Introduction

Cleft palate, or palatoschisis, is a congenital opening in the roof of the mouth caused by a failure of the palatal shelves to fuse.¹ The resultant opening permits communication between the mouth and nasal cavity. Cleft lip (cheiloschisis) and cleft of the primary palate can occur alone or in combination with cleft palate (secondary palate). The primary palate includes the incisive bones rostral to the palatine fissures. In 1 paper,¹ the paired maxillary processes are reported to expand medially, pushing the medial and lateral nasal processes toward the midline, where they merge to form the base of the nose and upper lip. A second report² noted that it is generally accepted that the nasal processes fuse with the maxillary processes, beginning at the palatine fissures to form the upper lip, alveolar process, and primary palate.

Caudal to this anatomic location is the secondary palate, which includes both the hard and soft palates.³ By definition, the secondary palate consists of the hard palate caudal to the palatine fissures as well as the soft palate.¹ The incisive, maxillary, and palatine bones comprise the hard palate. During fetal development, it is derived from an unpaired primary palatine process (primary palate) from the intermaxillary segment and the paired secondary palatine processes from the maxillary processes (secondary palate). The 3 processes normally unite to complete the formation of the palate.³ This is reported to occur during fetal development between days 25 and 28 in dogs.^4,5 Various classifications of cleft palate are noted in both the human and veterinary literature.^6–11

Cleft palate can be a heritable birth defect in humans and is generally considered a heritable defect in dogs.^11–16 Cleft palate causes can be syndromic (associated with other malformations) or nonsyndromic (an isolated feature).^1,6 There are a variety of genetic and nongenetic factors that may contribute to cleft palate formation in humans.^{1,2,6,17–27}

Cleft palate is one of the most common of the congenital defects in a number of canine breeds, especially in brachycephalic dogs.^1,2,28,29 Cleft palate primarily affects the dog’s ability to eat and breathe to a variable degree. Food, water, and particulate matter introduced into the exposed nasal cavity can result in the dog sneezing and snorting to clear the nasal cavity. Rhinitis and a nasal discharge may be noted.² Puppies are also more prone to aspiration pneumonia.¹ In 1 study,³⁰ it was reported that middle ear disease was seen in some dogs with cleft palate but without clinical signs of hearing impairment.

The soft palate (velum) originates from the caudal border of the hard palate, at the level of the caudal nasal spine of the palatine bone. It is flanked by the pterygoid bones, which comprise the bony walls of the pterygoid canal. The muscles of the soft palate, including the tensor veli palatini and levator veli palatini muscles, are covered by mucosa on both the oropharyngeal and nasopharyngeal surfaces. These 2 paired muscles, along with the palatinus and palatopharyngeal muscle layers, play a role in the processes of breathing and swallowing.^3,27,31 Sensory stimulation of the palate triggers the swallowing reflex.³² The soft palate provides a soft tissue barrier to prevent food and water from entering the choanae.³ Veloplasty (palatoplasty of the soft palate or velum) is particularly important in restoring normal speech in children with a focus on correcting the abnormal position of the muscles, especially the levator palati.³³ Speech in children with cleft palates is a major consideration regarding selection of the method of closure and the timing of the surgery.³⁴ Speech is not a factor when performing veloplasty in dogs, and permanent closure of the soft palate defect is the primary goal to restore normal eating and drinking.

There are 3 major goals in cleft palate repair in children: (1) anatomic closure of the defect, (2) reconstruction for development and production of normal speech, and (3) minimizing disturbances in maxillary growth and dentoalveolar deformities.³³ A number of studies in children have focused on those closure techniques that best support speech and do not substantially impact facial growth, prompting the development of a number of techniques to achieve these goals.²⁷ It has been noted in a 1970 research study that surgical manipulation of the mucoperiosteum can alter or retard maxillary growth in dogs.^1,35,36 It has been suggested that cleft palate closure should be delayed until maxillofacial growth has slowed/ceased and the canine and incisor teeth are fully erupted.¹ However, clinically relevant changes in maxillofacial growth have not been reported in the veterinary literature.¹

