Cheek Tooth Extraction Via a Minimally Invasive Transbuccal Approach and Intradental Screw Placement in 54 Equids

Evaluation of Three Methods of Sensory Function Testing for the Assessment of Successful Maxillary Nerve Blockade in Horses

Maxillary nerve blocks (MNBs) commonly facilitate dental surgeries in standing horses. The goal of this prospective, blinded, cross-over design trial including 15 client-owned horses was to evaluate 3 methods of sensory function testing for confirming a successful MNB. Testing was performed bilaterally before sedation, 5 min after sedation, and 15 and 30 min after MNB with 0.5% bupivacaine and involved a needle prick dorsal to each naris, hemostat clamping of each nostril, and gingival algometry (measuring sensitivity to pain). Responses to stimulation were numerically scored and scores were summed up to a total score. Total score increases on the blocked side by ≥ 2 between baseline and 30 min Post MNB recordings signified a successful MNB. Sedation in the preceding 6 h, presence of sino-nasal disease, side of dental pathology, age, butorphanol administration, and detomidine dosing (µg/kg/min) throughout the tooth extraction procedure were recorded. In 73% of horses, MNB was successful. Sedation in the preceding 6 h (P = .732), age (P = .936), side of pathology (P = .516), and sino-nasal disease (P = .769) were not associated with total scores. Detomidine dosage and butorphanol use did not differ between horses in which the MNB was considered successful and for those in which it was not (P = .967 and P = .538, respectively). Scores obtained with gingival algometry were less closely associated with total scores (rho = .649) than those obtained with needle prick and nostril clamping (rho = .819 and .892, respectively). Therefore, needle prick and nostril clamping are considered the more reliable methods for use in clinical practice to determine the success of an MNB.

Equine cheek tooth repulsion using small diameter repulsion pins: 20 cases

BACKGROUND

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.

OBJECTIVES

Describe the outcome for 20 cases after dental repulsion using small diameter repulsion pins.

STUDY DESIGN

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. Repulsions were carried out under sedation with a regional nerve block or under a short general anaesthetic, using a small diameter repulsion pin (3-5 mm). Intra-operative radiographs facilitated instrument placement. The alveolus was packed with polymethyl methacrylate post-extraction. Horses were re-examined at 4-6 weeks post-operatively.

RESULTS

Twenty cases were included. Patients had a mean age of 10.3 years old (range 5-16 years). The majority (75%) of teeth had pre-existing dental fractures. Maxillary (n = 15) and mandibular cheek teeth (n = 5) were all successfully repulsed, with 16 cases performed with the horse standing and 4 with the horse under general anaesthesia. Intra-operative complications included damage to the mandibular bone (n = 1). Short-term complications (n = 2) included superficial surgical site infection, and dehiscence of one sinus flap. Long-term complications included the recurrence of sinusitis (n = 1) and small intra-alveolar fragments causing persistent bitting problems in another patient.

MAIN LIMITATIONS

Retrospective study design, small number of cases.

CONCLUSIONS

When oral extraction fails, cheek tooth repulsion using small diameter repulsion pins is an effective extraction technique. The total intra- and post-operative complication rate was 25%, which is comparable to previously published complication rates for repulsion using Steinmann pins and also those encountered after trans-buccal screw extraction.

Corkscrew Technique for Extraction of Premolars and Molars in Standing Sedated Horses: Cadaveric Study and Clinical Cases

Several tooth extraction techniques are described in equine literature, and oral extraction techniques in standing sedated horses are popular among equine practitioners. The objectives of this study were to develop the corkscrew technique for cheek tooth extraction (CSET) in equine cadaver heads and evaluate this technique in clinical cases. We hypothesized that the CSET could be performed safely to extract cheek teeth in standing sedated horses. First, the CSET was attempted and developed in eight equine cadaver heads. Second, the CSET was performed in clinical cases between 2016 and 2020, and the following information was recorded: diagnosis, affected tooth, procedure duration, intraoperative difficulties, tooth size, postoperative complications, medication, hospitalization time, and 1-year follow-up. Sixteen CSET procedures were performed in eight equine skulls with a 75% success rate. In 24 clinical cases, 25 CSET procedures were attempted to extract 22 superior and 3 inferior cheek teeth. CSET was successful in 76% of procedures. Fractures of the tooth and stripping of screw threads were the major complications that led to the failure of CSET. CSET is a viable and safe technique to extract cheek teeth in standing sedated horses. Longitudinal drilling is a must for this technique to be successful.

