Introduction
A 6-hour-old female Swiss Fleckvieh calf (patient 1) was examined at a referral hospital for mandibular trauma. The calf was born without assistance on pasture and was found injured shortly thereafter. The calf did not receive any colostrum or treatment prior to referral. Physical examination identified a mandibular pars incisiva fracture (ie, fracture of the rostral aspect of the mandible [rostral mandibular fracture]) with a laceration of the oral mucosa and ventral displacement of teeth 701 to 704 (modified Triadan teeth numbering system [ie, left incisors 1 through 4]; Figure 1).
Photographs of the rostral aspect of the oral cavity of an anesthetized < 1-day-old female Swiss Fleckvieh calf (patient 1) with an open fracture of the pars incisiva of the mandible (rostral mandibular fracture) before (A) and after (B) the fracture site and surrounding tissues were surgically debrided and the laceration in the oral mucosa was closed with absorbable suture in an interrupted horizontal mattress pattern. The 4 incisors of the left hemimandible were displaced ventrally prior to surgical repair.
Citation: Journal of the American Veterinary Medical Association 258, 11; 10.2460/javma.258.11.1254
Photographs of the rostral aspect of the oral cavity of an anesthetized < 1-day-old female Swiss Fleckvieh calf (patient 1) with an open fracture of the pars incisiva of the mandible (rostral mandibular fracture) before (A) and after (B) the fracture site and surrounding tissues were surgically debrided and the laceration in the oral mucosa was closed with absorbable suture in an interrupted horizontal mattress pattern. The 4 incisors of the left hemimandible were displaced ventrally prior to surgical repair.
Citation: Journal of the American Veterinary Medical Association 258, 11; 10.2460/javma.258.11.1254
Photographs of the rostral aspect of the oral cavity of an anesthetized < 1-day-old female Swiss Fleckvieh calf (patient 1) with an open fracture of the pars incisiva of the mandible (rostral mandibular fracture) before (A) and after (B) the fracture site and surrounding tissues were surgically debrided and the laceration in the oral mucosa was closed with absorbable suture in an interrupted horizontal mattress pattern. The 4 incisors of the left hemimandible were displaced ventrally prior to surgical repair.
Citation: Journal of the American Veterinary Medical Association 258, 11; 10.2460/javma.258.11.1254
A catheter was aseptically placed in a jugular vein. Anesthesia was induced by and maintained with isoflurane. The calf was positioned in dorsal recumbency. The oral laceration and exposed mandibular bone were surgically debrided in a careful and thorough manner with continuous flushing of the wound with sterile 0.05% chlorhexidine solution. The laceration was then closed by use of 2–0 poliglecaprone 25 in an interrupted horizontal mattress pattern.
Following surgery, the calf received a bovine plasma transfusion (30 mL/kg [13.6 mL/lb], IV) because it was believed that it had not consumed any colostrum after birth. It also received sodium penicillin (30,000 U/kg [13,600 U/lb], IV, q 8 h for 5 days) and ketoprofen (3 mg/kg [1.4 mg/lb], IV, q 24 h for 2 days). The oral cavity was flushed with tap water on a daily basis while the calf remained hospitalized. The calf was able to suckle milk normally from a bottle immediately after surgery and was discharged from the hospital 6 days after surgery. Six months after surgery, the owner reported that the calf had normal eating habits and was comparable in size and body condition to herdmates of similar age.
A 2-day-old female Red Holstein calf (patient 2) was examined at a referral hospital for a rostral mandibular fracture. The calf was born following dystocia and forced extraction with a head loop. It reportedly received an adequate volume of colostrum within the first 24 hours after birth and received ketoprofen (3 mg/kg, IV) before referral to the veterinary hospital. At hospital admission, the calf's serum TP concentration (60 g/L; reference range, 50.7 to 71.1 g/L) was interpreted to be consistent with adequate transfer of maternal antibody (ie, adequate colostrum consumption or passive transfer of immunity). A fracture of the rostral mandible with laceration of the oral mucosa and ventral displacement of teeth 701 to 704 (left incisors 1 through 4) and 801 to 804 (right incisors 1 through 4) were diagnosed during physical examination.
