Optimal Age for Palatoplasty to Facilitate Normal Speech Development: What Is the Evidence?

Fig. 37.1

Vocabulary development within the first 3 years of life. The number of words used at 10–12 months of age is not “0” but usually 2–10 words. By 18 months, most children have at least 50 words, and in the next 6 months that number quadruples to 200. By the age of 3 years, most normal children have speaking vocabularies of about 1,000 words

37.3 What Constitutes Scientific Evidence in Clinical Research?

The strongest evidence that a particular treatment protocol is better than another comes from prospective clinical trials that include study not only of the “treatment group” but of a carefully matched control group over the same period of time (American Speech-Language-Hearing 2003; Friedman et al. 1996). Prospective studies with a study group and a control group are also termed “cohort studies” (Wissow and Pascoe 1990). This is in contrast to “case control studies,” which are usually retrospective in that they compare current cases with controls from the past (perhaps consisting of untreated cases or cases treated by an older method). Prospective clinical trials are the most difficult to execute. In fact, Wissow and Pascoe (Wissow and Pascoe 1990, p. 63) warned,

Clinical trials are poorly suited to studies of (1) multiple therapeutic modalities (because too many subjects are needed to evaluate the many possible therapeutic combinations); (2) small changes in a therapeutic plan (the effort it takes to do the study may outweigh the potential significance of the outcome); (3) therapies that may be changed during the course of the study so that the results are at risk for becoming obsolete before the study is completed; and (4) treatments with only rare outcomes or outcomes that will be observable at a time far distance in the future.
Note how strongly # 1, 2, 3, and the second half of #4 pertain to the study of the best timing for palatoplasty.
Shprintzen (1991) made several observations that should be kept in mind by anyone engaged in clinical research and certainly by those who would study the question of the optimum timing of palatoplasty. He pointed out that most research is guided by a specific motive, usually a vested interest of the investigator, meaning the individual has an a priori bias regarding the outcome. With regard to sample selection, he pointed out the necessity of acknowledging the heterogeneous etiology of clefting and the influence this variation may have on development. He stated (p. 137), “…if a unilateral cleft lip and palate occurs because of an intrinsic hypoplasia of one maxillary process, it would be anticipated that the intrinsic hypoplasia would remain a factor throughout postnatal growth….If a major source of variability [in post-surgical growth] is intrinsic differences in facial growth potential related to population heterogeneity, then the subject population must be made as homogeneous as possible.” He observed that, while investigators may have tried to eliminate all syndromic cases in their studies of this issue, none of the studies published up to the date of his commentary had held constant all the variables that could influence treatment outcome. At the same time, he warned (p. 138), “Holding all variables constant in patients with multiple problems is not only difficult, but the ethics of withholding treatment for the purposes of determining research outcome might have some difficulty passing an Institutional Review Board.”
Table 37.1 rank-orders research designs by the strength of the evidence they can provide. In a simpler form, we may segregate the aspects of research design that weaken a study’s conclusions versus those that lead to stronger supportive evidence for a particular treatment approach into “undesirable” versus “desirable”:

Undesirable
Desirable
Investigator undertakes the study to prove that his treatment protocol is better than another
Investigator has no prior bias as to outcome of the study
Results recoded only by the investigator without independent observations by unbiased judges
Unbiased observers/recorders of results
Single recorder/observer
Multiple independent observers/recorders, with measurement of intra- and inter-observer reliability
One-time assessment of results
Longitudinal observation of results
Retrospective review of records
Prospective study
Single group of patients, treated according to one protocol, no control group
Cohort studies, comparing two or more groups of homogeneous patients, one treated according to the protocol under study, the other untreated or treated by a standard, accepted protocol
No attempt to control for the multiple variables that may influence results
Control, or at least careful independent documentation, of all variables (e.g., absence of associated anomalies, type and extent of cleft, health history, ear disease and hearing loss, socioeconomic factors including parental nurturing and stimulation)
Table 37.1

Levels of evidence in clinical practice, ranked from weakest to strongest and what each type of evidence would require in a study attempting to relate age of palatoplasty to speech outcome
Source of evidence
What is involved
What would add strength to the evidence
Comments regarding the value of this form of evidence
A. “Expert opinion” or “clinical insight”
Minimally, one person’s opinion on what works best
Agreement by other “experts,” each with appropriate experience
Relatively easy to find; most vulnerable to dispute
aB. Retrospective case studies; all information taken from archived records (with or without historical controls)
Independent non-biased personnel who examine a pre-determined set of data recorded in a uniform format
Demonstration of intra- and interclinician reliability; historical controls would be patients with the same types and extents of clefts, non-syndromic, treated by some other surgical protocol
Probably the most common source of data on this question; subject to bias, especially if one or more of the investigators has a predetermined opinion; most difficult aspect is controlling for the myriad independent variables (e.g., hearing loss, overall health, socioeconomic factors, etc.) that affect outcome
aC. Retrospective case studies (archived ­information) combined with current clinical assessments
As in (B), above, plus current assessment of outcomes by independent, non-biased personnel using the same assessment protocol with all patients
Demonstration of intra- and interclinician reliability; control group(s) treated by other surgical protocols
Case histories  +  clinical assessments are very common, but, as in (B) above, investigator bias is frequently built into the research and control of independent variables is difficult
aD. Cohort studies (retrospective)
Investigator pairs each patient treated by Method X with a patient treated by Method Y. Each of the pair must match for the independent variables that could influence outcome
Demonstration of intra- and inter-clinician reliability; the larger the number of patients in each treatment group, and the longer the period of observation, the stronger the evidence
Currently a favored approach in studying this question, but extremely difficult to control for all the independent variables
aE. Cohort studies (prospective)
Investigator establishes the matched groups of patients before any treatment is rendered
Strength of study depends upon the investigator’s ability to hold everything constant for each pair in the matched groups except for outcome; longitudinal follow-up of outcome strengthens the study
Very difficult to execute due to demands of matching patients on all independent variables; also, in longitudinal studies, patient populations change over time (growth, health factors, ­relocation, etc.)
aF. Prospective randomized trials
Investigator randomly assigns treatment protocols (i.e., X, Y, Z) to patients who are matched for type and extent of cleft, age, sex, other health factors (ear disease, etc.)
As in (E), above
Randomizing treatments raises serious ethical issues; patient consent is a must. Hospital IRB approval difficult to obtain. Strongest level of evidence, but rarely achieved
Designs “B” through “F” would require IRB (Institutional Review Board) review. Please see comments regarding HIPAA (the Health Insurance and Accountability Act of 1996) following this table
aThe HIPAA (Health Insurance and Accountability Act of 1996) prohibits research personnel in health-care facilities from combing patient records unless permission has been granted by the patients themselves. The only person who can recruit the patients is the physician (clinician) who provided the care to the patient. This has an obvious impact in cleft palate/craniofacial care, where the preferred approach to care is through a multidisciplinary team (American Cleft Palate-Craniofacial Association 2000) and not by a single health-care professional. Historically, permission for examination of records or the sharing of information from patient records has not usually been obtained in the form currently required by HIPAA, rendering most retrospective studies impossible if they must meet HIPAA requirements. Information on HIPAA is available on the web at: www.hhs.gov/ocr/hipaa/
The summary to both Table 37.1 and the comments above might be “If you want to prove that a given surgical protocol produces better speech results in nonsyndromic children with clefts, you need to plan a prospective, randomized study with matched controls; two or more surgeons performing the same procedure (to prove that it is not the surgeon’s technique that is making the difference); all independent variables matched across patient pairs; large numbers of patients in each treatment group; results recorded by independent observers on standardized forms (not just anecdotal comments) and recorded over time rather than in a single post-treatment observation.”
Obviously, this description is one of a utopia that one can only keep in vision, not plan on reaching. The clinical researcher is therefore charged with the task of trying to come as close to this as possible and being very careful in the interpretation of the results, taking into account all the factors that could not be controlled.

37.4 A General Warning: “A” Does Not Cause “B”

Because we clinicians are so anxious to answer the question that is the focus of this chapter, we are very prone to jump to conclusions about cause and effect. The most common trap is assuming that because “B” is strongly associated with “A,” even if “B” always follows “A,” that “A” causes “B.” Friedman et al. (1996) termed this “causal inference.” A widely used analogy points out that Tuesday always follows Monday, but does that mean Monday causes Tuesday? Even if we were to see that maxillary arch collapse is present in 100 % of children with cleft lip and palate following palatoplasty at 12 months of age, that does not mean that either the palatoplasty technique or the age at palatoplasty caused the arch collapse.2 Cleft palate is not just a rearrangement or “disarrangement” of structures, but an inherent deficiency of tissue. The mere performance of palatoplasty, the particular surgical procedure employed, or the age at which it is performed thus cannot be blamed for subsequent arch ­collapse. On the other side of the argument, none of these three factors alone or in concert can be held responsible for either normal or abnormal subsequent development of communication development. If we were to segregate the physical variables from the nonphysical variables that determine outcome from palatoplasty, we would be looking at the following:

Physical factors
Nonphysical factors
Type and extent of original cleft
Developmental level (chronological age compared to cognitive and communication development)
Presence/absence of associated anomalies, syndromes, etc.
Parent-infant bonding, parental stimulation
Overall health history (particularly with regard to infant feeding and otologic health)
Other psychosocial issues affecting the family
Adequacy of pediatric care both before and after surgery
Adequacy of relationship between surgeon (or team) and the family both before and after surgery

37.5 An Updated Review of the Literature

The main points made in the review of 2004 (Peterson-Falzone 1996) were as follows:

1.

There was a very wide range in what clinicians considered to be “early” palatal surgery, e.g., the first 28 days of life (Denk and Magee 1996; Sandberg et al. 2002), 9–25 weeks (Copeland 1990), and up to 2–3 years (Koberg and Koblin 1973).
 
2.

Judgment as to whether or not palatoplasty had in fact provided an intact palate often consisted of only visual observation of the oral cavity3 (and sometimes only on a one-time basis), sometimes combined with rather pathetic “objective” measures, e.g., fogging on a mirror held beneath the child’s nose during speech (Blijdorp and Muller 1984). At the other end of the continuum, many studies combined comparatively rigorous perceptual data with a full armamentarium of instrumental assessments.
 
3.

The increased knowledge gained in the 1980s and 1990s regarding the effects of early structural constraints on pre-speech vocalizations and on later speech development in children with clefts could constitute a very good reason to perform palatal closure early, e.g., before the child reaches the milestone of producing his first meaningful words (Chapman 2011; Chapman et al. 2008; Estrem and Broen 1989; Grunwell and Russell 1987, 1988; Jones et al. 2003; O’Gara and Logemann 1988; O’Gara et al. 1994). Chapman (1991) found, as had previous researchers, that the process of phonologic acquisition in youngsters with clefts was “…slower, perhaps due to lingering or past articulatory and/or structural constraints on the speech mechanism.”
What Is New Relative to This Point: The closer we look at the effects of early structural constraints on communication development, the more trouble we find. For example, Chapman (1993) found that school-age children with repaired clefts who had persistent speech and language problems were also more likely to have reading problems in comparison to children with clefts whose speech and language skills were within normal limits. Of course, we have long known that children and adults with clefts are at increased risk for reading problems and other learning disabilities [please see ­Peterson-Falzone et al. (2010, pp. 380–384)].
A 2006 study on infant vocalizations (Thom et al. 2006) provided acoustic and nasal pressure data showing that normal infants show gradual acquisition of velopharyngeal closure in their syllable utterances in the first 6 months of life. This process is not complete by the age of 6 months but is well under way. The authors conjectured that knowledge of this developmental process might help determine optimal timing for palate repair. These results fit in well with the theoretical framework proposed by Kemp-Fincham et al. (1990). The latter authors, reviewing the literature on the ­development of speech motor control and phonetic development in infants, concluded that there is a particularly sensitive period or state of readiness between the ages of 4 and 6 months. Perhaps palatal closure before or during this time frame is important if we are to avoid the development of the maladaptive compensatory articulations that are so deleterious to speech intelligibility.
A 2008 study by Scherer and colleagues (2008) gave further validation to previous studies demonstrating the effects of early structural constraints (open clefts) on babbling at 12 months and subsequent size of consonant inventory when the children became toddlers. These authors found persistent vocalization and vocabulary deficits well beyond the time of palate closure, which in this study was 11–12 months. Note that this age is well within the time frame for ­palatal closure suggested by the American Cleft Palate-Craniofacial Association (2009). In comparison to a matched group of children without clefts, the children with clefts showed significant differences in frequency of babbling and “mean babbling level” at 12 months and deficits in speech sound accuracy and vocabulary production at 30 months of age. Scherer and colleagues (2008) recommended early intervention programs for babies with clefts to enhance speech and language development in babies with clefts.
 
4.

A much-cited earlier claim by Dorf and Curtin (1982, 1990) that the chronological age of 12 months for completion of palatal closure was a cutoff line for preventing the development of maladaptive compensatory misarticulations in children with clefts was not supported by subsequent studies (Dalston 1992; Peterson-Falzone 1990) in which an attempt was made to verify that cutoff age. In addition, Dalston (1992) and Peterson-Falzone (1990) pointed out the critical information, such as age at the time of assessment, that was missing from the Dorf and Curtin publications. Unfortunately, 12 months is still often cited as a magical goal line for the performance of palatoplasty, ignoring problems in the methodology of Dorf and Curtin.
 
5.

Despite the fact that their results could not be replicated in subsequent studies, Dorf and Curtin (1982) had made one very important point that was largely ignored by other ­investigators, namely, that the child’s “articulation age” (level of phonologic and phonemic development), not his chronologic age, should be a prime consideration when trying to plan the best timing for surgery. That is, speech and language development vary among children: Some are attempting to produce 10–12 meaningful words at that age, while others are just beginning to use “mama.” The more sounds and words the child is trying to produce, the more urgent the need for an intact palate and velopharyngeal system.
What Is New Relative to This Point: In a 2008 publication by Chapman and colleagues (2008), the authors tracked speech outcome in two matched groups of children with nonsyndromic clefts. One group was less lexically advanced (meaning that they were using fewer than five words) and younger (mean age of 11 months) when palate surgery was done. The second group was more lexically advanced (using five or more words) and a little older (mean age of 15 months) at the time of surgery. The children were assessed for 11 speech outcome measures between the ages of 33 and 42 months. The children in the first group had better articulation and less hypernasality than the children in the second group.
The authors pointed out that lexical difference between the two groups at the time of surgery would be expected because expressive vocabulary increases with age. They also pointed out that the children who were older and had larger vocabularies prior to surgery did not produce maladaptive compensatory misarticulations at a greater rate than children who were younger and had less advanced vocabularies; they simply exhibited poorer speech in general (Chapman and Hardin 1992). The authors did not have an explanation for the results, but suggested that future studies should compare children undergoing surgery by 6 months of age or prior to onset of babbling with children receiving surgery at approximately 12 months.
Interestingly, they did not specifically cite the results of Ysunza et al. (1988) who compared speech outcomes between groups of children operated at these exact ages.
 
6.

Clinical surveys in the 1960s, 1970s, 1980s, and 1990s awakened us to the fact that associated anomalies, sequences, associations, and syndromes were probably affecting development in at least 50 % of children with clefts (Jones 1988; Shprintzen et al. 1985a, b; Womersley and Stone 1987). It is very easy for anyone other than an experienced dysmorphologist to miss subtle signs of other congenital defects in children with clefts. Furthermore, it is easy to miss signs of cognitive delays, hearing loss, and other threats to development, particularly if a child is not evaluated by an interdisciplinary team. Mixing surgical results from normally developing children with results from syndromic, multiply involved, or cognitively delayed children seriously impairs our ability to make decisions about the effects of any specific treatment.
 
7.

Studies published during the 1990s on the ostensible relationship between timing of palatal surgery and subsequent speech development tended to support performance of surgery in the first 12–18 months of life, the exception to this general trend being the studies on primary veloplasty (reviewed in Sect. 37.6).4

(a) 

Although their report was entitled “Correlation Between the Age at Repair and Speech Outcomes in Patients with Isolated Cleft Palate,” Haapanen and Rantala (1992) did little to clarify the ­‑age-at-surgery ­question because they had only small, uneven numbers of subjects; none were operated before the age of 1 year; and speech results consisted only of general categorizations based on one-time perceptual judgments without independent or objective documentation. These authors reported better speech in children whose palates had been closed between the ages of 16 and 20 months, as opposed to those whose surgeries had taken place either earlier (12–15 months) or later (21–24 months). They came to this conclusion because none of the children in the middle group (16–20 months at closure) had developed compensatory articulations. However, the number of children in this group was less than half the number in each of the other two groups. This fact, plus the one-time-only assessment with no longitudinal data, rendered the conclusion tenuous at best.
 
(b) 

Marrinan et al. (1998) segregated 228 patients with four types of clefts (soft palate only, clefts of the hard and soft palate, unilateral cleft lip and palate, bilateral cleft lip and palate) into four groups based on age at closure: 8–10, 11–13, 14–16, and over 16 months. They found that secondary management for postoperative velopharyngeal inadequacy was necessary in 11 % of the 8–10 month group, 14 % of the 11–13 month group, 19 % of the 14–16 month group, and 32 % of the 16+ month group. This linear relationship between age at palate repair and need for a pharyngeal flap was reported to be statistically significant at the p  =  0.025 level. The likelihood of need for a pharyngeal flap was much greater in those children with clefts of the hard and soft palate (no lip cleft) or BCLP in comparison to those with clefts of the soft palate only or UCLP. In fact, in the latter two groups, age at palate repair was not statistically significant (ranging from 10 % need for pharyngeal flaps in the earliest repair up to 18 % in those repaired over the age of 16 months). The authors attributed this difference to the size of the cleft, since the vomer bone was attached in these two groups, whereas the need for secondary surgery in children with an unattached vomer (complete clefts of hard and soft palate or bilateral clefts) ranged from 12 % in the earliest repair group up to 50 % in those repaired over the age of 16 months.
 
(c) 

Ysunza et al. (1988) compared speech results in one group of children (N  =  41) whose clefts were closed at 12 months of age to another group (N  =  35) who were operated on at 6 months. This was a multifaceted study in which the postoperative evaluations included standardized perceptual evaluation of speech, videofluoroscopy, and nasopharyngoscopy. Somewhat surprisingly, early phonologic development was significantly better in the second group than in the first. In addition, none of the 6-month group showed subsequent development of maladaptive compensatory articulations, even though 6/35 (17 %) of them showed evidence of postoperative velopharyngeal inadequacy. By contrast, in the 8/41 (19 %) of the 12-month group that had VPI, 5 of these (62 %) developed compensatory articulations. There was no difference between the two groups in terms of degree of maxillary collapse when the patients were examined at 4 years of age. None had had either preoperative or postoperative orthopedic treatment. The authors concluded (p. 678), “Because maxillofacial growth was not significantly different in [the two] groups of patients, it seems that cleft palate closure at 6 months of age is a safe and reliable procedure for correcting velopharyngeal function in cleft palate patients.”
It is interesting that Ysunza et al. (1988), using a full range of perceptual and objective tests, found a significant difference between children whose palates were repaired at 6 months of age and those repaired at 12 months.5 As pointed out in ­Peterson-Falzone et al. (2001, 2010), these results may speak to the value of the theoretical framework proposed by Kemp-Fincham et al. in 1990 (Kemp-Fincham et al. 1990).
 
(d) 

A few surgeons in the 1990s were performing very early palatal closure (often simultaneous with lip closure) in the first weeks of life (Copeland 1990; Denk and Magee 1996; Sandberg et al. 2002). However, despite the fact that these papers were published 22 and 16 years ago, respectively, there have been no data on speech development in the babies so treated, nor has there been any independent substantiation of any of the early physical results of the surgery. Thus, these publications still constitute studies without results.
 
 

37.6 Primary Veloplasty: A Solution or a Problem?

Two-stage closure of the palate, with soft palate closure (often combined with lip closure) taking place in the first few months of life and closure of the hard palate delayed for variable periods of time (often until age 7 or beyond), continues to be the preferred treatment plan in many treatment centers. Those who prefer this approach state that closure of the lip and velum promotes a decrease in size of the hard palate cleft, making it easier to close at a later date with a less traumatic effect on the growing maxilla than would be the case with a complete surgical closure of the hard and soft palate in a single procedure. The timing of both the primary veloplasty and the later closure of the residual hard palate cleft has varied greatly both among treatment centers and in single centers that have changed their treatment regimen over time. Age at the time of soft palate closure has ranged from the first few weeks of life, 3, 6–8, 12–18 months, and up to the late age of 2 years and 6 months; age for closure of the hard palate has run the gamut from 12 months up to an extreme of 11–13 years (Bardach et al. 1984; Cosman and Falk 1980; DeLuke et al. 1997; Dingman and Argenta 1985; Friede et al. 1980, 1991; Greminger 1981; Harding and Campbell 1989; Hotz et al. 1978; Jackson et al. 1983; Kramer et al. 1996; Lohmander-Agerskov 1998; Lohmander-Agerskov and Soderpalm 1993; Lohmander-Agerskov et al. 1993, 1994, 1995, 1996a, b, 1997, 1998; Meijer and Cohen 1990; Noordhoff et al. 1987; Noverraz et al. 1993; Poupard et al. 1983; Rohrich and Gosman 2004; Schweckendiek and Kruse 1990; Tanino et al. 1997; Van Demark et al. 1989; Vedung 1995; Wu et al. 1988).6 7
In addition to the variability in timing and techniques of eventual hard palate closure in the regimen of primary veloplasty, interpretation of results of many clinical studies was complicated by (1) use of infant orthopedics in some clinic populations, primarily in Europe (Gnoinski 1982; