Modulation of synaptosomal plasma membrane-bound enzyme activity through the perturbation of plasma membrane lipid structure by bupivacaine

To determine whether young capuchin monkeys, Cebus apellaselectively interacted with others concerning novel foods, 11 infants (4.5-12 months) living in two groups were observed following presentation of familiar or novel foods. Foods were presented either to the whole group or to infants in a section of the home cage to which only they had access. Infants showed more frequent interest in others' food and picked up foods more frequently when foods were novel, and they tended to eat novel foods more frequently than familiar foods. The pattern was the same whether the foods were presented to the group or only to infants. Infants expressed interest in others' novel foods equally often before and after sampling these foods themselves. The frequency of interest in others' food correlated positively with age. It is concluded that acceptance of novel foods in these monkeys occurs readily regardless of socially provided information about edibility. Social interactions do not appear to make important contributions to acceptance of novel foods by infant capuchin monkeys.     

Pulp reactions to restoration of experimentally induced crown fractures

OBJECTIVES: Reattachment of the avulsed enamel-dentine coronal fragment to the remaining tooth structure has become an accepted clinical alternative to a resin composite build-up for the restoration of crown fractured teeth. Since little knowledge exists as to the pulpal response to this procedure, this study was designed to observe the condition of the pulp following experimentally induced crown fracture and restoration in monkeys. METHODS: Experiments were conducted in eight young green Vervet monkeys (Cercopithecus aethiops). In all, 64 fractured incisors were investigated. Light microscopic examination of pulp tissue specimens was carried out after 3 months of observation. RESULTS: The evaluation was restricted to specimens having a fracture plane within 2 mm of the pulp and no pulpal exposure. In general, pulp tissue was well preserved irrespective of the restorative procedure. Even if the restoration or the bonded tooth fragment had been lost during the follow-up period, the pulp generally remained in good condition. Inflammatory infiltrates where seen in only a few specimens and then as clusters of mononuclear leukocytes. Hard tissue repair was frequently observed and displayed various configurations from isolated hard tissue deposits to areas of extensive hard tissue repair in the coronal portion of the pulp. Pronounced hard tissue repair and occurrence of inflammatory cell infiltrates correlated with the presence of stainable bacteria on the fractured dentine surface. CONCLUSIONS: In the absence of direct exposure, reparative dentine is a frequent feature of the pulp's response to crown fracture and restoration with composite or reattachment of the crown fragment with dentine bonding. These restorative procedures appear to ensure continued function of the underlying pulp.     

Sleep disordered breathing and cardiomyopathy

OBJECTIVE: To describe the functional outcomes of weight loss and eating following a targeted chemoradiation protocol consisting of a selective supradose of intra-arterial cisplatin (150 mg/m2 per week for 4 weeks) with parenteral sodium thiosulfate and external-beam irradiation (1.8-2.0 Gy per fraction per day for 35 days). SUBJECTS AND DESIGN: Forty-seven patients with advanced head and neck cancer treated with a targeted chemoradiation protocol were monitored for weight and eating status before treatment and as long as 18 months after treatment. RESULTS: A statistically significant weight loss (P<.001) occurred during the targeted chemoradiation protocol, with a mean weight ratio of 90% of the starting weight. The ability to eat also declined, with an increase in reported swallowing difficulties and a need for percutaneous endoscopic gastrostomy tubes from 4 (9%) to 12 (26%). There were no significant changes in weight after the initial weight loss. Tumor stage and nodal involvement had no effect on weight loss. At the start of treatment, 18 patients (38%) reported normal eating and 4 (8%) required a feeding tube. By 18 months after treatment, 41 (87%) were eating normally, 34 (72%) reported normal eating, and 6 (13%) required a percutaneous endoscopic gastrostomy tube. CONCLUSIONS: Patients undergoing a targeted chemoradiation protocol for head and neck cancer lost about 10% of their pretreatment weight and had a decline in eating ability. Difficulty swallowing during the treatment may be due to adverse effects such as mucositis and nausea. By 18 months after therapy, most were able to eat normally and maintain their weight.     

