Maxillary distraction versus orthognathic surgery in cleft lip and palate patients: effects on speech and velopharyngeal function

Maxillary distraction versus orthognathic surgery in cleft lip and palate patients: effects on speech and velopharyngeal function

Int. J. Oral Maxillofac. Surg. 2010; 39: 633–640 doi:10.1016/j.ijom.2010.03.011, available online at http://www.sciencedirect.com Leading Clinical Pa...

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Int. J. Oral Maxillofac. Surg. 2010; 39: 633–640 doi:10.1016/j.ijom.2010.03.011, available online at http://www.sciencedirect.com

Leading Clinical Paper Cleft Lip and Palate

Maxillary distraction versus orthognathic surgery in cleft lip and palate patients: effects on speech and velopharyngeal function

H. D. P. Chua1, T. L. Whitehill2, N. Samman1, L. K. Cheung1 1 Discipline of Oral & Maxillofacial Surgery, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China; 2Division of Speech and Hearing Sciences, Faculty of Education, The University of Hong Kong, Hong Kong, China

H. D. P. Chua, T. L. Whitehill, N. Samman, L. K. Cheung: Maxillary distraction versus orthognathic surgery in cleft lip and palate patients: effects on speech and velopharyngeal function. Int. J. Oral Maxillofac. Surg. 2010; 39: 633–640. # 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. This clinical randomized controlled trial was performed to compare the effects of distraction osteogenesis (DO) and conventional orthognathic surgery (CO) on velopharyngeal function and speech outcomes in cleft lip and palate (CLP) patients. Twenty-one CLP patients who required maxillary advancement ranging from 4 to 10 mm were recruited and randomly assigned to either CO or DO. Evaluation of resonance and nasal emission, nasoendoscopic velopharyngeal assessment and nasometry were performed preoperatively and at a minimum of two postoperative times: 3–8 months (mean 4 months) and 12–29 months (mean 17 months). Results showed no significant differences in speech and velopharyngeal function changes between the two groups. No correlation was found between the amount of advancement and the outcome measures. It was concluded that DO has no advantage over CO for the purpose of preventing velopharyngeal incompetence and speech disturbance in moderate cleft maxillary advancement.

Maxillary hypoplasia is a common developmental problem in individuals with cleft lip and palate (CLP) and is thought to result from a combination of a congenital reduction in midfacial growth and the effects of the surgical scarring from cleft palate repair3. Many patients with this problem can benefit aesthetically and functionally from surgical correction. Traditionally, maxillary advancement was corrected by 0901-5027/070633 + 08 $36.00/0

what is now termed conventional orthognathic surgery (CO) although, since 1997, distraction osteogenesis (DO) has become an alternative option for the treatment of maxillary hypoplasia in patients with CLP3. When the maxilla is advanced surgically, the soft palate is thought to move forward, which may affect velopharyngeal function (VF). At the same time, improved occlusal relationships may improve speech articula-

Keywords: distraction; orthognathic surgery; cleft; speech; velopharyngeal function. Accepted for publication 16 March 2010 Available online 22 April 2010

tion. Studies reporting the influence of maxillary advancement on speech and VF have yielded different results. In a critical review of the effect of cranio-maxillofacial osteotomies and DO on speech and velopharyngeal status conducted by Chanchareonsook et al.1, the results varied considerably. While many studies reported that surgical advancement of the maxilla had no impact on speech and

# 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

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velopharyngeal status, others reported worsening in patients with pre-existing velopharyngeal impairment or those with borderline VF before surgery1. With regards to articulation, some studies found improvement in articulation and some no change1. Chanchareonsook et al.2 also noted that there were no clear differences in outcomes between CO and DO, although there were few systematic comparisons. The authors’ centre has been conducting a prospective randomized controlled trial to compare the speech outcomes and velopharyngeal status of patients with repaired cleft lip and palate, who underwent either CO or DO to correct maxillary hypoplasia. The early results (3 months postoperatively) showed that there was no statistically significant difference in either speech or VF between the two surgical techniques2. The sample size was small and the follow-up time short, so a longer follow-up with a larger sample size was recommended2. This study aimed to compare the longterm effects on speech (resonance and nasal emission) and VF in two groups of CLP patients indicated for moderate advancement, one treated with DO and the other with CO. The null hypothesis has been adopted to avoid bias: that there is no significant difference in the long-term effects on speech and VF in CLP patients undergoing either CO or DO. Materials and methods Participants

