Timing of palate repair affecting growth in complete unilateral cleft lip and palate

Does the Surgical Protocol Impact the Burden of Care of Patients With Cleft Lip and/or Palate?

AIM

To compare the burden of care in the first 7 years of life of patients with cleft lip and palate (CLP) treated with 2 different surgical protocols.

METHODS

The burden of care of patients with cleft palate (CP), unilateral (UCLP), and bilateral cleft lip and palate (BCLP), surgically treated with Protocol A (soft palate closure at 1 year with Veau-Wardill-Kilner pushback technique and hard palate closure between 5 and 7 years with Von Langenbeck procedure) and B (soft palate closure at 1 year with intravelar veloplasty by Sommerlad and hard palate closure using a vomer flap at time of lip repair) was compared. The burden of care was assessed from the patient's file from birth until 7 years old through the following disciplines: surgical, dental, audiological, logopedic, radiologic, and logistic. Group comparisons were performed using multivariable models with correction for confounders. Continuous and binary variables were analyzed with linear and logistic regression models respectively.

RESULTS

One hundred nineteen CLP patients were included (62 CP, 40 UCLP, and 17 BCLP). Sixty-eight were treated with protocol A and 51 with protocol B. Patients treated with protocol B spent less days in the hospital after surgery (P=0.628), had less postsurgical complications (P<0.001), lower need for secondary interventions (P=0.016), needed less orthodontic maxillary expansion (P=0.004), less ventilation tube insertions (P<0.001), less speech therapy (P<0.001), less extractions of deciduous teeth (P = 0.040), less consultations (P=0.008) and traveled less distance (P=0.019). Patients treated with protocol A were younger when their first orthopantomogram (P<0.001) and craniofacial x-rays (P<0.001) were taken, and these radiographs were taken more often (P=0.013 and <0.001, respectively).

CONCLUSIONS

Patients treated with protocol B experience a significantly lower burden of care in the first 7 years of life.

Cephalometric analyses of the correlation between nasal and maxilla morphology among adult patients with cleft

OBJECTIVE

To explore if the nasal profile is influenced by maxillary hypoplasia among patients with congenital cleft lip and palate.

METHODS

Young adult patients with cleft and noncleft controls were enrolled. Nasal and maxillary profiles were measured on lateral cephalometric radiographs. The Kruskal-Wallis and Tukey post-hoc tests were employed for intergroup comparison among various the cleft types, and Pearson's product moment correlation coefficients were calculated to detect the correlation between nasal and maxillary cephalometric measurements.

RESULTS

A total of 250 participants were enrolled, including 64 with unilateral cleft lip and alveolae; 22 with bilateral cleft lip and alveolae; 49 with unilateral cleft lip, alveolae, and palate; 35 with bilateral cleft lip, alveolae, and palate; and 80 controls. Patients with cleft demonstrated significant difference in nasal and maxillary profiles when compared with the normal controls. The nasal dorsum length had a significant positive correlation with anterior and posterior maxillary height. The upper nasal dorsum length had a significant negative correlation with the maxillary protrusion. Among patients with bilateral cleft, the nasal dorsum length was also significantly negatively correlated with the maxillary protrusion.

CONCLUSION

The nasal profile is closely related to the growth of maxillae among patients with cleft and the normal population.

Six-year Burden of Care for Nonsyndromic Unilateral Cleft Lip and Palate Patients: A Comparison Between Cleft Centers and Noncleft Centers

OBJECTIVE

To determine differences in burden of care between nonsyndromic patients with unilateral cleft lip and palate undergoing treatment at American Cleft Palate-Craniofacial Association (ACPA)-accredited centers and nonaccredited centers in New York State.

DESIGN

A retrospective review of the New York Statewide Planning and Research Cooperative System database from January 2001 to December 2014 was performed using ICD-9 and CPT coding.

PATIENTS, PARTICIPANTS

This study included patients with unilateral cleft lip and palate who underwent both lip and palate repairs during their first  6 years of life. Exclusion criteria included orofacial cleft syndromes, follow-up under  6 years, and one-stage combined cleft lip and palate repairs.

