Significant Difference In Shrinkage Research Articles

Volumetric changes in post hemiglossectomy reconstruction with anterolateral thigh free flap versus radial forearm free flap

The volume of the reconstructed tongue is considered a critical factor for tongue function. Studies investigating the difference in volume loss between the anterolateral thigh free flap (ALTF) and radial forearm free flap (RFFF) used in reconstruction of the tongue after hemiglossectomy are lacking. The aim of this study was to determine whether there is a significant difference in shrinkage between these two flaps. This was a retrospective study of all patients treated for tongue cancer by hemiglossectomy who underwent either ALTF or RFFF reconstruction at the University of Florida College of Medicine between January 2018 and April 2022. Computed tomography scans were used to measure the volumetric changes in the ALTF and RFFF at two time points over a 6-month period. Of the 85 patients assessed, 10 fulfilled the inclusion criteria: five were reconstructed with an ALTF and five with a RFFF. All underwent adjuvant radiotherapy. The mean ALTF percentage shrinkage was 39.6% ± 3.9%, while for the RFFF it was 51.1% ± 6.2% (P = 0.008). Therefore, it is recommended that the difference in volume loss between the two flaps is taken into consideration. It is suggested that in hemiglossectomy cases, the ALTF is made 1.4 times larger than the defect, while the RFFF is made 1.5 times larger.

Hybrid Interfacial Transition Zone between Wet-On-Wet Casted Concrete-Microstructure and Mechanical Properties.

The manufacture of elements containing two types of concrete allows for the minimization of the amount of Portland cement by matching the properties of concrete with local structural and durability requirements. The most common production method of the hybrid element is wet–on–hard and wet–on–wet. Casting wet–on–dry is the most common approach while casting wet–on–wet has been used mostly for concrete overlays and screeds. The study focuses on the wet–on–wet method but is applied in the production of vertical and horizontal elements. Bond-behavior and micro properties of the wet–on–wet casting interface of ultra–high–performance concrete (UHPC)–normal strength concretes are investigated. The obtained results indicate the formation of a hybrid interfacial transition zone between the two types of casted concrete. The binder matrix located in this zone appeared to combine properties of both used concrete. Porosity, phase composition, and presumably also strength, changed gradually. Furthermore, despite significant differences in shrinkage, no microcracking or delamination was observed in that zone. The ultimate flexural and compressive strength of the produced elements were either equal to the stronger concrete or were higher than the weaker of the used concrete.

Quantifying the shrinkage of laryngeal laser excisions: a case control study

Heat from transoral laser microsurgery can cause tissue shrinkage, impacting the surgical margin. This study aimed to compare shrinkage between cold steel and carbon dioxide laser resections of laryngeal lesions. A European Laryngological Society type II resection was performed on 10 mm 'lesions' marked on both the true and false folds of fresh-frozen human larynxes; specifically, laser resection was performed on the right side and cold steel resection on the left side. Twenty-eight larynxes were included. Tissue shrinkage was significantly higher in laser resection (35-45 per cent) compared to cold steel resection (8-14 per cent) (p < 0.0001). In most cases, there was no significant difference in shrinkage between true and false fold sites. This study demonstrates that specimen shrinkage is significantly higher in laser resections. This shrinkage will affect the size of the surgical margin; surgeons and pathologists should be aware of this when considering positive and close margins.

External iliac artery extension causes greater aneurysm sac regression than the bell-bottom technique or iliac branch endoprosthesis for repair of concomitant infrarenal aortic and iliac artery aneurysm

