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Alshami AM, Pompermayer E, Troteaga Alvarez C, Hoey S, Ryan J, Johnson JP. Comparison of Computed Tomography Assisted 3D Cephalometric Measurements in Straight Egyptian Arabian and Thoroughbred Horses. J Vet Dent 2024; 41:43-48. [PMID: 37753611 DOI: 10.1177/08987564231203918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/28/2023]
Abstract
Dental malocclusions are commonly encountered in horses. The objective of this study was to report the normal cephalometric values from skull computed tomography (CT) scans of adult Straight Egyptian Arabian (SEAR) and thoroughbred (TB) horses and to compare differences in the measurements between the two breeds. Standing skull CTs were performed on 29 clinically normal adult horses (15 SEAR; 14 TB) and cephalometric measurements were taken. All 9 cephalometric measurements, as well as the interincisal angle, were found to be significantly greater in TB than SEAR (P < 0.05). TB were found to have significantly greater facial line: mandibular length (FL/ML) ratios compared to SEAR (P = 0.002) whereas for the maxillary cheek teeth length: ethmoidal line ratio (Mxa/EtL), SEAR were found to have significantly greater values than TB (P = 0.0007). SEAR cephalometric measurements, as well as certain ratios, differ significantly from TB and could have an impact on the development of dental malocclusions in this breed. Further investigation is needed to ascertain whether these cephalometric differences between the two breeds predispose the SEAR to the development of dental malocclusions.
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Affiliation(s)
- Alanoud M Alshami
- Equine Veterinary Medical Center, A Member of Qatar Foundation, Doha, Qatar
| | | | | | - Seamus Hoey
- School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - Jackie Ryan
- Equine Veterinary Medical Center, A Member of Qatar Foundation, Doha, Qatar
| | - Jessica P Johnson
- Equine Veterinary Medical Center, A Member of Qatar Foundation, Doha, Qatar
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Sterkenburgh TR, Hartl B, Peham C, Nowak M, Kyllar M, Kau S. Temporomandibular joint biomechanics and equine incisor occlusal plane maintenance. Front Bioeng Biotechnol 2023; 11:1249316. [PMID: 37799811 PMCID: PMC10549988 DOI: 10.3389/fbioe.2023.1249316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 08/21/2023] [Indexed: 10/07/2023] Open
Abstract
In equine dentistry, the physiological incisor occlusal surface is visually perceived as a plane with a distinct inclination to the head's coronal plane, extending rostro-ventrally to caudo-dorsally. To better understand the formation of this inclined plane and its connection to dental wear, we investigated the hypothesis that it arises from masticatory movements and the considerable distance between mandibular articular heads and the incisor occlusal surfaces, acting as the three points of support for the mandibles. Leveraging data from a large-scale clinical study involving static and dynamic orthodontic measurements in horses, we approximated the mandibular movement range where incisor occlusion and dental wear occur. By introducing and testing a segment coordinate system, we explored possible angular deviations from the occlusal plane caused by mandibular roll and pitch rotations during two lateral mandibular movement patterns, protrusion and retrusion. Theoretical biomechanical calculations and simulations confirmed the visual perception of the incisor occlusal surface as a plane. To further examine our assumptions, we employed a simple mechanical simulator to assess incisor normal occlusion and provoked malocclusions (diagonal, smile, and frown bite) by modifying temporomandibular joint (TMJ) movement patterns. The results from clinical investigations were corroborated by both the theoretical analysis and mechanical simulations, strengthening our understanding of the biomechanical basis behind the physiological incisor occlusal plane maintenance in horses. These findings have significant implications for equine dental health and contribute to a thorough understanding of TMJ dynamics.