A catheter was aseptically placed in a jugular vein, and the calf received sodium penicillin (30,000 U/kg, IV) and ketoprofen (3 mg/kg, IV) prior to surgical debridement and repair of the laceration. The calf was anesthetized, and the laceration and fracture were debrided and repaired as described for patient 1 except that a Penrose drain was placed at the ventral aspect of the wound closure for drainage. The calf was discharged from the hospital 24 hours after surgery with instructions for administration of penicillin procaine G (30,000 U/kg, IM, q 24 h for 4 days) and ketoprofen (4.5 mg/kg [2 mg/lb], PO, once), daily flushing of the oral cavity with tap water, and removal of the Penrose drain 4 days after surgery. Thirteen months after surgery, the animal had normal eating habits and was comparable in size and body condition to herdmates of similar age. However, mild brachygnathia was present and 2 deciduous left incisors appeared to be slightly loose and discolored (Figure 2).
Photograph of the left lateral aspect of the rostral portion of the oral cavity of a 13-month-old Red Holstein heifer (patient 2) that underwent surgical repair of an open rostral mandibular fracture as described for the calf of Figure 1 at 2 days of age. All 8 incisors were ventrally displaced prior to fracture stabilization. Notice that the animal has mild brachygnathia and that the left incisors are slightly discolored, neither of which adversely affected the eating habits or growth of the animal.
Citation: Journal of the American Veterinary Medical Association 258, 11; 10.2460/javma.258.11.1254
Photograph of the left lateral aspect of the rostral portion of the oral cavity of a 13-month-old Red Holstein heifer (patient 2) that underwent surgical repair of an open rostral mandibular fracture as described for the calf of Figure 1 at 2 days of age. All 8 incisors were ventrally displaced prior to fracture stabilization. Notice that the animal has mild brachygnathia and that the left incisors are slightly discolored, neither of which adversely affected the eating habits or growth of the animal.
Citation: Journal of the American Veterinary Medical Association 258, 11; 10.2460/javma.258.11.1254
Photograph of the left lateral aspect of the rostral portion of the oral cavity of a 13-month-old Red Holstein heifer (patient 2) that underwent surgical repair of an open rostral mandibular fracture as described for the calf of Figure 1 at 2 days of age. All 8 incisors were ventrally displaced prior to fracture stabilization. Notice that the animal has mild brachygnathia and that the left incisors are slightly discolored, neither of which adversely affected the eating habits or growth of the animal.
Citation: Journal of the American Veterinary Medical Association 258, 11; 10.2460/javma.258.11.1254
A 4-day-old female Holstein-Friesian calf (patient 3) was examined at a referral hospital for an apparent traumatic injury to the mandible that was first noticed shortly after birth. The calf was born without assistance and had received amoxicillin (15 mg/kg [6.8 mg/lb], SC, q 24 h for 3 days) and meloxicam (0.5 mg/kg [0.23 mg/lb], SC, q 48 h) prior to referral. An open rostral mandibular fracture with the presence of fibrinous exudate at the wound site was identified during physical examination. Oral radiographs were obtained and revealed that the rostral aspect of the right hemimandible and teeth 801 to 804 (right incisors 1 through 4) and 701 (left incisor 1) were fractured at the level of the apical dental buds and displaced ventrally; the mandibular symphysis did not appear to be damaged (Figure 3). The calf's serum TP concentration (60 g/L) was interpreted to be consistent with adequate passive transfer of immunity.
Intraoral radiographic images of the rostral mandible of a female Holstein-Friesian calf (patient 3) with an open rostral mandibular fracture; images were obtained before (age, 4 days; A) and 9 days after (age, 13 days; B) surgical debridement and primary closure of the lacerated oral mucosa as described for the calf of Figure 1. A—A fracture was present at the ventral aspect of the rostral mandible, and the left first incisor and all 4 right incisors were fractured at the level of the apical dental buds. The mandibular symphysis appeared to be intact. The 5 fractured teeth were removed during surgical debridement of the open wound. B—The rostral aspect of the right hemimandible had an irregular and poorly marginated border, and the rostral aspect of the mandibular symphysis appeared to be widened with mild irregularities. Those radiographic findings were consistent with the early stages of osteomyelitis. Right is to the top in both images.
