Splint therapy for skeletal Class III malocclusion in the primary dentition

The objective of this study was to evaluate the effect of referral bias in a clinical audit of lymphoma in a university hospital. We compared demographic and clinical characteristics as well as survival for Jerusalem residents (local) and referred (distant) patients diagnosed from 1987 to 1992 and treated in our institution. Referred patients were younger (p < 0.0001), and less likely to be immigrants (p < 0.0001), than local patients. Aggressive non-Hodgkin's lymphomas (NHL) were more common in the referred population (p = 0.015). Survival for Hodgkin's disease was consistently better for local patients, but for patients with NHL the findings were reversed. In this study referred patients differed in their clinical and sociodemographic characteristics but did not consistently exhibit a worse outcome than that of local patients. The unpredictable nature of referral bias may be due to better functional status or resources among referred patients, or to selective referral for procedures such as bone marrow transplantation. While reports on the natural history of disease from tertiary institutions may be biased by referral patterns, the direction of the bias is not uniform.     

Case report. Dental Class I and skeletal Class III with unilateral right crossbite

Different forms of bone grafting materials are alluded to in this paper. Autogenous graft is superior to other bone grafting materials but is many times not available or the patient is not willing to utilize cranial or iliac crest bone. Allografts, Xenografts and bone substitute materials are the most widely used today in dentistry and especially those patients wishing to use dental implants as abutment support. The technique discussed utilizing surgical tissue design, tissue closure over the graft material and the tissue barrier can be used to produce a successful final result using a graft material of choice. It is quite certain that in the near future, the use of bone graft enhancement materials (bone morphogenic protein-like substances) will be used to enhance a quicker result. It is anticipated that growth factors, stimulating factors, bone morphogenetic proteins, and osteogenetic proteins will cause a bone graft to vascularize, solidify, incorporate, and function optimally in a shorter period of time. These materials will reduce the disability time and enhance the outcome of bone grafting in the dental profession. It is also anticipated that advanced tissue surgical techniques will give better vascularization to the new graft. The described technique is predictable and should give the operator the desired result.     

Non-surgical treatment of hepatocellular carcinoma

A decade ago, surgery was the only satisfactory treatment modality for hepatocellular carcinoma (HCC), but it was limited only to selected cases. For the majority of cases of HCC, systemic chemotherapy was one of the few treatment alternatives, but provided only marginal benefit. In the past 20 years, diagnostic methods have improved to an extent that small HCC less than 1 cm can be detected. Moreover, non-surgical treatment is available, of which regional therapy has been shown to prolong patients' survival, and may even replace surgical resection in some cases. Regional therapy is indicated for the treatment of HCC when there is no extrahepatic metastasis and the patient has adequate liver function reserve, thus permitting repeated therapy. Transcatheter hepatic arterial embolization (TAE) using various embolizers has been well documented to include controlled studies. However, it is not indicated for patients with thrombosed main portal veins. Its therapeutic effect is also doubtful when the tumour is infiltrative in nature or is hypovascular, too large or too small. Additional chemotherapeutic agents mixed into the embolizer with lipiodol and degraded starch microspheres or styrene-maleic acid-neocarzinostatin in which chemotherapeutic agents are embedded, are used with a better response, but the survival rate has not shown significant improvement. Ultrasound-guided local injection therapy is another new method of treatment of HCC. Of these techniques, percutaneous ethanol injection therapy (PEIT) is widely used with excellent results for small, encapsulated tumours in livers with less than three HCC. Percutaneous ethanol injection therapy can also be used in cases with portal vein thrombosis, but it is not suitable for patients having coagulopathy or ascites. Using acetic acid, OK-432, interferon or anti-cancer drugs in the injection therapy shows no further benefit over ethanol alone. Transcatheter echoguided thermotherapy or cryotherapy has been reported in small series of patients, as has target therapy with immune or radiotherapy and conformal radiotherapy. Preliminary studies show encouraging results. Systemic therapy with either single drug or multidrugs is ineffective, with a response rate of less than 20%. Immunotherapy, such as with interferon or other cytokines, is not beneficial. Hormone therapy has not been promising, except for treatment with tamoxifen, which has been reported to show some beneficial effect. Gene therapy is still in its infancy. In summary, recent progress in non-surgical treatment of HCC has resulted in a breakthrough of regional therapy looking quite promising. Moreover, a combination of different types of regional therapies may yield better outcomes in selected individuals.     

