The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Norberto P Giannini - One of the best experts on this subject based on the ideXlab platform.
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the chiropteran Premaxilla a reanalysis of morphological variation and its phylogenetic interpretation
American Museum Novitates, 2007Co-Authors: Norberto P Giannini, Nancy B SimmonsAbstract:Abstract The mammalian Premaxilla, which bears the incisor teeth, is composed of a body and two processes (nasal and palatine) that articulate with other rostral bones via four cranial sutures. In bats, the Premaxilla is modified in many ways, and this variation has been extensively used in bat systematics. The Premaxilla has provided characters to diagnose a number of important taxonomic groupings—most notably, the division of Microchiroptera into the infraorders Yinochiroptera and Yangochiroptera. Recent molecular studies have challenged the monophyly of Microchiroptera, and several families have been transferred to clades other than those in which they were placed traditionally. Because Premaxillary characters have figured prominently among those used to establish the traditional classification of bats, we compared the anatomy of the bone across suprageneric bat groups and provide revised descriptions of its variation. On the basis of extensive material examined, we generated 16 new characters, of whic...
S Sharma - One of the best experts on this subject based on the ideXlab platform.
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secondary correction of Premaxilla in bilateral cleft lip and palate with lag screw fixation
British Journal of Oral & Maxillofacial Surgery, 2020Co-Authors: J S Chauhan, S Sharma, N BandiAbstract:Abstract It is not unusual for the protruding Premaxilla to attain an undesirable position after the cleft lip repair. Such a Premaxilla may lead to considerable problems in facial aesthetics, or oral functions, or both in early childhood. These abnormal Premaxillas may produce difficulties in bone grafting and orthodontic treatment in late childhood. In such cases, surgical correction of the Premaxilla in childhood is justified. From 2013 to 2018, 11 children, aged 2 to 11 years, had a secondary ostectomy of their Premaxilla. A new stabilisation method (developed by us) was used to provide rigid fixation to the Premaxilla. The follow up period ranged from 1 - 6 years. The results were satisfactory in all except for a few minor issues in three patients. There was significant improvement in their appearance, oral functions, and most importantly in their quality of life. The need for secondary osteotomy of the Premaxilla should always be weighed against its potential complications. The fixation technique described by us, though, provides rigid fixation, but may potentially be associated with a few complications if not practised carefully.
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lag screw fixation of the Premaxilla during bilateral cleft lip repair
Journal of Cranio-maxillofacial Surgery, 2019Co-Authors: J S Chauhan, S SharmaAbstract:Abstract In synchronous primary Premaxillary setback and cleft lip repair for bilateral cases with severely protruding Premaxilla, stabilization of the Premaxilla is mostly achieved by gingivoperiosteoplasty. This kind of repair carries risk of impairment of blood supply to the Premaxilla and/or prolabium, and at the same time it cannot ensure adequate stabilization of the Premaxilla postoperatively. To overcome these problems, we have developed a unique technique of fixation of the Premaxilla. In this paper, we discussing this technique, its advantages, and potential complications associated with it. From 2016, 10 patients aged 4–10 months, with bilateral cleft lip and palate with Premaxillary protrusion (≥10 mm) underwent Premaxillary setback and cheilorhinoplasty in the same stage. Instead of gingivoperiosteoplasty, a ‘lag screw’ fixation technique was used to stabilize the Premaxilla. The follow-up period ranged between 5 and 32 months. In all the cases, we achieved adequate stabilization of the Premaxilla. None of the patients had any issue related to the vascularity of the Premaxilla or prolabium. There was no impairment in the eruption process of deciduous teeth in the Premaxillary segment. Overall aesthetic outcomes of the lip and nose were acceptable. This technique of Premaxillary fixation with lag screw gives us the liberty to perform primary cheilorhinoplasty along with Premaxillary setback in the same stage, without risking the vascularity of Premaxilla and prolabium. It ensures adequate stabilization of the Premaxilla, but evaluation of regular growth of the midface and, if needed, corrective orthodontic and surgical treatment in the follow-up periods are advisable.
Nancy B Simmons - One of the best experts on this subject based on the ideXlab platform.
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the chiropteran Premaxilla a reanalysis of morphological variation and its phylogenetic interpretation
American Museum Novitates, 2007Co-Authors: Norberto P Giannini, Nancy B SimmonsAbstract:Abstract The mammalian Premaxilla, which bears the incisor teeth, is composed of a body and two processes (nasal and palatine) that articulate with other rostral bones via four cranial sutures. In bats, the Premaxilla is modified in many ways, and this variation has been extensively used in bat systematics. The Premaxilla has provided characters to diagnose a number of important taxonomic groupings—most notably, the division of Microchiroptera into the infraorders Yinochiroptera and Yangochiroptera. Recent molecular studies have challenged the monophyly of Microchiroptera, and several families have been transferred to clades other than those in which they were placed traditionally. Because Premaxillary characters have figured prominently among those used to establish the traditional classification of bats, we compared the anatomy of the bone across suprageneric bat groups and provide revised descriptions of its variation. On the basis of extensive material examined, we generated 16 new characters, of whic...
J S Chauhan - One of the best experts on this subject based on the ideXlab platform.
