Congenital palatal defects are a fairly common malformation of major clinical impact in dogs.1,2 Such defects in dogs are associated with a failure to thrive, chronic rhinitis, and aspiration pneumonia.3–5 Definitive treatment of congenital palatal defects requires surgical correction. The surgical principles and techniques for congenital palatal defect repair in dogs have been described,3,6,7 but outcomes have not been systematically reported.
Surgical methods for hard palate repair in dogs include the VLB, BPF, and OLF techniques.3,8 The BPF and VLB techniques are usually reserved for relatively narrow hard palate defects, and the OLF technique is recommended for wider defects.8 Soft palate repair is typically performed by direct apposition of the mucosal edges of the defect, although other techniques have been described.9 The number of tissue layers used to close soft and hard palate defects is considered an important technical aspect. In general, 1-layer closure of hard palate defects is believed to be less robust than 2-layer closure.4,10 For soft palate repair, 3-layer closure is considered superior to 2-layer closure with or without tension-releasing incisions.6 To the authors' knowledge, potential differences in outcomes among surgical techniques and number of layers used for closure have not been investigated in dogs.
Age at the time of surgery is considered an important aspect when repairing congenital palatal defects in dogs.5,11 In general, surgical repair is recommended when a dog is only a few months old. However, the range of recommended ages in the veterinary literature is variable and wide.3,5,7 Although such recommendations are usually based on seemingly valid assumptions, the actual impact of age on surgical outcomes has not been reported, to the authors' knowledge.
Tissue availability for coverage of the defects is another important aspect of congenital palatal defect repair.2,4 Factors believed to influence tissue availability include patient size, skull type (brachycephalic, mesocephalic, or dolichocephalic), and defect severity.2,12 Tissue quality can also affect outcomes in dogs. Poor tissue quality is often attributed to a patient history of failed surgical repair attempts.4 A staged approach that includes strategic dental extractions prior to definitive defect repair has been proposed in situations in which tissue quality or availability is a concern.4 Whether any of these variables is associated with outcomes of congenital palatal defect repair in dogs is unknown.
Two measurable outcomes of surgical repair of congenital palatal defects are ONF formation and functional status. An ONF is considered to have formed after surgical repair when partial or total lack of healing has occurred because of surgical site dehiscence.13 Successful function is considered to have been achieved when normal clinical function of the oral and nasal cavities has been established via surgery, irrespective of whether ONF formation has occurred. The purpose of the study reported here was to determine the functional outcome of surgical repair of congenital palatal defects in dogs, the incidence of ONF formation, and whether patient age and size (measured indirectly via body weight) at the time of surgery, skull morphology, defect severity, history of surgical attempts prior to referral for definitive repair, and surgical techniques used for definitive repair were associated with ONF formation and functional outcome.
Materials and Methods
Case selection criteria
Client-owned dogs evaluated by clinicians of the Dentistry and Oral Surgery Services at the Cornell University Hospital for Animals between November 1, 2012, and May 31, 2016, and of the William R. Pritchard Veterinary Medical Teaching Hospital of the University of California-Davis between June 1, 2007, and May 31, 2016, were identified by review of the medical records and considered for inclusion in the study if they underwent surgical correction of congenital palatal defects. Dogs were included only when the surgery had been performed by a veterinary dentistry and oral surgery resident directly supervised by a board-certified veterinary dentist and no major technical complications occurred during palatal defect repair.
Data collection
Dog signalment data, including breed, sex, age, and body weight at the time of initial surgical defect repair at the referral hospital, were obtained from the medical record of each dog. Any history of failed surgical palatal defect repair was noted. The latest available clinical follow-up information was used to determine the functional outcome of surgical repair, which was classified as successful (ie, function of the oral and nasal cavities was clinically normal after surgical correction) or unsuccessful (ie, normal function was only partially clinically restored or function remained unchanged from before surgery). Additionally, the presence of an ONF after the surgical site had healed was noted for each dog when applicable as well as whether revision surgery had been performed to correct the ONF. On the basis of information provided in the medical record notes and clinical photographs when available, the anatomic location of each ONF was recorded as the hard palate, soft palate, or JHS. For dogs with concurrent lip or alveolar defects, corresponding data were not collected or analyzed as part of the study because of differences from the palatal components of the congenital defects in clinical and surgical implications.