Non-surgical treatment of abdominal aortic aneurysms

Percutaneous placement of an endovascular stent, with and without coils, in the treatment of large AAA in animal models is feasible, safe and effective. The covered stent sealed off AAA immediately after stent placement, however, it interrupted blood flow into arteries in the area covered by the stent. The uncovered stent prevented further expansion of the aneurysm and also significantly decreased the incidence of rupture. The long-term patency of branch arteries by the uncovered stent supported the possibility of safely using this approach in humans. Furthermore, either covered stent or uncovered stent with additional coils have the potential for treatment of acute aneurysm rupture or leaking. Most importantly, the aneurysm lumen in our model was gradually replaced by collagen after stent placement which further reduces the risk of aneurysm rupture: and this healing process was enhanced by the addition of coils. If proven safe and effective for humans as well, this technique has the potential for substantially reducing the morbidity and mortality associated with AAA.     

Oropharyngeal airway dimensions and functional-orthopedic treatment in skeletal Class II cases

Lambs sucking non-immunised ewes or ewes immunised 4-5 weeks before lambing with live attenuated, aromatic-dependent (aroA) Salmonella typhimurium (strain CS 332) were challenged orally at either 2, 4 or 7 days of age with virulent S. typhimurium (strain CS 94) at doses ranging from 10(9) to 10(13) colony forming units. No lambs displayed signs of clinical salmonellosis and all survived challenge but those sucking immunised ewes had organisms of the challenge strain in their faeces for much shorter periods of time than lambs of the control ewes. High titres of specific antibodies were measured in colostrum and milk of immunised ewes in comparison with very low titres measured in samples from control ewes; these differences were reflected by the titres of antibodies in the sera of corresponding lambs. At 2 days after lambing, the major antibody isotype in the colostrum of immunised ewes and sera of their lambs was IgM whereas at 7 days IgG1 was the predominant isotype. While it was clear that vaccination of pregnant ewes with the live attenuated vaccination conferred protection against experimentally-induced salmonellosis in their lambs, considerable protection was observed in control lambs in spite of there being very low titres of antibodies in the mammary secretion of their dams. The latter observation could be related to the presence of contain non-antibody potent bactericidal factors previously described in colostrum and milk.     

Early treatment of Class III malocclusion? Colin's case

This is the first of six simulated case reports accompanying the questionnaire detailed in the article 'How to Do It: Making Clinical Audit Work' found earlier in this issue. You will find comprehensive discussion of the problem of making a decision about the early treatment of Class III malocclusion.     

Maxillary development revisited: relevance to the orthopaedic treatment of Class III malocclusions

Normal development of the maxilla results not only from movements of its constituent skeletal units and bony apposition-resorption superficially, but also from the specific development of the antero-lateral regions. In Class III cases, correction of the skeletal dysmorphosis requires not only that the maxilla is in a correct position (in relation to the mandible) and that the correct occlusion is achieved, but also that there is good development of the exo-peri-premaxilla. This requires normalization of muscular posture (labio-mental, lingual, velo-pharyngeal) and of orofacial functions (nasal ventilation, swallowing, mastication). Postero-anterior traction using an orthopaedic mask can only accomplish part of the treatment of Class III. The action must always be complimented by other therapy aimed at correcting the underdevelopment of the antero-lateral regions. Facemask therapy is not only simple sagittal distraction, but is truly a method for treatment of Class III which is well understood and achieves excellent results. Taking into account the great diversity of anatomical forms of Class III malocclusion, it is not surprising that extra-oral postero-anterior traction gives widely varying results. The quality, however, depends principally on the method used. Orthodontists must not hesitate to call for the assistance of a surgeon each time the functional treatment is insufficient, particularly in cleft patients where the results depend more on surgical procedures, both primary and secondary, than on dentofacial orthopaedics.     