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Affiliation(s)
- Tomas Rudolf Sterkenburgh
- Polyclinic for Dental Preservation and Periodontology, University of Leipzig, Leipzig, Germany
- Department of Industrial Engineering, Business Administration and Statistics, DEGIN Doctoral Program, Universidad Politécnica de Madrid, Madrid, Spain
| | - Bettina Hartl
- Department of Pathobiology, Institute of Morphology, Vetmeduni Vienna, Vienna, Austria
| | - Christian Peham
- Department of Companion Animals and Horses, Movement Science Group, University Clinic for Horses, Vetmeduni Vienna, Vienna, Austria
| | - Michael Nowak
- Veterinary Practice Dr. M. Nowak, Equine Clinic Meerbusch, Meerbusch, Germany
| | - Michal Kyllar
- Department of Pathobiology, Institute of Morphology, Vetmeduni Vienna, Vienna, Austria
| | - Silvio Kau
- Department of Pathobiology, Institute of Morphology, Vetmeduni Vienna, Vienna, Austria
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Abstract
Odontoplasty (floating and occlusal equilibration) is the most commonly performed procedure in equine dentistry. From an anatomic perspective, an irregular occlusal surface, prominent cingula, transverse ridges, and enamel points all contribute to the function, form, and longevity of the equine cheek tooth. With limited reserve crown available and an average functional life range between 18 and 25 years, removal of tooth structure should be conservative. The authors consider a quality oral examination to be the most important dental procedure performed in the horse. Individual tooth evaluation should lead to a specific diagnosis and treatment plan. Tooth odontoplasty should be site-specific.
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Kau S, Failing K, Staszyk C. Computed Tomography (CT)-Assisted 3D Cephalometry in Horses: Interincisal Angulation of Clinical Crowns. Front Vet Sci 2020; 7:434. [PMID: 32851019 PMCID: PMC7403475 DOI: 10.3389/fvets.2020.00434] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/16/2020] [Indexed: 11/13/2022] Open
Abstract
The angle encompassed between opposing incisors in horses is assumed to decline with age. Previous studies merely consider the overall profile view of clinical crowns presuming a generalized angle, neglecting potential tooth position-dependent differences. Cephalometric measurements from 3D computed tomographic thick-slab reconstructions of single incisors within a global reference frame were used to determine clinical crown interincisal angulation (IIA) of 48 horses. Based on predefined dentoalveolar landmarks, IIA was defined as the angle enclosed by the respective labial axis of the clinical crown (LACC). A measurement repeatability analysis was conducted including a comparison of third incisor teeth IIA with data obtained by cephalometric implementation of previously described landmarks for third incisor teeth (lingual/palatal border). The age-related angle course and differences between tooth positions were investigated considering LACCs of permanent incisors. Determining IIA by LACCs exhibited a high level of reproducibility applying for all tooth positions (mean coefficient of variation = 0.65 %; mean SD ± 0.89°). The comparison method for third incisor teeth revealed two times higher mean dispersion of repeated measurements, P = 0.017. A non-linear model slightly increased predictability of angular changes over time as against linearity assumption. The angle decline was more distinctive in younger horses and appears to approach a final value in older ones. Third incisor teeth exhibited significantly higher angle decline compared to first and second incisor teeth, P < 0.0001. According to the results, age determination of horses using clinical crown IIA is not recommended. Rather, 3D cephalometry may provide a promising tool to determine interdental and dentofacial angles of distinct tooth positions in health and disease.
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Affiliation(s)
- Silvio Kau
- Department of Pathobiology, Institute of Topographic Anatomy, University of Veterinary Medicine Vienna, Vienna, Austria
- Faculty of Veterinary Medicine, Institute of Veterinary-Anatomy, -Histology and -Embryology, Justus-Liebig-University Gießen, Gießen, Germany
| | - Klaus Failing
- Unit for Biomathemathics and Data Processing, Faculty of Veterinary Medicine, Justus-Liebig-University Gießen, Gießen, Germany
| | - Carsten Staszyk
- Faculty of Veterinary Medicine, Institute of Veterinary-Anatomy, -Histology and -Embryology, Justus-Liebig-University Gießen, Gießen, Germany
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Szulakowski M, Mageed M, Steinberg T, Winter K, Gerlach K. Scintigraphic evaluation of cheek teeth in clinically sound horses. Vet Rec 2019; 185:481. [PMID: 31391285 DOI: 10.1136/vr.105459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 07/11/2019] [Accepted: 07/11/2019] [Indexed: 11/04/2022]
Abstract
Dental disorders are one of the top-ranking clinical domains in equine practice. Scintigraphy has emerged as a useful diagnostic imaging modality for equine dental diseases. There is a paucity of the normal scintigraphic uptake and its correlation with age. This prospective, cross-sectional, descriptive and pilot-designed study aimed to describe the radioisotope uptake (RU) patterns of the reserved crown and periodontal bone of the maxillary and mandibular cheek teeth (CT) in clinically sound horses and to evaluate the age effect on RU. For this purpose, 60 horses that underwent a bone scintigraphy for reason unrelated to head were included and divided equally into four age groups. Regions of interests (ROIs) were positioned around alveolar and periodontal bone of each maxillary and mandibular CT including their reserve crown, and a reference ROI positioned at the mandibular ramus. The count per pixel of each ROI was measured using a dedicated software and the RU ratio relative to the reference region was calculated. The results showed that the maxillary and mandibular CT had a standard RU pattern, where it increased from rostral to caudal, and peaked in the middle of dental arcades and decreased slightly towards the last CT. The maxillary CT had a higher RU compared with the mandibular CT, and there was no significant difference in the maxillary and mandibular CT uptake between age groups. This information may aid veterinarians evaluating potentially abnormal dental scintigraphy.