The 2 major veterinary surgical techniques for palatoplasty of the hard palate include the following: (1) the single mucoperiosteal rotational flap (“overlapping flap” or “mucoperiosteal hinge flap”)^29,37 and (2) the use of bilateral bipedicle advancement flaps of the hard palate mucoperiosteum.⁷ The traditional overlapping flap technique requires the elevation on a single broad-based flap, which is folded over the cleft. The bipedicle advancement flap technique is commonly referred to as the von Langenbeck technique, named after Dr. Bernard von Langenbeck in 1861. This technique utilizes 2 bipedicle mucoperiosteal flaps to close cleft palates in children.^27,33 The von Langenbeck technique appears to be the first technique reported for palatoplasty in children and the earliest technique used for canine cleft palate repair.^7,37

In recent years, the overlapping flap has been suggested as the preferred technique in the veterinary literature.^29,37 This preference is likely based on previous reports of partial dehiscence associated with the traditional von Langenbeck technique and theoretical advantages of its use as well as a surgeon’s training and personal preference. The overlapping flap is preferred by some to close wider defects whereas the von Langenbeck technique is preferred for narrower defects.^38,39

This paper describes simple surgical modifications of the traditional von Langenbeck technique for successful palatoplasty in 12 consecutive cases of cleft palate in the dog for closure of narrow and wide cleft palate defects.

Materials and Methods

Modified von Langenbeck surgical procedure

All dogs underwent general anesthesia for cleft palate repair, and anesthetic protocols were individualized for patient needs as determined by the clinical anesthesiology service. Each dog received perioperative cefazolin sodium (20 mg/kg, IV) and intraoperative lactated Ringer solution (5.0 mL/kg/h, IV). Each dog was placed in dorsal recumbency and the head stabilized with sandbags and surgical tape. The oral cavity was swabbed with 0.12% chlorhexidine gluconate solution prior to standard draping of the oral cavity. The oral cavity was suspended open with a spring-loaded oral speculum, with the tongue and endotracheal tube secured to the rostral mandible. A detailed oral examination was performed, and the cleft was carefully probed to determine the extent of the defect (Figure 1).

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Image of the oral cavity of an anesthetized 6-month-old spayed female pit bull–type dog cross in dorsal recumbency, referred for cleft palate treatment and included in a case series of 12 dogs referred between May 20, 2015, to March 24, 2022. Note the narrow cleft palate defect (arrow) in comparison to the lateral donor areas (arrow). Closure of this narrow cleft of the hard palate would be expected to be relatively simple. Both the modified von Langenbeck technique or the mucoperiosteal “overlapping flap technique” would effectively close this defect using a single layer suture closure.

Citation: Journal of the American Veterinary Medical Association 261, 4; 10.2460/javma.22.09.0421

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The soft palate defect was initially corrected by creating a mucosal incision along the inner margins of the soft palate border bilaterally. Beginning at the level of the caudal tonsillar crypts, the oropharyngeal mucosal surface of the soft palate was approximated with a series of interrupted 3-0 polydioxanone sutures (PDS Plus; Ethicon Inc) to the margin of the hard palate. Caudal sutures were preplaced to facilitate their proper positioning. Closure of the oral mucosal margins was completed in an identical fashion. Lateral release incisions were used only if incisional tension was noted during the closure.

The hard palate closure was performed by creating an incision medial to the upper dental arcades using a No. 15 scalpel blade. The edge of the palatal mucosa on both sides of the cleft were narrowly excised with a No. 11 scalpel blade. A Freer periosteal elevator and No. 15 scalpel blade were used to gently undermine and completely elevate each bipedicle mucoperiosteal flap along their medial and lateral borders. Care was taken to preserve the major palatine arteries exiting the major palatine foramen, located medial to the fourth premolars (108, 208) and the infraorbital vascular branches exiting the palatine incisures. Intraoperative hemorrhage was primarily controlled by digital compression with gauze sponges. Suction was used to remove blood from the nasal passage and oral cavity. The narrow rostral pedicle of each flap, at the level of the incisive papilla, was carefully preserved. Upon completion of the undermining procedure each flap was completely mobile, free of its dense underlying periosteal attachments.