A retrospective comparison of functional appliance treatment of Class III malocclusions in the deciduous and mixed dentitions

Endogenous tumour necrosis factor (enTNF) acts as a resistant factor against cytotoxicity of heat by induction of manganous superoxide dismutase (MnSOD), thereby scavenging reactive oxygen free radicals. On the other hand, it is also well known that heat shock proteins (HSPs), which are induced by heat-stress, behave as cytoprotecting factor against this stress. However, the relationship of these two resistant factors is not yet elucidated. In the present study we would therefore propose the possibility that enTNF enhances HSP72 expression. Heat-sensitive L-M (mouse tomourigenic fibroblast) cells, which normally do not express enTNF, were transfected with a nonsecretory-type human TNF expression vector to produce enTNF. Stable transfectants showed resistance to heat treatment and an increase of HSP72 expression. Conversely, when HeLa (human uterine cervical cancer) cells, which normally produce an appreciable amount of enTNF, were transfected with an antisense TNF mRNA expression vector to inhibit enTNF synthesis, their heat sensitivity was enhanced and HSP72 expression was reduced by half. In conclusion, these findings indicate that enTNF regulates heat-inducible HSP72 synthesis.     

The effect of treatment with the Bass appliance on skeletal Class II malocclusions: a cephalometric investigation

The purpose of this investigation was to study the short-term effects of treatment with the Bass appliance by comparative evaluation of treated and untreated skeletal Class II malocclusions. The subjects consisted of forty-seven Class II, division 1 malocclusion cases. Twenty-seven (14 girls, 13 boys) were treated with the Bass appliance for an average of 6 months. The remaining 20 cases (6 girls, 14 boys) served as a control. At the end of the 6 month treatment period the statistically significant treatment changes could be summarized as follows: the sagittal skeletal relationship was improved as a result of favourable growth responses in both the maxilla and the mandible. The overjet was reduced and the molar relationship was corrected as a result of the extended skeletal changes. Distal movement of the upper dentition was evident, with unchanged inclination of the maxillary incisors. Both anterior and posterior facial heights were increased without changes in the inclinations of the palatal and mandibular planes. No significant dental movement was observed in the mandible.     

Class III P-glycoproteins mediate the formation of lipoprotein X in the mouse

Cholestasis is associated with hypercholesterolemia and appearance of the abnormal lipoprotein X (LpX) in plasma. Using mice with a disrupted Mdr2 gene, we tested the hypothesis that LpX originates as a biliary lipid vesicle. Mdr2-deficient mice lack Mdr2 P-glycoprotein, the canalicular translocator for phosphatidylcholine, and secrete virtually no phospholipid and cholesterol in bile. Bile duct ligation of Mdr2(+)/+ mice induced a dramatic increase in the plasma cholesterol and phospholipid concentration. Agarose electrophoresis, density gradient ultracentrifugation, gel permeation, and electron microscopy revealed that the majority of phospholipid and cholesterol was present as LpX, a 40-100 nm vesicle with an aqueous lumen. In contrast, the plasma cholesterol and phospholipid concentration in Mdr2(-)/- mice decreased upon bile duct ligation, and plasma fractionation revealed a complete absence of LpX. In mice with various expression levels of Mdr2 or MDR3, the human homolog of Mdr2, we observed that the plasma level of cholesterol and phospholipid during cholestasis correlated very closely with the expression level of these canalicular P-glycoproteins. These data demonstrate that during cholestasis there is a quantitative shift of lipid secretion from bile to the plasma compartment in the form of LpX. The concentration of this lipoprotein is determined by the activity of the canalicular phospholipid translocator.     

