Retrospective evaluation of treatment time and efficiency of a predictable cantilever system for orthodontic extrusion of impacted maxillary canines

INTRODUCTION

Orthodontic extrusion of impacted maxillary canines requires careful biomechanical planning and the use of physiologic force. The aim of this study was to evaluate the time needed for orthodontic extrusion of impactions of different severities, using a device that can predictably apply forces under 0.6 N.

METHODS

Twenty-two patients who were consecutively treated were selected retrospectively, and a total of 30 impacted canines were studied. Indexes of impaction were used to measure severity on pretreatment panoramic radiographs. Statistical analysis was used to detect interactions between treatment time, complexity of impaction, age, and sex.

RESULTS

Treatment time was highly dependent on the patient's age; the shortest treatment time was observed in 11- to 12-year old patients. On the other hand, the severity of impaction had no effect on treatment time.

CONCLUSIONS

Applying physiologic force with the proposed device resulted in a short treatment time, which depended on the patient's age more than the impaction complexity. Few complications were associated with use of this device. Future prospective studies are needed to replicate these findings and confirm the recommended use of this device.

Expansion of permanent first molars with rapid maxillary expansion appliance anchored on primary second molars

Background

To evaluate how the amount of expansion of the primary second molars, the patient’s age, and the skeletal maturation stage influence the amount of expansion at the level of the permanent first molars.

Material and Methods

Fifty-five patients aged between 6 and 11 years with a cervical vertebral maturation stage of CS1 or CS2 were retrospectively selected. The intermolar width was measured before and after expansion to evaluate the amount of expansion achieved at the level of the primary second molars and the permanent first molars. Stepwise multiple linear regression was used to evaluate how the amount of primary molars expansion, the patient’s age, and the cervical vertebral maturation stage predict the amount of permanent molar expansion.

Results

A significant regression equation was found, and for every 1 mm of primary molar expansion, 0.91 mm of permanent molar expansion can be expected. An age between 6 and 11 years and the CS1 or CS2 skeletal maturation stage were not significant predictors of permanent molar expansion.

Conclusions

A rapid maxillary expansion appliance anchored on primary second molars is effective in expanding the permanent molars to correct a transverse maxillary deficiency in prepubertal patients, transferring the risks associated with the large forces used to the primary teeth.

Key words:Maxillary expansion, transversal deficiency, primary molars.

Many factors can affect the prevalence of hypertension in obese patients: role of cuff size and type of obesity

OBJECTIVE

To determine to what extent methodological errors, including measurements taken with inappropriate cuffs and/or inaccuracies in patient enrollment, can contribute to overestimating the prevalence of hypertension in overweight or obese women.

EXPERIMENTAL DESIGN

Randomized and comparative investigation in overweight or obese outpatient women of the Obesity Clinic, Internal Medicine Institute, Chieti University.

PATIENTS

In 1,791 overweight or obese women, randomly selected and stratified by age (41-60 years), blood pressure (BP) was taken with casual measurement in the morning. The entire study group was divided into two subgroups. In the first one, causal BP was measured with a standard-size cuff (RCS), while an appropriate large-size cuff was used for the second one (LCS). Patients of the latter subgroup were also divided by type of obesity (android and gynoid), based on their waist-to-hip ratio.

RESULTS

In the LCS subgroup, the hypertension prevalence rate was strikingly lower among overweight and obese women, as well as in the younger and older age groups, when compared with the corresponding RCS subgroups (p < 0.001). The hypertension prevalence rate was higher for all android obese subjects (53%), including younger (34%) and older (64%) groups, when compared with gynoid obese patients (29%, 18% and 42%, respectively).

CONCLUSIONS

A comparison of different reports on the prevalence of hypertension in obesity reveals considerable differences, due mainly to age, sex, race and income level. Nevertheless, our data seem to indicate that even after adjusting for the above-mentioned variables, two significant confounding factors, cuff hypertension and the prevalence of android obesity in the obese study population, could be responsible for over-estimating the prevalence of hypertension. It should be noted that for certain groups of overweight and obese women, the prevalence of hypertension becomes similar to the rate found among the general population, as reported in many large epidemiological surveys.