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Affiliation(s)
- Marcin Szulakowski
- Tierklinik Lüsche GmbH, Bakum, Germany.,Pferdepraxis Niemendal, Rheinbach, Germany
| | | | | | - Karsten Winter
- Institute of Anatomy, University of Leipzig, Leipzig, Germany
| | - Kerstin Gerlach
- University Equine Hospital, University of Leipzig, Leipzig, Germany
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Moine S, Flammer SA, de Jesus Maia-Nussbaumer P, Klopfenstein Bregger MD, Gerber V. Evaluation of the effects of performance dentistry on equine rideability: a randomized, blinded, controlled trial. Vet Q 2017; 37:195-199. [DOI: 10.1080/01652176.2017.1329598] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Affiliation(s)
- Sébastien Moine
- Department of Veterinary Clinical Sciences, Swiss Institute of Equine Medicine, University of Bern and Agroscope, Bern, Switzerland
| | - Shannon Axiak Flammer
- Department of Veterinary Clinical Sciences, Swiss Institute of Equine Medicine, University of Bern and Agroscope, Bern, Switzerland
| | - Päivi de Jesus Maia-Nussbaumer
- Department of Veterinary Clinical Sciences, Swiss Institute of Equine Medicine, University of Bern and Agroscope, Bern, Switzerland
| | - Micaël D. Klopfenstein Bregger
- Department of Veterinary Clinical Sciences, Swiss Institute of Equine Medicine, University of Bern and Agroscope, Bern, Switzerland
| | - Vincent Gerber
- Department of Veterinary Clinical Sciences, Swiss Institute of Equine Medicine, University of Bern and Agroscope, Bern, Switzerland
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Adams K, Schulz-Kornas E, Arzi B, Failing K, Vogelsberg J, Staszyk C. Functional anatomy of the equine temporomandibular joint: Collagen fiber texture of the articular surfaces. Vet J 2016; 217:58-64. [PMID: 27810212 DOI: 10.1016/j.tvjl.2016.09.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 09/09/2016] [Accepted: 09/23/2016] [Indexed: 11/29/2022]
Abstract
In the last decade, the equine masticatory apparatus has received much attention. Numerous studies have emphasized the importance of the temporomandibular joint (TMJ) in the functional process of mastication. However, ultrastructural and histological data providing a basis for biomechanical and histopathological considerations are not available. The aim of the present study was to analyze the architecture of the collagen fiber apparatus in the articular surfaces of the equine TMJ to reveal typical morphological features indicating biomechanical adaptions. Therefore, the collagen fiber alignment was visualized using the split-line technique in 16 adult warmblood horses without any history of TMJ disorders. Within the central two-thirds of the articular surfaces of the articular tubercle, the articular disc and the mandibular head, split-lines ran in a correspondent rostrocaudal direction. In the lateral and medial aspects of these articular surfaces, the split-line pattern varied, displaying curved arrangements in the articular disc and punctual split-lines in the bony components. Mediolateral orientated split-lines were found in the rostral and caudal border of the articular disc and in the mandibular fossa. The complex movements during the equine chewing cycle are likely assigned to different areas of the TMJ. The split-line pattern of the equine TMJ is indicative of a relative movement of the joint components in a preferential rostrocaudal direction which is consigned to the central aspects of the TMJ. The lateral and medial aspects of the articular surfaces provide split-line patterns that indicate movements particularly around a dorsoventral axis.
