Tissue Volume Loss Research Articles

Glucose administration after traumatic brain injury exerts some benefits and no adverse effects on behavioral and histological outcomes

The impact of hyperglycemia after traumatic brain injury (TBI), and even the administration of glucose-containing solutions to head injured patients, remains controversial. In the current study adult male Sprague–Dawley rats were tested on behavioral tasks and then underwent surgery to induce sham injury or unilateral controlled cortical impact (CCI) injury followed by injections (i.p.) with either a 50% glucose solution (Glc; 2g/kg) or an equivalent volume of either 0.9% or 8% saline (Sal) at 0, 1, 3 and 6h post-injury. The type of saline treatment did not significantly affect any outcome measures, so these data were combined. Rats with CCI had significant deficits in beam-walking traversal time and rating scores (p׳s<0.001 versus sham) that recovered over test sessions from 1 to 13 days post-injury (p׳s<0.001), but these beam-walking deficits were not affected by Glc versus Sal treatments. Persistent post-CCI deficits in forelimb contraflexion scores and forelimb tactile placing ability were also not differentially affected by Glc or Sal treatments. However, deficits in latency to retract the right hind limb after limb extension were significantly attenuated in the CCI-Glc group (p<0.05 versus CCI-Sal). Both CCI groups were significantly impaired in a plus maze test of spatial working memory on days 4, 9 and 14 post-surgery (p<0.001 versus sham), and there was no effect of Glc versus Sal on this cognitive outcome measure. At 15 days post-surgery the loss of cortical tissue volume (p<0.001 versus sham) was significantly less in the CCI-Glc group (30.0%; p<0.05) compared to the CCI-Sal group (35.7%). Counts of surviving hippocampal hilar neurons revealed a significant (~40%) loss ipsilateral to CCI (p<0.001 versus sham), but neuronal loss in the hippocampus was not different in the CCI-Sal and CCI-Glc groups. Taken together, these results indicate that an early elevation of blood glucose may improve some neurological outcomes and, importantly, the induction of hyperglycemia after isolated TBI did not adversely affect any sensorimotor, cognitive or histological outcomes.

Autologous Fat Transfer as a Facial Filler: Current and Future Applications

Over the past few decades, there have been tremendous advancements in the field of facial rejuvenation, especially with regards to injectable fillers. Injectable fillers have become a safe, efficacious solution to the soft tissue volume loss that plays a critical role in the aging face. The ideal filler is highly debated amongst physicians, and one must take into consideration the biocompatibility, cost, longevity, toxicity, carcinogenicity, and availability of the filler. In this article, we review the role of autologous fat as a facial filler, looking back at its inception, refinements through the years, and future direction, which have made it such a popular choice for soft tissue augmentation.

Equine model for soft-tissue regeneration.

Soft-tissue regeneration methods currently yield suboptimal clinical outcomes due to loss of tissue volume and a lack of functional tissue regeneration. Grafted tissues and natural biomaterials often degrade or resorb too quickly, while most synthetic materials do not degrade. In previous research we demonstrated that soft-tissue regeneration can be supported using silk porous biomaterials for at least 18 months in vivo in a rodent model. In the present study, we scaled the system to a survival study using a large animal model and demonstrated the feasibility of these biomaterials for soft-tissue regeneration in adult horses. Both slow and rapidly degrading silk matrices were evaluated in subcutaneous pocket and intramuscular defect depots. We showed that we can effectively employ an equine model over 6 months to simultaneously evaluate many different implants, reducing the number of animals needed. Furthermore, we were able to tailor matrix degradation by varying the initial format of the implanted silk. Finally, we demonstrate ultrasound imaging of implants to be an effective means for tracking tissue regeneration and implant degradation.

Combination of intense pulsed light, Sculptra, and Ultherapy for treatment of the aging face.