RESULTS

Eighty-eight patients were treated at cleft centers, and 29 patients at nonaccredited centers (  n = 117). Age at primary palatoplasty (13.0 months vs 18.1 months;   p = .019), total number of cleft operations (2.3 vs 2.7;   p = .012), and total number of primary cleft-specific procedures (2.2 vs 2.5;   p = .0049) were significantly lower for patients treated in cleft centers. Age at primary cheiloplasty (4.8 months vs 4.6 months;   p = .865), post-cheiloplasty length of stay (1.2 days vs 1.2 days;   p = .673), post-palatoplasty length of stay (1.5 days vs 1.9 days;   p = .211), average hospital admissions (2.2 vs 2.3; p = 0.161), and total complication rates (34.1% vs 21.1%; p = 0.517) did not differ significantly between cleft centers and noncenters.

CONCLUSIONS

This data demonstrates some significant differences in overall 6 year burden of care for nonsyndromic patients with unilateral cleft lip and palate treated at ACPA-accredited cleft centers versus nonaccredited centers.

Craniofacial and three-dimensional palatal analysis in cleft lip and palate patients treated in Spain

Growth alterations have been described in patients operated on for oral clefts. The purpose of this work was to analyze the craniofacial and palate morphology and dimensions of young adults operated on for oral clefts in early childhood in Spain. Eighty-three patients from eight different hospitals were divided into four groups based on their type of cleft: cleft lip (CL, n = 6), unilateral cleft lip and palate (UCLP, n = 37), bilateral cleft lip and palate (BCLP, n = 16), and cleft palate only (CPO, n = 24). A control group was formed of 71 individuals. Three-dimensional (3D) digital models were obtained from all groups with an intraoral scanner, together with cephalometries and frontal, lateral, and submental facial photographs. Measurements were obtained and analyzed statistically. Our results showed craniofacial alterations in the BCLP, UCLP, and CPO groups with an influence on the palate, maxilla, and mandible and a direct impact on facial appearance. This effect was more severe in the BCLP group. Measurements in the CL group were similar to those in the control group. Cleft characteristics and cleft type seem to be the main determining factors of long-term craniofacial growth alterations in these patients. Prospective research is needed to clearly delineate the effects of different treatments on the craniofacial appearance of adult cleft patients.

Superior Orbicularis Oris Muscle Activity in Children Surgically Treated for Bilateral Complete Cleft Lip and Palate

The aim of this cross-sectional study was to evaluate the electromyographic activity of the superior orbicularis oris muscle both in children surgically treated for bilateral complete cleft lip and palate (BCCLP) as well as in subjects without BCCLP. The study comprised 77 children aged 6.6 to 12.5 years. All the patients with clefts had previously undergone lip and palate surgery. The upper lip electromyographic (EMG) assessments were made with a DAB-Bluetooth device (Zebris Medical GmbH, Germany) at rest, while swallowing saliva, protruding lips and compressing lips. EMG measurements were also made when the subjects produced phonemes /p/, /b/, and /m/ with the vowel /a/. The Mann-Whitney U test was applied to statistically analyze the EMG values. Significantly higher median upper lip EMG activity under working conditions such as swallowing saliva, lip compression, and production of the phoneme /p/ with the vowel /a/ was observed in patients with BCCLP compared to those without a cleft. The results of the study showed that the upper lip muscle activity increases in children with BCCLP when swallowing saliva, compressing lips and during some speech movement tasks. This may be important in the aspect of the effect of surgical lip repair on the craniofacial growth.

Scandcleft randomized trials of primary surgery for unilateral cleft lip and palate: impact of maxillary dental agenesis on craniofacial growth and dental arch relationship in 8 year olds

BACKGROUND

It is suggested that dental agenesis affects maxillary protrusion and dental arch relationship in children with unilateral cleft lip and palate (UCLP). In addition, an association between the need for orthognathic surgery and dental agenesis is reported.

AIM

The aim was to study the impact of maxillary dental agenesis on craniofacial growth and dental arch relationship in 8-year-old children with UCLP.

SUBJECTS AND METHODS

The sample consisted of individuals with UCLP from Scandcleft randomized trials. The participants had available data from diagnosis of maxillary dental agenesis as well as cephalometric measurements (n = 399) and GOSLON assessment (n = 408) at 8 years of age.

