Commissural Defects Research Articles

Complex lower face reconstruction using a combined technique of Estlander flap and subscapular artery system free flaps

When advanced mandibular carcinoma is resected, the defect may include lip and oral commissure. Free flap insertion is commonly used to reconstruct the lip defect. Although improvements in the oral reconstructive method via free flap use have been reported, functional and aesthetic results of the oral sphincter remain limited. This case report describes two individuals presenting with massive lower face defects, including a lower lip defect and a mandibular bone defect. Reconstruction was accomplished using the Estlander flap and free subscapular system of flaps. In both cases, the free subscapular artery system flap was elevated from the mandibular bone defect and other mucosal defect. The lower lip and oral commissure defect was reconstructed via Estlander flap. Free flaps survived 100% and both cases healed without complication. Patients regained good oral sphincter function with no reports of drooling. Thus, in cases involving massive lower face resection, including that of the lower lip and mandibular bone, this method of reconstruction when combined with lip-switch flap and subscapular artery system flap can prove to be useful.

Single-Stage Turn-Over Muscular Hinge Flap With Burow's Full-Thickness Skin Graft to Repair Oral Commissure Defect

1Department of Dermatology, School of Medicine, Stanford University, Redwood City, California, Address correspondence and reprint requests to: Sumaira Z. Aasi, MD, Department of Dermatology, Stanford University, 450 Broadway St, Pavilion C 2nd Floor, Redwood City, CA 94063, or e-mail: [email protected] The authors have indicated no significant interest with commercial supporters.

Short-term and long-term memory deficits in handedness learning in mice with absent corpus callosum and reduced hippocampal commissure

The corpus callosum (CC) and hippocampal commissure (HC) are major interhemispheric connections whose role in brain function and behaviors is fascinating and contentious. Paw preference of laboratory mice is a genetically regulated, adaptive behavior, continuously shaped by training and learning. We studied variation with training in paw-preference in mice of the 9XCA/WahBid (‘9XCA’) recombinant inbred strain, selected for complete absence of the CC and severely reduced HC. We measured sequences of paw choices in 9XCA mice in two training sessions in unbiased test chambers, separated by one-week. We compared them with sequences of paw choices in model non-learner mice that have random unbiased paw choices and with those of C57BL/6JBid (‘C57BL/6J’) mice that have normal interhemispheric connections and learn a paw preference. Positive autocorrelation between successive paw choices during each session and change in paw-preference bias between sessions indicate that 9XCA mice have weak, but not null, learning skills. We tested the effect of the forebrain commissural defect on paw-preference learning with the independent BTBR T+ tf/J (‘BTBR’) mouse strain that has a genetically identical, non-complementing commissural trait. BTBR has weak short-term and long-term memory skills, identical to 9XCA. The results provide strong evidence that CC and HC contribute in memory function and formation of paw-preference biases.

A new technique for reconstruction of lower-lip and labial commissure defects: a proposal for the association of Abbe–Estlander and vermilion myomucosal flap techniques

Reconstruction of large lower-lip defects is a complex surgical procedure, especially when associated with defects that compromise the oral commissure. Various wide resections have been proposed with the aim to preserve orolabial function and achieve a pleasant esthetic result. However, no consensus exists on the optimum procedure. We propose a new technique that combines an Abbe-Estlander flap with a vermilion myocutaneous lower-lip flap. Five consecutive patients presenting with lower-lip and oral commissure defects underwent surgical procedure. Surgical outcomes were analyzed based on oral competence, symmetry, sensibility, ability to wear denture prostheses, and postoperative complications. All patients achieved satisfactory functional and esthetic results during the 12-month follow-up period. The association of the Abbe-Estlander flap and the vermilion myomucosal lower-lip flap provides reliable results for the reconstruction of small and large defects involving the lower lip and the oral commissure.