ObjectiveAneurysmal extension of abdominal aortic aneurysms (AAAs) to the common iliac artery (CIA) presents a technical challenge to successful endovascular abdominal aortic aneurysm repair (EVAR). In the present study, we compared sac shrinkage and perioperative outcomes after the bell-bottom technique (BBT), internal iliac artery embolization and external iliac artery extension (EIE), and iliac branch endoprosthesis (IBE). MethodsUsing the Vascular Quality Initiative database, a retrospective analysis was conducted for patients who had undergone EVAR from 2013 to 2019. The demographic, anatomic, and perioperative data were analyzed. All patients with a proximal aortic neck length <10 mm and aortic graft diameter >32 mm were excluded from the analysis. The patients were subdivided into four groups according to the distal limb strategy: group 1, control group with a bilateral common iliac artery limb <20 mm; group 2, BBT with either a unilateral or bilateral limb >20 mm; group 3, EIE technique; and group 4, IBE. The primary endpoint was the maximal change in the aortic diameter during follow-up. The secondary endpoints included postoperative complications and the rate of endoleak. ResultsThe records for 14,455 patients who had undergone EVAR were queried and 5788 met the anatomic criteria. The average age was 73 years, and 86.3% were men. The maximal change in the aortic diameter in the control, BBT, IBE, and EIE groups was −7.2 mm, −6.1 mm, −4.6 mm, and −6.8 mm, respectively (P = .06). The differences were not statistically significant on univariate analysis at an average follow-up of 405 days. However, on multivariable analysis (P = .01), compared with the control group, the BBT and IBE groups were 18.4% (odds ratio [OR], 0.816; 95% confidence interval [CI], 0.68-0.98) and 48.0% (OR, 0.52; 95% CI, 0.33-0.82) less likely to experience aneurysmal shrinkage, respectively. In contrast, the EIE group showed no significant difference in shrinkage compared with that in the control group. Multivariable analysis of the groups also revealed that compared directly with the BBT group, the EIE group was 69.5% more likely to have experienced shrinkage in the aortic aneurysmal diameter (OR, 1.70; 95% CI, 1.05-2.75). The BBT and IBE groups had a significantly higher rate of type II endoleaks (17.63% and 16.95%, respectively; P = .03). The EIE group had a higher rate of type Ib endoleaks (1.9%) compared with the BBT (1.1%), IBE (1.7%), and control (0.3%) groups (P = .01). No differences were found between the groups in terms of postoperative myocardial infarction (P = .47) or respiratory (P = .61) or intestinal (P = .71) complications. However, the rates of limb complications and reoperation were higher in the EIE group. ConclusionsThe present study revealed that the EIE technique was more likely to demonstrate shrinkage in the aortic aneurysmal diameter than were the BBT and IBE groups compared with the control group on multivariable analysis. The EIE technique was also more likely to result in aneurysmal sac shrinkage than was the BBT group, albeit with greater rates of limb-related complications.

Effects of long-term preservation on amphibian body conditions: implications for historical morphological research.

Measurements of historical specimens are widely applied in studies of taxonomy, systematics, and ecology, but biologists often assume that the effects of preservative chemicals on the morphology of amphibian specimens are minimal in their analyses. We compared the body length and body mass of 182 samples of 13 live and preserved (up to 10 years) anuran species and found that the body length and body mass of preserved specimens significantly decreased by 6.1% and 24.8%, respectively, compared to those measurements of their live counterparts. The changes in body length and mass also exhibited highly significant variations between species. Similarly, there were significant differences in shrinkage of body length and body mass between sexes, where males showed greater shrinkage in body length and body mass compared to females. Preservation distorted the magnitude of the interspecific differences in body length observed in the fresh specimens. Overall, the reduction in body length or mass was greater in longer or heavier individuals. Due to the effects of preservation on amphibian morphology, we propose two parsimonious conversion equations to back-calculate the original body length and body mass of studied anurans for researchers working with historical data, since morphological data from preserved specimens may lead to incorrect biological interpretations when comparing to fresh specimens. Therefore, researchers should correct for errors due to preservation effects that may lead to the misinterpretation of results.

Surgical Technique and Clinically Relevant Resection Cavity Dynamics Following Implantation of Cesium-131 Brachytherapy in Patients With Brain Metastases

Cesium-131 (Cs-131) brachytherapy is used to reduce local recurrence of resected brain metastases. In order to ensure dose homogeneity and reduce risk of radiation necrosis, inter-seed distance and cavity volume must remain stable during delivery. To investigate the efficacy of the "seeds-on-a-string" technique with intracavitary fibrin glue in achieving cavity volume stability. We placed intra-operative Cs-131 brachytherapy in 30 cavities post-resection of brain metastases. Seeds-on-a-string were placed like barrel staves within the cavity with fibrin glue. Serial MRI imaging occurred post-operatively. Pre-operative tumor volumes were compared with post-operative cavity volumes to evaluate volume stability. Thirty patients who underwent post-resective stereotactic radiosurgery (SRS) were used as a control group for volumetric comparison. Cs-131 and SRS patients exhibited consistent cavity shrinkage over the median 110-day follow-up (p<.001), with total median shrinkage of 56.5% (Cs-131) and 84.8% (SRS). During the first month when ~88% of Cs-131 dosage is delivered, however, there was non-significant volume decrease in the Cs-131 group (median 22.0%; p=.063), while SRS patients showed significantly more shrinkage (46.7%; p=.042). No events of radiation necrosis occurred in either group. Cs-131 patients exhibited significantly less cavity shrinkage than SRS patients during the first critical month with 88% Cs-131 dose delivery. This significant difference in shrinkage suggests that the intracavitary seeds-on-a-string technique facilitates increased cavity stability, promoting more homogenous dose delivery.

