The mandible in horses is the lower jawbone, essential for mastication and articulation with the skull. It comprises two halves that fuse at the mandibular symphysis and supports the lower teeth, playing a key role in the horse's ability to graze and process food. The mandible also provides attachment sites for muscles involved in chewing and facial expressions. Research on the equine mandible often focuses on its anatomy, development, and the impact of various dental and skeletal disorders. This page compiles peer-reviewed research studies and scholarly articles that investigate the structure, function, and clinical implications of the mandible in equine health and management.
Murch KM.Clinical findings, surgical repair and postsurgical care of a unilateral fracture of the mandible of a bull and of a bilateral mandibular fracture in a horse are described. Compression plating limited the pain suffered by the animals and resulted in a quick return to function of the mandibles.
Summers PM, Wells KE, Adkins KF.The features of an ossifying ameloblastoma in a 5-year-old gelding are described. The tumour developed in the angle of the right mandible and microscopically consisted of multiple follicles and islands of epithelial tissue adjacent to which were trabeculae of bone, osteoid and compact collagenous tissue.
Walthall JC, McKenzie RA.Horses grazing manily Cenchrus ciliaris and/or Panicum maximum var. trichoglume pastures on over 30 properties in southern central Queensland developed lesions of osteodystrophia fibrosa. Horses on individual properties in coastal Queensland grazing Setaria anceps, Brachiaria mutica or Pennisetum clandestinum also developed the disease. Ill-thrift, lameness, and fibrous swellings of nasal bones, maxillae and mandibles were observed. Calcium and phosphorus levels of pasture were normal but all the above pasture species contained oxalates which were suspected of causing the disease.
Jones RS.Surgical repair of a cleft palate was carried out in three horses. Mandibular symphisotomy allowed adequate exposure of the defect. The first subject, a young foal died from inhalation pneumonia but the other two made satisfactory recoveries. The problems of closure of the lip and symphysis are discussed.
Hort I.In this study the treatment of a mandibular fracture in a 26 year old Arab horse, the history during the subsequent 4 years and the anatomical post-mortem findings are presented and described.
Reported complication rates after dental repulsion for equine exodontia are high (up to 80%), but repulsion methods have changed notably in the last 20 years. Objective: Describe the outcome for 20 cases after dental repulsion using small diameter repulsion pins. Methods: Retrospective case series. Methods: Records of horses that underwent cheek tooth repulsion were reviewed (2014-2023). Inclusion criteria included: mandibular or maxillary cheek tooth extraction where oral extraction failed and repulsion was used to complete extraction, and where clinical follow up information was available....
Oikawa M, Ohishi H, Katayama Y, Kushiro A, Yoshikawa H, Yoshikawa T.A mass developed in the mandibular gingiva of a thoroughbred racehorse. When the horse could no longer eat unassisted, it was killed and immediately autopsied. Macroscopically, the mandible exhibited extensive osteolysis, with only a small amount of bone remaining around the tooth roots. The cut surface of the mass around the mandible consisted of neoplastic medullary tissue, in which osteogenesis was observed. The medullary tissue was composed of pleomorphic medium-sized to large cells, interlaced by collagen bundles. These cells had large, pale, round or ovoid, sometimes cleaved nuclei, with...
van der Kolk JH, van Hoorn CJ, van Garderen E, van den Belt AJ.An eighteen-year-old pony gelding was referred to the Faculty of Veterinary Medicine because of colic, due to cecal tympany. His haircoat was dull with long wavy hair. After medical treatment of the colic it was sent home three days later. Just before it had been dismissed the morning plasma glucose concentration measured 10.2 mmol.l-1. The basal plasma cortisol concentration was high (180 nmol.l1) and basal plasma ACTH concentration was highly elevated (> 960 pg.ml1). An ACTH-stimulation test was performed by intravenous administering of 0.25 mg synthetic ACTH 1 24 at 9.00 hours showing ad...