All patients with CLP, who were over 16 years of age and skeletally mature, and presenting with moderate maxillary hypoplasia requiring Le Fort I osteotomy were evaluated for recruitment into this study. The maxillary alveolar clefts were grafted and pre-surgical arch alignment and decompensation by fixed orthodontics completed. This was followed by a standard surgical assessment, dental model surgery and prediction tracing. Only patients who required maxillary advancement ranging from 4 to 10 mm based on the model surgery were recruited into the trial. Others with smaller planned advancement underwent CO, whereas those with larger advancement underwent DO and were excluded from the trial. Syndromic patients and patients who presented with systemic diseases were excluded. Patients who satisfied the inclusion criteria were randomly assigned into two surgical groups, for treatment by DO with internal maxillary distractors or by CO with mini-plate fixation.

A senior investigator (LKC) with extensive experience in both distraction and orthognathic surgery performed the clinical assessment and was in charge of the randomization of the patients using a table of random numbers generated by computer. The allocation was concealed until informed consent was being explained to the patients. The study was approved by the Faculty of Dentistry Ethics Committee and all patients involved in the study provided written consent. The surgery was supervised by LKC and was conducted in the Discipline of Oral and Maxillofacial Surgery, The University of Hong Kong between June 2002 and January 2008.

Intervention

A standard Le Fort I osteotomy and down fracturing was performed4. Maxillary segmentalization was carried out if necessary according to the dental model surgical plan. In the CO group, the maxilla was fully mobilized to the pre-planned position. Custom-made arch bars were ligated to the maxillary and mandibular dental arches and the teeth placed in the occlusal wafer followed by intermaxillary fixation with wire loops. The mobilized maxilla was fixed with two titanium mini-plates on each side at the zygomatic buttress and the pyriform region. Intermaxillary fixation was removed and the accuracy of the dental interdigitation was checked. A standardized technique of maxillary distraction with the use of internal distractors was developed for the DO group. A similar vestibular incision and bone cuts as for CO was made. The maxilla was fully mobilized but not transposed to the final occlusal position. Internal bone-borne maxillary distractors (Synthes, Pennsylvania, USA) were then inserted. The distractors on either side were activated for a few millimetres to check the correctness of maxillary transport, with the aim of reaching good occlusal interdigitation. The mucosal wound was then closed by continuous suturing to leave the activator rod external to the mucosal wound for later activation. Mandibular osteotomies, if needed, were performed in the same operation. After a latency of 3 days, activation was commenced at 1 mm per day in two rhythms with an activating key by the patients themselves or their relatives until a class I incisal relationship was achieved. Light orthodontic elastic traction was applied to control the occlusion in both groups during the early postoperative period.

Outcomes

The primary outcome of the study was the long-term skeletal stability of CO and DO in CLP patients. This was assessed by comparing serial lateral cephalographs taken at different postoperative times. The secondary outcomes of the study were dental relapse, morbidities, speech and VF changes, soft tissue changes and psychological profile changes. Clinical relapse and morbidities were recorded using questionnaires. Speech and VF changes were assessed using nasoendoscopy, perceptual speech assessment and nasometer. The changes in the soft tissue were compared using serial lateral cephalographs taken preoperatively and postoperatively at different time intervals. Psychological profiles were measured using standardized questionnaires (Social Avoidance and Distress Scale, Satisfaction with Life Scale and Culture-free Self Esteem Inventory). This manuscript will only focus on two of the secondary outcomes: speech and VF changes. The sample size was calculated based on the primary outcome. In the pilot study, the skeletal relapse of cleft maxillary distraction and orthognathic surgery was compared. A sample size of 42 (n = 21 per group) was suitable for obtaining statistically valid data. The authors were able to determine a statistically significant difference (p < 0.05) between CO and DO when the mean horizontal relapse was more than 0.14 mm at 80% power.