Skeletal effects of early treatment of Class III malocclusion with maxillary expansion and face-mask therapy

The effectiveness of maxillary expansion and face-mask therapy in children with Class III malocclusion was studied in a sample of 46 subjects in mixed dentition and compared with a control sample of 32 subjects with untreated Class III malocclusion. Treated and untreated samples were divided into early and late mixed-dentition groups to aid identification of the optimum timing of the orthopedic treatment of the underlying skeletal disharmony. Cephalometric analysis was based on a stable basicranial reference system, appropriate for longitudinal studies started in the early developmental ages. The level of significance for intergroup comparisons was set at a p value of 0.01. Significant forward displacement of the maxillary complex was found in the early-treatment group. The region of the pterygomaxillary suture, in particular, showed significant changes in the subjects treated during early mixed dentition. No significant maxillary modifications were recorded in the late-treatment group. Both early and late groups exhibited smaller increments in mandibular protrusion and larger increments in the intermaxillary vertical relationship compared with their respective Class III control groups. Only children treated at an early age, however, showed a significant upward and forward direction of condylar growth, leading to smaller increments in total mandibular length. These results indicate that the combination of a bonded maxillary expander and face-mask therapy is more effective in early mixed dentition than in late mixed dentition, especially with regard to the magnitude of the protraction effects on maxillary structures.     

The arc index in evaluation of Class III malocclusion

Lateral cephalometric radiographs were obtained for 46 individuals (18 men and 28 women) aged 20 to 30 years. The sample consisted of Taiwanese with Class III malocclusions and prognathic facial profiles. A modification of the Sassouni arch analysis was used to evaluate this group. All parameters were compared with the norms for adult Taiwanese. The facial pattern of the Class III group was similar to that reported in other studies. The maxilla was in a retrusive position; the lengths of the maxilla and the mandible were significantly different from those in the normal group; the mandibular central incisor was retroinclined; and the total gonial angle, upper gonial angle, and lower gonial angle in the Class III group were significantly different from those angles in the normal group in both sexes. The arc index represented the maxillomandibular positional relationship. There was a statistically significant difference between the mean arc indexes of the Class III and the normal groups. The results indicated that the more negative the arc index, the greater the Class III tendency.     

An alternative in implant prosthetic treatment

Implant treatment is generally recognized as a very complex endeavour, requiring a great deal of expense and time. This however does not have to be the case. The following case involves the prosthetic treatment of a single implant utilizing composite material for crown fabrication, and resin cement retention, much like conventional treatment utilized when restoring endodontically treated teeth.     

Thin-plate spline analysis of the cranial base in subjects with Class III malocclusion

The role of the cranial base in the emergence of Class III malocclusion is not fully understood. This study determines deformations that contribute to a Class III cranial base morphology, employing thin-plate spline analysis on lateral cephalographs. A total of 73 children of European-American descent aged between 5 and 11 years of age with Class III malocclusion were compared with an equivalent group of subjects with a normal, untreated, Class I molar occlusion. The cephalographs were traced, checked and subdivided into seven age- and sex-matched groups. Thirteen points on the cranial base were identified and digitized. The datasets were scaled to an equivalent size, and statistical analysis indicated significant differences between average Class I and Class III cranial base morphologies for each group. Thin-plate spline analysis indicated that both affine (uniform) and non-affine transformations contribute toward the total spline for each average cranial base morphology at each age group analysed. For non-affine transformations, Partial warps 10, 8 and 7 had high magnitudes, indicating large-scale deformations affecting Bolton point, basion, pterygo-maxillare, Ricketts' point and articulare. In contrast, high eigenvalues associated with Partial warps 1-3, indicating localized shape changes, were found at tuberculum sellae, sella, and the frontonasomaxillary suture. It is concluded that large spatial-scale deformations affect the occipital complex of the cranial base and sphenoidal region, in combination with localized distortions at the frontonasal suture. These deformations may contribute to reduced orthocephalization or deficient flattening of the cranial base antero-posteriorly that, in turn, leads to the formation of a Class III malocclusion.     