RESULTS

A statistically significant difference was found for ANB between individuals with agenesis of two or more maxillary teeth (mean 1.52°) in comparison with those with no or only one missing maxillary tooth (mean 3.30° and 2.70°, respectively). Mean NSL/NL was lower among individuals with agenesis of two or more maxillary teeth (mean 9.90°), in comparison with individuals with no or one missing maxillary tooth (mean 11.46° and 11.45°, respectively). The number of individuals with GOSLON score 4-5 was 47.2% in the group with two or more missing maxillary teeth and 26.1% respectively 26.3% in the groups with no or one missing maxillary tooth. No statistically significant difference was found in the comparison between individuals with no agenesis or with agenesis solely of the cleft-side lateral.

CONCLUSION

Maxillary dental agenesis impacts on craniofacial growth as well as dental arch relationship and should be considered in orthodontic treatment planning.

Innovative Molecular and Cellular Therapeutics in Cleft Palate Tissue Engineering

Clefts of the lip and/or palate are the most prevalent orofacial birth defects occurring in about 1:700 live human births worldwide. Early postnatal surgical interventions are extensive and staged to bring about optimal growth and fusion of palatal shelves. Severe cleft defects pose a challenge to correct with surgery alone, resulting in complications and sequelae requiring life-long, multidisciplinary care. Advances made in materials science innovation, including scaffold-based delivery systems for precision tissue engineering, now offer new avenues for stimulating bone formation at the site of surgical correction for palatal clefts. In this study, we review the present scientific literature on key developmental events that can go awry in palate development and the common surgical practices and challenges faced in correcting cleft defects. How key osteoinductive pathways implicated in palatogenesis inform the design and optimization of constructs for cleft palate correction is discussed within the context of translation to humans. Finally, we highlight new osteogenic agents and innovative delivery systems with the potential to be adopted in engineering-based therapeutic approaches for the correction of palatal defects. Impact statement Tissue-engineered scaffolds supplemented with osteogenic growth factors have attractive, largely unexplored possibilities to modulate molecular signaling networks relevant to driving palatogenesis in the context of congenital anomalies (e.g., cleft palate). Constructs that address this need may obviate current use of autologous bone grafts, thereby avoiding donor-site morbidity and other regenerative challenges in patients afflicted with palatal clefts. Combinations of biomaterials and drug delivery of diverse regenerative cues and biologics are currently transforming strategies exploited by engineers, scientists, and clinicians for palatal cleft repair.

The Influence of Four Different Treatment Protocols on Maxillofacial Growth in Patients with Unilateral Complete Cleft Lip, Palate, and Alveolus

BACKGROUND

The purpose of this study was to evaluate the effect of four different treatment protocols on maxillofacial growth in patients aged 7 to 8 years with unilateral complete cleft lip, palate, and alveolus.

METHODS

Sixty-one patients with nonsyndromic unilateral complete cleft lip, palate, and alveolus were entered into this study and grouped as follows: group 1 patients had a repaired lip and an unrepaired palate; group 2 patients underwent one-stage palatoplasty; group 3 patients underwent two-stage palatoplasty; and group 4 patients underwent lip adhesion and two-stage palatoplasty. The control group was composed of 16 patients with unilateral incomplete cleft lip. The Kolmogorov-Smirnov test was used to test the nature of data distribution. The Bonferroni test and the Kruskal-Wallis H test were used for multiple comparisons.

RESULTS

Group 5 showed a more protruding maxilla (basion-nasion-A point, basion-nasion-anterior nasal spine, sella-nasion-anterior nasal spine; p < 0.05), longer maxillary sagittal length (anterior nasal spine-posterior maxillary point; p < 0.05) and maxillary basal sagittal length (A point-posterior maxillary point; p < 0.05), and a better jaw relationship (A point-nasion-B point angle; p < 0.05) than groups 2, 3, and 4. Group 2 had higher anterior facial height (anterior nasal spine-nasion, anterior nasal spine-menton, nasion-menton; p < 0.05) and posterior facial height (registration point-posterior maxillary point; p < 0.05) than groups 3 and 4. Groups 2 and 3 had better maxillary position (sella-pterygomaxillary fissure; p < 0.05) and deeper bony pharynx (basion-posterior maxillary point; p < 0.05) than group 4.