Facial aging is a gradual process that involves a complex interaction of multiple factors including cutaneous photodamage and laxity, subcutaneous tissue volume loss, and bony resorption. These features have all been show to significantly improve with intense pulsed light (IPL), microfocused ultrasound (MFUS, Ultherapy), and poly-L-lactic acid (PLLA). To review the use of IPL, MFUS, and PLLA in combination with the treatment of facial aging. Despite their extensive individual safety record, there is little data regarding combination therapy with these minimally invasive modalities. IPL, MFUS, and PLLA may be safely performed in a single treatment session to target multiple tissue planes concurrently without increased adverse events.

Hyaluronic acid: essential properties and considerations for aesthetic practice

Generally, by the age of 30 years, structural changes start to become noticeable on the face. The redistribution of fat, combined with both the loss of bone and soft tissue volume and decreased dermal elasticity and thickness, contribute to the formation of fine lines, wrinkles and folds. In the past, surgical procedures were the dominant method for tackling signs of facial ageing. However, this two-dimensional technique is giving way to the three-dimensional volume restoration that dermal fillers provide. Hyaluronic acid (HA) is present among all living organisms and plays an integral part in the maintenance and regulation of moisture within tissues, due to its high affinity for water. There are a number of factors affecting the properties of each HA-based filler on the market, including molecular weight, cross-linking, swelling, modulus and particle size and distribution. Each dermal filler is appropriate for different areas and types of treatment. Although there is no single filler that is appropriate for every type of treatment in all patients, correct adjustments of the above properties could lead to the production of a more ‘ideal’ dermal filler.

The evaluation of tissue mass loss in the incision line of prostate with benign hyperplasia performed using holmium laser and cutting electrode.

IntroductionThe aim of this study is to compare the changes in the incision line of prostatic adenoma using a monopolar cutting electrode and holmium laser, as well as the assessment of associated tissue mass and volume loss of benign prostatic hyperplasia (BPH).Material and methodsThe material used in this study consisted of 74 preparations of prostatic adenoma obtained via open retropubic adenomectomy, with an average volume of 120.7 ml. The material obtained cut in vitro before fixation in formaldehyde. One lobe was cut using holmium laser, the other using a monopolar cutting electrode. After the incision was made, tissue mass and volume loss were evaluated. Thermocoagulation changes in the incision line were examinedunder light microscope.ResultsIn the case of the holmium laser incision, the average tissue mass loss was 1.73 g, tissue volume loss 3.57 ml and the depth of thermocoagulation was 1.17 mm. When the monopolar cutting electrode was used average tissue mass loss was 0.807 g, tissue volume loss 2.48 ml and the depth of thermocoagulation was 0.19 mm.ConclusionsWhere holmium laser was used, it was observed that the layer of tissue with thermocoagulation changes was deeper than in the case of the monopolar cutting electrode. Moreover, it was noticed that holmium laser caused bigger tissue mass and volume loss than the cutting electrode.

CANNABINOID USE IN PROGRESSIVE INFLAMMATORY BRAIN DISEASE (CUPID) MRI SUB–STUDY

IntroductionIn progressive Multiple Sclerosis (MS), there is no proven therapy for preventing accumulation of irreversible disability. The pathological substrate of irreversible disability in MS is neuroaxonal loss, and brain tissue...

Structural Abnormalities in Bipolar Euthymia: A Multicontrast Molecular Diffusion Imaging Study