Dog age at the time of initial repair was subsequently categorized as 3 to 6 months, > 6 to 8 months, or > 8 months. As an indirect measure of size, body weight was categorized as < 1 kg (2.2 lb), 1 to 10 kg (2.2 to 22 lb), > 10 to 25 kg (22 to 55 lb), or > 25 kg. Skull type (brachycephalic, mesocephalic, or dolichocephalic) was objectively established from measurements obtained on CT images (ie, skull index values), as described elsewhere.12 When CT images were unavailable, skull type was determined subjectively by use of clinical images and extra- and intraoral examination findings. The relative width of soft and hard palate defects as assessed via CT images, clinical photographs, or both was classified as severe when the defect extended beyond 50% of the relative width of the anatomic area involved (ie, soft or hard palate) excluding the teeth when applicable, moderate when the defect occupied 25% to 50% of the anatomic area excluding the teeth when applicable, or mild when the defect occupied < 25% of the anatomic area excluding the teeth when applicable.
Defect repair
For each dog, surgical planning had been based on defect severity and tissue availability as grossly assessed, findings of preoperative CT images of the head (including computer-generated 3-D reconstructions) when available, and surgeon's choice. All dogs were considered free of aspiration pneumonia at the time of surgery according to their historical, clinical, and, in most situations, thoracic radiographic findings. Anesthesia was performed, and recovery was monitored under the direct supervision of a board-certified veterinary anesthesiologist; postoperative care included ≥ 1 night of hospitalization for analgesic intervention and respiratory monitoring in an intensive- or intermediatecare unit. Analgesic and systemic antimicrobial administration was performed for all dogs; the agents used as well as the dose and duration differed on the basis of the patient's clinical status and clinician's choice.
The surgical technique used to repair hard palate defects was recorded for each dog as VLB, BPF, or OLF. The number of tissue layers used to close hard palate defects was recorded as 1 layer when the edges of the palatal mucosal flaps were apposed without underlying connective tissue support or as 2 layers when the edges of the palatal mucosal flaps were apposed with underlying connective tissue support. The surgical approach was recorded as staged if strategic dental extractions had been performed 4 to 6 weeks prior to hard palate defect repair or as unstaged when no dental extractions were performed prior to cleft palate repair.
The surgical technique used to close soft palate defects was recorded, including whether partial-thickness lateral mucosal tension-releasing incisions had been performed. The number of tissue layers used to close soft palate defects was recorded as 2 layers when nasal mucosa and oral mucosa were closed individually or 3 layers when nasal mucosa, muscularis, and oral mucosa were closed individually.
Statistical analysis
The χ2 and Fisher exact tests were used to investigate possible differences in functional outcome and ONF formation for dogs with respect to age and body weight category at the time of initial repair, history of failed surgical repair attempts, skull type, surgical techniques used, and defect severity category with the aid of statistical software.a Values of P < 0.05 were considered significant. Owing to the small sample size, no multivariate analyses were performed.
Results
Dogs
Twenty-six dogs (13 sexually intact males, 7 sexually intact females, 5 neutered females, and 1 spayed female) were included in the study. Dogs were classified as mixed-breed dog (n = 4), Boxer (3), English Bulldog (3), pit bull–type dog (3), Labrador Retriever (2), French Bulldog (2), Chihuahua (1), German Short-haired Pointer (1), German Wirehaired Pointer (1), Golden Retriever (1), Great Dane (1), Maltese (1), Shih Tzu (1), Vizsla (1), and Yorkshire Terrier (1). Mean age at the time of surgery was 9.1 months (range, 3.5 to 21 months), and mean body weight at the same point was 11.4 kg (25.1 lb; range, 0.7 to 33.7 kg [1.5 to 74.1 lb]). Five dogs were 3 to 6 months of age at the time of surgery, 6 dogs were > 6 to 8 months of age, and 15 dogs were > 8 months of age. Three dogs weighed < 1 kg (2.2 lb) at the time of surgery, 10 dogs weighed 1 to 10 kg (2.2 to 22 lb), 10 dogs weighed > 10 to 25 kg (22 to 55 lb), and 3 dogs weighed > 25 kg.
Fourteen dogs were brachycephalic and 12 were mesocephalic; no dog was dolichocephalic. Four dogs had a history of failed surgical attempts to repair their congenital palatal defect prior to inclusion in the study.