CONCLUSIONS

In patients aged 7 to 8 years with unilateral complete cleft lip, palate, and alveolus, both one- and two-stage palatoplasty inhibited maxillary sagittal growth. Vomer flap repair with denuded bone inhibited maxillary vertical growth. Lip adhesion did adversely affect maxilla position.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Early or delayed palatoplasty in complete unilateral cleft lip and palate patients? A systematic review of the effects on maxillary growth

The aim of this study was to review the effects of early and late hard palate repair on maxillary growth. PubMed, Scopus, Web of Science, LILACS, Cochrane Library CENTRAL databases, OpenGrey, Google Scholar, and Clinical Trials were searched using a PICO strategy, with terms related to unilateral cleft lip and palate (UCLP) and timing of repair. Methodological quality evaluation was carried out using the Fowkes and Fulton guidelines, and quality (or certainty) of evidence and strength of recommendations were evaluated using GRADE (grading of recommendations, assessment, development and evaluation). Five retrospective and non-randomized studies were included in the study. Folkes and Fulton assessment showed a high risk of bias in all articles and very low levels of certainty (GRADE). The results showed conflicting findings for comparisons of the effects of timing of repair of hard palate in UCLP. Two studies presented better maxillary growth in a group operated on later (18 months after birth), two presented no differences between the results, and another presented better results in the group operated on earlier than 18 months of age. At this point, it cannot be proven or refuted that postponing hard palate surgery brings benefits for maxillary growth. Studies included in this review did not show similar conclusions. Randomized clinical trials present some ethical issues that make them difficult to perform.

Growth of Palate in Unilateral Cleft Lip and Palate Patients Undergoing Two-stage Palatoplasty and Orthodontic Treatment

The purpose of this study was to investigate the long-term effects of two-stage palatoplasty on the morphology of the maxillary alveolar arch and occlusion using plaster models of the maxilla and mandible obtained from patients with unilateral complete cleft lip and palate who also underwent orthodontic treatment. A total of 20 patients undergoing two-stage palatoplasty by Perko's method (Group T) were enrolled. Plaster models of the maxilla and mandible were obtained from each patient at Time 1, on commencement of orthodontic treatment in the mixed dentition period; at Time 2, on that of orthodontic treatment in the permanent dentition period; and at Time 3, on completion of active orthodontic treatment. Analysis of occlusion and morphological analysis were performed using a 3-dimensional measuring system. The results were compared with 15 patients who underwent one-stage palatoplasty by the push-back method using a mucoperiosteal flap (Group P). Alveolar morphology and the relationship between the maxilla and mandible were satisfactory in Group T. The palates in Group T were deeper and larger than those in Group P. Alveolar collapse in Group T was milder, and impairment of the alveolar morphology less notable than in Group P, as surgical invasion to the anterior alveolar region was avoided during the palatal growth period. These results suggest that two-stage palatoplasty is advantageous for jaw development.

Growth and Development of Craniofacial Structures in Patients at Different Ages With Unrepaired Submucous Cleft Palate

PURPOSE

Submucous cleft palate (SMCP) is a particular subtype of cleft palate deformity; research related to the craniofacial features of patients with SMCP is comparatively rare. The study objective was to perform a cephalometric comparison of the craniofacial features of patients with SMCP and non-cleft controls at different ages.

MATERIALS AND METHODS

The sample in this cross-sectional study was composed of 2 groups: SMCP patients and non-cleft controls. The primary predictor variables were study group (cleft and non-cleft) and age. Age was divided into 3 groups. The outcome variables of interest were craniofacial measurements. The measurements used reflect cranial length, cranial angle, maxillary sagittal length and protrusion, maxillary vertical height, pharyngeal depth, facial height, mandibular length and protrusion, mandibular plane angle, and intermaxillary relation. Adjusted cephalometric craniofacial measurements between the groups were compared in 3 age groups using generalized linear models after being adjusted for age and gender.

RESULTS

The study included 60 SMCP patients and 60 non-cleft controls. SMCP patients and non-cleft controls were divided into 3 subgroups: those aged 5 to 7 years, those aged 9 to 11 years, and those aged 18 to 30 years. Patients with SMCP at age 5 to 7 years showed a shortened cranial base length, maxillary sagittal length and height, and bony pharynx depth. Patients with SMCP at age 9 to 11 years showed a smaller maxillary sagittal length and bony pharynx depth and an inharmonious jaw relationship. Patients with SMCP at age 18 to 30 years showed a smaller maxillary sagittal length and height and an inharmonious jaw relationship.