Citation: Journal of the American Veterinary Medical Association 258, 11; 10.2460/javma.258.11.1254
Intraoral radiographic images of the rostral mandible of a female Holstein-Friesian calf (patient 3) with an open rostral mandibular fracture; images were obtained before (age, 4 days; A) and 9 days after (age, 13 days; B) surgical debridement and primary closure of the lacerated oral mucosa as described for the calf of Figure 1. A—A fracture was present at the ventral aspect of the rostral mandible, and the left first incisor and all 4 right incisors were fractured at the level of the apical dental buds. The mandibular symphysis appeared to be intact. The 5 fractured teeth were removed during surgical debridement of the open wound. B—The rostral aspect of the right hemimandible had an irregular and poorly marginated border, and the rostral aspect of the mandibular symphysis appeared to be widened with mild irregularities. Those radiographic findings were consistent with the early stages of osteomyelitis. Right is to the top in both images.
Citation: Journal of the American Veterinary Medical Association 258, 11; 10.2460/javma.258.11.1254
Intraoral radiographic images of the rostral mandible of a female Holstein-Friesian calf (patient 3) with an open rostral mandibular fracture; images were obtained before (age, 4 days; A) and 9 days after (age, 13 days; B) surgical debridement and primary closure of the lacerated oral mucosa as described for the calf of Figure 1. A—A fracture was present at the ventral aspect of the rostral mandible, and the left first incisor and all 4 right incisors were fractured at the level of the apical dental buds. The mandibular symphysis appeared to be intact. The 5 fractured teeth were removed during surgical debridement of the open wound. B—The rostral aspect of the right hemimandible had an irregular and poorly marginated border, and the rostral aspect of the mandibular symphysis appeared to be widened with mild irregularities. Those radiographic findings were consistent with the early stages of osteomyelitis. Right is to the top in both images.
Citation: Journal of the American Veterinary Medical Association 258, 11; 10.2460/javma.258.11.1254
The calf was anesthetized and underwent surgical debridement of the open fracture and wound closure as described for patient 1, except that the fractured teeth were removed. Following surgery, the calf received sodium penicillin (30,000 U/kg, IV, q 8 h for 5 days) and ketoprofen (3 mg/kg, IV, q 24 h for 2 days).
Seven days after surgery, there was partial dehiscence of and purulent discharge present at the most rostral 1.5 cm of the suture line. Oral radiographs were obtained 9 days after surgery and compared with those obtained prior to surgery. The radiographs obtained 9 days after surgery revealed that the rostral aspect of the right hemimandible had an irregular and poorly marginated border, and the rostral aspect of the mandibular symphysis appeared to be widened with mild irregularities (Figure 3). Those radiographic findings led to a presumptive diagnosis of osteomyelitis of the rostral aspect of the right hemimandible.
On the ninth day after surgery, the calf was sedated with xylazine (0.1 mg/kg [0.045 mg/lb], IM) and ketamine (4 mg/kg [1.8 mg/lb], IV) for careful debridement of the dehisced suture line. The debridement was performed by continuous flushing of the wound with sterile 0.05% chlorhexidine solution. A Penrose drain was placed at the ventral aspect of the dehisced portion of the suture line, and the dehisced edges of the suture line were left to heal by second intention. The sedation and surgical debridement procedures were repeated on day 14 after surgery. Following the first revision surgery (debridement), administration of sodium penicillin (30,000 U/kg, IV, q 8 h) was resumed and continued for 14 days, and administration of danofloxacin (1.25 mg/kg [0.57 mg/lb], IV, q 24 h for 3 days) was initiated. The suckling behavior of the calf remained good despite the postsurgical complication. The calf was discharged from the hospital 27 days after the initial surgery. Three months after hospital discharge, the calf had normal eating habits despite the presence of mild brachygnathia.
Discussion
The mandible consists of 2 hemimandibles, each with a vertical and horizontal ramus. The horizontal ramus contains the alveoli for the molars and premolars at its more caudal aspect and the alveoli for the incisors at its most rostral aspect. The mandibular canal runs longitudinally within the horizontal ramus from the mandibular foramen to the mental foramen and contains the inferior alveolar nerve, which is a branch of the mandibular nerve.
Mandibular fractures are common in cattle. Although unilateral fractures of the horizontal ramus involving the molars are common in adult animals, fractures of the rostral aspect of 1 or both hemimandibles and the mandibular symphysis are most common in calves.1 The most common cause of mandibular fractures in calves is obstetric manipulation owing to dystocia.2,3,4 However, among the 3 calves of the present report, only 1 had a history of dystocia and assisted birth. Mandibular fractures are often open to the oral cavity and may be infected by the time that they are diagnosed. Therefore, administration of perioperative antimicrobials to affected animals is generally warranted. Reduction and stabilization of mandibular fractures are indicated to alleviate signs of pain and allow patients to resume normal eating or suckling behavior.
In cattle, intraoral acrylic splints, interdental wiring, U bars, external fixators (including pinless external fixators), lag screw fixation, and plating have been used for surgical management of mandibular fractures.1 Mandibular fractures generally heal well because of the rich vascularization of oral tissues. However, complications, such as premature loosening of surgical implants, osteomyelitis, and tooth root abscesses, have been reported following reduction and stabilization of mandibular fractures in cattle. External coaptation for fracture stabilization has been successfully used to treat calves with rostral mandibular fractures.5 The present report described the successful use of oral mucosal sutures as the sole means of stabilizing rostral mandibular fractures in 3 neonatal calves.
For the 3 calves with open rostral mandibular fractures described in the present report, surgical debridement and primary closure (suturing) of the lacerated oral mucosa provided adequate fracture stabilization to allow the calves to resume normal suckling behavior immediately after surgery. Thus, we believe that this simple surgical approach is a viable alternative for the treatment of open rostral mandibular fractures in neonatal calves.
The procedure described in the present report cost less than the surgical application of orthopedic implants for fracture stabilization. All 3 calves of the present report were anesthetized for the procedure, which substantially added to the overall cost of patient management. However, the use of deep sedation and mandibular regional anesthesia may be adequate for the procedure to be performed and cost less than the use of general inhalation anesthesia. A mental foramen nerve block anesthetizes the teeth, soft tissues, and bone of the rostral mandible and is fairly easy to perform, although anatomic irregularities may affect its efficacy. The α2-adrenergic receptor agonists (eg, xylazine and medetomidine) commonly used for sedation in cattle can adversely affect cardiopulmonary function, especially in neonates, and should be used with caution. In neonates, the induction and maintenance of general anesthesia by use of only a volatile anesthetic, such as isoflurane, has several advantages over sedation with α2-adrenergic receptor agonists. Volatile anesthetics are absorbed and eliminated by the lungs independent from hepatic and renal function, which allows rapid adjustment of anesthetic depth, particularly in the event of excessive cardiovascular or respiratory depression. The procedure described in the present report was easy to perform and did not require any specialized equipment; therefore, it should be feasible to perform in field situations with the patient under deep sedation and use of mandibular regional anesthesia. When treating neonatal animals, particular care should be taken during administration of anesthetics and sedatives because of the immaturity of the CNS and cardiopulmonary, hepatic, renal, and metabolic systems.
Complications associated with the rostral mandibular fracture stabilization technique described in the present report included osteomyelitis in 1 calf and the development of mild brachygnathia in that calf and another. Mandibular fractures are frequently open fractures and therefore predisposed to becoming infected. However, mandibular fractures generally heal quickly owing to the rich vascularization of oral tissues, even in the presence of osteomyelitis. In the present report, the calf that developed osteomyelitis healed without further complications after the infected site was surgically debrided on 2 separate occasions 9 and 14 days after the initial surgery. Calves with open rostral mandibular fractures that undergo surgical debridement alone without primary closure of the lacerated oral mucosa can develop severe osteomyelitis that necessitates euthanasia.2,6 Early intervention in the form of surgical debridement and stabilization of open mandibular fractures combined with the administration of perioperative antimicrobials is believed essential to improve patient outcome. Of the 3 calves described in the present report, the only calf that developed osteomyelitis was not referred for surgical correction until > 72 hours after the initial trauma, and the infection developed despite initiation of antimicrobial treatment on the farm prior to referral. This emphasized the fact that, in calves with open rostral mandibular fractures, antimicrobial administration is unlikely to prevent osteomyelitis in the absence of fracture decontamination by means of surgical debridement. For calves with open rostral mandibular fractures, we believe that primary closure of the laceration in the oral mucosa protects the fracture site from further contamination and speeds the healing process.