A series of 3-0 polydioxanone sutures were placed using a vertical mattress suture pattern. In narrow width areas of each flap, horizontal mattress sutures were occasionally employed along with the vertical mattress pattern. The more caudal mattress sutures were occasionally preplaced to facilitate suture placement. The mattress sutures were directed at the thicker vertical ridges of the palatal rugae to improve suture purchase. Sutures were tied to evert the palatal margins, assuring direct contact of the underlying connective tissue surfaces. Following completion of the vertical mattress suture placement, 4-0 polydioxanone interrupted sutures were placed between the vertical mattress sutures to assure proper alignment of the margins, eliminating any offset edges (“stair-step” defect).

All patients were recovered in our critical care unit under observation for residual hemorrhage and assessment of breathing. Dogs were placed on maintenance lactated Ringer solution (2 mL/kg/h, IV) until discharge from the hospital the following morning. Intravenous cefazolin was continued every 8 hours during hospitalization with methadone (0.1 mg/kg, IV, q 6 to 8 h). Dogs were discharged the following day on amoxicillin–clavulanic acid (Clavamox; 13.75 mg/kg, PO, q 12 h) and gabapentin (5 to 10 mg/kg, PO, q 8 to 12 h) for 7 days.

Results

Surgery and postoperative period

Complete undermining of each bipedicle mucoperiosteal flap fully facilitated their advancement over the hard palate defect. Care was taken to preserve the major palatine and sphenopalatine vessels supplying the length of each flap. Vertical mattress sutures were primarily placed in the elevated rugal folds for better tissue purchase. Interrupted sutures, placed between the vertical mattress sutures, assured proper alignment of the incisional margins. The everted incisional ridge formed after closure bolstered the incision above the underlying bone defect while improving the surface area contact of the connective tissue surface of each flap for proper healing (Figure 2). In 1 dog, the rostral area of the cleft had limited donor tissue width bilaterally. In this case, the prominent nasal septum was integrated into the closure (Figure 3). This precluded the need to consider a staged second flap procedure.

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Image of oral cavity of an anesthetized 6-month-old sexually intact male pit bull–type dog in dorsal recumbency and included in the study described in Figure 1. A—Note the narrow cleft of the hard (star) and soft (arrow) palates. B—Successful closure with the modified von Langenbeck technique. Both bipedicle mucoperiosteal flaps were completely mobilized by elevating them from the underlying periosteal attachments. Note the everted closure as a result of the series of 3-0 polydioxanone vertical mattress sutures (black arrows). Smaller supplemental 4-0 polydioxanone interrupted sutures (yellow arrows) were used to accurately align the flap margins, eliminating offset (stair-step) incisions.

Citation: Journal of the American Veterinary Medical Association 261, 4; 10.2460/javma.22.09.0421

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Image of the oral cavity of an anesthetized 7.5-month-old sexually intact male pit bull–type dog included in the study described in Figure 1. A—Note the narrow donor areas at the level of the premolars (arrows) in comparison to the wide cleft of the hard palate. Such wide defects of the hard palate may be poorly amenable to the traditional overlapping or hinge mucoperiosteal flap. The modified von Langenbeck technique was used, taking advantage of both lateral donor tissue sites. B—Note the prominent septum (star). The lines demarcate the lateral margins of the bipedicle flaps. Note the narrow width of the donor areas in relation to the width of the palatal cleft; both bipedicle flaps are essential to the closure of this defect. C—The soft palate cleft is closed first with a series of interrupted 3-0 polydioxanone sutures. The incised margins of the soft palate allow for a 2-layer closure of the nasopharyngeal and oropharyngeal mucosal surfaces, beginning at the level of the caudal tonsillar crypts. In closing the soft palate, the caudal sutures are normally preplaced to assure their proper placement. Note the probe tip illustrating the elevated flap (arrow). D—To close this rostral defect, the ventral mucosal surface of the cartilaginous nasal septum was excised. Three 3-0 polydioxanone sutures were then preplaced in the septum. In turn, the suture ends were directed into the flap margins, facilitated by the use of a 22-gauge hypodermic needle. E—The sutures were tied to complete the closure. The septum was incorporated into the closure since the narrow width of the rostral flap pedicles precluded their approximation alone without creating excessive tension on this segment of the palatoplasty. The flap margins contact the surface of the septum; a small gap between the margins of both flaps can be noted beneath the sutures. F—The sedated patient approximately 3 weeks after surgery. Note the donor defects covered with granulation tissue, with evidence of epithelialization progressing from the mucosal margins (arrows). G—Close-up view of the area of the incisive papilla. The rostral 7 mm of the septal closure dehisced (arrow), although the remainder of the septal patch healed uneventfully to the undersurface of the flaps. This small opening had no effect on the dog’s eating and drinking.