Results of bony chest wall reconstruction with expanded polytetrafluoroethylene soft tissue patch.

The early and long-term outcomes of bony chest wall reconstruction with expanded polytetrafluoroethylene (Gore-Tex) soft tissue patch remain a concern. No clinical study has reported the shrinkage of Gore-Tex following reconstruction to date. Thirty-seven patients who underwent bony chest wall reconstruction from 1994 to 2012 were retrospectively reviewed. Postoperative chest computed tomography images of 17 patients were examined, and shrinkage of reconstruction materials was measured and compared. Gore-Tex was used for reconstruction in 18 patients, autologous materials were used in 14, Marlex mesh was used in four, and Medifit felt was used in one. No surgery-related deaths were observed. Twenty patients experienced early postoperative complications. Four patients experienced local infection. One patient with Marlex-mesh experienced empyema 33 days postoperatively. Chest drainage time in the Gore-Tex patients was significantly lower than in patients with other types of prosthetic reconstruction. No dislocation or dehiscence was found. Shrinkage of Gore-Tex was absent in 4 patients and acceptable in seven patients. No granulation formation was evident around the Gore-Tex, No significant difference in shrinkage was seen between the different materials used. Chest wall reconstruction with Gore-Tex was feasible with favorable early and long-term results.

Drying characteristics of selected local vegetables

Fresh tomatoes, okra and pepper were uniformly sliced to 1cm thickness and dried using cabinet and vacuum oven drying at 45oC to moisture contents of 12.5% and 11.8% for tomatoes, 13.0% and 12.0% for Okra, 11.0% and 10.5% for Pepper. Weight loss at 5 minutes interval and consequently the drying rates at every 30 minutes were observed. The dried products were also analyzed for bulk density, viscosity, pH and rehydration. The sensory evaluation of the dried samples, using preference test showed that drying with cabinet drier gave an acceptable result for tomatoes and okra in terms of colour and texture. For pepper, better-dried products were obtained with vacuum oven drying in terms of colour. There was no significant difference in shrinkage by the two drying methods in all the samples at both 1% and 5% levels of probability.

Effect of a Light-Emitting Diode on Composite Polymerization Shrinkage and Hardness

This study evaluated the effect of light-emitting diodes (LEDs) on polymerization shrinkage and bottom-to-top hardness ratios of composites. Six LEDs (Elipar FreeLight, 3M ESPE, St. Paul, MN, USA; Versalux, Centrix, Shelton, CT, USA; Ultra-Lume LED2, Ultradent, South Jordan, UT, USA; Zap LED only, CMS-Dental/Soft-Core Texas, North Richland Hills, TX, USA; Zap dual light; and L.E. Demetron I, Kerr Manufacturing Inc., Orange, CA, USA) and a quartz-tungsten-halogen (QTH) light (Optilux 501, Kerr Manufacturing Inc.) were tested. Ten specimens each of a microhybrid (Point 4, Kerr Manufacturing, Inc.) and a hybrid (Filtek Z250, 3M ESPE, St. Paul, MN, USA) composite, measuring 2 mm thick by 5 mm in diameter, were polymerized using each of the lights. Linear shrinkage was recorded using a contactless displacement instrument. Ten specimens were also polymerized with each light to determine the Knoop hardness number (KHN) at the top and bottom surfaces. For the microhybrid, Zap dual light had the least volumetric shrinkage 2.08% (+/- 0.33) and Elipar FreeLight had the highest 3.02% (+/- 0.73). There was no significant difference (p < or = .05) in shrinkage for the LEDs when compared with the Optilux 501. The hybrid showed the least amount of shrinkage with the L.E. Demetron I, 1.42% (+/- 0.12), and the greatest with the Zap dual light, 2.47% (+/- 0.31). The Ultra-Lume LED2 (p < or = .05) and Zap LED and dual light (p < or = .001) had significantly greater shrinkage than did the Optilux 501. Zap LED had the lowest depth of cure with a bottom KHN of 11.46 (+/- 2.71) and 33.62 (+/- 3.57) for the microhybrid and hybrid, respectively. The L.E. Demetron I had the highest bottom hardness value for the microhybrid, with a value of 40.65 (+/- 1.50). The Optilux 501 had the highest bottom hardness value for the hybrid, with a value of 62.03 (+/- 0.82). The Zap LED and dual light and Versalux lights had significantly lower bottom-to-top hardness ratios than did the QTH (p < or = .001) with the microhybrid. There was no statistically significant difference in shrinkage for the microhybrid with any of the lights tested. The hybrid, however, showed significantly less shrinkage with the halogen compared with the Ultra-Lume LED2 and Zap LED and dual light. All LEDs had equal or lower bottom hardness values than did the QTH, except for L.E. Demetron I with the microhybrid.