Partial Bipaddling of PMMC Flap in Full Thickness Cheek Defects involving Lip Commissure: A Novel Technique

ABSTRACTThe reconstruction of cheek along with large lip commissural defect after excision of primary tumor is still a challenge. Though primary reconstruction with microsurgical technique is the preferred meth od, du e to infrastru ctural c on strain ts in developing countries it cannot be offered to all the patients. A number of other techniques have been described earlier, but some of them lead to microstomia, whereas other leads to oral incompetence or poor esthetic outcomes. We are proposing a novel technique of partial bipaddling of pectoralis major myocutaneous (PMMC) flap for reconstruction of such defect. This reconstruction procedure is technically less demanding with an acceptable cosmetic and functional outcome.How to cite this articleChaturvedi P, Joshi P. Partial Bipaddling of PMMC Flap in Full Thickness Cheek Defects involving Lip Commissure: A Novel Technique. Int J Head Neck Surg 2013;4(3):113-114.

Hippocampal commissure defects in crosses of four inbred mouse strains with absent corpus callosum

It is known that four common inbred mouse strains show defects of the forebrain commissures. The BALB/cJ strain has a low frequency of abnormally small corpus callosum, whereas the 129 strains have many animals with deficient corpus callosum. The I/LnJ and BTBR T+ tf/J strains never have a corpus callosum, whereas half of I/LnJ and almost all BTBR show severely reduced size of the hippocampal commissure. Certain F1 hybrid crosses among these strains are known to be less severely abnormal than the inbred parents, suggesting that the parent strains have different genetic causes of commissure defects. In this study, all hybrid crosses among the four strains were investigated. The BTBR × I/Ln hybrid expressed almost no defects of the hippocampal commissure, unlike its inbred parent strains. Numerous three-way crosses among the four strains yielded many mice with no corpus callosum and severely reduced hippocampal commissure, which shows that the phenotypic defect can result from several different combinations of genetic alleles. The F2 and F3 hybrid crosses of BTBR and I/LnJ had almost 100% absence of the corpus callosum but about 50% frequency of deficient hippocampal commissure. The four-way hybrid cross among all four abnormal strains involved highly fertile parents and yielded a very wide phenotypic range of defects from almost no hippocampal commissure to totally normal forebrain commissures. The F2 and F3 crosses as well as the four-way cross provide excellent material for studies of genetic linkage and behavioral consequences of commissure defects.

Frizzled-3a and slit2 genetically interact to modulate midline axon crossing in the telencephalon

The anterior commissure forms the first axon connections between the two sides of the embryonic telencephalon. We investigated the role of the transmembrane receptor Frizzled-3a in the development of this commissure using zebrafish as an experimental model. Knock down of Frizzled-3a resulted in complete loss of the anterior commissure. This defect was accompanied by a loss of the glial bridge, expansion of the slit2 expression domain and perturbation of the midline telencephalic–diencephalic boundary. Blocking Slit2 activity following knock down of Frizzled-3a effectively rescued the anterior commissure defect which suggested that Frizzled-3a was indirectly controlling the growth of axons across the rostral midline. We have shown here that Frizzled-3a is essential for normal development of the commissural plate and that loss-of-function causes Slit2-dependent defects in axon midline crossing in the embryonic vertebrate forebrain. These data supports a model whereby Wnt signaling through Frizzled-3a attenuates expression of Slit2 in the rostral midline of the forebrain. The absence of Slit2 facilitates the formation of a midline bridge of glial cells which is used as a substrate for commissural axons. In the absence of this platform of glia, commissural axons fail to cross the rostral midline of the forebrain.