Citation: Journal of the American Veterinary Medical Association 261, 4; 10.2460/javma.22.09.0421

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Soft palate closure was successfully accomplished using a 2-layer technique. The nasopharyngeal and oropharyngeal mucosal surfaces, separated by incising the left and right mucosal margins of the cleft, were approximated with interrupted absorbable sutures. In 1 dog, simple release incisions were used to reduce incisional tension on the soft palate closure without the need to undermine the tissues (Figure 4).

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Image of the oral cavity in an anesthetized 8-month-old sexually intact male Poodle in dorsal recumbency and included in the study described in Figure 1. A—Note the wide defect of the soft palate (arrows). The cleft of the hard palate is relatively narrow by comparison, with sufficient donor tissue for closure using the modified von Langenbeck technique. B—Closure of the hard and soft palate defects. Although uncommonly needed, release incisions were used to reduce incisional tension during closure of the soft palate (arrows).

Citation: Journal of the American Veterinary Medical Association 261, 4; 10.2460/javma.22.09.0421

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A small amount of capillary bleeding was noted in the postoperative period but largely subsided by the following morning. No attempt was made to examine the surgical area in the immediate postoperative period. Owners were instructed to feed each dog soft food and avoid any hard treats or chew toys. Exercise was restricted to short leash walks when dogs were taken outdoors to urinate/defecate over the next month. On the recheck examination, the primary surgical incisions of the hard and soft palate had healed, with the exception of a small area at the level of the incisive papilla. A small residual slit opening < 7 mm was noted in each patient. The bilateral donor defects were largely epithelialized by 3 weeks after surgery. All dogs were reported to be eating soft food, drinking, and breathing normally at this time. As noted, follow-up telephone conversation was performed 6 months later. A third long-term follow-up, spanning 9 to 91 months after surgery, indicated 10 dogs were doing well; only 2 dogs were lost to follow-up at this time.

Discussion

The oral mucoperiosteal surface of the canine hard palate is highlighted by a series of prominent ridges and depressions running perpendicularly to the axis of the head: the palatal rugae. The primary source of circulation to the hard palate is from the left and right major palatine arteries arising from the major palatine foramen, located medial to the fourth premolars (108, 208). The paired vessels extend rostrally; branches of these vessels enter the palatine fissures as the sphenopalatine arteries.³ The primary source of circulation to the soft palate is from the minor palatine arteries. Preservation of these vascular pedicles is essential to successful palatoplasty procedures.³⁰

Computed tomographic findings in dogs has demonstrated variable abnormalities in individual dogs, including the following: abnormal development of the incisive and maxillary bones, absent or poorly developed nasal septum, hypoplastic nasal turbinates, vomer abnormalities, incomplete cribiform plate, abnormal tympanic bullae, anomalous frontal sinuses, otitis media, anomalous frontal sinuses, and displaced ventricles or ventriculomegaly. Other abnormalities noted on CT included unilateral hypoplasia of the mandible and zygomatic arch, an open parieto-occipital suture, stylohyoid bone abnormalities, and missing calvarium bones (occipital, temporal, frontal, and parietal) as well as an enlarged nasopharynx.² In this retrospective study,² it was acknowledged that they were unable to compare the value of CT versus physical examination with palpation or probing of the defects. A detailed oronasal examination is the most important component for assessing cleft palate dogs and determining options for closure. While preoperative CT may not essential to cleft palate repair in many cases, it may be useful nonetheless in planning a problematic closure and detecting other anomalies on the basis of a complete history and physical examination of each dog.