Evidence from decades of magnetic resonance imaging (MRI) research in bipolar disorder has been summarized in meta-analyses of various MRI modalities. Notably, although structural MRI studies suggest gray matter reductions are restricted to specific cortical regions, functional MRI has also shown involvement of subcortical dysfunction. Such disparity in results is open to discussion and requires further exploration with additional MRI modalities. We applied whole-brain high angular resolution molecular diffusion imaging to compare different properties of the water diffusion process in brain tissues, using different contrasts. Specifically, we looked at fractional anisotropy, mean diffusivity, probability of return to the origin, and generalized fractional anisotropy in a sample of 40 euthymic patients with bipolar disorder and 40 well-matched healthy control subjects. Convergent abnormalities were detected by contrasts in various tissue types. Apart from alterations in white matter (in corpus callosum, cingulum bundle, corona radiata, and superior fronto-occipital fasciculus) and cortical gray matter (in medial frontal cortex, left insula, Heschl's gyrus, and cerebellum), three of the contrasts (fractional anisotropy, mean diffusivity, and generalized fractional anisotropy) revealed abnormalities in subcortical structures, including the hippocampus, the thalamus and the caudate nucleus. Our findings point to a wider pattern of axonal pathology in bipolar disorder than previously thought. Although findings related to cortical gray matter are consistent with structural meta-analyses, subcortical abnormalities suggest a cytoarchitectonic basis for previously reported subcortical dysfunction. Diffusion results could be interpreted in terms of loss of tissue volume and/or altered membrane permeability, agreeing with both hypotheses of mitochondrial malfunction and neuroinflammation.

Magnetic resonance imaging following endoscopic nasopharyngectomy with a potassium-titanyl-phosphate (KTP) laser for early locally recurrent nasopharyngeal carcinoma

This study aims to investigate the spectrum of magnetic resonance imaging (MRI) features following endoscopic potassium-titanyl-phosphate (KTP) laser nasopharyngectomy. From January 2005 to December 2010, a total of 35 patients underwent KTP laser nasopharyngectomy for early recurrent NPC (rT1 or rT2) at our institute. Those who were lost to follow-up (N = 2) were excluded. Among the remaining patients, ten were proved to have locally recurrent disease and the other 23 not locally recurrent within 2 years of postoperative follow-up. Their serial MRIs were evaluated. Postoperative nasopharyngeal mucosal changes were present in all of the subjects on first follow-up MRI, ranged from focal mucosal thinning (19/33, 57.6 %), focal mucosal thickening (8/33, 24.2 %) to mixed thinning and thickening (6/33, 18.2 %). Nasopharyngeal submucosal soft tissue volume loss was found in 23 (23/33, 69.7 %), and parapharyngeal soft tissue necrosis was found in 3 (3/33, 9.1 %). Postoperative bone marrow change involved the clivus in 31 (31/33, 93.9 %) and the petrous or pterygoid in 17 (17/33, 51.5 %). There were no significant differences between the two groups in the changes of mucosa, adjacent soft tissue, and skull base on the first MRI. The evaluation of serial MRIs disclosed that the patients in the recurrent group were more likely to develop new or enlarging mucosal masses (p = 0.01) and enlarging skull base changes (p = 0.0001). KTP laser nasopharyngectomy induces mucosal and skull base changes that could be misinterpreted as tumor progression on early postoperative MRI scans. Sequential imaging is required to distinguish between postoperative changes and progressive disease.

Tissue Repair through Cell Competition and Compensatory Cellular Hypertrophy in Postmitotic Epithelia

In multicellular organisms, tissue integrity and organ size are maintained through removal of aberrant or damaged cells and compensatory proliferation. Little is known, however, about this homeostasis system in postmitotic tissues, where tissue-intrinsic genetic programs constrain cell division and new cells no longer arise from stem cells. Here we show that, in postmitotic Drosophila follicular epithelia, aberrant but viable cells are eliminated through cell competition, and the resulting loss of local tissue volume triggers sporadic cellular hypertrophy to repair the tissue. This "compensatory cellular hypertrophy" is implemented by acceleration of the endocycle, a variant cell cycle composed of DNA synthesis and gap phases without mitosis, dependent on activation of the insulin/IGF-like signaling pathway. These results reveal a remarkable homeostatic mechanism in postmitotic epithelia that ensures not only elimination of aberrant cells through cell competition but also proper organ-size control that involves compensatory cellular hypertrophy induced by physical parameters.