Shrinkage in the Body Length of Myctophid Fish (Diaphus Slender-Type spp.) Larvae with Various Preservatives

There was significant shrinkage in the body lengths of larvae of the myctophid fish Diaphus slender-type spp. for the first two weeks after they were preserved in 5% and 10% formalin, 70% and 90% ethyl alcohol, and 70% isopropyl alcohol solutions. The shrinkage was greatest in 70% isopropyl alcohol, followed by 90% ethyl alcohol, 70% ethyl alcohol, and the formalin solutions. No significant difference in shrinkage was observed between the 5% and 10% formalin solutions. Linear regressions described the relationships between body length before and after 140 days of preservation.

The effect of monopolar radiofrequency treatment pattern on joint capsular healing. In vitro and in vivo studies using an ovine model.

The purpose of this study was to compare joint capsular healing after two delivery patterns of monopolar radiofrequency energy: 1) uniform treatment of the joint capsule (paintbrush pattern) and 2) multiple single linear passes (grid pattern). First, an in vitro study was performed to compare the percent shrinkage of these two treatment patterns using the femoropatellar joints (stifles) of six sheep. Monopolar radiofrequency energy (settings, 70 degrees C/15W) was applied to the lateral joint capsule; the treated area was approximately 10 x 10 mm. There was no significant difference in shrinkage between the grid (27% +/- 8.7%) and paintbrush (29% +/- 7.9%) patterns. In the in vivo study, stifles of 24 sheep were randomly assigned to the paintbrush or the grid pattern groups and treatment was performed arthroscopically. Sheep were sacrificed immediately after surgery, or at 2, 6, or 12 weeks after surgery. At 6 weeks after surgery, confocal microscopy demonstrated that treated areas had almost completely repaired in the grid group; some nonviable areas were still present in the paintbrush group. Mechanical testing at 6 weeks indicated that joint capsule in the grid group had better mechanical properties than capsule in the paintbrush group. This study revealed that radiofrequency treatment of joint capsule in a grid pattern allowed faster healing than tissue treated in a paintbrush pattern.

Effect of processing method on the dimensional accuracy and water sorption of acrylic resin dentures

Statement of problem. Acrylic resin complete dentures exhibit certain unavoidable dimensional changes. Processing shrinkage and expansion due to water uptake are 2 important aspects influencing dimensional accuracy. Purpose. This study investigated linear dimensional changes and water sorption of dentures processed by dry and wet heat with different rates of cooling. Methods. Fine crosses marked on tinfoil inserts were placed at the incisive papilla and tuberosity regions of edentulous maxillary casts and incorporated into the dentures during polymerization by 3 processing techniques. A traveling microscope was used to measure the distances between the reference points to determine dimensional changes. Water uptake and content were determined by the mass changes of the dentures with an electronic balance. Data of linear dimensional change and water sorption were analyzed by multivariate analysis of variance and analysis of variance, respectively. Bonferroni simultaneous confidence intervals (95%) were applied for multiple comparison. Results. Dry heat–processed and water bath–processed acrylic resin dentures did not exhibit significant differences in shrinkage (0.42% to 0.58%) at water saturation. Amounts of water sorption of dentures processed by dry and wet heat (0.50 and 0.48 mass%, respectively) were not significantly different, and their associated expansion did not entirely compensate for the processing shrinkage. The initial water content of dry heat–processed dentures (1.77 mass%) was unexpectedly slightly higher than that of wet heat–processed dentures (1.68 mass%). The rate at which the dentures cooled did not affect their initial water content and subsequent water uptake. Conclusions. Water uptake of dry and wet heat–processed acrylic resin dentures after deflasking was in both cases low, and the dentures did not reveal significant differences in shrinkage at water saturation. Air oven–processed and water bath–processed acrylic resin dentures show similar dimensional shrinkage at water saturation. (J Prosthet Dent 1999;81:300-4.)