Prospective Comparative Study of Lower Lip Defects Reconstruction With Different Local Flaps

Squamous cell carcinoma is the most common malignancy related to the lips (95%), and the lower lip is more commonly involved. Loss of tissue in the lower lip is treated with a variety of techniques, depending on the extension and location of the defect. This was a prospective case series. In this study, 41 patients with squamous cell carcinoma (30 males, 11 females) who were referred to Razi Hospital of Tehran University of Medical Sciences between 2007 and 2008 and underwent lower-lip reconstruction were included. Defects were divided into 4 groups: less than 30%, between 30% and 50%, between 50% and 80%, and more than 80%. Five different local flaps were used for lower-lip reconstruction. Karapandzic flap was used for 9 patients, double reversed-Abbe flap for 6 patients, Abbe-Estlander and step-ladder flaps for 8 patients, and 10 patients underwent reconstruction operation with reversed-Abbe flap. In comparison to reversed-Abbe flap and step-ladder flap, there were no differences functionally and aesthetically except that the step-ladder flap was a single-stage procedure, but the reversed-Abbe flap had 2 stages. There were no functional problems in patients with Estlander flap, but these patients complained of lip asymmetry. There were no functional complaints and aesthetic problems in patients with double reversed-Abbe flap at 3 months after the operation. In patients with 30% to 50% defect of the lower lip, there was no functional and aesthetic difference between Abbe flap and step-ladder flap. Estlander flap is a good choice for reconstruction of lateral or commissural defects of the lower lip. In patients with 50% to 80% defect, it is better to use bilateral reversed-Abbe instead of the Karapandzic flap.

Reconstruction of Medium-Sized Defects of Oral Commissure by Combining Double Full-Thickness Cheek Rhomboidal Flaps and a Small Lip Switch Flap

Reconstruction of oral commissure defects aims at securing oral competence and providing an acceptable appearance. The methods described by using either a cross lip flap or a flap from the adjacent cheek skin and mucosa may not be able to achieve such goals if each method is used on its own. We have combined double full-thickness cheek rhomboidal flaps with a small lip switch flap from the remaining lip segment to reconstruct medium-sized full-thickness defects of the oral commissure, following tumor excision in 7 patients. The functional and aesthetic outcomes were assessed by the evaluation of 3 parameters under each category. Each parameter received a score of good, moderate, or poor. Six patients had a good overall functional score. Microstomia was noted only in 1 patient. The overall aesthetic score for all the 7 patients was moderate. In conclusion, reconstruction of medium-sized commissural defects by the present technique achieves adequate oral competence and a satisfactory cosmetic result.

Molecular regulation of the developing commissural plate

Coordinated transfer of information between the brain hemispheres is essential for function and occurs via three axonal commissures in the telencephalon: the corpus callosum (CC), hippocampal commissure (HC), and anterior commissure (AC). Commissural malformations occur in over 50 human congenital syndromes causing mild to severe cognitive impairment. Disruption of multiple commissures in some syndromes suggests that common mechanisms may underpin their development. Diffusion tensor magnetic resonance imaging revealed that forebrain commissures crossed the midline in a highly specific manner within an oblique plane of tissue, referred to as the commissural plate. This specific anatomical positioning suggests that correct patterning of the commissural plate may influence forebrain commissure formation. No analysis of the molecular specification of the commissural plate has been performed in any species; therefore, we utilized specific transcription factor markers to delineate the commissural plate and identify its various subdomains. We found that the mouse commissural plate consists of four domains and tested the hypothesis that disruption of these domains might affect commissure formation. Disruption of the dorsal domains occurred in strains with commissural defects such as Emx2 and Nfia knockout mice but commissural plate patterning was normal in other acallosal strains such as Satb2(-/-). Finally, we demonstrate an essential role for the morphogen Fgf8 in establishing the commissural plate at later developmental stages. The results demonstrate that correct patterning of the commissural plate is an important mechanism in forebrain commissure formation.

In the absence of frazzled over-expression of Abelson tyrosine kinase disrupts commissure formation and causes axons to leave the embryonic CNS.