Autologous Fat Transfer in Aesthetic Facial Recontouring

Autologous fat graft transplantation has become increasingly popular in recent years. The recognition that soft tissue volume loss contributes to the aging of the face has driven the use of this procedure. Tumescent lipoaspirate provides ready accessibility of tissue for this transplantation, despite some perceived deficiencies in the predictability of volume maintenance with this method. We report our experience with immediately processed sedimented fat transfer for facial grooves and volume correction. A retrospective review of a consecutive series of 75 autologous fat transfers from October 2008 to July 2011 in 8 female patients between ages 46 and 73 years was conducted at Georgia Health Sciences University. The grafting was performed to improve facial aesthetic contours. Twenty-two were performed for correction of grooves and creases: 12 for nasolabial fold, 4 glabella, and 6 nasojugal. Fifty-three transfers were performed for volume augmentation: 17 malar, 14 submalar, 11 lip, 8 temple, 2 chin, and 1 jowl. A tumescent technique with manual syringe harvest was used. The abdomen was the most frequently used donor site. The tumescent was decanted from the lipoaspirate. Oil and nonviable fat were excluded. Care was taken to reduce the time from harvest to transplantation, with no syringe transfers, minimizing potential oxidation and injury of the tissue. The mean volume of fat transferred was 24 mL (range, 4-54 mL). Mean follow-up was 25 months (range, 6-36 months). A second session of fat transfer was required in a small percentage. Complications included minor asymmetry in 1 patient (resolved with graft manipulation) and prolonged swelling in another. No postoperative cellulitis or fat necrosis was reported. Clinical evaluations and patients reported a satisfactory result 88% of the time. Patients universally reported (100%) a desire to have the procedure performed again. Autologous fat transfer for facial soft tissue contouring is simple, safe, inexpensive, and effective. Its ready availability, natural integration into host tissues, and potentially permanent correction make it particularly useful for this application. All patients were satisfied with the soft, natural appearance.

How Much Do Focal Infarcts Distort White Matter Lesions and Global Cerebral Atrophy Measures?

Background: White matter lesions (WML) and brain atrophy are important biomarkers in stroke and dementia. Stroke lesions, either acute or old, symptomatic or silent, are common in older people. Such stroke lesions can have similar signals to WML and cerebrospinal fluid (CSF) on magnetic resonance (MR) images, and may be classified accidentally as WML or CSF by MR image processing algorithms, distorting WML and brain atrophy volume from the true volume. We evaluated the effect that acute or old stroke lesions at baseline, and new stroke lesions occurring during follow-up, could have on measurement of WML volume, cerebral atrophy and their longitudinal progression. Methods: We used MR imaging data from patients who had originally presented with acute lacunar or minor cortical ischaemic stroke symptoms, recruited prospectively, who were scanned at baseline and about 3 years later. We measured WML and CSF volumes (ml) semi-automatically. We manually outlined the acute index stroke lesion (ISL), any old stroke lesions present at baseline, and new lesions appearing de novo during follow-up. We compared baseline and follow-up WML volume, cerebral atrophy and their longitudinal progression excluding and including the acute ISL, old and de novo stroke lesions. A non-parametric test (Wilcoxon’s signed rank test) was used to compare the effects. Results: Among 46 patients (mean age 72 years), 33 had an ISL visible on MR imaging (median volume 2.05 ml, IQR 0.88–8.88) and 7 of the 33 had old lacunes at baseline: WML volume was 8.54 ml (IQR 5.86–15.80) excluding versus 10.98 ml (IQR 6.91–24.86) including ISL (p < 0.001). At follow-up, median 39 months later (IQR 30–45), 3 patients had a de novo stroke lesion; total stroke lesion volume had decreased in 11 and increased in 22 patients: WML volume was 12.17 ml (IQR 8.54–19.86) excluding versus 14.79 ml (IQR 10.02–38.03) including total stroke lesions (p < 0.001). Including/excluding lacunes at baseline or follow-up also made small differences. Twenty-two of the 33 patients had tissue loss due to stroke lesions between baseline and follow-up, resulting in a net median brain tissue volume loss (i.e. atrophy) during follow-up of 24.49 ml (IQR 12.87–54.01) excluding versus 24.61 ml (IQR 15.54–54.04) including tissue loss due to stroke lesions (p < 0.001). Including stroke lesions in the WML volume added substantial noise, reduced statistical power, and thus increased sample size estimated for a clinical trial. Conclusions: Failure to exclude even small stroke lesions distorts WML volume, cerebral atrophy and their longitudinal progression measurements. This has important implications for design and sample size calculations for observational studies and randomised trials using WML volume, WML progression or brain atrophy as outcome measures. Improved methods of discriminating between stroke lesions and WML, and between tissue loss due to stroke lesions and true brain atrophy are required.