The prevalence of hypertension in gynaecoid and android obese women

Until now the different epidemiological studies performed have yielded widely different results in terms of the prevalence of hypertension in obese patients. This is mainly due to methodological errors in blood pressure (BP) measurements, including such false positives as white-coat or cuff hypertension, and more recently, to the different distribution in the study population of obese subjects at risk of hypertension (android obesity type). In 803 obese outpatient women (body mass index range: 28-45) randomly selected and subdivided into younger and older groups, and into android and gynaecoid, the casual BP was measured in the morning with a large size cuff. In addition, in 82 obese outpatients casual BP was measured simultaneously with the large and a standard size cuff. Another group of 94 patients was submitted to 24-h ambulatory blood pressure monitoring (ABPM). The aim was to observed if the use of inappropriate cuffs, or the incidence of white-coat hypertension and the prevalence of obese subjects at risk of hypertension, may contribute considerably to overestimating the prevalence of hypertension in obesity. The hypertension prevalence rate was 37.6% for the entire study group. The prevalence rate was 26.2% in women with gynaecoid type of obesity and 47.1% in android obese subjects. We could conclude that the use of inappropriate cuffs, office or white-coat hypertension and the prevalence of obese subjects at risk of hypertension, may contribute considerably to overestimating the prevalence of hypertension in obesity. The number of hypertensive subjects in younger obese subjects with gynaecoid fat distribution is similar to non-obese subjects who are age-adjusted, but our data confirm that the prevalence of hypertension in android type of obesity is significantly higher than in non-obese subjects.

[What is the real prevalence of hypertension in obesity?]

Many confounding variables (age, sex, race, income level) may contribute to an incorrect estimate of the prevalence of hypertension in the obese population. Furthermore, as far as methodology is concerned, both casual morning BP measurement and, the use, in the obese patient, of inappropriate cuffs both also contribute significantly to the overestimation with the inclusion of false positives even in relevant percentages. Different types of obesity (android or gynoid; visceral or subcutaneous) should be considered when enrolling obese patients in prevalence studies being android or visceral obesity at a higher hypertensive risk. At last and overall, universally recognized cutoff-points for obesity and hypertension should always be used when studying prevalence of hypertension among general population and/or among obese patients. When such conditions are not taken into account, inaccurate and misleading conclusions on the real prevalence of hypertension in obesity may result.

Correlations between endocrine gland ultrastructure and hormone titers in the fifth larval instar of Manduca sexta

Correlations were made between endocrine gland ultrastructure and circulating hormone titers of Manduca sexta to investigate the mechanisms of hormone biosynthesis and secretion. Both the prothoracic glands (PTG), which secrete ecdysone, and the corpora allata (CA), which secrete juvenile hormone (JH), were studied. In the prothoracic glands, the intracellular spaces increase in area and reach their maximum size following the major ecdysteroid peak in the fourth and fifth larval instars. Within the intercellular spaces are multivesicular sacs (MVS), structures which are clusters of vesicles bounded by another membrane. Since these sacs are largely depleted of their internal vesicles after the second cycle of tropic hormone stimulates the PTG to secrete ecdysone, the MVS probably release a gland cell product at this time. In the CA, concentric whorls of smooth endoplasmic reticulum are present in larval glands, when the JH titer is high, but are absent from pupal CA when the JH titer is low. The peak of JH at Days 6-8 of the fifth larval instar occurs after an increase is seen in the neurosecretory cell axon diameters suggesting that the CA are stimulated by a brain hormone to release JH. The number of Golgi complexes increases in pupal CA and dense bodies are present in pupal but not larval glands. These Golgi complexes may be involved in the manufacture of lysosomal enzymes which degrade JH within the gland itself.

[Presence of cytomegalovirus in maternal milk]

The AA. make in evidence the role of the milk as carrier of Cytomegalovirus. The virus was isolated in the 23.5% of the 17 specimens of milk examinated within the first 48 hours from the delivery. The contemporary observation of the urins of the womans was negative.