VF assessment

All patients underwent a nasoendoscopy examination preoperatively and at 3, 12 and 24 months postoperatively to determine their velopharyngeal status. All patients were examined using a flexible nasoendoscope (Kay Rhino-Laryngeal Stroboscope RLS 9100B, KayPentax, Lincoln Park, NJ; Olympus ENF type P-4, Olympus America Inc., Melville, NY, USA). The scope was connected to a cold light supply to allow visualization. The image obtained from the scope was visualized on a colour monitor and recorded onto the computer. Patients were asked to sit with their necks extended and head tilted backward about 158. Topical anaesthesia using 4% cocaine was sprayed into the nasal cavity in order to maximize patient comfort and cooperation and to diminish secretion. The nasoendoscopy was performed using the same nostril in each subject at the preoperative and postoperative examinations by the same senior investigator (NS).

Maxillary distraction versus orthognathic surgery in cleft lip and palate patients After introduction of the nasoendoscope through the nostril, the tip was positioned above the level of the velopharyngeal orifice. The boundary of the velopharyngeal orifice was defined by the posterior border of the soft palate (velum), left and right lateral pharyngeal walls and the posterior pharyngeal wall. Each patient was asked to provide a speech sample, as instructed by the attending speech-language pathologist (TW). The ‘Cantonese Nasendoscopy Speech Protocol’, developed by Whitehill23 was used. The protocol asks patients to pronounce their name, age, count from 1 to 20, and requires sustained production of two vowels, consonant-vowel repetitions (e.g. ‘pa pa pa’, ‘ti ti ti’), sustained/s/, sentences loaded with plosives, fricatives and nasals, and non-speech activities such as blowing, whistling and swallowing. Each assessment took about 3–5 min. For patients presenting with pharyngeal flaps, both pharyngeal orifices were included in the assessment so that all borders could be seen in a single view. Each portal was examined individually. The clinical nasoendoscopy findings were evaluated on completion of each examination and the diagnosis was noted in the clinical record. This included: classification of VF (adequate closure, borderline competence, mild, moderate or severe incompetence), the consistency of the VF, any phoneme effects (e.g. better closure achieved for plosives), and pattern of closure (e.g. circular, coronal)18. These clinical observations were not used for assessment of VF in this study. Rather, all the nasoendoscopy data were retrieved and transferred to a mini-digital video tape (Sony Corporation, Tokyo, Japan) by a technician (SH) not involved in the study. The videos were edited by this technician (SH) using Music Fan’s Factory (Color7 Tech, Alabama, USA) to eliminate the patient’s name and age. The videos were randomized across groups (CO and DO) and the time of evaluation (preoperative and postoperative) and were assigned a number by the technician (SH). The analysis design was a randomized blind evaluation of the velopharyngeal gap closure. The 6-point rating scale developed by Chanchareonsook et al.2 was used, with the velopharyngeal resting position as the baseline (Table 1). The scale was based on the protocol recommended by Golding-Kushner et al.7 The rating procedures followed those developed by Chanchareonsook et al.2 namely: a panel of three judges (HDC, TW and NS) analyzed the data by examining velopharyngeal movement during the nasoendoscopic procedure. A judgment

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Table 1. Nasoendoscopy rating scale2. 0.00 = Severe VPI, or no movement of velopharyngeal structures 0.25 = Severe VPI, or minimal velopharyngeal closure 0.50 = Moderate VPI, or moderate velopharyngeal closure 0.75 = Mild VPI, or velopharyngeal closure between moderate and touch closure 0.90 = Borderline touch closure, or pin hole closure 1.00 = No VPI, or complete velopharyngeal closure VPI = velopharyngeal incompetence

was made independently by each examiner after each sample. A comparison of the ratings between the examiners was then made. If all three or two of the three assessors provided the same rating, this represented the final rating for any specific sample. If the three assessors had three different ratings, the rating was repeated until there was agreement between at least two judges; discussion was allowed during such cases. If the pattern of velopharyngeal closure was inconsistent, the maximum velopharyngeal closure during the entire protocol was used to represent the final rating. In cases where pharyngeal flaps were present, the judges were asked to focus on the port with the poorest closure.