Defects
In all dogs, the congenital palatal defect involved both the soft and hard palates. Four dogs had concurrent congenital lip and alveolar defects; however, surgical repair of these defects had not been pursued or had been performed at a different time. No detailed morphological characterization of every defect, as has been previously described in dogs,12 was possible owing to the lack of available CT findings for some dogs. Of the 26 hard palate defects, 6 (23%) were classified as mild, 13 (50%) as moderate, and 7 (27%) as severe. Of the 26 soft palate defects, 11 (42%) were classified as mild, 9 (35%) as moderate, and 6 (23%) as severe.
Defect repair
Computed tomography had been used in the surgical planning for 22 of 26 (85%) dogs. Hard palate defect closure was performed with the OLF technique for 16 of 26 (62%) dogs, the BPF technique for 7 (27%) dogs, and the VLB technique for 3 (12%) dogs (Figure 1). Two-layer closure for hard palate defect repair was performed for 22 (85%) dogs, and single-layer closure was performed for 4 (15%) dogs. Strategic dental extractions (ie, a staged surgical approach) were performed for 9 (35%) dogs prior to definitive closure of palatal defects. Two-layer closure of the soft palate was performed for 8 (31%) dogs, and 3-layer closure was performed for 18 (69%) dogs (Figure 2). Lateral half-thickness tension-releasing incisions were performed for soft palate closure for 11 (42%) dogs. No electro-cautery was used for any dog. Closure had been performed with 4–0, 5–0, or 6–0 poliglecaprone 25b in a simple interrupted pattern, except for the muscularis of the soft palate, which was sometimes closed in a simple continuous pattern.
Representative photographs showing the surgical techniques used for congenital hard palate defect repair in dogs. A—The BPF technique and a 2-layer closure approach were used in a 1-year-old male Labrador Retriever. The sutured nasal mucosa prior to flap repositioning is visible (arrow). B—In the same dog immediately after surgery, the flaps have been secured. C—The VLB technique and a 2-layer closure approach were used in a 5-month-old female pit bull–type dog. The sutured nasal mucosa prior to flap repositioning is visible (arrow). D—In the same dog immediately after surgery, the flaps have been secured. E—The OLF technique was used in a 4-month-old male English Bulldog. Notice the deciduous dentition. This dog also had a complete left lip and alveolar congenital defect. F—The OLF technique was also used in a 9-month-old male mixed-breed dog 4 weeks after strategic dental extraction had been performed. Notice the bilateral absence of the third incisor, canine, and first, second, and third premolar teeth. In panels E and F, the intact major palatine artery is visible (asterisks).
Citation: Journal of the American Veterinary Medical Association 253, 11; 10.2460/javma.253.11.1445
Representative photographs showing the surgical techniques used for congenital hard palate defect repair in dogs. A—The BPF technique and a 2-layer closure approach were used in a 1-year-old male Labrador Retriever. The sutured nasal mucosa prior to flap repositioning is visible (arrow). B—In the same dog immediately after surgery, the flaps have been secured. C—The VLB technique and a 2-layer closure approach were used in a 5-month-old female pit bull–type dog. The sutured nasal mucosa prior to flap repositioning is visible (arrow). D—In the same dog immediately after surgery, the flaps have been secured. E—The OLF technique was used in a 4-month-old male English Bulldog. Notice the deciduous dentition. This dog also had a complete left lip and alveolar congenital defect. F—The OLF technique was also used in a 9-month-old male mixed-breed dog 4 weeks after strategic dental extraction had been performed. Notice the bilateral absence of the third incisor, canine, and first, second, and third premolar teeth. In panels E and F, the intact major palatine artery is visible (asterisks).
Citation: Journal of the American Veterinary Medical Association 253, 11; 10.2460/javma.253.11.1445
Representative photographs showing the surgical techniques used for congenital hard palate defect repair in dogs. A—The BPF technique and a 2-layer closure approach were used in a 1-year-old male Labrador Retriever. The sutured nasal mucosa prior to flap repositioning is visible (arrow). B—In the same dog immediately after surgery, the flaps have been secured. C—The VLB technique and a 2-layer closure approach were used in a 5-month-old female pit bull–type dog. The sutured nasal mucosa prior to flap repositioning is visible (arrow). D—In the same dog immediately after surgery, the flaps have been secured. E—The OLF technique was used in a 4-month-old male English Bulldog. Notice the deciduous dentition. This dog also had a complete left lip and alveolar congenital defect. F—The OLF technique was also used in a 9-month-old male mixed-breed dog 4 weeks after strategic dental extraction had been performed. Notice the bilateral absence of the third incisor, canine, and first, second, and third premolar teeth. In panels E and F, the intact major palatine artery is visible (asterisks).