Contemporary Neurotoxins and Injectable Fillers

The last decade or so has brought a remarkable evolution in nonsurgical facial treatments. This is especially true in the area of injectable treatments for facial rhytids, volume restoration and augmentation, and muscular hyperactivity. The facial plastic surgeon now has a wide array of injectable products available for the management of everything from facial spasm to fine rhytids to extensive soft tissue atrophy and volume loss. New technologies that have evolved have reduced potential complications from more traditional fillers such as bovine collagen, while at the same time a variety of products have been optimized for specific esthetic or anatomic problems.

Multimodal Quantitative Magnetic Resonance Imaging of Thalamic Development and Aging across the Human Lifespan: Implications to Neurodegeneration in Multiple Sclerosis

The human brain thalami play essential roles in integrating cognitive, sensory, and motor functions. In multiple sclerosis (MS), quantitative magnetic resonance imaging (qMRI) measurements of the thalami provide important biomarkers of disease progression, but late development and aging confound the interpretation of data collected from patients over a wide age range. Thalamic tissue volume loss due to natural aging and its interplay with lesion-driven pathology has not been investigated previously. In this work, we used standardized thalamic volumetry combined with diffusion tensor imaging, T2 relaxometry, and lesion mapping on large cohorts of controls (N = 255, age range = 6.2-69.1 years) and MS patients (N = 109, age range = 20.8-68.5 years) to demonstrate early age- and lesion-independent thalamic neurodegeneration.

Nicotinamide mononucleotide adenylyl transferase 1 protects against acute neurodegeneration in developing CNS by inhibiting excitotoxic-necrotic cell death

Hypoxic-ischemic (H-I) injury to the developing brain is a significant cause of morbidity and mortality in humans. Other than hypothermia, there is no effective treatment to prevent or lessen the consequences of neonatal H-I. Increased expression of the NAD synthesizing enzyme nicotinamide mononucleotide adenylyl transferase 1 (Nmnat1) has been shown to be neuroprotective against axonal injury in the peripheral nervous system. To investigate the neuroprotective role of Nmnat1 against acute neurodegeneration in the developing CNS, we exposed wild-type mice and mice overexpressing Nmnat1 in the cytoplasm (cytNmnat1-Tg mice) to a well-characterized model of neonatal H-I brain injury. As early as 6 h after H-I, cytNmnat1-Tg mice had strikingly less injury detected by MRI. CytNmnat1-Tg mice had markedly less injury in hippocampus, cortex, and striatum than wild-type mice as assessed by loss of tissue volume 7 d days after H-I. The dramatic protection mediated by cytNmnat1 is not mediated through modulating caspase3-dependent cell death in cytNmnat1-Tg brains. CytNmnat1 protected neuronal cell bodies and processes against NMDA-induced excitotoxicity, whereas caspase inhibition or B-cell lymphoma-extra large (Bcl-XL) protein overexpression had no protective effects in cultured cortical neurons. These results suggest that cytNmnat1 protects against neonatal HI-induced CNS injury by inhibiting excitotoxicity-induced, caspase-independent injury to neuronal processes and cell bodies. As such, the Nmnat1 protective pathway could be a useful therapeutic target for acute and chronic neurodegenerative insults mediated by excitotoxicity.

