Velopharyngeal Competence and Incompetence
NAOTUGUNITTA, D.D.S. ICHIKOKITANO, PH.D. TOMOMIMASUDA, B.A.
Objective: The purpose of this study was to investigate the relationship be-tween craniofacial and nasopharyngeal morphology and velopharyngeal func-tion in submucous cleft palate.
Design and Patients: Fifty-two lateral cephalometric radiographs of 46 sub-mucous cleft palate (SMCP) patients with velopharyngeal competence (24 pa-tients) and incompetence (22 papa-tients) at 4 and 7 years of age were studied. The patients had not received any surgical or orthodontic treatment prior to cephalography being performed.
Results: Significant differences were found between cephalometric variables (N-Ba, N-S-Ba angle) in children with velopharyngeal competence and incom-petence. However, the results of our study showed that cephalometric data alone are not useful for predicting velopharyngeal function and can not serve as an absolute prognostic indicator.
Conclusion: There are many factors that can influence velopharyngeal func-tion in SMCP patients. Cephalometric data did not demonstrate a strong rela-tionship to velopharyngeal function.
KEY WORDS: cephalometrics, craniofacial morphology, speech, submucous cleft palate, velopharyngeal function
Submucous cleft palate (SMCP) is a congenital anomaly in which there is imperfect muscle union across the velum. This anomaly was first described by Roux in 1825 (Lermoyez, 1892). Kelly (1910) reported on congenital insufficiency of the palate because of imperfect development of the hard and soft palate, which he called submucous cleft palate. The anatomical triad, originally described by Calnan (1954), consists of a bifid uvula, midline muscular diastasis, and notching of the posterior border of the bony palate. Although many clinical and char-acteristic facial features in patients with SMCP, demonstrated by cinefluorographic voice studies, videonasoendoscopy, vi-deofluoroscopy, and audiometry, have been described, studies using cephalometric analysis have been limited (Kaplan, 1975; Lewin et al., 1980; Kono et al., 1981; Garcia-Velasco et al.,
Dr. Park and Dr. Omori are plastic surgeons, Dr. Kato and Dr. Nitta are pediatric dentists, and Dr. Kitano and Ms. Masuda are speech-language pa-thologists, Shizuoka Children’s Hospital, Shizuoka, Japan.
Portions of this paper were presented at the 12th International Congress of the International Confederation for Plastic, Reconstructive and Aesthetic Sur-gery; June 27, 1999; San Francisco, California.
Submitted November 1999; Accepted November 2000.
Reprint requests: Dr. Susam Park, Shizuoka Children’s Hospital, 860 Uru-shiyama, Shizuoka 420-8660, Japan. E-mail firstname.lastname@example.org.
1988; Haseda and Tsukada, 1988; Park et al., 1994; Wakao et al., 1997).
There is a great variety of speech disorders in SMCP pa-tients (McWilliams, 1991). The aim of this study was to in-vestigate the relationship between craniofacial morphology and velopharyngeal function in SMCP patients.
Fifty-two lateral cephalograms of 46 patients (21 girls and 25 boys) with SMCP were traced for this study. Twenty-four pa-tients (12 girls and 12 boys) showed velopharyngeal compe-tence (VPC), and 22 patients (9 girls and 13 boys) showed velopharyngeal incompetence (VPI). Cephalograms were taken twice, at 4 and 7 years of ages, in six patients. We included the extra cephalograms to enlarge the small sample size to generate reasonable probability of statistical differences.
Submucous cleft palate was diagnosed when obvious mid-line muscular diastasis was detected by thorough peroral and nasoendoscopic examinations. A bifid uvula was seen in all patients, and a bony notch on the posterior hard palate was detected in all but one patient. The patients were divided into two age groups (Table 1). None of the patients had received
TABLE 1 Sample Distribution Number Mean Age (SD) Velopharyngeal Function VPC* Group VPI* Group 4 y Girls Boys 13 13 4 y 0 mo (3 m) 4 y 0 mo (2 m) 7 6 6 7 7 y Girls Boys 10 16 7 y 2 mo (3 m) 6 y 11 mo (2 m) 6 9 4 7 Total 52 28 24
* VPC5velopharyngeal competency; VPI5velopharyngeal incompetency.