Combined brachytherapy and external beam radiotherapy in normal monkey brains--experimental radiation necrosis evaluated by sequential magnetic resonance imaging

Radiation-induced brain damage was evaluated using sequential magnetic resonance (MR) imaging in monkeys more than 1 year after either brachytherapy or combined brachytherapy and external beam radiotherapy (EBRT). MR images were obtained 1 week, 1 month, 3 months, and subsequently every 3 months after brachytherapy, and the volume of the lesions was measured. In all four monkeys receiving only brachytherapy and three of the four animals receiving combined brachytherapy and EBRT, MR imaging revealed only transient extensive edema 1 week after treatment and ring enhancement, which was maximal 3 months after treatment, surrounding the implantation site. In one of the four animals undergoing combined brachytherapy and EBRT, MR images obtained 9 months after treatment showed an irregularly extending enhanced lesion with edema. MR images obtained 15 months after brachytherapy in this monkey showed the lesion extended into the contralateral hemisphere through the corpus callosum. Necropsy revealed severe radiation necrosis. This animal developed a very similar MR imaging presentation to that often encountered in human brains after combined brachytherapy and EBRT.     

Auditory function in 70- and 75-year-olds of four age cohorts. A cross-sectional and time-lag study of presbyacusis

Sucrose acetate isobutyrate (SAIB), a mixture of esters of sucrose with a composition approximating the name sucrose diacetate hexaisobutyrate, has been used for over 30 yr in many countries as a 'weighting' or 'density-adjusting' agent in non-alcoholic carbonated and non-carbonated beverages. As part of the demonstration of safety of SAIB as a direct food additive in human diets, a program of toxicity testing was started in the late 1950s that culminated in extensive studies of SAIB in rodents, monkeys and humans over the last decade. This review summarizes the toxicity data, accrued up until 1988, that precede the safety studies published elsewhere in this issue. SAIB has been shown to have very low acute and chronic toxicities in rats, monkeys, and, except for effects on the liver, in dogs at feeding levels of up to 10% in the diet. Slight effects seen in rats and monkeys at levels of 10% in the diet are unlikely to be directly caused by exposure to SAIB. In dogs, however, SAIB causes decreases in bromosulfophthalein (BSP) and indocyanine green (ICG) elimination from the serum immediately following a single dose, indicative of interference with biliary excretion. On repeated feeding in dogs, SAIB caused increases in serum alkaline phosphatase levels, but enzymes indicative of toxic effects on the liver were unaffected. On prolonged feeding to dogs, SAIB caused changes in liver morphology revealed by electron microscopy. All of these effects were reversed when SAIB was withdrawn from the diet. The no-effect level for these effects in dogs was near 5 mg/kg body weight, but these effects were not seen in rats fed up to 4 g/kg body weight/day, monkeys fed up to 10 g/kg body weight/day, or humans fed up to 20 mg/kg body weight/day. The toxicity and pharmacological studies in dogs, rats and monkeys suggest that the effect of SAIB on biliary excretion and liver morphology in dogs is essentially pharmacological rather than toxicological in nature and that the difference between the effects in dogs at levels as low as 5 mg/kg body weight/day, and the lack of effects in rats or monkeys at levels up to 10 g/kg/day is not merely a quantitative difference between species, but an absolute qualitative difference.     

Performance of a weight-lifting task by normal and deafferented monkeys.

The role of topographic information from a moving limb in controlling the trajectory of the limb was explored by comparing the ability of 3 normal and 2 unilaterally deafferented monkeys to generate criterion elbow flexions when opposed by different weights. When lifting initially unknown weights, both groups of monkeys reached maximum positions that were inversely related to load. The performance of the deafferented monkeys approached that of the normal monkeys on these first lifts of initially unknown weights. The preceding load had a greater effect on the initial lifts of the deafferented monkeys than on those of the normal monkeys. When allowed to repeatedly lift the same weight, both groups obtained a high density of reinforcement, but the responses of the deafferented monkeys were more dependent on the weight. The results are consistent with the hypothesis that the mechanical properties of muscle make an important contribution to compensation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Object permanence in rhesus monkeys (Macaca mulatta).

We evaluated the performance of 6 adult rhesus monkeys (Macaca mulatta) on object permanence tasks. In Experiment 1, monkeys received search tasks that correspond to Stages 4, 5, and 6 of object permanence. Subjects were successful on tasks of visible displacements (Stages 4 and 5) but failed to find the object in invisible displacements (Stage 6). The monkeys adopted a search strategy of investigating a specific hiding location. In Experiment 2, monkeys were given a second opportunity to find the object if they investigated a location that was part of the displacement on their first search. Subjects relied on the same search strategy identified in Experiment 1. In Experiment 3, the experimenter hid the object in her hand rather than a container. The monkeys failed to recover the object, and individual differences were found in the strategies used. These results suggest that the upper limit of object permanence in rhesus monkeys is Stage 5. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of selective neonatal temporal lobe lesions on socioemotional behavior in infant rhesus monkeys (Macaca mulatta).

Normal infant monkeys and infant monkeys with neonatal damage to either the medial temporal lobe or the inferior temporal visual area were assessed in dyadic social interactions at 2 and 6 months of age. Unlike the normal infant monkeys, which developed strong affiliative bonds and little or no behavioral disturbances, the lesioned monkeys (each of which was observed with an unoperated control) exhibited socioemotional abnormalities and aberrant behaviors. The socioemotional changes predominated at 6 months of age and were particularly severe in monkeys with medial temporal lesions. In both the pattern and time course, the socioemotional deficits produced by the neonatal medial temporal lesions bear a striking resemblance to the behavioral syndrome in children with autism. Further analysis of these lesion-induced abnormalities in nonhuman primates may therefore provide insight into this debilitating human developmental disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fluoride toxicity: a biochemical and scanning electron microscopic study of enamel surface of rabbit teeth

The present study has been carried out to investigate the effect of fluoride toxicity on the morphology as well as inorganic chemical constituents of rabbit teeth. Rabbits were administered sodium fluoride at a dose of 10 mg NaF/kg body weight every 24 h for 18 and 23 months. The incisor and molar teeth (whole tooth) were investigated for fluoride, calcium and phosphorus content in 18- and 23-month treated animals. The enamel surfaces of incisor teeth of 23-month treated animals were examined under scanning electron microscope. A significant increase in fluoride levels and significant decrease in calcium content was found following fluoride administration for 18 and 23 months as compared to control. Ca/P ratio was significantly increased only in 23-month treated animals. The scanning electron micrographs revealed hypoplastic, rough, uneven, pitted and cracked enamel surfaces covered with granular deposits as a result of excessive intake of fluoride. It can be concluded that long term fluoride administration leads to severe structural alterations on the enamel surface, possibly through defective mineralization.     

Angiographic patterns of splenic lesions following blunt trauma. An experimental study in monkeys

Splenic angiography was performed before and after graded blunt trauma to the spleen in 15 monkeys. In 9 of these, followup angiography could be performed in week or more later. Pronounced spasm of the splenic artery and leakage of contrast medium into the peritoneal cavity were found to imply a serious prognosis. Local reversible spasm of arterial branches can cause transient defects in parenchymal filling. Larger defects corresponding to hematoma, extravasation of contrast medium, and displacement of vessels may be compatible with good primary prognosis. If, however, these signs indicate that the lesion is of sufficient magnitude and has a peripheral location there is a risk that extensive bleeding will occur. So-called delayed ruptures never occurred in this study.     

Live attenuated simian immunodeficiency virus (SIV)mac in macaques can induce protection against mucosal infection with SIVsm

OBJECTIVE: To investigate whether vaccination of macaques with attenuated simian immunodeficiency virus (SIV)macC8 could induce long-term protective immunity against rectal exposure to SIVsm and intravenous exposure to the more divergent HIV-2. DESIGN AND METHODS: Eight months after vaccination with live attenuated SIVmacC8, four cynomolgus monkeys were challenged with SIVsm intrarectally and another four vaccinated monkeys were challenged with HIV-2 intravenously. Sixteen months after SIVmacC8 vaccination, another two monkeys were challenged with SIVsm across the rectal mucosa. Two vaccinees shown to be protected against SIVsm were rechallenged 8 months after the first challenge. Ten naive animals were used as controls. Serum antigenaemia, virus isolation, antibody responses, cell-mediated immunity and CD4+ and CD8+ T-cell subpopulations were monitored. PCR-based assays were used to distinguish between virus populations. RESULTS: At the time of challenge, eight out of 10 vaccinees were PCR-positive for SIVmacC8 DNA but no virus could be isolated from peripheral blood mononuclear cells. After SIVsm challenge, three out of six vaccinees were repeatedly SIVsm PCR-negative. In one of the three infected monkeys, the challenge virus was initially suppressed but the monkey ultimately developed AIDS after increased replication of the pathogenic virus. Rechallenged monkeys remained protected. All HIV-2-challenged vaccinees became superinfected. All controls became infected with either SIVsm or HIV-2. At the time of challenge the vaccinees had neutralizing antibodies to SIVmac but no demonstrable cross-neutralizing antibodies to SIVsm or HIV-2. Titres of antigen-binding or neutralizing antibodies did not correlate with protection. Cytotoxic T-cell responses to SIV Gag/Pol and virus-specific T-cell proliferative responses were low. CONCLUSION: The live attenuated SIVmacC8 vaccine was able to induce long-term protection against heterologous intrarectal SIVsm challenge in a proportion of macaques but not against the more divergent HIV-2, which was given intravenously.     

Subchronic toxicity studies with the leukotriene D4 antagonist RG 12525

Preclinical safety studies with the leukotriene D4 antagonist RG 12525 were conducted by the oral route in mice, rats, and monkeys. Oral administration of RG 12525 was repeated daily in studies up to 6 months in duration. RG 12525 was shown to have limited high-dose toxicity after repeated oral administration. The effects of RG 12525 were strongly dependent upon the species considered. High doses of RG 12525 caused significant increases in liver weight in mice, rats, and monkeys that were associated with diffuse hepatocellular hypertrophy in mice and rats but not in monkeys. No related clinical chemistry changes were observed in any of the species and hepatic activities of peroxisomal enzymes or cytochrome P450 were increased only slightly. Proliferation of brown adipose tissue (BAT) was observed in rats and mice but not in monkeys. The BAT reaction was more pronounced in the interscapular area but it was also observed in other subcutaneous locations as well as in mediastinal and bone marrow fat. In all locations, the RG 12525-induced BAT had some morphological similarities with cold-adapted BAT. Repeated administration of RG 12525 at high doses to female rats resulted in a lack of progression to the luteal phase of the estrous cycle that was reversible after discontinuation of treatment. Finally, RG 12525 was nephrotoxic in mice with males being more sensitive than females.     

Transplantation of the fetal olfactory placode restores reproductive cycles in female rhesus monkeys (Mucaca mulatta) bearing lesions in the medial basal hypothalamus

The purpose of this study was to determine whether loss of the reproductive cycle after lesions of the medial basal hypothalamus can be reversed by transplantation of the embryonic olfactory placode (OP) into female rhesus monkeys. Seven adult female rhesus monkeys with regular menstrual cycles received bilateral radiofrequency lesions in the arcuate nucleus and the median eminence. After confirmation of anovulation in these monkeys, four monkeys were stereotaxically implanted with the OP obtained from monkey fetuses on embryonic days 35-36. The remaining three monkeys were similarly implanted with embryonic cerebellum (CB) as a control. Fetuses were delivered by cesarean section, and the OP and CB were immediately dissected out using a stereomicroscope. Fetal tissue was then cut into small pieces (< 1 mm3), mixed with artificial cerebrospinal fluid containing small pieces of Gelfoam, and stereotaxically injected into the infundibular recess of the third ventricle. The recovery of ovulatory cycles in recipient monkeys was observed for at least 6 months; sex skin color changes and menstrual records were obtained daily, and serum samples for LH, estrogen, and progesterone were obtained twice a week. Three of four OP-transplanted monkeys resumed their ovulatory cycles within 2 months, whereas the fourth monkey, an elderly female, failed to recover her cycle. In contrast, none of the three CB-transplanted monkeys resumed ovulatory cycles. Histological examination indicated that 1) lesion scars were present in the median eminence-stalk region as well as the medial basal portion of the arcuate nucleus of all seven brains; and 2) cartilage was present in the third ventricles of the OP-implanted brains. Moreover, immunocytochemical staining revealed that in all OP monkeys, small, round, and immature LHRH-positive cells with fine short processes were found in the third ventricle and/or median eminence-stalk region, whereas no similar LHRH cells were found in CB-transplanted monkeys. It is concluded, therefore, that implantation of LHRH neurons derived from the fetal OP can result in resumption of the ovulatory cycle in female monkeys whose own LHRH pulse-generating mechanisms were impaired. Moreover, the results suggest that LHRH neurons derived from embryonic OP possess the physiological functions necessary for the stimulation of gonadotropin secretion.     