Consensus listening was undertaken by two qualified speech-language pathologists (TW, JC), both of whom were experienced in evaluating the speech of patients with cleft palate. Both (TW, JC) were blinded to the patient group and whether the samples were preoperative or postoperative. The raters listened to the audio-samples at the same time using Sennheiser HD 212 Pro headphones (Sennheiser Electronic Corporation, Connecticut, USA). They made their judgments independently and then compared their findings. If there was a disagreement, the samples were played again and discussed until a consensus was reached. After reaching a consensus, the rating was recorded.

Perceptual speech assessment

Speech examinations were carried out on the same visit as the velopharyngeal assessment. During each session, an experienced speech-language pathologist examined each patient to evaluate resonance (hypernasality and hyponasality), nasal emission and articulation. The articulation results are not reported here, but have been analyzed separately. The speech examination was conducted in a quiet room. Each patient was asked to read a standard Cantonese/Chinese reading passage and the Cantonese Osteotomy Deep Test, a list of single words designed to tap the Cantonese phonemes most vulnerable to change with osteotomy24. Speech samples were recorded using a Sony TCD-D3 Digital (DAT) tape recorder. A Sony ECM-909 microphone was used, with a mouth to microphone distance maintained at approximately 10 cm. Evaluation of hypernasality, hyponasality and nasal emission was based on a 30 s sample edited from each reading passage speech sample using Main Actor V5.5 (MainConcept, Aachen, Germany) by a technician not involved in the study. The audiorecordings were re-named as numbers, randomized (across surgical groups and time of evaluation) and transferred to a compact disc, which was played using a Mac mini-computer (Apple, California, USA). The parameters involved in the speech analysis and the rating scales are presented in Table 2.

Nasalance assessment

Nasality was assessed using a nasometer (Kay Elemetrics, Model 6200, KayPENTAX, New Jersey, USA). The nasometer was calibrated according to the manufacturer’s instructions, and the headset device was adjusted by the speech-language pathologist. This headset device separated the oral and nasal cavities using a baffle plate. Two microphones mounted on the top and bottom of the plate collected acoustic energy during speech. The instrument then computed a ratio of the acoustic data acquired by the two microphones (nasal energy divided by oral plus nasal energy). This ratio is called nasalance, which is considered an acoustic correlate of perceived nasality and is expressed as a percentage. Calibration was made before the assessment of each subject. Each patient read an oral passage aloud23, which contained no nasal phonemes. If Table 2. Speech variables and rating scale. Speech variable

Rating scale

Hypernasality

0 = No hypernasality 1 = Mild hypernasality 2 = Moderate hypernasality 3 = Severe hypernasality

Hyponasality

1 = Hyponasality 0 = No hyponasality

Nasal emission

1 = Present 0 = Absent

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an error occurred during reading, the subject was asked to repeat the test. The mean percentage nasalance was calculated for each patient at each time period. Previous studies have recommended various cut-off points for nasalance values such as 32%6 and 26%9. In this study, a nasalance value higher than 30% was considered to be indicative of hypernasality23. A 2-point nasalance scale was thus derived, where 1 is above/outside normal limits (nasalance above 30%), 0 is within normal limits (30% nasalance or below). In view of missing data at various postoperative time points, only two postoperative data points for each patient were included in all the analyses. Wherever available, the third postoperative data was chosen. This resulted in a postoperative mean time of 4 months (range 3–8 months; SD 4.13) and another of 17 months (range 12–29 months; SD 5.78). These first and second postoperative time

Fig. 1. Flow diagram of patient recruitment.

points will be referred to as post1 and post2, respectively. Statistical methods

An exact x2 test was performed to determine if there was a statistically significant difference between patients who showed an improvement, no change or deterioration in the different assessment parameters. Pearson’s correlation was performed to determine any correlation between the amount of surgical maxillary advancement and the different assessment parameters. Results VF