Dental sectioning for intraoral equine cheek teeth extractions: 29 cases

The objectives of this retrospective study were to describe cheek teeth extraction by the sectioning technique, the decision making to use this technique and its potentially associated complications. Sectioning for dental extraction purpose was used in 29/461 (6.3%) of cases. Oro-sinusal fistula was the main post-operative complication, with 4/29 (13.7%) cases developing a macroscopic communication between the alveolus of the tooth extracted and the adjacent sinus compartment. All teeth where sectioning was attempted were successfully extracted. Sectioning for dental extraction appears to be a safe technique that can be used instead of or in addition too other minimal invasive cheek teeth extraction techniques. Thorough preoperative planning including oroscopic examination and medical imaging modalities are required to help in decision making, as well as excellent sedation and analgesia and horse compliance.

Standing equine cheek tooth extraction: A multivariate analysis of the effect of antibiotics on the risk of post-operative complications

BACKGROUND

Commonly, cheek tooth extraction performed in standing horses using perioperative prophylactic antibiotics, results in low post-operative complication rates. However, no studies have documented the relevance of perioperative antibiotics to the risk of post-operative complications.

OBJECTIVES

To examine the association between perioperative antibiotics and post-operative complications after standing cheek tooth extraction.

STUDY DESIGN

Retrospective cohort study.

METHODS

Information from clinical records and follow-up questionnaires relating to horses subjected to cheek tooth extractions between September 2016 and May 2020 was obtained. Post-operative complications and associations with perioperative antibiotics, age, sex, breed, diagnosis, tooth position, and extraction method were analysed using multivariate logistic regression.

RESULTS

A total of 305 horses were included, and of these 71 (23.3%) received perioperative antibiotics. Antibiotics were not associated with the risk of complications in 264 horses that underwent standard oral extraction; 9/49 (18.4%) that received antibiotics and 35/215 (16.3%) that did not receive antibiotics experienced postoperative complications (P = 1, RR = 0.89, OR = 1, OR CI = [0.41; 2.46]). Of 41 horses that had cheek tooth extraction through minimally invasive transbuccal cheek tooth extraction (MTE), 5/22 (22.7%) that received antibiotics and 10/19 (52.6%) that did not receive antibiotics, experienced postoperative complications. Although not statistically significant when adjusting for multiple comparisons (naïve P = 0.04, adjusted P = 0.26, RR = 2.32, OR = 4.48, OR CI = [1.05; 19.11]), this finding is clinically relevant. Younger age was also significantly associated with development of complications (P = 0.02, OR = 0.92 per year, OR CI = [0.87; 1.36]).

MAIN LIMITATIONS

The retrospective nature of the study leads to uncontrollable potential confounders and there is a relatively low number of MTE cases.

CONCLUSION

Perioperative antibiotics were not associated with a lower complication rate in horses subjected to standard standing cheek tooth extraction. Use of perioperative antibiotics in conjunction with MTE may be merited, although further investigations are needed.

Clinical, Diagnostic and Histological Findings Involving Cheek Teeth Hypercementosis in Nine Horses