FIGURE 1 Cephalometric landmarks. N5nasion; S5sella turcica; Ba
5basion; A5point A; ANS5anterior nasal spine; PMP5posterior maxillary point (junction of the palatal plane and a line drawn perpendic-ular to the plane from the pterygomaxillary fissure); U5tip of the soft palate; PPW5point at which the palatal plane extension intersects the posterior pharyngeal wall.
any surgical or orthodontic treatment before the cephalograms were taken, and the possibility of prior treatment having an effect on maxillary development was therefore eliminated. All of the patients were Orientals. Patients with significant cranio-facial deformity, neurological deficits, severe developmental delay, or hearing loss were excluded from this study.
Cephalograms were taken at rest in the natural head posi-tion. The cathode-to-film distance was 165 cm. All radiographs were traced and analyzed by two of the authors. Cephalometric landmarks and the measurement variables are shown in Figure 1. From these landmarks, 13 angular, linear, and proportional measurements of the facial skeleton and nasopharynx were carried out, and means and standard deviations were calculat-ed. An adequate ratio was calculated mathematically using the soft palate length U) and the pharyngeal depth (PMP-PPW; Wada et al., 1997). As the cephalograms were taken at rest, landmarks and measurements of the mandible could not be used.
Velopharyngeal function was assessed using a protocol that involved the repetition of Japanese vowels and several con-sonants, five Japanese words, and three Japanese sentences as well as assessment of conversational speech (Abe et al., 1980; Ohira et al., 1993). All speech evaluations were done in the same manner by an experienced speech pathologist and by two of the authors independently of each other. Based on an as-sessment of hypernasality and nasal escape, each patient was placed in one of four speech groups (Park et al., 2000). Ceph-alograms during /a:/ and /i:/ phonation, videofluoroscopy, and nasoendoscopy were generally used as helpful adjuncts for the assessment of velopharyngeal function. To determine clinical relevance and because of the small sample size, the patients were then combined into two groups: (1) one group of patients with complete or adequate velopharyngeal function who did not require any surgical treatment (VPC group) and (2) one group of patients with incomplete or inadequate
velopharyn-geal function who were candidates for surgical treatment (VPI group).
A Mann-Whitney U test was used to compare all cephalo-metric measurements between VPC and VPI groups and be-tween sex group. Three angular measurements and an adequate ratio were also compared at 4 and 7 years of age. A p value of less than .05 was considered significant. Furthermore, S-N-A angle, S-N dimension, anterior facial height, posterior facial height, and depth of the midface were compared with the Jap-anese normative values (Sakamoto, 1959; Ono, 1960). These data, since they were expressed as mean values and standard deviations, were analyzed using the Student’s t test.
The mean values and standard deviations of cephalometric measurements for all groups at 4 and 7 years of age are pre-sented in Tables 2 through 5.
Cranial Base (Table 2)
Significant differences in N-Ba and cranial base flexure (N-S-Ba angle) were found between 4-year-old boys in the VPC and VPI groups. S-Ba and N-Ba at 4 years of age and N-Ba at 7 years of age were significantly longer in boys than in girls. No other significant differences were found. The S-N lengths were also compared with the Japanese norms provided by
Sak-TABLE 2 Cephalometric Measurements in Cranial Base S-N† M SD S-Ba† M SD N-Ba† M SD ∠BaSN‡ M SD 4 y Girls VPC§ VPI§ Boys VPC VPI 61.0 60.6 61.5 62.5 64.2 61.3 2.3 2.6 1.8 3.4 4.1 2.0 35.8* 36.0 35.5 37.9* 37.4 38.4 1.9 2.1 1.8 3.0 2.9 3.3 89.7* 88.9 90.6 92.7* 95.2* 90.7* 3.2 3.2 3.2 3.9 4.0 2.4 133.9 132.5 136.2 134.2 138.4* 130.6* 4.5 5.3 0.6 7.6 6.1 7.1 7 y Girls VPC VPI 63.6 62.5 65.1 3.1 3.5 1.6 36.4 36.7 35.8 4.2 5.2 2.l8 92.2* 90.7 94.4 5.4 6.6 1.9 133.0 130.4 136.9 6.1 7.1 5.2 Boys VPC VPI 65.6 68.1 62.4 5.3 4.2 5.0 39.6 39.6 39.5 4.1 3.3 5.1 97.2* 98.7 95.2 6.2 5.8 6.6 129.3 130.4 128.1 5.1 7.1 3.9
† Linear variables were anterior cranial base length, S-N (sella to nasion); posterior cranial base length, S-Ba (sella to basion); and cranial base length, N5Ba (nasion to basion).
‡ Angular measurement was a saddle angle,∠BaSN (basion5sella nasion). § VPC5velopharyngeal competency; VPI5velopharyngeal incompetency. * p,.05.