Biocompatibility of Optibond and XR-Bond adhesive systems in nonhuman primate teeth

This study evaluated the histologic responses of two different adhesive systems on the teeth of seven healthy adult monkeys. Class V cavities in 128 teeth were observed at 7,21 to 27, and 90 to 97 days. Statistical data showed no significant differences in pulp inflammation between the Optibond (Kerr), XR-Bond (Kerr), and IRM (Caulk) groups in pulps at the three time intervals. Some odontoblastic disruption and inflammation was seen in pulps restored with XR-Primer at the three time intervals. Pulp healing was similar in teeth treated with both direct-capped Optibond and calcium hydroxide, and there was no significant increase in pulpal inflammation with time. No abscesses or necrotic pulps were seen in any teeth. Optibond and XR-Bond adhesive systems are biologically acceptable in nonhuman primate pulp tissues.     

Changes in bone mass and bone biomarkers of cynomolgus monkeys during pregnancy and lactation

A substantial amount of calcium is transferred from the mother to the fetus and infant during pregnancy and lactation. Involvement of the skeleton in meeting this demand should be reflected in changes in bone mass and turnover. The purpose of the study was to determine the effects of pregnancy, lactation, and recovery on the skeleton in 43 young (prepeak bone mass) female monkeys. Whole body (WBBMC) and lumbar vertebrae 2-4 bone mineral content were determined by dual x-ray absorptiometry at baseline and 1, 4, and 10 months postpartum. Alkaline phosphatase, bone Gla protein, and urinary crosslinks were measured at baseline, during the third trimester, and 1, 4, and 10 months postpartum. Compared to nonpregnant, nonlactating monkeys, pregnant monkeys had similar rates of bone mass gain (nonpregnant, nonlactating WBBMC, 25+/-9 mg/day; pregnant WBBMC, 20+/-14 mg/day). Compared to pregnant monkeys, lactating females had increased bone turnover, as indicated by elevated bone biomarker levels (lactating alkaline phosphatase, 259+/-20 IU/L) and decreased bone mass (lactating WBBMC, -99+/-21 mg/day). Densitometry showed that bone mass gain in the lactating monkeys did not compensate for lactational loss by 10 months postpartum (WBBMC, 6.95+/-9 mg/day). This lack of recovery may have been due to the fact that serum estrogen concentrations were just beginning to return to baseline at 10 months postpartum. In conclusion, the cynomolgus monkey skeleton responds similarly to that of women during pregnancy and lactation. Recovery from lactational bone loss is not complete by 10 months postpartum.     

Quantitative behavioral study of the acute and long-term effects of two-stage bilateral 6-OHDA-induced lesions of the nigrostriatal dopaminergic system in monkeys.

Bilateral lesions of the nigrostriatal dopaminergic system (2-stage lesions separated by 5–6 months) were induced in 3 monkeys trained to initiate forelimb-reaching movements toward a visual target. After each lesion, analysis of the task performance over several months of regular testing showed that the latency to initiate the movement was permanently prolonged in monkeys showing 90% or more striatal dopamine depletion, whereas animals with less severe depletion completely recovered the task performance. Several months after a unilateral nigrostriatal damage, a lesion on the other side produced impairments only on the side of the body contralateral to that second lesion and did not reinstate the deficits on the side previously affected by the first lesion. This suggests that the remaining intact nigrostriatal dopaminergic system may not be involved in the long-term behavioral recovery observed in monkeys with a unilateral lesion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fatal disseminated cercopithecine herpesvirus 1 (herpes B infection in cynomolgus monkeys (Macaca fascicularis)