Hypercementosis is infrequently reported to affect the cheek teeth of horses and presents as mineral deposits either attached (peripheral) or solitary ovoid (nodular) structures in the tooth bearing region. There is overlap between radiological and histological appearance of hypercementosis, cementoma, and equine odontoclastic tooth resorption and hypercementosis (EOTRH). The clinical presentation, imaging features, surgical management, and histological findings of nine horses that presented for dental lesions and associated hypercementosis of cheek teeth are reported. Horses were 4-15 years old and presented for either nasal discharge or facial swelling. Peripheral and nodular mineral structures were identified using radiographs or computed tomography in six and three horses, respectively. Eight of nine cases involved maxillary cheek teeth. Of six cases with peripheral hypercementosis, three had enlargement of the apical cross-sectional area that was greater than the coronal cross-sectional area thus preventing extraction along the normal eruption pathway and necessitating sectioning (two cases) and repulsion. Nodular hypercementosis lesions were extracted in three of the four cases. Post-extraction complications occurred in five cases; four cases required additional procedures. All horses returned to their intended use, ie riding or pasture. Histology of extracted dental and proliferative mineral material revealed hypercementosis characterized by large sheets of eosinophilic matrix with lacunae (usually empty; presumed artifact) and frequent, irregular, basophilic cement lines. All cases had evidence of chronic inflammation, such as caries, chronic fractures and/or pulpitis. The findings of this case series share many features with previous published descriptions of cementoma and with histological findings of hypercementosis lesions of EOTRH. Further investigation into differentiation of these entities is warranted.

Unilateral, Rostral Maxillary Sinusitis Resulting from Displacement and Retention of an Alveolar Plug in a 4-Year-Old Horse

Sinusitis is a common occurrence in horses and often develops secondary to dental disease. Extraction of cheek teeth in horses is associated with variable degrees of complications and although postoperative displacement and retention of alveolar plugs has been identified as one such potential complication, few cases of resulting sinusitis have been reported. This manuscript describes a four-year-old Thoroughbred mare that was presented for chronic unilateral left-sided mucopurulent nasal discharge after extraction of the left maxillary second molar tooth two months earlier. Radiographic and computed tomographic (CT) examinations revealed a well circumscribed, soft tissue opacity in the left rostral sinus compartment. Intraoral examination revealed feed impacted in the alveolus of the extracted tooth and an oral sinus fistula. Upper airway endoscopy showed thick, purulent material at the nasomaxillary aperture. Sinoscopy showed unexpectedly clean frontal, dorsal conchal and caudal maxillary sinuses. The alveolar dental plug associated with previous exodontia became apparent within the sinus and was removed through the sinoscopy portal. Repeat endoscopies confirmed progressive clearance of the sinusitis during hospitalization. Unilateral nasal discharge returned three months later. An abscess within the sinus had formed. Complete resolution of the sinusitis was achieved after lancing the abscess and further sinus lavage. Sinoscopy through a frontal sinus trephination portal proved useful in diagnosis and treatment. Detailed evaluation of structures allowed for rapid establishment of adequate drainage and communication between all sinus compartments without osteoplastic surgery.

Successful treatment of a chronic oroantral fistula infected with extensively drug resistant bacteria using long-term oesophageal tube feeding and several non-conventional treatments in a horse

BACKGROUND

Chronic oroantral fistulae (OAF) with secondary sinusitis can occur following repulsion of cheek teeth in horses.

CASE REPORT

An 8-year-old Andalusian cross gelding presented with an iatrogenic clinical crown fracture of tooth 209, which underwent repulsion of its apical portion (day 0). The horse was treated with intramuscular penicillin and intravenous gentamicin (5 days), followed by oral trimethoprim-sulphonamide (10 days) and then oral doxycycline (14 days). The acute iatrogenic OAF created during the initial repulsion persisted; a chronic OAF was identified on day 24. On day 48, septic sinusitis with multidrug-resistant (MDR) Escherichia coli was confirmed. Although susceptible to enrofloxacin in vitro, 30 days of therapy was unsuccessful. Subsequent serial cultures grew multiple MDR and extensively drug-resistant (XDR) gram-negative microorganisms. Whole-genome sequencing (WGS) revealed multiple sequence types of E. coli, with a range of resistance and virulence genes. The orientation of the OAF, regional osteomyelitis and septic sinusitis were confirmed with computed tomography on day 70. On day 74, enteral nutrition was provided through a cervical oesophagostomy tube for 3 months for prevention of oral feed contamination. The OAF was treated with various alternative therapeutics, including apple cider vinegar, propolis and amikacin impregnated products, until resolution on day 116.

CONCLUSION

These non-conventional therapeutics, antimicrobials and long-term oesophagostomy contributed to the successful treatment of a complicated OAF. In the future, WGS may be useful to inform antimicrobial selection when MDR or XDR organisms are identified.