Lifting technique and abdominal belt usage: a biomechanical, physiological and subjective investigation

Some 10 male subjects carried out a repetitive lifting task for 15 min under four conditions on separate days. Subjects used either a squat lifting or a stoop lifting technique with or without an abdominal belt on each day. Measurements of spinal shrinkage, heart rate, perceived exertion and regional body pain were made under each condition. Although there was a significant difference in spinal shrinkage under all lifting conditions compared with shrinkage during 15 min of quiet standing (4.36 ± 2.24 vs. 1.13 ± 1.18 mm), there were no significant differences in shrinkage between the conditions. The subjects' heart rates were higher during the squat lift than the stoop lift (123 vs. 97 beats/min; p < 0.001). While the squat lift was perceived to be the safest lift by 90% of the subjects, 60% regarded this lift as the least preferred method (with or without the belt). Although all 10 subjects perceived the safest lifting method to involve the use of the belt, 50% rated the belt as their least preferred lifting condition. The findings cast doubt on the efficacy and acceptability of both abdominal belts and the practice of training workers in ‘safe’ lifting techniques and indicate that individual characteristics and preferences need to be considered when attempting to improve the safety of manual handling operations in industry.

Polymerization Shrinkage of Restorative Resins Using Laser and Visible Light Curing

This in vitro investigation compared the amount of linear shrinkage that occurs when a light-cured composite resin is cured with a visible light source, and also with an argon laser. When composite resins are light-cured, they undergo a certain degree of polymerization shrinkage, which can be clinically significant and affect the efficacy of the restoration. A new protocol utilizes laser curing instead of conventional visible light. Two hybrid composite resins were used, Z100 and TPH-Spectrum. Dimensional change was measured in a linear direction, using a calibrated light-microscope. A total of 40 samples of composite resin was tested using two curing lights, and two hybrid composite resins, resulting in four groups of 10 samples (n = 10) each. According to manufacturer instructions, curing time for the laser was 10 sec, and for visible light was 40 sec. With TPH-Spectrum, the mean shrinkage with visible light was 0.583% compared to that with laser light which was 0.591%. With Z100, the mean shrinkage with visible light was 0.565%, compared to that with laser light which was 0.551%. There was no significant difference in amount of shrinkage of hybrid composite resins between using visible light or laser light. There was also no significant difference in shrinkage between the two hybrid composites for either light source.

The effects of mercaptoethanol-formaldehyde on tissue fixation and protein retention.

The study compared the effects of mercaptoethanol-formaldehyde and formaldehyde alone, on tissue fixation and protein retention in human and mouse tissues. Shrinkage of tissues and the penetration rate of the fixatives were assessed. The cross-linking ability of the fixatives was determined by viscometry, sodium dodecyl sulphate-polyacrylamide gel electrophoresis, and spectrophotometry, using bovine serum albumin and human haemoglobin. Tissues fixed in buffered 0.0025% mercaptoethanol-4% formaldehyde showed good nuclear and cytoplasmic detail, better than those fixed in buffered 4% formaldehyde. There was no significant difference in shrinkage. A mixture of 0.0025% mercaptoethanol-4% formaldehyde penetrated faster into adult liver than 4% formaldehyde. The mean penetration rate (+/-SE) or coefficient of diffusibility of 0.0025% mercaptoethanol-4% formaldehyde into adult liver was 1.32 +/- 0.01 and that of 4% formaldehyde was 1.12 +/- 0.06 (p < 0.04). Both fixatives diffused more rapidly into mouse liver than into human liver. The cross-linking ability of mercaptoethanol-formaldehyde depends on the concentration of the fixative and the time of fixation. Bovine serum albumin (15%) and 0.1% mercaptoethanol alone formed a gel, whilst electrophoresis showed monomers in the supernatant. Mercaptoethanol (0.1%) also rapidly decreased the absorption at 420 nm, suggesting denaturation. It seems that mercaptoethanol increases the number of thiol groups available to form cross-links with formaldehyde. This study demonstrated that mercaptoethanol-formaldehyde fixed and cross-linked tissues better than formaldehyde at 3 h and 4 h, but not at 1 h and 2 h. The most effective concentration of mercaptoethanol for tissue fixation in 4% formaldehyde is 0.0025%.

Shrinkage and psychophysical load ratings in self-paced and force-paced lifting work and during recovery.