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Affiliation(s)
- K Adams
- Institute of Veterinary-Anatomy, -Histology and -Embryology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Frankfurter Str. 98, 35390 Giessen, Germany
| | - E Schulz-Kornas
- Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - B Arzi
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - K Failing
- Unit for Biomathematics and Data Processing, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Frankfurter Str. 95, 35390 Giessen, Germany
| | - J Vogelsberg
- Institute of Veterinary-Anatomy, -Histology and -Embryology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Frankfurter Str. 98, 35390 Giessen, Germany
| | - C Staszyk
- Institute of Veterinary-Anatomy, -Histology and -Embryology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Frankfurter Str. 98, 35390 Giessen, Germany.
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Pereira TP, Staut FT, Machado TS, Brossi PM, Baccarin RY, Michelotto PV. Effects of the Oral Examination on the Equine Temporomandibular Joint. J Equine Vet Sci 2016. [DOI: 10.1016/j.jevs.2016.04.091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Abstract
The objective of this study was to investigate the effect of routine dental occlusal equilibration treatment on dressage horse performance. Sixteen horses (11 treated; 5 untreated) ridden by a single rider performed a standardized dressage test twice and were scored by two experienced dressage judges according to recognized movements and rider cues. All horses were sedated and a full-mouth speculum was used to facilitate a complete oral examination. Treated horses had dental equilibration performed using a motorized dental instrument. The horses performed a second test 48-hours after dental equilibration, exactly as the baseline test, with the judges and rider blinded as to treatment group. The total test score as well as the individual movement scores were evaluated for equality of variance and statistical tests were applied to determine the influence of treatment. There was no significant improvement in the test score of horses that had received occlusal equilibration.
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Abstract
It has been suggested that dental abnormalities lead to temporomandibular joint inflammation and pain that may be mitigated by regular dental care. There is considerable literature on the pathophysiology of equine joint disease including studies on cytokine profiles in diseased appendicular joints. This study examined the effects of age and dental malocclusions summarized as a dental pathology score on equine temporomandibular joint cytokine (IL-1, IL-6, IL-8, TNF α and TGF-β1, -β2, -β3) concentrations. TGF-β3 was not detected in any joint sample. IL-1, IL-6 and TNF α were not influenced by age. Foals had significantly lower concentrations of IL-8 and TGF-β1, and higher levels of TGF-β2 compared with older horses. Age did not effect cytokine concentration in older horses although there was a trend towards increasing IL-8 with age. The dental pathology score increased with age in mature horses, however there was no effect of dental pathology score on cytokine concentration. There was no effect of incisor eruption, and presence or number of periodontal lesions on temporomandibular joint cytokine concentration. Our findings indicate that age but not dental pathology affected temporomandibular joint proinflammatory cytokine concentration in this population of horses.