Minimizing Equine Tooth Extraction Complications

Oral extraction has become the most popular extraction technique owing to its high rate of success with minimal major complication. Repulsion continues to produce unacceptably high iatrogenic complication rates. To avoid tooth repulsion, veterinary dentists have introduced procedures to facilitate difficult intraoral extractions and surgical extraction techniques. Minimizing complications is best achieved preoperatively. A comprehensive preoperative evaluation and treatment plan allows the dentist to predict intraoperative complication and prepare for procedures to produce the best outcome. With proper case selection and adherence to extraction principles, the primary veterinarian and the veterinary dentist can perform equine tooth extractions with minimal complications.

Adjunct Extraction Techniques in Equine Dentistry

Adjunct extraction techniques are used when the shape or integrity of the tooth, the shape or size of the patient's oral cavity, the location of the tooth, or the location of the proximal teeth prevents or complicates standard oral extraction. Techniques described and discussed include partial coronectomy, tooth sectioning, minimally invasive buccotomy, transbuccal screw extraction, and commissurotomy.

Assessment of clinical and computed tomographic findings for association with the outcome of intraoral cheek tooth extraction in horses and ponies

OBJECTIVE

To describe clinical and CT findings for horses and ponies undergoing intraoral cheek tooth extraction and assess potential associations between these features and outcome of the procedure.

ANIMALS

74 horses and 7 ponies.

PROCEDURES

Medical records were searched to identify horses and ponies that underwent CT and intraoral extraction of ≥ 1 cheek tooth with standing sedation. Signalment and clinical variables were recorded, and CT scans were reviewed. Anatomic location and measurements of affected teeth; abnormalities of the periodontium, pulp, infundibula, roots, and tooth shape; fracture presence and type; presence of sinusitis; and affected sinus cavities were assessed by a surgeon and a radiologist. Intraoral extraction outcome was recorded as successful (complete removal of the tooth in 1 intraoral extraction procedure) or unsuccessful. Univariable and multivariable logistic regression analyses were performed to assess associations between clinical or CT findings and outcome.

RESULTS

89 cheek teeth (80 maxillary and 9 mandibular) were included in the analyses. Sixty of 89 (67%) cheek teeth were extracted successfully (56/80 [70%] maxillary and 4/9 [44%] mandibular cheek teeth). Only presence of a simple fracture (vs no fracture) was associated with outcome on multivariable regression analysis; odds of successful intraoral extraction were significantly lower when this feature was present.

CONCLUSIONS AND CLINICAL RELEVANCE

Most extractions of cheek teeth in the study sample were successful, and results may be useful for practitioners in refining cheek tooth extraction plans for horses and ponies. Further studies are required to assess whether specific CT findings can be used to predict the outcome of intraoral extraction in equids.

Transcutaneous Lateral Alveolar Ostectomy for Standing Surgical Extraction of Mandibular First Molar in an 8-Year-Old Miniature Horse

An 8-year-old, 125 kg (275 lb) female miniature horse was evaluated for a persistently thickened left mandible and cutaneous fistula. Pulp horn defects were identified in pulp horns 1 and 3 of tooth 309 and occlusal pulp exposure was detected with a dental explorer. Radiography of the left mandibular dental quadrant revealed changes consistent with apical infection of tooth 309. Following the failure of oral extraction, a standing surgical approach was taken for transcutaneous lateral alveolar ostectomy and extraction. Roots were sectioned at the level of the furcation and elevated from the surgical site, and the remaining reserve crown was luxated and repulsed into the oral cavity. Healing of the surgical site and alveolus was uncomplicated.

A long-term study of equine cheek teeth post-extraction complications: 428 cheek teeth (2004-2018)

BACKGROUND

Complications, especially delayed alveolar healing, are common following equine cheek teeth extraction, however, limited objective information is available on the prevalence and nature of these problems.

OBJECTIVES

To document the type and prevalence of complications that occur following equine cheek tooth extraction and to identify possible risk factors for these complications that could be used to predict their occurrence and hopefully reduce their prevalence.

STUDY DESIGN

Retrospective cohort study.