CONCLUSIONS

SMCP is associated with progressive maxillary retrognathism and reduced profile convexity from childhood to adulthood.

Electromyographic analysis of superior orbicularis oris muscle function in children surgically treated for unilateral complete cleft lip and palate

PURPOSE

The aim of this study was to assess the electrical activity of the superior orbicularis oris muscle in children surgically treated for unilateral complete cleft lip and palate (UCCLP).

MATERIAL AND METHODS

The sample comprised 45 patients 6.38-12.68 years of age with UCCLP and 40 subjects 6.61-11.71 years of age with no clefts. Electromyographical (EMG) recordings were taken with a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany) in the rest position and during saliva swallowing, lip protrusion and reciprocal compression of the lips, as well as while producing the phonemes /p/, /b/, and /m/ combined with the vowel /a/.

RESULTS

The electrical activity of the upper lip during saliva swallowing and lip compression was significantly greater in the cleft group. Similar resting level activity was observed in both groups. During the production of the /p/, /b/, and /m/ phonemes combined with the vowel /a/ the results showed no significant differences in the EMG activity between children with UCCLP and noncleft subjects.

CONCLUSION

Patients with UCCLP have abnormal upper lip function characterized by increased activity of the superior orbicularis oris muscle during saliva swallowing and lip compression, and this may affect facial morphology.

Three-dimensional analysis of maxillary development in patients with unilateral cleft lip and palate during the first six years of life

OBJECTIVES

The purpose of this work was to analyse early upper-jaw development in patients with unilateral cleft lip and palate (UCLP) treated using two different concepts and to compare shape and size developments between these two groups and a group of noncleft patients.

MATERIALS AND METHODS

A total of 204 maxillary casts available for this study from 50 UCLP patients were analyzed for upper-jaw development based on three-dimensional measurements performed with a Reflex Microscope from birth up to 71 months of age. Thirty-five of these 50 patients were part of an early treatment group (two-stage cleft closure with single-stage palatoplasty at an age of 10-14 months) and 15 were part of a late treatment group (two-stage cleft closure with palatoplasty at an age of 4-7 years). The control group included 39 casts of 17 noncleft patients.

RESULTS

Analysis of shape and size between the patients in the three groups yielded statistically significant differences between the cleft and the noncleft patients. In both treatment groups, we made observations typically associated with cleft formation like lateralization, asymmetry of the greater and lesser cleft segments, and pronounced vertical deviations of the segments. Viewed in all dimensions, however, the patients in the early treatment group approached the control group more closely, although a statistically significant difference was still observed.

CONCLUSION

Our results suggest that the timing of hard-palate closure is not a decisive factor for upper-jaw development. Intrinsic factors (initial cleft width, presence of tooth buds) and the surgeon's skills appear to have a much more defining role.

Influence of different palate repair protocols on facial growth in unilateral complete cleft lip and palate

OBJECTIVE

To address the question of whether one- or two-stage palatal treatment protocol has fewer detrimental effects on craniofacial growth in patients aged 5 years with unilateral complete cleft lip and palate.

MATERIALS AND METHODS

Forty patients with non-syndromic unilateral complete cleft lip and palate (UCCLPs) who had received primary cleft lip repair at age 6-12 months and cleft palate repair at age 18-30 months were selected in this study. Eighteen UCCLP patients who received two-stage palate repair were selected as group 1, and 22 UCCLP patients who received one-stage palate repair were selected as group 2. The control group consisted of 20 patients with unilateral incomplete cleft lip (UICL patients) whose age and gender matched with UCCLP patients. A one-sample Kolmogorov-Smirnov test was used to analyze the nature of data distribution. Bonferroni test and Kruskal-Wallis H tests were used for multiple comparisons.

RESULTS

Both case groups showed reduced maxillary sagittal length (ANS-PMP, A-PM, p < 0.05) and retrusion of the maxilla (S-Ptm, p < 0.05), A point and ANS point (Ba-N-A, Ba-N-ANS, p < 0.05). Patients treated with two-stage palate repair had a reduced posterior maxillary vertical height (R-PMP, p < 0.05).