In another clinical report,6 calves with simple rostral mandibular fractures that underwent application of external coaptation for fracture stabilization developed prognathism, possibly as a consequence of inadequate longitudinal compression across the fracture site. Interestingly, the calves of that report5 with comminuted rostral mandibular fractures and loss of bone at the fracture site, which could have shortened the bone, did not develop prognathism. The surgical procedure described in the present report involved debridement of bone at the fracture site, which might have led to a slight shortening of the horizontal ramus. Two of the 3 calves of the present report subsequently developed mild brachygnathia; however, the condition did not affect the eating behavior or growth of the affected animals.
Historically, mandibular fracture in neonatal calves was associated with a poor prognosis, even with fracture stabilization, owing to the development of enteritis or septicemia.2 It is essential that calves with mandibular fractures undergo a complete physical examination so that concomitant diseases can be identified and appropriately treated and managed. Neonatal animals with mandibular fractures may have concomitant hypothermia, hypoglycemia, dehydration, and acidosis, which may become life-threatening if not promptly treated, because of the immaturity of the cardiopulmonary, hepatic, renal, and metabolic systems. The serum IgG concentration should always be determined in neonatal calves (and other ruminants) for assessment of passive transfer of immunity. Inadequate or failure of passive transfer of immunity can contribute to the development of sepsis, pneumonia, and enteritis, which may adversely affect patient outcome. For the calves of the present report, serum TP concentration was used as a proxy for serum IgG concentration for assessment of passive transfer of immunity because there is good correlation between serum TP and IgG concentrations.7 Passive transfer of immunity is considered adequate in healthy 1-day-old calves with a serum TP concentration > 52 g/L (equivalent to a serum IgG concentration > 10 g/L)7; however, a serum TP concentration > 55 g/L is preferred as an indicator of adequate passive transfer of immunity in critically ill neonatal calves.
Most of the drugs received by the calves of the present report were administered in an extralabel manner in accordance with all regulations governing such use in food-producing animals in Switzerland. However, the extralabel drug use described for the calves of this report may be prohibited in other countries.
For the 3 calves with open rostral mandibular fractures described in the present report, surgical debridement of the fracture site and surrounding tissues and primary closure of the laceration in the oral mucosa with absorbable suture in a simple interrupted horizontal mattress pattern provided adequate stabilization of the fracture and resulted in a positive outcome. One calf developed mild osteomyelitis at the fracture site, which resolved with additional surgical debridement and antimicrobial treatment. That calf and another developed mild brachygnathia; however, the condition did not affect their eating habits or growth. The described procedure was easy to perform, did not require any specialized equipment, and was less expensive than other fracture stabilization methods. Therefore, we believe the procedure can be an effective and economic on-farm treatment alternative for neonatal calves with rostral mandibular fractures.
Acknowledgments
The authors declare that there were no conflicts of interest.
Abbreviations
| TP | Total protein |
References
- 1. ↑
Ducharme NG, Desrochers A. Mandibular fractures, osteomyelitis, and neoplasia. In: Fubini SL, Ducharme NG, eds. Farm animal surgery. 2nd ed. St Louis: Elsevier, 2017;228–237.
- 3. ↑
Ravary B, Millemann Y, Maillard R, et al. Mandibular fractures in cattle. Point Vét 2004;35:38–43.
- 4. ↑
Desrochers A. Mandibular fractures in cattle, in Proceedings. Am Coll Vet Surg Cong 2011;657–659.
- 5. ↑
Taguchi K, Hyakutake K. External coaptation of rostral mandibular fractures in calves. Vet Rec 2012;170:598–601.
- 6. ↑
Nuss K, Kostlin R, Elma E, et al. Mandibular fractures in cattle—treatment and results. Tierarztl Prax 1991;19:27–33.
- 7. ↑
Weaver DM, Tyler JW, VanMetre DC, et al. Passive transfer of colostral immunoglobulins in calves. J Vet Intern Med 2000;14:569–577.