BackgroundIn the Drosophila embryonic nerve cord, the formation of commissures require both the chemoattractive Netrin receptor Frazzled (Fra) and the Abelson (Abl) cytoplasmic tyrosine kinase. Abl binds to the cytoplasmic domain of Fra and loss-of-function mutations in abl enhance fra-dependent commissural defects. To further test Abl's role in attractive signaling, we over-expressed Abl in Fra mutants anticipating rescue of commissures.Methodology/Principal FindingsThe Gal4-UAS system was used to pan-neurally over-express Abl in homozygous fra embryos. Surprisingly, this led to a significant decrease in both posterior and anterior commissure formation and induced some commissural and longitudinal axons to project beyond the CNS/PNS border. Re-expressing wild-type Fra, or Fra mutants with a P-motif deleted, revert both commissural and exiting phenotypes, indicating that Fra is required but not a specific P-motif. This is supported by S2 cell experiments demonstrating that Abl binds to Fra independent of any specific P-motif and that Fra continues to be phosphorylated when individual P-motifs are removed. Decreasing midline repulsion by reducing Robo signaling had no effect on the Abl phenotype and the phenotypes still occur in a Netrin mutant. Pan-neural over-expression of activated Rac or Cdc42 in a fra mutant also induced a significant loss in commissures, but axons did not exit the CNS.Conclusion/SignificanceTaken together, these data suggest that Fra activity is required to correctly regulate Abl-dependent cytoskeletal dynamics underlying commissure formation. In the absence of Fra, increased Abl activity appears to be incorrectly utilized downstream of other guidance receptors resulting in a loss of commissures and the abnormal projections of some axons beyond the CNS/PNS border.

Dorsal telencephalon-specific RA-GEF-1 knockout mice develop heterotopic cortical mass and commissural fiber defect

Dorsal telencephalon-specific RA-GEF-1 knockout mice develop heterotopic cortical mass and commissural fiber defect

Calcium Hydroxylapatite (Radiesse) for Correction of the Mid- and Lower Face: Consensus Recommendations

Restoring volume in the middle and lower portions of the face is becoming an indispensable component of modern facial rejuvenation. Radiesse (BioForm Medical, San Mateo, Calif.) is an injectable filler material composed of synthetic calcium hydroxylapatite microspheres (30 percent) suspended in an aqueous carrier gel (70 percent). At present, Radiesse is indicated in the United States for correction of moderate to deep nasolabial folds and for correction of the signs of facial fat loss (lipoatrophy) in people with human immunodeficiency virus. Its off-label use in other facial aesthetic indications is widely reported in the literature. The ability of Radiesse to provide immediate and durable effects has fueled interest in its use for expanded aesthetic applications, particularly in the middle and lower face. The authors' consensus panel, consisting of a cross-section of experts in plastic surgery, facial plastic surgery, and dermatology, was convened to review the scientific literature and compare clinical experiences regarding the use of calcium hydroxylapatite. This report describes the characteristic effects of aging in the middle and lower face and reviews the composition of calcium hydroxylapatite, its safety and durability, and its appropriate use in a variety of facial applications, including nasolabial folds, correction of human immunodeficiency virus-associated lipoatrophy, augmentation of the malar, submalar, and zygomatic regions, and correction of oral commissure defects, marionette lines, and prejowl sulcus. Recommendations for Radiesse use in each area, including anesthesia, and injection techniques are provided. Measures for enhancing patient comfort, anticipating and minimizing potential complications, and optimizing aesthetic results are also discussed.