Maggi R, Mudimba D, Marruchella G.A 11-year-old, Haflinger breed mare developed a slowly growing mass, protruding on the ventral aspect of the mandible. On palpation, the lesion was pedunculated, very firm, cold and not painful. Radiographic examinations showed a radiopaque, multi-lobular, "mushroom-like" lesion, which arose from the mandibular cortex without involving the bone marrow cavity. Thereafter, the mass was excised for cosmetic purposes. Microscopically, the lesion mainly consisted of bone trabeculae, covered by a thick layer of connective tissue resembling the periosteum. History and clinical findings allowed the te...
Durket E, Kersh K, Dembek K, Riedesel E, Silverstone A, Kraus KH.To determine the influence of plate fixation (locking or dynamic compression) and the site of application (ventral [V] or ventrolateral [VL]) on the resistance to bending of transverse mandibular fractures. Methods: Ex vivo, simple randomized study. Methods: Mandibles harvested from adult equine cadavers (n = 18). Methods: Bilateral osteotomies were created 1 cm caudal to the mental foramen and perpendicular to the long axis of each mandible. Mandibles were fixed with 1 of 3 methods: (1) VL dynamic compression plate (DCP), (2) V-DCP, or (3) VL locking compression plating (LCP). Construct...
Tirosh-Levy S, Tatz A, Kelmer G.A 6-month-old Arabian filly escaped its handler while being led and slipped on pavement. The referring veterinarian recognized severe, soft tissue damage to the filly's lower jaw and referred the filly to the Veterinary Teaching Hospital for surgical management. Blessure de dégantage mandibulaire chez une pouliche arabe. Une pouliche arabe âgée de 6 ans s’est échappée de son préposé pendant qu’il la menait et a glissé sur la chaussée. Le vétérinaire traitant a reconnu des dommages graves aux tissus mous de la mâchoire inférieure de la pouliche et a recommandé la pouliche à l...
Spoormakers TJP, Wiemer P.To describe a symphyseal osteotomy stabilised with two short locking compression plates (LCPs) for treatment of class 2 malocclusions. Methods: Case series. Methods: Five horses (age range 8 months to 5¾ years) with overjets and/or overbites ranging from 6 to 32 mm and from 0 to 60 mm, respectively, were treated by osteotomy through the caudal third of the mandibular symphysis, cranial to the interdental space. After cranial distraction and ventral rotation of the rostral part of the mandible, two short (5/6 hole), bent 3.5 mm LCPs were applied ventro-laterally and secured with two or three l...
Larsen EA, Lack AC, Wassack E.The use of poloxamer 407 gels have been reported in several studies to prolong the release of drugs at the injection site. Oral lesions unrelated to dental disease are rare but may result in ulceration and sequestration of bone. To date, there have been no reports on the use of penicillin G potassium poloxamer 407 gel and its effect on wound healing. The present case report describes the use of a penicillin G potassium poloxamer 407 gel for the treatment of a sublingual abscess involving the mandible in a 20 year old Arabian mare who initially presented with acute onset of dysphagia, hypersali...
Erasha AM, Nazih M, Ali S, Alsafy M, El-Gendy S, Sayed RKA.A significant extent of researches in veterinary study have been focused on dental structure; however, there are scanty ones on the orientation and identification of their cusps. Therefore, the present article aimed to spot a light on arrangement pattern of dental cusps in the camel as a folivorous and graminivorous animal. This study was conducted on eight heads of adult, healthy camel of both sexes, collected from slaughter houses. To perform exact orientation of cusps of molar teeth, additional radiological and CT scans were performed on the mandible as a landmark that should facilitate the...
Schreeg ME, Radkin M, Haugland J, Murphy BG, Rushton S, Linder KE.Ameloblastic carcinoma is a malignant odontogenic neoplasm that has been reported only rarely in veterinary species. A 16-y-old Arabian crossbred mare was presented for evaluation of a hard mass on the body of the mandible, with evidence of osteolysis on radiographs. Incisional biopsies revealed an invasive neoplasm comprised of spindloid epithelial cells with a high mitotic count and partial dual cytokeratin-vimentin immunoreactivity. The horse was euthanized because of rapid tumor progression 3 mo after presentation. Postmortem evaluation revealed partial obliteration of the mandible by a ...
