nature Reserve, China

The food composition of Great Cormorant (Phalacrocorax carbo) was studied by analyzing 360 faecal samples collected from their roosting sites at the East Dongting Lake National Nature Reserve in south-central China during November 2008 and January 2009. A total of 223 fish otoliths were retrieved. Only sagittal otoliths (N = 74) with intact margins, good medial relief, and well-defined sulcus were used to identify the prey-fish species and to reconstruct prey-fish size. Through shape indices and elliptical Fourier analyses, these otoliths were identified as belonging to two cyprinid fish species, crucian carp Carassius auratus (72%) and white amur bream Parabramis pekinensis (28%). The otolith size (maximum length, Lo)—prey-fish size (standard length, Ls) relationships determined for the two fish species were Ls = −19. 5 + 37.1 Lo (N = 74; R2 = 0.95; P < 0.05) for crucian carp and Ls = −31.9 + 36.9 Lo (N = 70; R2 = 0.97; P < 0.05) for white amur bream. The back-calculated Ls from the otoliths retrieved from the faeces were 96.2 ± 10.2 mm (range 72.7–110.4 mm) for crucian carp and 86.3 ± 10.4 mm (range 74.1–104.6 mm) for white amur bream. Based on setnet sampling of the fish community near roosting sites, crucian carp and white amur bream were found as the first and second most abundant species. Great Cormorants were very selective for the size range of prey. These results demonstrate that analysis of otoliths retrieved from faeces can be an effective, inexpensive, and non-invasive method to identify prey-fish species and to estimate prey-fish size in studies of diet composition for piscivorous birds.

Safety Margin in Excision of Basal Cell Carcinoma

The aim of this study was to evaluate the intact margin after surgery regarding common method with consideration of 4 mm safe margin. Fifty patients with basal cell carcinoma operated in Tabriz Sina hospital, were chosen randomly and pathological report of these patients after surgery was evaluated with consideration of presence of intact margin. In pathologic report before operation of these patients, Basal cell carcinoma was certified. Also, brief data of these patients history was studied from present cases. Forty eight of 50 (96%) patients had intact margin after surgery and just in two patients (4%), lesion was excised insufficiently and they had involved margin. With brief study of patients' history, most of them had advanced ages and the most common site of tumor presentation was head and neck. The most of these patients had exposure with so much sun light that was accounted an important etiology. With comparison of mentioned statistical results with other reports from other countries, this rate is considered in acceptable range and surgical method is done properly in this hospital and consideration of 4 mm of tumoral margin is enough.

Effects of riparian manipulation on stream communities in small streams: Two case studies

The effects of riparian manipulation in New Zealand are described for two case studies, one a short‐term study of the effects of the removal of riparian vegetation on fish, and the second, a long‐term study of the effect of re‐establishment of riparian vegetation on fish and benthic macro invertebrates. The first case study was an experiment carried out between November 2001 and May 2002. Overhanging bank vegetation and in‐stream wood were removed from short reaches of a small pastoral stream that had intact riparian margins, resulting in a change in stream structure with the formation of shallow uniform runs rather than pool and riffle structures as in unmodified reaches. The removal of bank cover and consequential instream habitat changes reduced inanga (Galaxias maculatus) densities by a factor of four within months of vegetation removal, showing the importance of instream cover and habitat to inanga. Adult longfin eel (Anguilla dieffenbachii) also became less abundant in the cleared reaches, but elvers (Anguilla spp.) became more abundant. In the second case study, pastoral sections in two small streams draining from native forest catchments were restored in 1995/96 by planting riparian vegetation and preventing stock access. After 10 years, the restoration efforts had more than doubled the numbers of giant kokopu (G. argenteus) and redfin bullies (Gobiomorphus huttoni), slightly increased numbers of banded kokopu (G. fasciatus), and decreased shortfin eel (A. australis) numbers by about 40%. The macroinvertebrate communities changed so that they became more similar to those at upstream native forest reference sites. These two case studies show that riparian margins can influence the composition of the fish and macroinvertebrate communities in small streams through the effects on cover, instream habitat and probably water temperature. Riparian restoration was most effective for the fish species that use cover and pool habitat.

Influence of core material on fracture resistance and marginal adaptation of restored root filled teeth

To investigate ex vivo the influence of direct placement core materials on the fracture strength and marginal adaptation of root filled maxillary central incisors restored with glass fibre-reinforced posts, various core materials and all-ceramic crowns. Forty-eight human maxillary incisors were root filled. Posts were placed and teeth restored with composite cores and crowns (n = 8). Six core materials were examined after thermal cyclic and mechanical loading (TCML). Fracture force was determined under static loading. The marginal adaptation at the interfaces between cement-tooth and cement-crown were categorized as 'intact margin' or 'marginal gap' using scanning electron microscopy. Statistical analysis was undertaken with the Mann-Whitney U-test (alpha = P < or = 0.05). Median fracture strength varied between 204 N (low viscous experimental core) and 1094 N (Multicore). No difference in fracture resistance was found with varying viscosity of the core material. The layering technique improved the fracture performance (P = 0.059) to a minor degree. Crowns with dedicated core materials (Rebilda 1063 N; Multicore 1094 N) had a significantly higher fracture resistance than crowns with a conventional restorative material (Tetric Ceram 509 N). Significantly poorer marginal adaptation before TCML was found for the layering technique at the tooth-cement interface and for all experimental cores after TCML. At the crown-cement interface significant differences in marginal adaptation could be determined between Multicore-layered core (P = 0.002) and Multicore-Rebilda (P = 0.001) after TCML. The fracture strength of post and core restorations was dependent on the core material and bonding system. Marginal adaptation was influenced by the method of application of the core material and by TCML.