Autologous granular fat transplantation in facial rejuvenation

Objective To investigate methods and experience of autologous granular fat transplantation by correction of aging face. Methods 178 cases of aging face subjects were treated by liposuction. Then autologous granular fat was harvested by liposuction,centrifuged and purified, and injected into marked areas of aging face. The injection process should be controled by multilevel and multiple tennel, in order to supplement the loss of facial soft tissue volume and improve the aging face. Results The follow-up period ranged from 3 months to 3 years. All the subjects had a satisfactory results with no obvious complications such as fat liquefaction, infection and ulceration. The effect of autologous granular fat transplantation was obvious and permanent. Conclusions Autologous granular fat transplantation is a safe and effective surgical technique for facial soft tissue augmentation that can effectively improve aging face and worthy of clinical application. Key words: Transplantation, autologous; Fat granule; Aging face

Orbitofacial Rejuvenation of Temple Hollowing With Perlane Injectable Filler

Temple hollowing with soft tissue volume loss is well recognized in HIV lipoatrophy. Similar changes occur as part of aging, with skeletalization of the orbital rim and clipping of the eyebrow tail. The authors report their initial experience treating temple volume loss and orbitofacial asymmetry with nonanimal stabilized hyaluronic acid (NASHA). This study was a retrospective, interventional case series with a patient satisfaction questionnaire and independent physician grading of results. Patients initially received approximately 1 mL of Perlane (Q-Med, Uppsala, Sweden; Medicis, Inc., Scottsdale, Arizona) injected into the superficial fascia of each temple. The filler was placed behind the frontozygomatic process to soften the bony contour of the lateral orbital rim. Outcome measures included satisfaction with injection procedure, fulfillment of expectations, satisfaction with appearance, change in self-confidence, the need for retreatment, and complications. Twenty patients were treated, for a total of 39 temples. Mean follow-up was nine months (range, four to 14 months). Patients were primarily female (90%), all were Caucasian, and their ages ranged from 20 to 60 years. Eighteen patients had age-related temple hollowing, one had dysthyroid volume loss, and one had hollowing due to orbitotemporal neurofibromatosis. The majority had 1-mL injections to each side (range, 0.3-3 mL). One patient received 3 mL to correct asymmetry. The procedure was well tolerated with ice pack cooling and no local anesthesia. Of 16 patients who replied to the questionnaire, 13 were very or moderately satisfied and requested repeat treatment, whereas three were only mildly satisfied or ambivalent. Side effects included transient mild or moderate discomfort, superficial vein prominence, and localized bruising. This series suggests the effective and safe application of Perlane in temple hollow rejuvenation and correction of asymmetry. It offers tolerability, high patient satisfaction, few complications, and the option of reversibility.

Volumetric Facelift: Evaluation of Rhytidectomy with Alloplastic Augmentation

Facial aging occurs as a result of soft tissue atrophy and resorption of the bony skeleton, which results in a loss of soft tissue volume and laxity of the overlying skin. Volumetric augmentation is a key component of facial rejuvenation surgery, and should be considered of equal importance to soft tissue lifting. Augmentation can be accomplished with synthetic fillers, autologous grafts, soft tissue repositioning techniques, and/or alloplastic implants. Only alloplastic implants, however, provide truly long-term volumetric correction. To date, there have been no large series dealing with the complications and results of implantation performed concurrently with rhytidectomy, which we have termed "volumetric rhytidectomy." We present our experience with 100 patients treated with a combination of malar and chin implants and rhytidectomy, compared to 200 patients who underwent rhytidectomy alone. The authors performed a retrospective review of patients treated with a combination of silicone malar and chin augmentation with rhytidectomy versus patients treated with rhytidectomy alone. Both groups of patients underwent close postoperative evaluation at 3 days, 1 week, 2 weeks, and 1 month. All patients were surveyed at 6 months to assess aesthetic satisfaction. Complication rates were noted and tabulated. Statistical analysis was performed to evaluate for any differences in the two groups. Between 2002 and 2006, 100 patients underwent malar and chin implantation along with rhytidectomy; 200 patients underwent rhytidectomy alone. In the first group, there were a total of 6 cases in which implant removal was necessary, and 2 cases in which revision was required. There were no statistically significant differences (p < 0.05) observed between the two groups with respect to major or minor hematoma, seroma, infection, sensory nerve injury, facial nerve injury, hypertrophic scarring, dehiscence, skin sloughing, or revision. Volumetric rhytidectomy reliably augments the malar and mental areas, allows for subtle skeletal contouring, and results in successful rejuvenation. Rhytidectomy is relatively safe to perform concurrently with silicone augmentation, and does not result in an increased complication rate as compared to rhytidectomy alone.