Vlaminck LE, Steenhault M, Maes D, Huys L, Gasthuys F.This study investigated the placement of an intra-alveolar prosthesis of bone substitute on gingival/periodontal health in 5 ponies following repulsion of cheek teeth 108 and 208. In each pony, one randomly chosen alveolus was allowed to heal by second intention while the other was filled with a non-resorbable, biocompatible bone substitute. At 6, 12 and 24-months after surgery, both maxillary arches were evaluated for wear abnormalities and for gingival health using a periodontal scoring system. Recorded changes included development of overgrowths on mandibular cheek teeth, widening of maxill...
Haralambus RM, Werren C, Brehm W, Tessier C.To report use of a pinless external fixator (PEF) for unilateral mandibular fractures in 9 equids. Methods: Case series. Methods: Equids (n=9) with unilateral mandibular fractures. Methods: All fractures were stabilized with the AO/ASIF PEF using a minimum of 4 clamps, under general anesthesia. Fracture configuration, complications, outcome, and owner satisfaction were evaluated. Results: All fractures were stabilized; 2 equids were euthanatized; 1 because of an inability to stand after surgery and 1 because of owner decision after PEF dislodgement. Seven repairs healed with good outcome and o...
Mählmann K, Noguera Cender A, Ehrle A, Lischer CJ.To describe a novel fixation of open, unstable, unilateral mandibular fractures applying a locking compression plate as an external skeletal fixator (ESF-LCP). Methods: Four horses and one dromedary. Methods: Short case series. Methods: Animals presented with unstable, open, unilateral fractures of the mandible. Fracture fixation was performed under general anesthesia. A 4.5/5.5 narrow LCP was applied externally above the level of the skin and combined with intraoral tension band wiring. Results: Fracture fixation was achieved successfully using an ESF-LCP. Minimal tissue manipulation was requ...
Vidović A, Jansen D.The first part of this case report describes the surgical treatment of a unilateral mandibular fracture in the standing horse by using a fixateur type I. By the time of implant removal, the fracture had completely healed. However, during implant removal, an implant failure of 2 of the 4 implants occurred with fragments remaining in the bone. The second part of the report focuses on the development of a special surgical instrument that was designed for removal of the implant fragments. Furthermore, the surgical method allowing the entire extirpation of the fragments within a second surgery is d...
Handy LH, Peyton LC, Calderwood-Mays MB, Ackerman N.A diagnosis of gingival hyperplasia in a 22-year-old Quarter Horse gelding was confirmed by histologic examination. Clinical signs included difficulty eating hay, and a large, intraoral soft tissue mass measuring 13 x 8 x 4.5 cm. The mass was located in the mucosa on the lingual aspect of the caudal left portion of the mandible, ventral to the base of the tongue, and covered the second and third lower molars, extending rostrally along the buccal mucosa to the premolars. The left maxillary second and third molars were overgrown with sharp edges. Lateral radiography of the mandible revealed abse...
Gfrerer L, Michel S, Fürst AE, Piskoty G, Weisse B, Montavon S, Jackson MA. The goal of this study was to generate mandibular fractures in three regions of the diastema using a metal impactor to simulate a kick from a horse and to determine the mean deceleration in the initial phase of the impact event, the maximum contact force, the impact energy necessary to create a fracture and the duration of the impact. Methods: Thirty heads of horses aged between 5 and 20 years and euthanatized for various reasons were used. The heads were attached to a steel bar at the occiput at an axial angle of 45 degrees so that the body of the mandible was positioned horizontally ...
Mirahmadi F, Koolstra JH, Fazaeli S, Lobbezoo F, van Lenthe GH, Snabel J, Stoop R, Everts V.Nutrition of articular cartilage relies mainly on diffusion and convection of solutes through the interstitial fluid due to the lack of blood vessels. The diffusion is controlled by two factors: steric hindrance and electrostatic interactions between the solutes and the matrix components. Aging comes with changes in the cartilage structure and composition, which can influence the diffusion. In this study, we treated fibrocartilage of mandibular condyle with ribose to induce an aging-like effect by accumulating collagen crosslinks. The effect of steric hindrance or electrostatic forces on the d...
Godoy VM, Oliveira NFOE, Paretsis NF, Silva SCD, Souza AF, De Zoppa ALDV, Corrêa RR.This report describes the combination of two surgical fracture repair techniques and the postoperative management of a mandibular diastemal fracture in a two-year-old mare. The mare was referred to a veterinary hospital with a laceration over the body of the right mandible. Radiographic assessment revealed two mesial fracture lines involving the second premolar tooth and a ventrally displaced bone fragment. The mare was treated under general anesthesia and the fracture was corrected using open reduction and plate fixation. A 3.5 mm narrow 15-hole locking compression plate with seven locking ...
Lima AE, Piñeros DDV, Alibrando BB, Bittar MJ, de Souza AF, Mendes RP, de Freitas SH, Bernardino T, Corrêa RR.The anatomical variations of the maxillary septum and the septal bullae can generate challenges during the interpretation of radiographs of the horses' heads and make it difficult to accurately identify the sites affected in sinus disorders. The description of the radiographic appearance of these structures is currently scarce in the scientific literature. This work aims to describe the anatomical and radiographic characteristics of the maxillary septum and maxillary septal bullae in horses. Six chemically preserved equine cadaver heads were used which, after being submitted to the maxillary o...
Nourinezhad J, Abdi A, Moarabi A, Hanafi MG, Fatahian Dehkordi RA, Tomańska A.Visualizing the major salivary glands (MSGs) in domestic mammals using plain radiology and identifying damaged their structures is impossible. To accurately display MSGs, the knowledge of normal sectional imaging anatomy is essential for veterinarians, aiding them significantly in identifying the exact relations and position of MSGs; however, no reports on the MSGs sectional imaging anatomy in this species have been made. Objective: This study aimed to evaluate computed tomography (CT), magnetic resonance imaging (MRI) and gross sections of MSGs. Methods: Seven healthy adult donkeys were used ...
Ostmeier M, Schellenberger F, Troillet A, Scharner D.Mouth specula with incisor bite plates shift the pressure from all teeth exclusively to the incisors in the opening phase which leads to increased forces on dental, osseous, and soft tissue structures of the horse's head. The potentially pathological character of these forces is described clinically by single reports of maxilla and mandible fractures occurring during the use of opened mouth specula. This study describes these forces on incisor teeth in horses during odontoplasty of cheek teeth under sedation. Measurements were documented using a modified "Günther" mouth speculum fitted with a...
Mendes RP, Lima AE, da Cunha R, Bittar MJ, Vasconcelos CC, Piñeros DDV, Corrêa RR.Radiographic examination of the skull is a well-established and indispensable procedure for the diagnostic evaluation of dental and paranasal sinus disorders in horses. Complementary projections make significant contributions to radiographic diagnosis in nasal conchae disorders. This article describes a complementary radiographic projection designed for the evaluation of the conchal sinuses and bullae in horses. Six equine cadaveric heads were used. Specimens were dissected, and openings were created in the ventral and dorsal nasal conchae for the introduction of radiopaque material. The new r...
Mendes RP, Gonzaga MS, Matheus MM, Bittar MJ, Doria RGS, Corrêa RR.Developmental and eruption abnormalities are common and can result in progressive dental diseases. Ectopic eruption of the affected tooth may be the result of these processes. This study aims to report the occurrence of a permanent mandibular tooth in a horizontal position, with retention of the corresponding deciduous tooth, in a miniature horse. A 2-year-old female miniature horse was admitted to the veterinary hospital with a hard swelling on the left mandibular ramus, which had been growing continuously for three months. After a complete evaluation, it was concluded that the swelling was t...