Epidermal cell kinetics in lichen planus.

The epidermis in lichen planus presents an apparently paradoxical situation. There are on the one hand epidermal hypertrophy acanthosis and hypergranulosis, and on the other, destruction of the generative compartment with erosion of the basal layer. In order to understand how the two processes can co-exist, thirty-five lichen planus papules from twenty-five patients were injected intracutaneously with IO μ Ci of tritiated thymidine. Sixteen of these lesions were removed after 50-60 min and nineteen were removed after longer intervals of up to 10 days. Autoradiographs prepared from biopsied lesions demonstrated that keratinocytes had migrated into the lichen planus lesion from the intact margins, replaced the eroded basal layer and repopulated the epidermis of the lesion. It is concluded that the changes observed in the epidermis seen in lichen planus can be interpreted as the result of a continuous process of (1) erosion and (2) repopulation in an attempt at healing of the wounded area.

Influence of enamel wetness on resin composite restorations using various dentine bonding agents: Part I—effects on marginal quality and enamel microcrack formation

To investigate the influence of enamel wetness on marginal quality and enamel microcrack formation using various dentine bonding adhesives; and to determine the changes of marginal quality and enamel microcracks over time. Forty extracted molars were each prepared with a cylindrical cavity and divided into five groups. Groups 1-4 were acid-etched and treated separately with either an ethanol-based adhesive (Single Bond) or an acetone-based adhesive (Prime&Bond NT) on either dry or wet enamel. Teeth in Group 5 were treated with a self-etching adhesive (Clearfil SE Bond). Epoxy replicas of different stages were taken after cavity preparation, after restoration, after 24 h storage, and after thermocycling test. These replicas were examined under a scanning electron microscope for their restorative marginal quality and enamel microcrack. Quantitative measurement was performed to measure the length ratio of different margin patterns, and enamel microcracks. There was no difference in the marginal quality when ethanol-base adhesive was applied on dry or wet dentin. The group using acetone-based adhesive on the dry enamel presented higher intact margin ratio than the group on wet enamel did only after restoration. Using self-etching primer led to higher open margin ratio at all stages. Enamel microcracks were found in all five groups and were higher in groups using acetone-based adhesives. Enamel wetness did not show a significantly adverse effect on the marginal quality of the restorations using either acetone- or ethanol-based adhesive. Using self-etching adhesive may lead to high incidence of margin deterioration.

Intraoral widening and lengthening of the mandible in baboons by distraction osteogenesis

Purpose: The purpose of this study was to analyze the skeletal and dental positional changes and histomorphology of the distraction regenerates and mucogingival periosteal tissues that occurred after simultaneous widening and bilateral lengthening of the mandible in baboons by a miniaturized intraoral bone-borne distraction appliance. Materials and Methods: Distraction appliances were activated 5 days after vertical ramus and symphyseal osteotomies at a rate of 0.9 mm/d for 10 days. The appliances were then stabilized for 8 weeks, after which the animals were killed. The distraction gaps and gingival tissues were analyzed clinically, histologically, and by standardized radiographic studies. Results: Positional changes of the canines and incisor apices were proportional to the skeletal movements. Tipping of both incisors toward the center of the distraction gap was observed. Proportionate movement of the superior and inferior portion of the distracted segments was noted. Newly formed longitudinal trabecular columns parallel to the vector of distraction originated from the intact margins of alveolar bone contiguous with the adjacent teeth. Active histogenesis occurred in the stretched mucogingival periosteal tissues located in the distraction gaps. Conclusions: The results of this investigation support the clinical use of the miniaturized intraoral bone-borne distraction appliance to selectively widen and lengthen the mandible. The orientation of the mandibular distractors must be parallel to the common vector of distraction, which should be parallel to the maxillary occlusal plane. The formation of a bone regenerate in the alveolar region depends on the presence of an adequate bone interface on either side of the distraction gap.

Intraoral widening and lengthening of the mandible in baboons by distraction osteogenesis

Purpose: The purpose of this study was to analyze the skeletal and dental positional changes and histomorphology of the distraction regenerates and mucogingival periosteal tissues that occurred after simultaneous widening and bilateral lengthening of the mandible in baboons by a miniaturized intraoral bone-borne distraction appliance. Materials and Methods: Distraction appliances were activated 5 days after vertical ramus and symphyseal osteotomies at a rate of 0.9 mm/d for 10 days. The appliances were then stabilized for 8 weeks, after which the animals were killed. The distraction gaps and gingival tissues were analyzed clinically, histologically, and by standardized radiographic studies. Results: Positional changes of the canines and incisor apices were proportional to the skeletal movements. Tipping of both incisors toward the center of the distraction gap was observed. Proportionate movement of the superior and inferior portion of the distracted segments was noted. Newly formed longitudinal trabecular columns parallel to the vector of distraction originated from the intact margins of alveolar bone contiguous with the adjacent teeth. Active histogenesis occurred in the stretched mucogingival periosteal tissues located in the distraction gaps. Conclusions: The results of this investigation support the clinical use of the miniaturized intraoral bone-borne distraction appliance to selectively widen and lengthen the mandible. The orientation of the mandibular distractors must be parallel to the common vector of distraction, which should be parallel to the maxillary occlusal plane. The formation of a bone regenerate in the alveolar region depends on the presence of an adequate bone interface on either side of the distraction gap.