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Affiliation(s)
- James L Carmalt
- Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
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Smyth T, Allen AL, Carmalt JL. Clinically significant, nontraumatic, degenerative joint disease of the temporomandibular joints in a horse. EQUINE VET EDUC 2015. [DOI: 10.1111/eve.12382] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- T. Smyth
- Department of Large Animal Clinical Sciences; Western College of Veterinary Medicine; University of Saskatchewan; Saskatoon Saskatchewan Canada
| | - A. L. Allen
- Department of Veterinary Pathology; Western College of Veterinary Medicine; University of Saskatchewan; Saskatoon Saskatchewan Canada
| | - J. L. Carmalt
- Department of Large Animal Clinical Sciences; Western College of Veterinary Medicine; University of Saskatchewan; Saskatoon Saskatchewan Canada
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Jørgensen E, Christophersen MT, Kristoffersen M, Puchalski S, Verwilghen D. Does temporomandibular joint pathology affect performance in an equine athlete? EQUINE VET EDUC 2014. [DOI: 10.1111/eve.12268] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- E. Jørgensen
- Department of Large Animal Sciences; University of Copenhagen; Tåstrup Denmark
| | | | - M. Kristoffersen
- Helsingborg Regional Animal Hospital - Evidensia; Helsingborg Sweden
| | - S. Puchalski
- Helsingborg Regional Animal Hospital - Evidensia; Helsingborg Sweden
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine; University of California; Davis USA
| | - D. Verwilghen
- Department of Large Animal Sciences; University of Copenhagen; Tåstrup Denmark
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Gunnarsdottir H, Van der Stede Y, De Vlamynck C, Muurling F, De Clercq D, van Loon G, Vlaminck L. Hospital-based study of dental pathology and faecal particle size distribution in horses with large colon impaction. Vet J 2014; 202:153-6. [DOI: 10.1016/j.tvjl.2014.07.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 07/17/2014] [Accepted: 07/21/2014] [Indexed: 10/25/2022]
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Simhofer H, Niederl M, Anen C, Rijkenhuizen A, Peham C. Kinematic analysis of equine masticatory movements: comparison before and after routine dental treatment. Vet J 2010; 190:49-54. [PMID: 20971663 DOI: 10.1016/j.tvjl.2010.09.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2009] [Revised: 09/06/2010] [Accepted: 09/19/2010] [Indexed: 10/18/2022]
Abstract
The objective of this study was to compare masticatory movements before and after dental treatment using kinematic analysis. The masticatory movements of 15 adult Warmblood horses with mild dental pathology chewing standardised hay were recorded on three consecutive days before and three times after (days 7, 21, 28) dental correction. The results of the leading mandibular tracking marker, located at the caudal edge of the inter-mandibular suture, were compared statistically. Reproducibility of measurements prior to dental treatment was excellent (P<0.05). Rostrocaudal mandibular motion was significantly reduced after dental correction (9±2mm vs. 8±2mm; P=0.046). Oscillations during the power stroke were significantly reduced after dental correction (R(2)=98.3%±0.3 vs. 98.8%±0.3; P=0.050). Although significant changes were observed in individual horses, the overall results of lateral and dorsoventral mandibular motion did not reveal significant differences. In conclusion, kinematic analysis of masticatory movements provided reproducible results and may be useful to evaluate changed movement patterns following dental correction.
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A comparison of the occurrence of common dental abnormalities in stabled and free-grazing horses. Animal 2010; 4:1697-701. [DOI: 10.1017/s1751731110000893] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Evaluation of the long-term oral consequences of equine exodontia in 50 horses. Vet J 2008; 178:419-24. [DOI: 10.1016/j.tvjl.2008.09.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/19/2008] [Indexed: 11/19/2022]
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Ramzan PHL, Marr CM, Meehan J, Thompson A. Novel oblique radiographic projection of the temporomandibular articulation of horses. Vet Rec 2008; 162:714-6. [DOI: 10.1136/vr.162.22.714] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- P. H. L. Ramzan
- Rossdales Equine Hospital and Diagnostic Centre; Cotton End Road Exning Suffolk CB9 7NN
| | - C. M. Marr
- Rossdales Equine Hospital and Diagnostic Centre; Cotton End Road Exning Suffolk CB9 7NN
| | - J. Meehan
- Rossdales Equine Hospital and Diagnostic Centre; Cotton End Road Exning Suffolk CB9 7NN
| | - A. Thompson
- Rossdales Equine Hospital and Diagnostic Centre; Cotton End Road Exning Suffolk CB9 7NN
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Bonin SJ, Clayton HM, Lanovaz JL, Johnston T. Comparison of mandibular motion in horses chewing hay and pellets. Equine Vet J 2007; 39:258-62. [PMID: 17520978 DOI: 10.2746/042516407x157792] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASONS FOR PERFORMING STUDY Previous studies have suggested that temporomandibular joint (TMJ) kinematics depend on the type of food being masticated, but accurate measurements of TMJ motion in horses chewing different feeds have not been published. HYPOTHESIS The temporomandibular joint has a larger range of motion when horses chew hay compared to pellets. METHODS An optical motion capture system was used to track skin markers on the skull and mandible of 7 horses as they chewed hay and pellets. A virtual marker was created on the midline between the mandibles at the level of the 4th premolar teeth to represent the overall motion of the mandible relative to the skull during the chewing cycle. RESULTS Frequency of the chewing cycles was lower for hay than for pellets. Excursions of the virtual mandibular marker were significantly larger in all 3 directions when chewing hay compared to pellets. The mean velocity of the virtual mandibular marker during the chewing cycle was the same when chewing the 2 feeds. CONCLUSIONS The range of mediolateral displacement of the mandible was sufficient to give full occlusal contact of the upper and lower dental arcades when chewing hay but not when chewing pellets. POTENTIAL RELEVANCE These findings support the suggestion that horses receiving a diet high in concentrate feeds may require more frequent dental prophylactic examinations and treatments to avoid the development of dental irregularities associated with smaller mandibular excursions during chewing.