The single “mucoperiosteal flap” was first reported in the veterinary literature in 1974 to close clefts of the hard palate in 3 dogs.³⁷ This technique was previously reported in the human literature. However, calling this single pedicle oral flap the “mucoperiosteal flap” is misleading: there are other mucoperiosteal flaps employed in hard palate repairs. As noted, it also is referred to as the “overlapping flap” or “hinge flap” in the veterinary literature.^37,40 When elevating the traditional overlapping flap in dogs, the outer margin of the flap is created immediately medial to the gingiva/dental arcade. Once undermined and elevated from the underlying hard palate, this broad-based narrow flap is folded over the palatal defect, inverting the oral mucosal surface to face the exposed nasal cavity. The leading edge of the flap is tucked (or “overlapped”) beneath the elevated mucosal edge bordering the opposite side of the cleft. Mattress suture closure, occasionally termed the “vest over pants” pattern, is used to secure the overlapped margins. The advantages suggested for the single overlapping flap include the following: less tension on the suture line, the suture line not directly over the cleft, the bone margin of the cleft supporting the incision, and a “stronger scar” by overlapping of the incisional margins.²⁹ The literature fails to note that the arc of the flap, during its placement over the cleft, results in a shorter flap, in some cases by a few millimeters. As previously noted, there are surgeons who cite their personal preference for using the overlapping flap for wider cleft palate defects.^38,39

One of the historical problems associated with clinical veterinary reports, pertaining to cleft palate repair, is the relative lack of detail pertaining to the width of the cleft in relation to the 2 lateral mucosal donor areas of the palate required to close the defect. The donor area width is that area of the flap measured between the inner margin of the upper dental arcade and the edge of the cleft. Creating a flap 1.5 times larger than the palatal defect has been suggested as a guideline, without substantiation.²⁹ In assessing cleft palate defects, there is no exact numerical guideline for closure per se. Rather, it is the measured width of the lateral donor bed(s) in relation to the width of the hard palate defect that is the primary consideration in determining the best closure option(s). Simply put, the surgeon must assess the width of the donor area(s) to determine if the flap(s) can span the entire cleft and accommodate suture placement with minimal tension on the closure. Based on the author’s personal surgical experience, either palatoplasty technique can be used effectively in narrow defects. In wide defects, equal to or larger than a unilateral donor area, the traditional overlapping mucoperiosteal flap alone may have insufficient width to span the cleft. In the event the unilateral traditional overlapping flap is judged to be too narrow to adequately cover the palatal defect, removal of the dental arcade 4 to 6 weeks prior to surgery has been advocated to create a longer overlapping flap by including the medial/lateral gingival tissue and adjacent mucosal margin.³⁸ This maneuver also has the potential for widening bipedicle mucoperiosteal flaps in a similar fashion. Unfortunately, the canine patient is subject to the extraction of multiple teeth, the necessity of a second delayed surgery, and a substantial increase in costs incurred by the owner.

Dogs with a long, narrow muzzle and a proportionately wide palatal cleft are among the most challenging cases for palatoplasty. Bilateral bipedicled mucoperiosteal flaps, which take advantage of both lateral mucoperiosteal donor areas, may be a better option for closure compared to the traditional overlapping flap design. In 1 dog, the rostral portion of the cleft was so wide that the margins of both flaps were secured to the rostral nasal septum to reduce the risk of dehiscence secondary to excessive incisional tension (Figure 3).