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secondary correction of Premaxilla in bilateral cleft lip and palate with lag screw fixation
British Journal of Oral & Maxillofacial Surgery, 2020Co-Authors: J S Chauhan, S Sharma, N BandiAbstract:Abstract It is not unusual for the protruding Premaxilla to attain an undesirable position after the cleft lip repair. Such a Premaxilla may lead to considerable problems in facial aesthetics, or oral functions, or both in early childhood. These abnormal Premaxillas may produce difficulties in bone grafting and orthodontic treatment in late childhood. In such cases, surgical correction of the Premaxilla in childhood is justified. From 2013 to 2018, 11 children, aged 2 to 11 years, had a secondary ostectomy of their Premaxilla. A new stabilisation method (developed by us) was used to provide rigid fixation to the Premaxilla. The follow up period ranged from 1 - 6 years. The results were satisfactory in all except for a few minor issues in three patients. There was significant improvement in their appearance, oral functions, and most importantly in their quality of life. The need for secondary osteotomy of the Premaxilla should always be weighed against its potential complications. The fixation technique described by us, though, provides rigid fixation, but may potentially be associated with a few complications if not practised carefully.
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lag screw fixation of the Premaxilla during bilateral cleft lip repair
Journal of Cranio-maxillofacial Surgery, 2019Co-Authors: J S Chauhan, S SharmaAbstract:Abstract In synchronous primary Premaxillary setback and cleft lip repair for bilateral cases with severely protruding Premaxilla, stabilization of the Premaxilla is mostly achieved by gingivoperiosteoplasty. This kind of repair carries risk of impairment of blood supply to the Premaxilla and/or prolabium, and at the same time it cannot ensure adequate stabilization of the Premaxilla postoperatively. To overcome these problems, we have developed a unique technique of fixation of the Premaxilla. In this paper, we discussing this technique, its advantages, and potential complications associated with it. From 2016, 10 patients aged 4–10 months, with bilateral cleft lip and palate with Premaxillary protrusion (≥10 mm) underwent Premaxillary setback and cheilorhinoplasty in the same stage. Instead of gingivoperiosteoplasty, a ‘lag screw’ fixation technique was used to stabilize the Premaxilla. The follow-up period ranged between 5 and 32 months. In all the cases, we achieved adequate stabilization of the Premaxilla. None of the patients had any issue related to the vascularity of the Premaxilla or prolabium. There was no impairment in the eruption process of deciduous teeth in the Premaxillary segment. Overall aesthetic outcomes of the lip and nose were acceptable. This technique of Premaxillary fixation with lag screw gives us the liberty to perform primary cheilorhinoplasty along with Premaxillary setback in the same stage, without risking the vascularity of Premaxilla and prolabium. It ensures adequate stabilization of the Premaxilla, but evaluation of regular growth of the midface and, if needed, corrective orthodontic and surgical treatment in the follow-up periods are advisable.
Roi Holzman - One of the best experts on this subject based on the ideXlab platform.
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Co-evolution of the Premaxilla and jaw protrusion in cichlid fishes (Heroine
2016Co-Authors: Darrin C. Hulsey, Phillip R. Hollingsworth, Roi HolzmanAbstract:The ability of Perciform fishes to protrude their jaw has likely been critical to the trophic diversification of this group, which includes approximately 20 % of all vertebrates. The length of the ascending process of the Premaxilla is thought to influence the maximum extent that cichlids and other Perciforms protrude their oral jaw. Using a combination of morphometrics, kinematics, and new phylogenetic hypotheses for 20 Heroine cichlid species, we tested the evolutionary relationship between the length of the Premaxillary ascending process and maximum jaw protrusion. In this clade, the length of the ascending process of the Premaxilla ranged from 11.6–32.7 % with respect to standard length whereas maximum jaw protrusion ranged from 3.5–23.4 % with respect to standard length. The evolutionary relationships among the Heroine cichlids obtained from the genetic partitions cytochrome b, S7, and RAG1 showed limited concordance. However, correlations between the length of the ascending process and maximum jaw protrusion were highly significant when examined as independent contrasts using all three topologies. Evolutionary change in the length of the ascending process of the Premaxilla is likely critical for determining the amount of jaw protrusion in Perciform groups such as cichlid fishes. © 2010 The Linnean Societ
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Co-evolution of the Premaxilla and jaw protrusion in cichlid fishes (Heroine: Cichlidae)
Biological Journal of the Linnean Society, 2010Co-Authors: C. Darrin Hulsey, Phillip R. Hollingsworth, Roi HolzmanAbstract:The ability of Perciform fishes to protrude their jaw has likely been critical to the trophic diversification of this group, which includes approximately 20% of all vertebrates. The length of the ascending process of the Premaxilla is thought to influence the maximum extent that cichlids and other Perciforms protrude their oral jaw. Using a combination of morphometrics, kinematics, and new phylogenetic hypotheses for 20 Heroine cichlid species, we tested the evolutionary relationship between the length of the Premaxillary ascending process and maximum jaw protrusion. In this clade, the length of the ascending process of the Premaxilla ranged from 11.6–32.7% with respect to standard length whereas maximum jaw protrusion ranged from 3.5–23.4% with respect to standard length. The evolutionary relationships among the Heroine cichlids obtained from the genetic partitions cytochrome b, S7, and RAG1 showed limited concordance. However, correlations between the length of the ascending process and maximum jaw protrusion were highly significant when examined as independent contrasts using all three topologies. Evolutionary change in the length of the ascending process of the Premaxilla is likely critical for determining the amount of jaw protrusion in Perciform groups such as cichlid fishes. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 619–629.