Adding Versatility to the Reconstruction of Intraoral Lining

Reconstruction of a full-thickness cheek defect, especially one associated with a large lip and oral commissure defect, remains a challenge. After tumor excision, replacement of the oral mucosa is often necessary. The oral mucosa is a thin, pliable lining. Because the skin of the forearm is ideally suited for replacement of oral lining, being thin, pliable, and predominantly hairless, the radial forearm flap is the most frequently used soft-tissue flap for this purpose. In addition, the vascularity of the area allows substantial variation in the design of the flap, both in relation to its site and size. On the other hand, the radial forearm flap might be unusable in some occasions, such as in the case presented here. Thus, a search for an alternative free flap is required. We used a prefabricated scapular free flap to reconstruct a large concomitant lip and full-thickness cheek defect resulting from perioral cancer ablation. We introduce a new "opened pocket" method for reconstruction of the intra-oral lining without folding the flap. Resection of the tumor resulted in a defect including 45% of the upper lip, 50% of the lower lip, and a large, full-thickness defect of the cheek. The resultant defect was temporarily closed with a split-thickness skin graft. Meanwhile, the left scapular fasciocutaneous flap was prefabricated for permanent closure of the defect. The left scapular flap was outlined horizontally, and the flap orientation for the defect was estimated. Then, the distal portion of the flap was harvested and incised to create lips and oral commissure. Afterward, the raw surface under the neo-lip regions and the base where the flap was raised was grafted with one piece from a thick, split-thickness skin graft. Fourteen days later, the patient was taken back to the operating room for reconstruction of the defect with free transfer of a prefabricated scapular fascia-cutaneous flap. The grafted distal region of the flap was raised with the deep fascia located under the graft. Thus, a pocket was obtained. The flap was placed in the defect for final tailoring. Mucosal defect was evaluated to decide where the pocket was to be opened. Then, the grafted fascial portion of the flap was incised from the free edge to the neocommissure. Consequently, lower and upper lip mucosa were achieved by opening the pocket. The prefabricated flap was adapted to the defect with the appropriate sutures. The superior thyroid artery and internal jugular vein were used as recipient vessels. The postoperative period was uneventful. There were no healing problems of the suture lines of the opened pocket, and both labial sulci were quite adequate. The patient was able to resume a soft diet 10 days after the operation. She also had a satisfactory oral competence and an acceptable appearance, without microstomia. Despite its disadvantages, prefabrication can make the scapular fascia-cutaneous flap suitable for reconstruction of a large, concomitant lip and full-thickness cheek defect when other more appropriate flaps are not available. The opened pocket method appears not only to add flexibility to the restoration of the intra-oral lining but also reduces the stress resulting from free flap adaptation.

Reconstruction of Perioral Defects Following Resection for Oral Squamous Cell Carcinoma

The aim of this study was to review and describe techniques for the reconstruction of large, complex perioral defects after resection of oral squamous cell carcinoma with emphasis on cosmetic and functional outcome. A review of techniques and selected case presentations using different flap designs for the reconstruction of large perioral defects following resection of squamous cell carcinoma was performed. The Bernard and Karapandzic flaps were used for large lower lip defects. A Zisser flap technique was used to reconstruct a large commissure defect. All reconstructed patients had acceptable functional results and healed without complication. The large lower lip defects were easily closed with the Bernard and Karapandzic flaps. The commissure defect was reconstructed using the Zisser technique. While cosmesis was acceptable in all cases, the commissure was the most difficult region to reconstruct with a favorable appearance. There were no flap failures. The Karapandzic flap led to greater rounding of the commissure area and the composite resection resulted in a lack of lower lip support that was improved with prosthesis. Function was noted to be excellent in the Bernard and Karapandzic flaps, with the patients able to purse lips and blow up balloon-type devices. The Bernard, Karapandzic, and Zisser flaps provide a predictable method to reconstruct large perioral defects following resection for oral cancer. Subsequent fabrication of a prosthesis can aid in lip support for the resected area.

Development of midline cell types and commissural axon tracts requires Fgfr1 in the cerebrum

The adult cerebral hemispheres are connected to each other by specialized midline cell types and by three axonal tracts: the corpus callosum, the hippocampal commissure, and the anterior commissure. Many steps are required for these tracts to form, including early patterning and later axon pathfinding steps. Here, the requirement for FGF signaling in forming midline cell types and commissural axon tracts of the cerebral hemispheres is examined. Fgfr1, but not Fgfr3, is found to be essential for establishing all three commissural tracts. In an Fgfr1 mutant, commissural neurons are present and initially project their axons, but these fail to cross the midline that separates the hemispheres. Moreover, midline patterning defects are observed in the mutant. These defects include the loss of the septum and three specialized glial cell types, the indusium griseum glia, midline zipper glia, and glial wedge. Our findings demonstrate that FGF signaling is required for generating telencephalic midline structures, in particular septal and glial cell types and all three cerebral commissures. In addition, analysis of the Fgfr1 heterozygous mutant, in which midline patterning is normal but commissural defects still occur, suggests that at least two distinct FGF-dependent mechanisms underlie the formation of the cerebral commissures.