Two adult female cynomolgus monkeys (Macaca fascicularis) that had been housed together for 4 months died within 2 weeks of each other after brief illnesses. Monkey No. 1 presented with collapse, watery stool, and hypothermia and died overnight. Monkey No. 2 presented with dyspnea, nasal discharge, leukopenia, and hypoproteinemia and was euthanized after 2 days. Both animals had peritoneal effusions, massive necrosis of pharyngeal, esophageal, and gastric mucosa, and multifocal hepatic and pancreatic necrosis. Monkey No. 2 also had lingual ulcers and locally extensive necrosis of spleen, adrenal glands, and lymph nodes. Large numbers of eosinophilic intranuclear inclusion bodies were present in epithelial and syncytial cells adjoining the necrotic foci in Monkey No. 2 but were absent in Monkey No. 1. Monkey No. 1 seroconverted to cercopithecine herpesvirus 1 (CHV-1, commonly known as herpes B) in the month before death. CHV-1 was isolated from a sample of stomach from Monkey No. 2, and electron microscopy of liver from this animal demonstrated herpesvirus particles within hepatocytes. Both animals were seropositive for simian type D retrovirus, and the virus was cultured from the liver of Monkey No. 2. A diagnosis of disseminated CHV-1 infection was made, possibly occurring secondary to immunosuppression due to infection with simian type D retrovirus. Although a high percentage of cynomolgus monkeys are apparently infected with CHV-1, disseminated disease is rare. Because infection with CHV-1 in humans is associated with a high fatality rate, familiarity with the lesions of disseminated infection with this virus is important.     

The effects of long-term ovariectomy and estrogen replacement therapy on learning and memory in monkeys (Macaca fascicularis).

This study determined the effects of estrogen loss and replacement therapy on learning and memory function in monkeys (Macaca fascicularis). The ability to learn, remember, and perform reversals of object discriminations and the accuracy on a spatial delayed response task were found to be comparable in young adult surgically menopausal monkeys receiving estrogen or placebo treatment for 5 or 16 months. Learning and memory abilities were comparable with baseline values following 2, 12, or 24 months of ovariectomy in monkeys. Pre- and postoperative injections of scopolamine in a subset of monkeys revealed only subtle increases in sensitivity on the delayed response task following ovariectomy. These observations in surgically menopausal monkeys have some parallels with those made in surgically menopausal women and suggest that, in the absence of other confounding factors, certain aspects of learning and memory may not be influenced by estrogen in primates. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of CO2 laser in treatment of cervical dentinal hypersensitivity

The effectiveness of CO2 laser therapy in the reduction and elimination of dentinal hypersensitivity in vivo and its thermal effects on tooth surfaces in vitro were investigated. Twenty-three patients with 91 sensitive teeth participated in this study and were followed for 3 months. The parameters used with CO2 laser were 1 W in a continuous wave mode and irradiation time ranging from 5 to 10 s. Hypersensitivity was assessed by thermal stimulus (a blast of air from a dental syringe). Thermal effects were measured by thermography using 10 extracted human teeth. After laser treatment, all patients were immediately free from sensitive pain. Over 3 months, the CO2 laser treatment reduced dentinal hypersensitivity to air stimulus by 50%. All teeth remained vital with no adverse effects. Thermography revealed no temperature increase on irradiated tooth surfaces subjected to water coolant. These results show that the CO2 laser is useful in the treatment of cervical dentinal hypersensitivity without thermal damage to pulp.     

A dosimetric analysis of behavioral effects of acute toluene exposure in rats and humans

Contradictory findings from studies on pretreatment malalignment as a risk factor for relapse of maxillary incisor alignment may be due to inappropriate sample selection and measurement technique. In an attempt to clarify the issue, 745 sets of study models made before (T1) and after (T2) orthodontic treatment and at long-term out of retention (T3) were screened. On the basis of the configuration of the maxillary anterior teeth on the T3 study models, three groups were established: one with significant spacing (group 1, n = 30); one with significant irregularity (group 2, n = 49); and one with perfect alignment (group 3, n = 28). The occlusal surfaces of the 321 maxillary study models at T1, T2, and T3 were photocopied and the tooth anatomic contact points digitized. An algorithm was used to fit the dental arch to the digitized points. Amount of incisor rotation and anatomic contact point displacement of the maxillary anterior teeth relative to the dental arch were computer generated. Interdental spaces in the maxillary anterior segment, as well as overjet and overbite, were measured manually. Nonstructural data were collected from the charts. Logistic regression analyses revealed that irregularity was associated with greater anatomic contact displacement and with greater incisor rotation both at T1 and T2 (P < 0.01). Similar analyses also revealed that spacing was associated with greater interdental spaces at T1 and T2 (P < 0.01). Correlation analyses revealed that the pattern of pretreatment rotational displacement has a strong tendency to repeat itself after retention (P < 0.001), as opposed to the pattern of contact point displacement and interdental spacing.