TABLE 4 Cephalometric Measurements in Facial Height Anterior Upper Facial Height* M SD Posterior Upper Facial Height* M SD Depth of Midface* M SD 4 y Girls VPC† VPI† 43.0 41.9 44.2 2.3 2.6 1.9 36.5 36.3 36.8 1.6 1.5 1.7 52.7 53.2 52.1 3.9 4.4 3.3 Boys VPC VPI 44.4 43.8 45.2 2.4 2.9 2.1 36.9 36.9 36.9 2.3 2.6 2.2 52.9 53.0 52.8 5.4 6.8 3.6 7 y Girls VPC VPI 47.6 46.6 49.2 3.9 4.7 2.1 41.2 41.1 41.4 2.4 2.8 2.4 57.1 56.7 57.7 1.8 1.8 2.0 Boys VPC VPI 49.4 49.3 49.7 3.5 3.8 3.3 41.6 41.5 41.9 3.1 3.6 2.6 57.5 57.6 57.4 4.0 4.6 3.4
* Linear variables. Anterior upper facial height is the distance from the anterior nasal spine to the intersection with a line drawn perpendicular to the sella5nasion (SPN) plane from the anterior nasal spine. Posterior upper facial height is the distance from the posterior max-illary point (PMP) to the intersection with a line drawn perpendicular to the S-N plane from the PMP. Midfacial depth is the distance from point A to the intersection with aline drawn perpendicular to the y-axis from point A. The y-axis is a line perpendicular to the S-N plane through the sella point(s).
† VPC5velopharyngeal competency; VPI5velopharyngeal incompetency.
TABLE 3 Cephalometric Measurements in Maxilla ANS-PMP† M SD ∠SNA‡ M SD ∠SN-PP‡ M SD 4 y Girls VPC§ VPI§ 44.0* 44.0 44.0 2.1 2.1 2.4 80.6 81.7 79.2 4.0 4.4 3.5 8.3 8.1 8.5 3.5 4.8 1.3 Boys VPC VPI 46.1* 47.8 44.7 2.5 2.2 1.9 78.8 77.2 80.1 3.6 3.3 3.9 8.8 8.4 9.2 2.1 1.9 2.3 7 y Girls VPC VPI 48.0 46.9 49.6 2.8 3.0 1.7 82.5 83.4 81.1 3.6 3.9 2.9 7.4 6.4 8.7 3.8 3.6 4.1 Boys VPC VPI 48.5 48.4 48.6 3.3 4.0 2.3 79.9 78.7 81.4 3.6 3.1 3.8 8.7 8.1 9.6 3.8 4.2 3.3
† Linear variable was a basal maxilla length, ANS5PMP (anterior nasal spine to posterior maxillary point).
‡ Angular measurements were the S-N-A angle,∠SNA (sella-nasion5A) and the angle of the SN plane to palatal plane,∠SN-PP (S-N plane and palatal plane).
§ VPC5velopharyngeal competency; VPI5velopharyngeal incompetency. * p,.05.
TABLE 5 Cephalometric Measurements in Nasopharynx
PMP-Ba† M SD PMP-U† M SD PMP-PPW† M SD Adequate Ratio (PMP-U/ PMP-PPW)† M SD 4 y Girls VPC§ VPI§ 39.1 38.4 49.9 2.3 2.4 1.9 22.5 21.8 23.3 2.9 2.9 3.0 16.3 14.4 18.6 4.8 2.8 5.8 1.45 1.56 1.32 0.37 0.34 0.40 Boys VPC VPI 39.4 39.9 39.0 2.5 3.3 1.6 22.4 22.8 22.2 2.1 2.8 2.1 15.9 14.0 16.9 4.8 5.0 4.7 1.55 1.69 1.42 0.53 0.54 0.53 7 y Girls VPC VPI 40.8 40.2 41.7 3.6 3.9 3.3 24.2 24.4 24.0 4.2 4.1 5.1 20.5 18.4* 23.5* 3.4 2.8 1.3 1.21 1.34 1.02 0.29 0.27 0.21 Boys VPC VPI 40.1 40.6 39.5 3.1 3.2 3.1 24.8 25.6 23.7 2.6 2.8 2.1 18.0 18.5 17.4 4.0 4.4 3.7 1.44 1.47 1.41 0.38 0.48 0.24
† Linear variables were maxillocranial variable (PMP to Ba), length of soft palate (PMP to U), and depth of nasopharynx (PMP to PPW). Adequate ratio was derived of soft palate length and depth of nasopharynx.