It is possible for a surgeon to combine the use of the traditional overlapping flap technique with a bipedicle mucoperiosteal flap from the opposing side of the cleft.⁴¹ The author has previously performed this combination of palatoplasty techniques successfully when it was apparent the elevated overlapping flap alone could not adequately cover the defect. However, combining the 2 flap techniques may be of no particular advantage over using the modified von Langenbeck technique alone.

Reported surgical failures in the veterinary literature (dehiscence, oronasal fistula formation involving the closure) of the von Langenbeck technique in dogs are, in part, the likely result of veterinarians adapting the general surgical guidelines for its use in children, without taking into account the thickness of the palatal tissue and prominent rugal folds specific to the dog. The lateral incisions have been referred to as “release incisions” in the human literature, although a variable amount of tissue undermining is needed for bipedicle flap elevation in children. Unfortunately, the veterinary literature has also referred to the linear incisions created medial to the upper dental arcade as “release incisions.”^7,40,42,43 While a release incision does in fact reduce tension on closure of the soft palate, this same incision alone will not reduce tension for palatoplasty of the hard palate. However, these incisions are a necessary step in developing the bipedicle advancement flaps. To mobilize the hard palatal tissues and minimize incisional tension during closure in dogs, each bipedicle flap must be completely elevated from the firm connective tissue attachments to the underlying palatal bone. As previously noted, tension on the closure is the major cause of dehiscence in cleft palate repair.^2,41

Single layer and 2-layer closure options have been reported in the von Langenbeck technique in children. One paper⁴⁰ in the veterinary literature also advocated a 2-layer closure when employing the von Langenbeck technique. In this article, closing the deeper layer of this proposed 2-layer (dual flap) technique required the use of the medial margins of the bipedicle flaps; this maneuver unfortunately reduces the remaining width of each flap required to span the entire cleft in dogs. Approximation of the delicate nasal mucosa in narrow cleft palate defects has also been advocated prior to advancement of a mucoperiosteal flap.³⁸ Other surgeons have suggested placement of horizontal mattress sutures to approximate the deeper mucoperiosteal layer of bipedicle flaps prior to final suture approximation of the flap margins using interrupted sutures.³⁸

This report demonstrates that, by using these simple modifications of the von Langenbeck technique in dogs, a single-layer closure was very effective in closing canine cleft palate defects. Reflecting the human literature, veterinary papers have advocated the use of a simple interrupted suture pattern for apposing the flap margins using the traditional von Langenbeck technique.^7,38,42–44 However, 1 human surgical reference⁴⁵ illustrated the use of interrupted sutures, horizontal mattress sutures, and vertical mattress sutures in approximating the mucoperiosteal flaps; no preference of a given suture pattern was reported. As noted in this report, the vertical mattress suture pattern was considered superior to the interrupted pattern in dogs for 4 reasons: (1) the everting suture pattern negates the tendency for the mucosal edges to curl or scroll inwards; (2) this pattern directly approximates the underlying collagen layers of each flap, improving the likelihood of collagen cross-linkage to each apposed surface by fibroblasts; (3) this everting pattern “tents” the incision, forming an inherent structural ridge of support to the aligned bipedicle mucoperiosteal flaps over the cleft; and (4) the space between the vertical mattress sutures allows for the placement of finer interrupted sutures to offset “stair-stepping” or the offset alignment of the incision that is occasionally noted when using a mattress pattern. While the minor upwards curvature of the everted pattern does slightly decrease the width of each flap, this single-layer closure allows the entire width of each flap to effectively span the cleft.⁴¹ When apposing the bilateral mucoperiosteal flaps, the surgeon can take advantage of the comparatively thicker “peaks or ridges” of the canine palatal rugae when placing the vertical mattress sutures for better tissue purchase.