CONCLUSIONS

Our results indicated that maxillary sagittal length and position could be perturbed by both one- and two-stage palate repair. Vomer flap repair inhibited maxilla vertical growth. Delayed hard palate repair showed less detrimental effects on maxillary growth compared to early hard palate repair in UCCLP patients aged 5 years.

Vertical maxillary growth after two different surgical protocols in unilateral cleft lip and palate patients

Objective : The aim of the present study was to compare vertical maxillofacial growth in patients born with unilateral cleft lip and palate (UCLP) who were treated using two different surgical protocols. Design : A retrospective cohort study. Subjects : We studied 92 patients with complete UCLP (61 male and 31 female) treated at Sahlgrenska University Hospital in Gothenburg, Sweden: 46 consecutive patients born between 1965 and 1974 who underwent surgical treatment according to the Wardill-Kilner (W-K) protocol and 46 consecutive patients born between 1982 and 1989 who underwent surgical treatment according to the Gothenburg delayed hard palate closure (DHPC) protocol. Methods : We analyzed lateral cephalograms obtained at 10 years of age. Results : Patients treated according to the Gothenburg DHPC protocol had significantly greater anterior upper facial height, anterior maxillary height, overbite, and inclination of the maxilla than those treated with the W-K protocol. Both techniques led to similar posterior upper facial height. Conclusion : The Gothenburg DHPC protocol in patients with complete UCLP results in more normal anterior maxillary vertical growth and overbite and therefore increased maxillary inclination at 10 years of age.

Calvarial periosteal graft for second-stage cleft palate surgery: a preliminary report

OBJECTIVE

The objectives of cleft palate surgery are to achieve optimal outcomes regarding speech development, hearing, maxillary arch development and facial skull growth. Early two-stage cleft palate repair has been the most recent protocol of choice to achieve good maxillary arch growth without compromising speech development. Hard palate closure occurs within one year of soft palate surgery. However, in some cases the residual hard palate cleft width is larger than 15 mm at the age of two. As previously reported, integrated speech development starts around that age and it is a challenge since we know that early mobilization of the mucoperiosteum interferes with normal facial growth on the long-term. In children with large residual hard palate clefts at the age 2, we report the use of calvarial periosteal grafts to close the cleft.

MATERIAL AND METHODS

With a retrospective 6-year study (2006-2012) we first analyzed the outcomes regarding impermeability of hard palate closure on 45 patients who at the age of two presented a residual cleft of the hard palate larger than 15 mm and benefited from a periosteal graft. We then studied the maxillary growth in these children. In order to compare long-term results, we included 14 patients (age range: 8-20) treated between 1994 & 2006. Two analyses were conducted, the first one on dental casts from birth to the age of 6 and the other one based on lateral cephalograms following Delaire's principles and TRIDIM software.

RESULTS

After the systematic cephalometric analysis of 14 patients, we found no evidence of retrognathia or Class 3 dental malocclusion. In the population of 45 children who benefited from calvarial periosteal grafts the rate of palate fistula was 17% vs. 10% in the overall series.

CONCLUSION

Despite major advances in understanding cleft defects, the issues of timing and choice of the surgical procedure remain widely debated. In second-stage surgery for hard palate closure, using a calvarial periosteal graft could be the solution for large residual clefts without compromising adequate speech development by encouraging proper maxillary arch growth.

Maxillary growth in a congenital cleft palate canine model for surgical research

We have recently presented the Old Spanish Pointer dog, with a 15-20% spontaneous congenital cleft palate rate, as a unique experimental model of this disease. This study aimed to describe the cleft palate of these dogs for surgical research purposes and to determine whether congenital cleft palate influences maxillofacial growth. Seven newborn Old Spanish Pointer dogs of both sexes, comprising a cleft palate group (n = 4) and a normal palate group (n = 3), were fed using the same technique. Macroscopic photographs and plaster casts from the palate, lateral radiographs and computer tomograms of the skull were taken sequentially over 41 weeks, starting at week 5. The cleft morphology, the size and the tissue characteristics in these dogs resembled the human cleft better than current available animal models. During growth, the cleft width varies. Most of the transverse and longitudinal measures of the palate were statistically lower in the cleft palate group. The cleft palate group showed hypoplasia of the naso-maxillary complex. This model of congenital cleft palate seems suitable for surgical research purposes. A reduced maxillofacial pre- and post-natal development is associated to the congenital cleft palate in the Old Spanish Pointer dog.