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Affiliation(s)
- S J Bonin
- McPhail Equine Performance Center, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan 48854, USA
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Carmalt JL, Allen AL. Effect of rostrocaudal mobility of the mandible on feed digestibility and fecal particle size in horses. J Am Vet Med Assoc 2006; 229:1275-8. [PMID: 17042731 DOI: 10.2460/javma.229.8.1275] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the effect of rostrocaudal mobility (RCM) of the mandible during extension and flexion of the atlanto-occipital joint on weight gain, feed digestibility, and fecal particle size in horses. DESIGN Randomized controlled trial. ANIMALS 34 pregnant mares housed in 1 barn. PROCEDURES Horses were randomized into a treatment (n = 17) or control (17) group. All horses were sedated, and the distance between the rostral portions of the upper and lower incisor arcades was determined during extension and flexion of the atlanto-occipital joint; mandibular RCM was calculated as the difference between these values. In the treatment group, measurements were made after dental floating. Body weight was recorded 1 day before dental floating and at intervals after mandibular RCM determination for a period of 24 weeks. Feces were collected from each horse during two 5-day periods. Samples of feed and feces were analyzed to determine feed digestibility; particle size analysis was performed on dried fecal samples. RESULTS Data obtained from each group of horses revealed that RCM of the mandible did not affect weight gain, feed digestibility, or particle size in feces; there were no differences among breeds. Controlling for age and number of dental lesions did not significantly affect results. CONCLUSIONS AND CLINICAL RELEVANCE In horses, RCM of the mandible did not appear to affect weight gain, feed digestibility, or fecal particle size. On the basis of these and other published data, the assumption that dental abnormalities affect digestion detrimentally in horses needs to be reevaluated.
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Affiliation(s)
- James L Carmalt
- Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
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Bonin SJ, Clayton HM, Lanovaz JL, Johnson TJ. Kinematics of the equine temporomandibular joint. Am J Vet Res 2006; 67:423-8. [PMID: 16506903 DOI: 10.2460/ajvr.67.3.423] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To develop a method of measuring 3-dimensional kinematics of the temporomandibular joint (TMJ) in horses chewing sweet feed. ANIMALS 4 mature horses that had good dental health. PROCEDURE Markers attached to the skin over the skull and mandible were tracked by an optical tracking system. Movements of the mandible relative to the skull were described in terms of 3 rotations and 3 translations. A virtual marker was created on the midline between the rami of the mandibles at the level of the rostral end of the facial crest to facilitate observation of mandibular movements. RESULTS During the opening stroke, the virtual midline mandibular marker moved ventrally, laterally toward the chewing side, and slightly caudally. During the closing stroke, the marker moved dorsally, medially, and slightly rostrally. During the power stroke, the mandible slid medially and dorsally as the mandibular cheek teeth moved across the occlusal surface of the maxillary cheek teeth. The 4 horses had similar chewing patterns, but the amplitudes varied among horses. CONCLUSIONS AND CLINICAL RELEVANCE The TMJ allows considerable mobility of the mandible relative to the skull during chewing. The method presented in this report can be used to compare the range of motion of the TMJ among horses with TMJ disease or dental irregularities or within an individual horse before and after dental procedures.
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Affiliation(s)
- Stephanie J Bonin
- Mary Anne McPhail Equine Performance Center, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, 48824, USA
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Affiliation(s)
- P H L Ramzan
- Beaufort Cottage Stables, Newmarket, Suffolk, UK
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