Citation: Journal of the American Veterinary Medical Association 253, 11; 10.2460/javma.253.11.1445
Representative photographs showing the surgical techniques used for congenital soft palate defect repair in dogs. A and B—A 2-layer closure approach was used for a 3-month-old female mixed-breed dog with a moderate soft palate defect. Notice the partial-thickness lateral incisions (arrows) performed to release tension at the suture line. C and D—A 3-layer closure approach was used for a 3-month-old female pit bull–type dog with a mild soft palate defect. Notice the muscularis layer that was sutured (arrow) prior to closure of the oral mucosa and the absence of tension-releasing incisions.
Citation: Journal of the American Veterinary Medical Association 253, 11; 10.2460/javma.253.11.1445
Representative photographs showing the surgical techniques used for congenital soft palate defect repair in dogs. A and B—A 2-layer closure approach was used for a 3-month-old female mixed-breed dog with a moderate soft palate defect. Notice the partial-thickness lateral incisions (arrows) performed to release tension at the suture line. C and D—A 3-layer closure approach was used for a 3-month-old female pit bull–type dog with a mild soft palate defect. Notice the muscularis layer that was sutured (arrow) prior to closure of the oral mucosa and the absence of tension-releasing incisions.
Citation: Journal of the American Veterinary Medical Association 253, 11; 10.2460/javma.253.11.1445
Representative photographs showing the surgical techniques used for congenital soft palate defect repair in dogs. A and B—A 2-layer closure approach was used for a 3-month-old female mixed-breed dog with a moderate soft palate defect. Notice the partial-thickness lateral incisions (arrows) performed to release tension at the suture line. C and D—A 3-layer closure approach was used for a 3-month-old female pit bull–type dog with a mild soft palate defect. Notice the muscularis layer that was sutured (arrow) prior to closure of the oral mucosa and the absence of tension-releasing incisions.
Citation: Journal of the American Veterinary Medical Association 253, 11; 10.2460/javma.253.11.1445
Outcomes
The mean postoperative follow-up period was 22.4 weeks (range, 2 to 96 weeks). Overall, functional success was achieved for 22 (85%) dogs, as determined from the latest available follow-up information. Oronasal fistula formation occurred in 13 (50%) dogs after congenital palatal defect repair (Figure 3), and complete healing of the hard and soft palates was achieved for the other 13 (50%) dogs. Twenty-five ONFs were identified in the 13 affected dogs: 13 in the hard palate, 7 at the JHS, and 5 in the soft palate.
Representative photographs showing ONF formation after congenital palatal defect repair in dogs. A—A relatively small defect is visible just lateral to the incisive papilla on the left (arrow) in the dog represented in Figure 1 panels E and F. B—The defect in panel A was confirmed to be an ONF after probing of the area. C—This 9-month-old male Vizsla has 2 ONFs, one located in the rostral third (white arrow) and the other in the middle third (black arrow) of the hard palate. The VLB technique had been used initially for this dog. Notice the missing premolar teeth bilaterally, which were extracted prior to ONF repair. D—An ONF was noted in the soft palate of a 1-year-old male Great Dane several weeks after initial repair.
Citation: Journal of the American Veterinary Medical Association 253, 11; 10.2460/javma.253.11.1445
Representative photographs showing ONF formation after congenital palatal defect repair in dogs. A—A relatively small defect is visible just lateral to the incisive papilla on the left (arrow) in the dog represented in Figure 1 panels E and F. B—The defect in panel A was confirmed to be an ONF after probing of the area. C—This 9-month-old male Vizsla has 2 ONFs, one located in the rostral third (white arrow) and the other in the middle third (black arrow) of the hard palate. The VLB technique had been used initially for this dog. Notice the missing premolar teeth bilaterally, which were extracted prior to ONF repair. D—An ONF was noted in the soft palate of a 1-year-old male Great Dane several weeks after initial repair.
Citation: Journal of the American Veterinary Medical Association 253, 11; 10.2460/javma.253.11.1445
Representative photographs showing ONF formation after congenital palatal defect repair in dogs. A—A relatively small defect is visible just lateral to the incisive papilla on the left (arrow) in the dog represented in Figure 1 panels E and F. B—The defect in panel A was confirmed to be an ONF after probing of the area. C—This 9-month-old male Vizsla has 2 ONFs, one located in the rostral third (white arrow) and the other in the middle third (black arrow) of the hard palate. The VLB technique had been used initially for this dog. Notice the missing premolar teeth bilaterally, which were extracted prior to ONF repair. D—An ONF was noted in the soft palate of a 1-year-old male Great Dane several weeks after initial repair.