Acquired Oral Commissure Defect: A Complication of Prolonged Endotracheal Intubation

A number of complications during and following endotracheal intubation of infants are well described in the literature. We describe a rare case of an oral commissure defect acquired from prolonged endotracheal intubation in a ventilator-dependent preterm infant.

Survey of 21 inbred mouse strains in two laboratories reveals that BTBR T/+ tf/tf has severely reduced hippocampal commissure and absent corpus callosum

A morphometric survey of brain size and forebrain commissures of 21 inbred mouse strains from the Jackson Laboratory was done with animals tested in two laboratories as part of the Mouse Phenome Project. Strain BTBR T/+ tf/tf was found to have 100% total absence of the corpus callosum as well as severe reduction of the hippocampal commissure in almost every animal, the most severe commissure defect observed to date in any commercially available mouse strain. The strain 129S1/SvImJ had a milder defect with incomplete penetrance. Crosses of BTBR mice with inbred strains BALB/cWah1, 129P1/ReJ, and the recombinant strain 9XCA/Wah having a severe commissure defect supported a two-locus model of the genetic defect in these strains. Brain size varied greatly among strains but for any one strain was almost identical in mice housed for 5 weeks in the two laboratories. Sex differences in brain weight and forebrain commissure sizes were not statistically significant.

Regulated vnd expression is required for both neural and glial specification in Drosophila.

The Drosophila embryonic CNS arises from the neuroectoderm, which is divided along the dorsal-ventral axis into two halves by specialized mesectodermal cells at the ventral midline. The neuroectoderm is in turn divided into three longitudinal stripes--ventral, intermediate, and lateral. The ventral nervous system defective, or vnd, homeobox gene is expressed from cellularization throughout early neural development in ventral neuroectodermal cells, neuroblasts, and ganglion mother cells, and later in an unrelated pattern in neurons. Here, in the context of the dorsal-ventral location of precursor cells, we reassess the vnd loss- and gain-of-function CNS phenotypes using cell specific markers. We find that over expression of vnd causes significantly more profound effects on CNS cell specification than vnd loss. The CNS defects seen in vnd mutants are partly caused by loss of progeny of ventral neuroblasts-the commissures are fused and the longitudinal connectives are aberrantly positioned close to the ventral midline. The commissural vnd phenotype is associated with defects in cells that arise from the mesectoderm, where the VUM neurons have pathfinding defects, the MP1 neurons are mis-specified, and the midline glia are reduced in number. vnd over expression results in the mis-specification of progeny arising from all regions of the neuroectoderm, including the ventral neuroblasts that normally express the gene. The CNS of embryos that over express vnd is highly disrupted, with weak longitudinal connectives that are placed too far from the ventral midline and severely reduced commissural formation. The commissural defects seen in vnd gain-of-function mutants correlate with midline glial defects, whereas the mislocalization of interneurons coincides with longitudinal glial mis-specification. Thus, Drosophila neural and glial specification requires that vnd expression by tightly regulated.

Arytenoid adduction technique for correction of Paralytic Dysphonia

Development of phonosurgical techniquec like Medialization Laryngoplasty (M. L.) or Thyroplasty has opened new horizon in the management of paralytic dysphonia. The Arytenoid Adduction (A. A.) technique as originally described by professor Isshiki of Japan added a new dimension for improvement of voice in cases of paralytic dysphonia particularly in large posterior commissure defects. 9 cases of primary and secondary arytenoid adduction technique done as complementary to medialization laryngoplasty over a period of 2 years are described.