METHODS

Clinical records of all cheek teeth extractions performed between February 2004 and September 2018 were examined and written questionnaires sent to owners. Details of post-extraction complications were analysed and logistic regression was used to evaluate potential associations between the likelihood of post-extraction nonhealing alveolus managed by the authors and the variables: age, breed, reason for extraction, Triadan position and extraction technique.

RESULTS

Post-extraction complications were recorded following 58/428 extractions giving an overall complication rate of 13.6%, that caused a longer term clinical problem in 34/428 (7.9%) cases, with complications being asymptomatic or quickly self-resolving in the other 24 cases (5.6%). The most frequent complication was alveolar bone sequestration, including alveolar infection. Risk of developing a post-extraction alveolar disorder managed by the authors (n = 53) increased following extraction of the mandibular 06s, 07s or 08s compared with all other cheek teeth combined (P = .001); for cheek teeth with apical infections (P = .002) compared with those without; and following repulsion or minimally invasive transbuccal extraction (MTE) than following oral extraction (P = .01 and P = .02 respectively).

MAIN LIMITATIONS

Length of time between exodontia and survey data collection for some cases, use of clinical records and survey data and biases associated with decision to treat.

CONCLUSIONS

In agreement with previous studies, oral extraction had the lowest risk of complications. This study provides new information regarding the prevalence, types and risk of development of post extraction complications. Knowledge of these risk factors may help reduce these complications.

Successful Treatment of a Persistent Oroantral Fistula via Transbuccal and Transnasal Endoscopic Debridement in a Horse

We report an unusual case of a young Quarter Horse with a large dental fracture fragment displaced into the maxillary sinus, leaving an oroantral communication that caused food impaction and metaplastic calcification in the sinus and facial deformation with cutaneous fistulation. Oral extraction of a remaining tooth fragment from its alveolus was succeeded by a maxillary sinusotomy for removal of the abnormal sinus contents. Since the oroantral fistula did not heal spontaneously following the placement of a silicone dental prosthesis, minimally invasive transbuccal and transnasal endoscopic approaches were used to encourage closure of the oroantral fistula by alveolar granulation. The clinical, diagnostic, and therapeutic features of this case may be helpful to clinicians when dealing with similar cases.

Equine cheek tooth extraction: Comparison of outcomes for five extraction methods

BACKGROUND

Post-operative complications are reported for all methods of equine cheek tooth extraction but not all methods carry the same risks. An outcome comparison for commonly used methods is needed so that clinicians can make informed treatment decisions.

OBJECTIVES

We conducted a side-by-side comparison of five cheek tooth extraction methods, comparing types and incidence of complications among oral extraction, tooth repulsion (three surgical approaches) and lateral buccotomy techniques.

STUDY DESIGN

Retrospective clinical study using hospital medical records.

METHODS

Medical records of all horses undergoing cheek tooth extraction between 1997 and 2013 were reviewed. Logistic regression was used to determine the likelihood of various post-operative complications, comparing oral extraction, tooth repulsion by maxillary and mandibular trephination or maxillary sinus bone flap, and lateral buccotomy.

RESULTS

The study included 137 horses and 162 cheek teeth extractions. Oral extraction was successful in 71% of patients in which it was attempted. Oral extraction (n = 55) had the lowest incidence of complications (20%) and repulsion by sinus bone flap (n = 20) the highest (80%). Complication rates for repulsion by maxillary (n = 19) and mandibular trephination (n = 28), and extraction by lateral buccotomy (n = 15) were 42, 54 and 53%, respectively. Cheek tooth repulsion by sinus bone flap significantly increased the odds of damage to adjacent teeth, post-operative sinusitis, damage to alveolar bone, delayed alveolar granulation and orosinus fistulation. Repulsion by maxillary trephination significantly increased the odds of superficial incisional surgical site infection; and extraction by lateral buccotomy significantly increased the odds of facial nerve neuropraxia. Post-operative pyrexia was more common in all repulsion methods.

MAIN LIMITATIONS

Some clinically relevant differences may have been missed due to small group numbers in several categories.

CONCLUSIONS

Oral extraction was associated with fewer post-operative complications than any other methods. Standing oral extraction remains the preferred choice, and recent surgical advances promise to further improve its success rate.