The cytoplasmic loops between domains II and III and domains III and IV in the skeletal muscle dihydropyridine receptor bind to a contiguous site in the skeletal muscle ryanodine receptor

Excitation-contraction coupling in skeletal muscle is a result of the interaction between the Ca2+ release channel of skeletal muscle sarcoplasmic reticulum (ryanodine receptor or RyR1) and the skeletal muscle L-type Ca2+ channel (dihydropyridine receptor or DHPR). Interactions between RyR1 and DHPR are critical for the depolarization-induced activation of Ca2+ release from the sarcoplasmic reticulum, enhancement of DHPR Ca2+ channel activity, and repolarization-induced inactivation of RyR1. The DHPR III-IV loop was fused to glutathione S-transferase (GST) or His-peptide and used as a protein affinity column for 35S-labeled, in vitro translated fragments from the N-terminal three-fourths of RyR1. RyR1 residues Leu922-Asp1112 bound specifically to the DHPR III-IV loop column, but the corresponding fragment from the cardiac ryanodine receptor (RyR2) did not. Construction of chimeras between RyR1 and RyR2 showed that amino acids Lys954-Asp1112 retained full binding activity, whereas Leu922-Phe1075 had no binding activity. The RyR1 sequence Arg1076-Asp1112, previously shown to interact with the DHPR II-III loop (Leong, P., and MacLennan, D., H. (1998) J. Biol. Chem. 273, 7791-7794), bound to DHPR III-IV loop columns, but with only half the efficiency of binding of the longer RyR1 sequence, Lys954-Asp1112. These data suggest that the site of DHPR III-IV loop interaction contains elements from both the Lys954-Phe1075 and Arg1076-Asp1112 fragments. The presence of 4 +/- 0.4 microM GST-DHPR II-III or 5 +/- 0.1 microM His-peptide-DHPR III-IV was required for half-maximal co-purification of 35S-labeled RyR1 Leu922-Asp1112 on glutathione-Sepharose or Ni2+-nitrilotriacetic acid. Dose-dependent inhibition of 35S-labeled RyR1 Leu922-Asp1112 binding to GST-DHPR II-III and GST-DHPR III-IV by His10-DHPR II-III and His-peptide-DHPR III-IV was observed. These studies indicate that the DHPR II-III and III-IV loops bind to contiguous and possibly overlapping sites on RyR1 between Lys 954 and Asp1112.     

Activation of the alternative complement pathway and production of factor H by skeletal myotubes

Recent negative findings regarding differences in blood pressure (BP) and heart rate (HR) reactivity at work between Type A and Type B workers may stem from the failure to note the stressors to which they were exposed. In this naturalistic study, an objective work stressor--varying levels of ambient noise--was individually monitored among 123 normotensive males. We examined the relationship of Type A behavior (assessed by the Thurstone Temperament Schedule) to ambulatory BP and HR reactivity under high and low noise conditions. We also tested the hypothesized mediating function of tension arousal. Results of multiple regression analyses indicated that when workers were exposed to high noise levels (> or = 80 dB(A)), Type A behavior was positively related to diastolic BP (p = 0.029) and HR reactivity (p = 0.0001), even after adjusting for clinic values, time of measurement, worker activities, and body position during measurement. When the same workers were exposed to low noise levels, the results were not significant. This suggests that noise constitutes a stressor for Type A individuals, and highlights the importance of noting the actual stressor-exposure condition. In addition, Type A individuals reported high tension, noted concurrently with the ambulatory measurements. Tension arousal was also related to BP and HR reactivity. Adding the tension variable to the above regressions weakened the relationship between Type A behavior and BP and HR reactivity. Thus, the tension experienced by Type A workers exposed to noise stress may have served as a mediator of cardiovascular reactivity.