The purpose of this study was to investigate the effects of the load on the human spine during force-paced and self-paced lifting and subsequent rest. Five women and five men worked under self-paced and force-paced (4 lifts/min) conditions on two days lifting a box for 30 min. The weight of the box was determined by the rating of acceptable load (RAL) method. During the work the lift rate was observed, and subjects made rating of perceived exertion (RPE) in 5 min intervals. The stature was measured with a staturemeter before and after the work period and during the following 30 min rest lying. In self-paced work women had a higher lift rate than men (p less than 0.05). In general, RPEs increased towards the end of the lifting period but RPEs did not differ between women and men or between self-paced and force-paced work. The mean shrinkage during the 30 min work was in self-paced work 5.1 +/- 2.0 mm for women and 5.8 +/- 1.2 mm for men, and in force-paced work 5.8 +/- 2.3 mm and 6.8 +/- 2.2 mm, respectively. There were no significant differences in shrinkage at work between women and men nor between the two different pacing methods. During the 30 min rest recumbent the subjects regained almost the same amount of height as they had lost during lifting. The rapid shrinkage and recovery when loading and unloading suggest that a few minutes rest lying after heavy activities would be beneficial for the spine.

Changes in stature following drop jumping and post-exercise gravity inversion

Spinal shrinkage, measured by changes in stature, is used as an index of spinal loading as alterations reflect changes in intervertebral disc height. Shrinkage induced by various physical activities may be reversed using gravity inversion. The present purpose was to examine the shrinkage induced by a drop jumping regimen and evaluate gravity inversion post-exercise. Eight males, aged 20-31, performed two separate experimental protocols, each on different dates at 1400 h. Subjects stood for 30 min before undertaking an exercise regimen, consisting of five sets of five drop jumps from a height of 1 m, rebounding over a hurdle 0.5 m high. For 20 min, directly following the exercise regimen, subjects on one occasion stood and on a second occasion undertook gravity inversion. Shrinkage was monitored for 40 min after this post-exercise treatment. The stadiometer used to measure shrinkage was accurate to 0.05 mm. The exercise regimen caused a mean shrinkage of 1.68 and 1.81 mm for the two testing sessions. Post-exercise inversion and standing for 20 min increased stature by 5.18 and 0.76 mm, respectively (P less than 0.01). The 40-min standing period following inversion caused a rapid loss in stature (4.07 mm). At 30 min into this recovery period, there was no significant difference in shrinkage for either of the regimens. Results suggest that effects of an inversion treatment are short-lasting.

Spinal shrinkage with three different types of chair whilst performing video display unit work

The aim of the study was to investigate the magnitude of spinal shrinkage during video display unit (VDU) work when subjects were sitting on chairs with different design with forward-sloping seats with or without backrest, armrest or knee support and when using a conventional chair with horizontal seat. Three different chairs were investigated: A “Conventional chair” with horizontal seat, B “Ullman chair” with front half of seat sloping forward and back half horizontal, and C “Balans chair” with forward-sloping seat plus knee support. Eight healthy subjects used to professional VDU work volunteered to participate in this field study, which was performed at their own workplaces. The median shrinkage after a three-hour period was 1.3, 1.8 and 3.1 mm for chairs A, B and C, respectively. All subjects shrank more (p < 0.05) when sitting on the chair with knee support (C) than when sitting on the conventional chair. There was no statistically significant difference in shrinkage between chairs A and B, or between chairs B and C.

Factors Influencing Quality in Pork. B. Commercially Cured Bacona,b

SUMMARYA total of 227 pork carcasses, varying in weight, chronological age, and loin intramuscular fat content, provided bellies for a study of some factors possibly associated with bacon quality. Tenderness scores of bacon significantly improved with a decrease in age and weight and with an increase in intramuscular fat content of the longissimus dorsi. The bacons derived from the 36–42‐month packer carcasses were less tender than those from the other age and weight categories studied. Juiciness scores were not associated with carcass weight, age, or intramuscular fat content of the longissimus dorsi.The bellies shrank approximately 13% during the curing, smoking, and skinning processes. There were differences in shrinkage due to weight and age groups, but no significant differences in shrinkage due to intramuscular fat content of the longissimus dorsi were found.The mean value of the percentage of separable lean in bacon from the 227 carcasses was 31.7%. Average shrinkage during the cooking of the sliced bacon was approximately 66%. Lean bacon shrank significantly less than did fat bacon.About 19% of the bacons were considered to be excessively salty, and originated from carcasses possessing a more highly unsaturated fat.