Citation: Journal of the American Veterinary Medical Association 253, 11; 10.2460/javma.253.11.1445
Revision surgery to address persistent clinical signs was performed for 12 of the 13 dogs with postoperative ONF formation. The other dog had a small, subclinical ONF identified in the soft palate 2 weeks after palatal defect repair, and no revision surgery was performed; this dog was lost to follow-up. Only 1 revision surgery was performed in 8 dogs, and > 1 revision surgeries were performed in 4 dogs. The functional outcome was successful for 7 of the 8 dogs that received only 1 revision surgery and for only 1 of the 4 dogs that received > 1 revision surgery.
Compared with dogs in other age categories, dogs > 8 months of age at the time of initial defect repair at the referral hospital were more likely to have an ONF form in the hard palate (P = 0.046) or JHS (P = 0.03) after surgery. Compared with dogs in other body weight categories, dogs weighing < 1 kg at the time of initial repair were more likely to have an unsuccessful functional outcome (P = 0.004). Compared with dogs with no history of failed surgical attempts, dogs with a history of failed surgical attempts were more likely to have ONF formation at the JHS (P = 0.02). No significant differences in outcome variables were identified among dogs grouped by other characteristics, including skull type, defect severity of the hard palate and the soft palate independently, surgical technique used to close the hard palate, number of tissue layers used for closure of the soft palate and of the hard palate independently, staged versus nonstaged approach for hard palate closure, and releasing versus no releasing incisions for soft palate closure.
Discussion
To the authors' knowledge, the present study represented the first in which outcomes of congenital palatal defect surgical repair in dogs were systematically documented. The study was also the first to investigate whether ONF formation or functional outcome was associated with patient age and size at the time of initial repair at a referral hospital, skull type, defect severity, history of failed surgical attempts, and technical aspects of the repair.
In general, the observed high overall functional success rate supported the notion that surgical repair of congenital palatal defects carries a good prognosis in dogs, as has been previously suggested.3,8 However, it should be noted that the included dogs were treated by surgeons with specialized skill sets, who had access to state-of-the-art surgical planning tools in a multidisciplinary medical environment. Those factors are known to impact outcomes of surgical palatal defect repair in people14–16 and likely influenced outcomes for the evaluated dogs. Whether our results would be reproducible in other clinical settings or with different standards of care remains to be determined. The results also indicated that ONF formation was a common sequela to surgical repair of congenital palatal defects in dogs and that revision surgery was often necessary to achieve a successful functional outcome, consistent with what has been anecdotally suggested for dogs5,7,17 and what has been reported for people.13,18
In most dogs in which postsurgical ONF formation occurred in the present study, the site involved the hard palate and the JHS. Although to our knowledge, no similar reports exist in the veterinary literature for comparison, these findings were consistent with reported findings for people, in whom the JHS and the rostral (ie, anterior) area of the hard palate are the 2 most common sites of ONF formation after congenital palatal defect repair.13 It has been suggested that postsurgical ONF formation is common at the JHS in people because this is an anatomic area where surgical closure under tension is common,13 and the same likely applies to dogs.
Some cases of ONF formation in the dogs of the present study were in the rostral portion of the hard palate. Because this area is usually the widest portion of the hard palate (ie, is where the palatine fissures are located), it is likely more susceptible to dehiscence because more tension at the surgical site is required for closure than in the narrower, more caudal portions of the defect. Oronasal fistula formation in the soft palate was less common than in the hard palate and JHS, with an observed incidence of soft palate ONF formation of 19% (5/26). This percentage is comparable with that reported for people (15.7%).13 The difference in the incidence of ONF formation between the hard and soft palate was likely due to differences in the surgical anatomy of these 2 areas, which may allow better preservation of blood supply after surgical manipulation of the soft palate versus the hard palate, thereby rendering dehiscence less likely.