Micro‐computed tomography of tooth tissue volume changes following endodontic procedures and post space preparation

To compare the volume of hard tooth tissue lost after caries removal, access cavity preparation, root canal preparation, fibre post space and cast post preparation in carious premolar teeth. The null hypothesis tested was that there is no difference between the volumes of hard tooth tissue lost expressed as a percentage of the preoperative hard tooth tissue volume, after each operative procedure. Twelve extracted human premolars with mesial or distal carious cavities penetrating into the pulp chamber were selected. Teeth were scanned using a microCT scanner. After each operative procedure the loss of hard tooth tissue volume was measured. The data were statistically analysed using one-way analysis of variance and Fisher's PLSD test with statistical significance set at alpha = 0.01. The percentage of preoperative hard tooth tissue volume lost after caries removal was 8.3 +/- 5.83, after access cavity preparation the loss of volume reached 12.7 +/- 6.7% (increase of 4.4%). After root canal preparation, fibre post space and cast post preparation the hard tissue volume lost reached, 13.7 +/- 6.7 (increase of 1%), 15.1 +/- 6.3 (increase of 1.4%) and 19.2 +/- 7.4 (increase of 4.1%) respectively. Each procedure performed after caries removal significantly increased (P < 0.01) the amount of hard tissue volume lost with the exception of the root canal preparation. Access cavity and post space preparation are the procedures during root canal treatment which result in the largest loss of hard tooth tissue structure. Cast post space preparation causes a larger loss of tooth structure than fibre post space preparation. This should be taken into account when planning root canal treatment and restoration of root filled teeth that are to be restored with cuspal coverage restorations.

Masseter Muscle Reattachment After Mandibular Angle Surgery

Altering the dimensions of the mandibular angle by alloplastic augmentation or skeletal reduction requires elevation of the insertion of the masseter muscle, including the pterygomasseteric sling. Disruption of the pterygomasseteric sling during exposure of the inferior border of the mandible can cause the masseter muscle to retract superiorly, resulting in a loss of soft tissue volume over the angle of the mandible and a skeletonized appearance. Subsequent contraction of the masseter elevates the disinserted edge of the muscle and not only increases the skeletonized area, but also exaggerates the deficiency by causing a soft tissue bulge above it. The authors describe the disinsertion of the masseter and the resulting deformity as a potential complication of mandibular angle surgery and review the technique for repair. The records of 60 patients (44 primary, 16 secondary) who presented for alloplastic mandible augmentation between 2003 and 2008 were reviewed. Nine patients presented with clinical signs of disruption of the pterygomasseteric sling after mandibular angle surgery. Five patients had clinical signs consistent with complete disruption. Two of these patients requested reconstruction. The other four had signs consistent with partial disruption. Through a Risdon approach, the masseter was successfully reinserted using drill holes placed at the inferior border of the mandible. Masseter disinsertion is a previously unreported sequelae after aesthetic surgery for the angle of the mandible. The resultant static and dynamic contour deformity can be corrected by reattaching the muscle to the inferior border of the mandible.