The age to perform palatoplasty and the technique selected can have an impact on a successful outcome in humans, and the research in this area is extensive.⁴⁵ One summary paper³⁸ suggested that soft palate closure should be performed between 6 to 12 months of age in children, although there are some surgeons who perform palatoplasties between 12 to 18 months of age. However, speech, facial growth, and hearing are major considerations in determining the best time to close cleft palate defects.^45–47

In the veterinary literature, there is no general agreement on the optimal time to close palatal defects in dogs. Historically there is wide variance in the timing of palatoplasty surgery in dogs, which is likely based on the surgeon’s preference or by simply quoting a preceding literature source. These preferences include 6 weeks,⁴⁸ 7 weeks,⁴⁹ 6 to 8 weeks,⁴⁴ 7 to 9 weeks,⁴² 7 to 8 weeks,⁴⁰ 8 to 10 weeks,⁷ 8 to 12 weeks,⁴³ 10 to 12 weeks,³⁷ 2 to 4 months,⁵⁰ and 3 to 4 months.⁵¹ This wide span of preferences simply adds to the confusion on the optimal time for canine palatoplasty. It has been suggested that waiting until 5 months of age runs the risk of the defect enlarging.²⁹ This, however, is contrary to the author’s clinical experience. The cleft either remains proportional to the lateral palatal donor areas or proportionately decreases in width when compared to the initial assessment of the defect at birth. Another study³⁸ suggested that oronasal fistula formation may be greater in dogs over 8 months of age. This was not recognized in this current case study.

As noted in this case series, the author prefers to wait a minimum of 5 months, allowing time for the tensile strength of the palatal tissue to increase for added suture security in a healthy, well-nourished dog. As previously noted, your first attempt at closure is the best opportunity for close palatal defects.⁴¹ Any advantage in closure reduces the risk of dehiscence. Each subsequent failed surgical attempt at cleft palate repair results in decreased tissue elasticity, increased scar tissue deposition, and circulatory compromise.

A small area of dehiscence (< 7 mm) was noted at the level of the incisive papilla when each dog was rechecked postoperatively. This is due to the fact that flaps in this rostral area cannot be fully mobilized without (1) the risk of damaging the rostral flap circulation from the sphenopalatine vascular branches and (2) inadvertently cutting the rostral pedicle that anchors the bipedicle flap. This small opening could be closed at a later time with a labial flap or by elevating and rotating the rostral pedicle of one or both bipedicle flaps at a later time as a second-stage procedure. However, the dogs were unaffected by its presence and required no additional surgery. Food and water normally pass caudal to this small defect without incident. No nasal discharge was noted in the dogs.

The author does not advocate the use of an esophagostomy or pharyngostomy feeding tube postoperatively. The palatal closure is continuously exposed to saliva, swallowing, lingual contact, and motion during breathing. Brief exposure to soft food when feeding the dog is not an issue to the normal healing process. A broad-spectrum antimicrobial and analgesics are recommended for 1 week following surgery. To enhance postoperative comfort, infraorbital nerve blocks can be safely employed prior to surgery to supplement the use of postoperative analgesics.

The purpose of presenting this case series was to demonstrate how simple modifications of the von Langenbeck technique can be used to successfully close cleft palate defects in dogs. There is no intentional inference that this technique is superior to other palatoplasty techniques. On the contrary, each cleft palate dog has unique anatomic factors that play a role in planning and selecting the best surgical closure option(s). Surgeons normally consider the palatoplasty procedure in which they have confidence based on their individual clinical experience. In this case series, the modified von Langenbeck technique was effective in closing both narrow and wide hard palate defects in 12 consecutive canine cases. Successful execution of this technique requires the complete elevation of each flap, facilitating their tension-free advancement over the palatal cleft. Vertical mattress sutures evert the flap margins, allowing for direct collagen surface contact for proper healing. Placement of sutures in the rugal folds increases the tissue purchase to reduce the risk of suture cutout. Smaller interrupted sutures positioned between vertical mattress sutures maintained proper alignment of the opposed flap margins. The incisional ridge created with the vertical mattress pattern forms an inherent structural support to the incision that spans the underlying bone defect of the cleft. The author waits a minimum of 5 months before closing cleft palate defects, enabling the donor areas time to mature, improving their ability to retain sutures more effectively (Appendix).

Supplementary Materials

Supplementary materials are posted online at the journal website: avmajournals.avma.org