The association between dog age at the time of initial palatal defect repair and the incidence of ONF formation in the hard palate and JHS was a relevant one, particularly given the uncertainty in the veterinary literature in this regard. For example, it has been postulated that surgery should be avoided in dogs before the canine and incisor teeth have fully erupted.5 This rationale is partially based on the fact that surgical manipulation of palatal tissues in developing dogs can interfere with maxillofacial growth in experimental conditions.11 However, the generalizability of this experimental finding to typical clinical circumstances is unclear, particularly given the major differences in maxillofacial proportions among the various dog breeds and skull types regardless of surgery. On the other hand, concern exists that the eruption of permanent teeth close to a previously surgically manipulated area may interfere with this surgical repair or result in occlusal abnormalities.5 Until that possibility has been investigated via controlled studies, it remains hypothetical. Finally, it has been recommended that surgery be performed on dogs at an age when sufficient tissues are available.3 Indeed, this notion likely explains why initial surgeries were performed at such a relatively old age (ie, mean age of 9.1 months) in the dogs of the present report. However, given the immense differences in dog sizes, this recommendation is a relative but not an absolute one. Academic discussion aside, we believe that the results of the present study suggested that the risk of ONF formation in the hard palate and JHS, and thus the risk of requiring revision surgery, may be reduced if surgical palatal defect repair is performed when dogs are < 8 months of age.
The finding that ONF formation in the hard palate was more common in dogs with a history of failed surgical repair attempts was not surprising and was consistent with previously reported findings.4 This situation is usually attributed to the fibrous tissue formation, tissue retraction, and a reduction in blood supply that result from a previous dehiscence event.4,18,19
Another relevant finding of the study reported here was the association between body weight and functional outcome. Given the unavailability of more objective retrievable data, body weight was used as an indirect measure of dog size. Our interest in dog size was based on the assumption that outcomes of congenital palatal defect repair would be better for larger dogs because larger areas of tissue would be available than for smaller dogs. Acknowledging that body weight in dogs does not necessarily correlate with dog size (and thus skull dimensions and surface area of palatal tissues available for repair), we were not surprised to find a higher incidence of unsuccessful functional outcome in dogs < 1 kg than in heavier dogs. A body weight < 1 kg at the time of congenital palatal defect repair in dogs may represent a threshold at which surgical access and tissue manipulation are so limited that the outcome may be compromised when applying standard techniques.
Conversely, skull type was associated with neither functional outcome nor incidence of ONF formation in any anatomic location, despite considerable differences in skull dimensions (and possibly in defect morphology as well) between brachycephalic and mesocephalic dogs. Because dolichocephalic dogs were not represented in our study, it is unknown whether the same findings could be expected in dolichocephalic dogs as well.
No association was identified between defect severity and outcome in the present study. This was unexpected given that defect severity can adversely impact outcomes of congenital palatal repair in people.20 However, the analysis did not take into consideration the possible simultaneous effect of other relevant variables, such as surgical technical aspects. Therefore, the lack of association between defect severity and the assessed outcomes could have been attributable to the low statistical power associated with a fairly small sample size.
The lack of association between the technical aspects of surgical repair and outcomes in the present study should also be interpreted with caution. No inferences should be made regarding whether the prognosis for or incidence of ONF formation is similar among the OLF, BPF, or VLB techniques or whether performing or not releasing incisions for soft palate repair, using 1 or 2 layers for hard palate repair or 2 or 3 layers for soft palate repair, or the severity of soft palate and hard palate defects has no effect on surgical outcomes. Instead, the findings suggested that when standard surgical techniques for congenital palatal defect repair in dogs were judiciously applied on the basis of previously described principles, and following a regimented diagnostic and surgical planning approach, a good outcome was achieved for most dogs, with a predictable incidence of ONF formation, even in situations involving unfavorable characteristics such as wide defects.
No grafts or membranes were used for surgical repair in any dog in the present study. Recreation of anatomically normal hard tissues has been described clinically and experimentally.21–23 However, no clinical trials have been reported in which the benefits or adverse effects were evaluated for grafting of osseous defects associated with orofacial clefts in small animals.
We conclude that the success rate of congenital palatal defect repair was high for the dogs of the present study, but that revision surgery to address ONF formation was often necessary to achieve a successful functional outcome. The prognosis following congenital palatal defect repair may be poorer for dogs weighing < 1 kg than for heavier dogs and the risk of ONF formation in the hard palate or JHS after such surgery may be greater for dogs > 8 months of age or with a history of failed surgical repair attempts. This information would be useful for making clinical and surgical decisions and determining the prognosis for dogs with congenital palatal defects.
ABBREVIATIONS
| BPF | Bipedicle flap |
| JHS | Junction between the hard and soft palates |
| OLF | Overlapping flap |
| ONF | Oronasal fistula |
| VLB | von Langenbeck |
Footnotes
JMP statistical software, version 13.1.0, SAS Institute, Cary, NC.
Monocryl, Ethicon Inc, Cincinnati, Ohio.
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