§ VPC5nasopharyngeal competency; VPI5nasopharyngeal incompetency. * p,.05.
amoto (1959), Ono (1960), and the Japanese Society of Pe-diatric Dentistry (1995), but no significant differences were found between norms and SMCP patients.
Maxilla (Table 3)
There were no significant differences between the VPC and VPI groups in maxillary measurements (ANS-PMP, S-N-A an-gle, and SN-PP angle). ANS-PMP at 4 years of age was sig-nificantly longer in boys than in girls.
Facial Height (Table 4)
There were no significant differences in facial height mea-surements (anterior and posterior upper facial heights, midface depth) between the VPC and VPI groups when stratified by age and sex. The means and standard deviations of these three
measurements at each age were also compared with the Jap-anese norms (Sakamoto, 1959; Ono, 1960), but no significant differences were found.
Nasopharynx (Table 5)
Maxillocranial variable (PMP-Ba) and PMP-U showed a gradual increase with age, but there were no significant dif-ferences between the VPC and VPI groups. PPM-PPW was significantly smaller in 7-year-old girls in the VPC group than in girls of the same age in the VPI group. Adequate ratio (PMP-U/PPM-PPW) decreased between 4 and 7 years of age. There were no significant differences in ‘‘adequate ratios’’
be-tween the VPC and VPI groups and bebe-tween both age and sex groups.
There have been many studies on the craniofacial and na-sopharyngeal morphology of patients with cleft palate (Bis-hara, 1973; Ross, 1987; Mazaheri et al., 1994; Wada et al., 1997). However, few studies have focused on the craniofacial and nasopharyngeal morphology of patients with SMCP. Cephalometric analysis provides information on several fac-ets of the changes in SMCP patients. Kaplan (1975) stated that patients with classic and occult SMCP usually demonstrate characteristic maxillary hypoplasia. Haseda and Tsukada (1988) also reported underdevelopment of the maxilla, but Wakao et al. (1997) reported that maxillary growth was nor-mal. Weatherley-White et al. (1972) investigated the relation-ship between relative palatal length and speech by performing cineradiologic studies and concluded that patients with SMCP whose ratio of palate to pharynx was 1.5 or more were likely to have normal speech.
The present study was an attempt to identify cephalometric measurements that could be used as an indicator or predictor of patients whose velopharyngeal function would require sur-gical treatment. Although we found some significant differ-ences between the VPC and VPI groups, these differdiffer-ences were not present at every age. For example, PPM-PPW was significantly smaller in 7-year-old girls in the VPC group than in girls of the same age in the VPI group, but mean values of PPM-PPW in 7-year-old boys in the VPC group were longer than those in boys of the same age in the VPI group. Although the patients with a palate-to-pharynx adequacy ratio of 1.0 or less tended to have poor velopharyngeal function, the patients with a ratio greater than 1.2 did not always show good velo-pharyngeal function. This is because many factors can influ-ence velopharyngeal function. Weatherley-White et al. (1972) reported that there was relative shortness, poor mobility, and weakness of the soft palate in patients with SMCP. Cranio-facial and nasopharyngeal morphology is one of the factors involved, but it is difficult to predict VPI group membership by cephalograms alone. Thus, cephalometrics is not an ab-solute prognostic indicator but an adjunct for velopharyngeal function in SMCP. Repeated evaluation combining cephalog-raphy, videofluoroscopy, nasoendoscopy, and other methods is recommended for predicting velopharyngeal function in SMCP.
We compared some data (S-N-A angle, S-N dimension, an-terior facial height, posan-terior facial height, and midfacial depth) at each age with the Japanese norms (Sakamoto, 1959; Ono, 1960; Japanese Society of Pediatric Dentistry, 1995) to assess the characteristic craniofacial features of SMCP. Unfor-tunately, some important cephalometric parameters could not be compared with Japanese norms because of differences in the cephalometric landmarks. Some of our patients showed flattening of the maxilla, but no significant differences were
found between our patients with SMCP and the Japanese nor-mal values.
SMCP is defined as the abnormal attachment of the palatal muscles, but the intrinsic growth potential, its variations, and pathogenesis remain unclear. Various complex interactions contribute to the growth and development of craniofacial and nasopharyngeal structures. The small sample size after we sep-arated groups according to sex and age reduced the chances of identifying significant differences. However, it is possible that significant differences may be found in a future study using a larger sample size.
The relationship between lateral cephalograms and velopha-ryngeal function was studied in patients with SMCP. Despite some significant differences, it was found that cephalometric measurements are not strongly related to velopharyngeal func-tion. Several craniofacial parameters were also compared with Japanese norms, but no significant differences were found.
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