Twenty-one patients (11 CO, 10 DO) had a complete data set and were included in the nasoendoscopic assessment (Fig. 1). The demographic profiles of the patients

are presented in Table 3. For these 21 patients, 63 samples (video image plus speech recording), separated into preoperative, post1 and post2, were available for assessment. Three samples were randomly selected, re-named and used for the intra-judge (test–retest) reliability. These 3 were added to the original 63 samples, forming a total of 66 samples. The 3 assessors were in agreement in 54 (81%) samples. In the remaining 12 samples (19%), the assessors were in partial agreement (i.e. 2 of the 3 assessors gave the same rating). For those samples where there was partial agreement, it was noted that there was only one scale difference in the ratings given. For the three randomly selected samples for the intra-judge reliability, all three assessors gave the same rating as for the original samples (100% intra-judge reliability). The nasoendoscopy ratings for individual patients are presented in Table 4. At

Maxillary distraction versus orthognathic surgery in cleft lip and palate patients Table 3. Demographic profile of patients. CO group

DO group

No

%

No

%

Gender Male Female

6 5

54.55 45.45

5 6

45.45 54.55

Age 16–17 18–19 20–21 22

5 3 3 0

45.45 27.27 27.27 0.00

1 5 3 2

9.09 45.45 27.27 18.18

Diagnosis RUCLP LUCLP BCLP CP

3 5 2 1

27.27 45.45 18.18 9.09

3 5 2 1

27.27 45.45 18.18 9.09

RUCLP – right unilateral cleft lip and palate; LUCLP – left unilateral cleft lip and palate; BCLP – bilateral cleft lip and palate; CP – cleft palate.

the preoperative stage, 5 patients had borderline touch closure (0.9), 2 had mild velopharyngeal incompetence (VPI; 0.75), 1 moderate VPI (0.5) and 13 had complete velopharyngeal closure (1.0). At post1, 6 patients presented with borderline touch closure, 1 patient moderate VPI and 14 complete closure. At post2, 7 patients had borderline touch closure, 1 moderate VPI and 13 had complete velopharyngeal closure. Of patients who presented with incomplete velopharyngeal closure at post1

(n = 7), 3 patients (C2, C15, C19) with borderline closure were from the CO group, with maxillary advancement of 4 mm (2 patients) and 9 mm (1 patient). The remaining four patients were from the DO group, three patients (D6, D14, D20) with maxillary advancement of 4, 5 and 6 mm were found to have borderline touch closure. One patient (D4), with an advancement of 7 mm had moderate VPI. The nasoendoscopy results were further classified into patients who showed an improvement, no change, or deterioration

Table 4. Amount of advancement and nasoendoscopy results. Patients CO group C1 C2 C6 C7 C9 C12 C15 C18 C19 C21 C22 DO group D3 D4 D5 D6* D7* D9 D14 D15 D19 D20

Amount of advancement (mm)

Nasoendoscopy rating Pre-op

Post1

Post2

4 5 8 4 8.5 6 9 4 4 6 10

1 1 0.9 0.75 1 1 0.9 1 1 1 0.9

0.9 1 1 1 1 1 0.9 1 0.9 1 1

0.9 1 1 0.9 1 1 0.9 1 0.9 1 0.9

4 7 7 5 5 10 4 6 9.5 6

1 0.5 1 0.75 1 0.9 0.9 1 1 1

1 0.5 1 0.9 1 1 0.9 1 1 0.9

0.9 0.5 1 1 0.9 1 1 1 1 1

Nasoendoscopy rating: 1.00 = no VPI, 0.90 = borderline touch closure, 0.75 = mild VPI, 0.50 = moderate VPI, 0.25 = minimal VP closure, 0.00 = no movement of VP structure. * Patient with superior based (Hogan’s) pharyngoplasty.

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in velopharyngeal status after surgery. An exact x2 test showed no significant difference between the number of subjects who showed ‘improvement’, ‘deterioration’, and ‘no change’ in their velopharyngeal status between the two types of surgery at post1 (x2 = 0.56, p > 0.05) and post2 (x2 = 0.49, p > 0.05). Pearson’s correlation also showed no significant correlation between the amount of maxillary advancement and the velopharyngeal status at post1 (r = 0.04, p > 0.05) and post2 (r = 0.08, p > 0.05). Resonance

Twenty-two patients (11 CO, 11 DO) with complete data sets were included in the resonance analysis. Three samples were randomly selected, re-named and used for the intra-judge reliability. These 3 samples were added to the original 66 samples making a total of 69 samples available for assessment. The samples were randomized across surgical groups and times. For the 69 samples, 65 (94%) rating judgments were agreed by the 2 assessors. The remaining four samples (6%) were played again and discussed in order to arrive at the final judgment. For the three randomly selected samples used for the intra-judge reliability, both assessors gave the same rating when compared with the original samples (i.e. 100% agreement). In the CO group, the resonance of all 11 patients was considered normal preoperatively (Table 5). At post1, four patients were rated as mildly hypernasal, and their status remained as such at post2. Only one patient (C11) showed hyponasality at post1. Preoperatively and at post2, his resonance was judged to be within normal limits. This patient was excluded from further analysis as the hyponasality was related to a cold or allergic rhinitis on the day of examination. In the DO group, 2 of 11 patients (D3, D4) had hypernasality preoperatively (Table 4). The status of these patients did not change at post1 and post2. One patient (D5) who had normal speech preoperatively showed mild hypernasality at post1; his status returned to normal at post2. No significant correlation was found between the amount of advancement and resonance (post1, r = 0.42, p > 0.05; post2, r = 0.38, p > 0.05). There was no significant correlation between resonance and velopharyngeal status preoperatively (r = 0.47, p > 0.05), at post1 (r = 0.21, p > 0.05) or post2 (r = 0.54, p > 0.05). The resonance changes of patients were categorized as ‘no change’, ‘deteriorated’

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Table 5. Amount of advancement, hypernasality and nasal emission. Hypernasality Patient

Nasalance

Nasal emission

Amount of advancement (mm)

Pre

Post1

4 5 4 8 4 8.5 6.5 6 9 4 6

0 0 0 0 0 0 0 0 0 0 0

0 0 0 1 0 1 1 0 1 0 1

0 0 0 1 0 1 0 0 1 0 1

0 0 0 0 0 1 0 0 0 0 0

1 0 0 0 0 1 0 0 0 0 0

1 0 0 0 0 1 0 1 0 0 0

1 1 0 0 0 0 0 0 0 0 0

1 1 1 0 0 0 0 0 0 0 0

1 1 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0

0 1 0 0 0 0 0 0 0 0 0

CO group C1 C2 C3 C6 C7 C9 C11 C12 C15 C18 C21 DO group D3 D4 D5 D6* D7* D11 D12 D13 D14 D15 D17

4 7 7 5 5 7 6 6 4 6 10

Post2

Pre

Post1

Post2

Hypernasality rating: 0 = no hypernasality, 1 = mild hypernasality; Nasal emission rating: 0 = absent, 1 = present. Note: only one patient exhibited hyponasality. This patient is discussed in the text. * Patient with superior based (Hogan’s) pharyngoplasty.

or ‘improved’. There were no statistically significant differences between the CO and DO groups that showed improved, deteriorated and no change, at post1 p > 0.05) and post2 (x2 = 2.2, (x2 = 0.39, p > 0.05).

patients who had nasal emission changes after maxillary advancement between CO and DO (post1, x2 = 2.20, p > 0.05; post2, x2 = 0.37, p > 0.05).

Table 6. Amount of advancement and nasalance scores. Patients

Nasal emission

In the assessment of nasal emission, there was total (100%) agreement between the 2 assessors on the 66 samples from 22 subjects. In the CO group, one patient (C9) had nasal emission preoperatively (Table 5). The nasal emission of this patient, who had advancement of 8.5 mm, was still present during the assessment at post1 and post2. Another patient (C1) developed nasal emission after an advancement of 4.0 mm at post1and there was no improvement at post2. One further patient (C12) only presented with nasal emission at post2 after an advancement of 6.0 mm. The presence of nasal emission was not detected at post1. In the DO group, one patient (D4) with maxillary advancement of 7.0 mm had nasal emission at post2. There was no significant correlation between the amount of advancement and nasal emission (post1, r = 0.04, p > 0.05; post2, r = 0.10, p > 0.05). There were no significant differences in the number of

Twenty patients had complete preoperative and postoperative data (Table 6) and their findings are summarized below. The mean nasalance scores of the CO and DO groups preoperatively were 16.99 and 21.50, respectively. A two-way mixed ANOVA, where group (DO vs. CO) was the first factor (between-group) and time (preoperative vs. post1 vs. post2) was the second factor (within-group), was performed. There was no statistically significant difference in the mean nasalance scores between the two groups (F = 0.450, p = 0.811). Pearson’s correlation showed that there was no significant correlation between the amount of advancement and the nasalance scores at post1 (r = 292, p > 0.05) and post2 (r = 0.083, p > 0.05). Pearson’s correlation also showed that there was no significant correlation between nasalance score and velopharyngeal status at post1 (r = 0.002, p > 0.05) and post2 (r = 0.01, p > 0.05). There was no significant correlation between nasalance score and hypernasality preoperatively (r = 0.16, p > 0.05) and at post1 (r = 0.19, p > 0.05) and post2 (r = 0.37, p > 0.05). Patients were classified into those who ‘deteriorated’, ‘improved’ or had ‘no change’. A x2 test showed no significant difference between number of patients who showed ‘improvement’, ‘deterioration’ and ‘no change’ of

CO group C1 C11 C3 C7 C9 C12 C15 C21 C18 C22

DO group D3 D4 D5 D6* D7* D11 D12 D13 D14 D17 *

Advancement (mm)

Pre-op

Post1

Post2

4 6.5 4 4 8.5 6 9 6 4 10

27.28 11.06 16.79 18.44 16.82 5.04 16.96 23.53 9.76 24.21

16.57 20.87 8.20 22.47 31.99 17.30 48.84 4.38 14.08 5.23

61.14 14.42 40.40 11.68 32.20 10.67 16.17 30.73 17.73 20.74

Mean score

16.99

18.99

25.59

7 5 6 4 5 4 7 6 7 10

18.09 7.40 43.25 11.62 6.98 47.90 14.76 10.38 5.77 48.87

18.54 13.11 14.85 10.45 6.46 41.41 32.88 8.99 11.84 29.44

19.43 22.97 2.59 14.92 5.35 42.65 45.36 4.36 8.21 32.95

Mean score

21.50

18.80

19.88

Patient with superior based (Hogan’s) pharyngoplasty.

Maxillary distraction versus orthognathic surgery in cleft lip and palate patients velopharyngeal status between the two types of surgery (post1, x2 = 2.40, p > 0.05; post2, x2 = 3.09, p > 0.05). There were no significant differences in the nasalance status (above 30% vs. below 30%) preoperatively, at post1 and post2 in both the CO and DO groups (p > 0.05 for all). There were no adverse events recorded from the above intervention or assessment. Discussion

The effect of maxillary advancement on speech and VF remains controversial, particularly in CLP patients. Several reports have concluded that maxillary advancement has no real adverse effect on the speech of CLP patients13. Others have reported deterioration in velopharyngeal closure and speech after maxillary advancement12. Some studies suggested an association between the amounts of forward advancement and changes in speech outcomes. The cut-off points for CO before any changes in speech occur was variable and were reported as 1016, 158 and 18–20 mm17. Schwarz and Gruner17 found evidence to suggest that, with increasing maxillary advancement, VF was negatively correlated. The range of maxillary advancement in their study was 18–20 mm. Okasaki et al.16 reported a similar finding, although the range of maxillary advancement was smaller (5– 10 mm). They found that two patients with maxillary advancement of 10 mm developed more severe hypernasality. McCarthy et al.14 and Watzke et al.22 found no difference between patients who had maxillary advancement of less than 10 mm and those with greater than 10 mm. In this study, of 11 patients who received CO, 2 patients developed deterioration in their VF even with an advancement of only 4.0 mm. Both changed from complete closure to borderline touch closure. In the analysis of the nasalance scores, four patients showed an increase in their nasalance scores to above the normal limits postoperatively. When patients who developed deterioration in their VF and those who had an increase in their nasalance were compared, only one patient developed both conditions. This patient had only 4 mm of maxillary advancement. The reason for deterioration in VF and nasalance in such a small advancement remains unclear. In the DO group, two patients (D3, D7) developed deterioration in their VF after advancements of 4.0 and 5.0 mm, respectively.

Both patients, with complete closure preoperatively and at post1 changed to borderline touch closure at post2. Both had nasalance scores below 30%. Another patient (D20), who had an advancement of 6 mm had complete closure preoperatively, deteriorated to touch closure at post1 and returned to having complete closure at post2. In this study, most patients (20 of 22) had normal resonance preoperatively. Four patients in the CO group developed mild hypernasality at post1 and their status remained the same at post2. In the DO group, patients who presented with hypernasality preoperatively (D3, D4) had the same status at post1 and post2. One patient with normal resonance developed hypernasality at post1, but returned to normal resonance at post2. Only one patient from the CO group (C9) had nasal emission preoperatively, which was still present at post2. Two more patients (C1, C12) developed nasal emission postoperatively (post2). One started at post1 and the other patient only had nasal emission at post2. There was no correlation between nasalance and change in resonance in this study. This could have been due to a ‘floor’ effect as most patients had normal nasalance preoperatively. These findings support the conclusion of Nellis et al.15 that the correlation between nasalance scores and judges’ ratings of hypernasality was not statistically significant. A weak correlation could be found in some studies, such as in a group of 43 Dutch patients with VPI reported by Keuning et al.11 Another factor to consider is the presurgical nasality and velopharyngeal status. Several authors, including Witzel and Munro25 and Janulewicz et al.10 concluded that in CLP patients, preoperative hypernasality and borderline VF are risk factors for deterioration in function after surgery. In the present study, patients who presented with a pre-existing borderline touch closure either had improvement in their VF or maintained the same status. None of the patients with borderline touch closure deteriorated after maxillary advancement. The preliminary results from the authors’ centre reported by Chanchareonsook et al.2 showed that there were no significant differences between patients who received maxillary advancement by conventional Le Fort I osteotomy and DO. The outcome measures were the same as those in the current study: velopharyngeal gap size, hypernasality, nasal emission and nasalance.

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This randomized controlled trial has shown that adaptation of the velopharyngeal mechanism after CO and DO is an individual response and is very variable. Owing to its unpredictability, it is the authors’ view that all CLP patients being considered for maxillary advancement by either CO or DO should be counselled preoperatively about the risks and benefits to speech and VF changes. A general conclusion, based on the results of this study, is that DO has no advantage over CO for the purpose of preventing VPI and speech disturbance in moderate cleft maxillary advancement. Funding

This clinical study was supported by a Competitive Earmarked Research Grant from the Hong Kong Research Grant Council (Reference code: HKU 7577/05 M). Competing interests

Nil. Ethical approval

Ethical approval was given by the Ethics committee of the Faculty of Dentistry, The University of Hong Kong (Ref.1/8/12d). Acknowledgements. The authors would like to acknowledge the contributions of Dr. Joyce Chun, who assisted with speech data collection and analysis; Mr. Sam Hui, who performed all the data transfer; Ms. Vicki Yip for her assistance with the illustrations and Mr. Shadow Yeung, who provided statistical assistance. References 1. Chanchareonsook N, Samman N, Whitehill T. The effect of cranio-maxillofacial osteotomies and distraction osteogenesis on speech and velopharyngeal status: a critical review. Cleft Palate Craniofac J 2006: 43: 477–487. 2. Chanchareonsook N, Whitehill TL, Samman N. Speech outcome and velopharyngeal function in cleft palate: comparison of Le Fort I maxillary osteotomy and distraction osteogenesis – early results. Cleft Palate Craniofac J 2007: 44: 23–32. 3. Cheung LK, Chua HDP. A meta-analysis of cleft maxillary osteotomy and distraction osteogenesis. Int J Oral Maxillofac Surg 2005: 35: 14–24. 4. Cheung LK, Chua HDP, Hagg MB. Cleft maxillary distraction versus orthognathic surgery: clinical morbidities and surgical relapse. Plast Reconstr Surg 2006: 118: 996–1008.

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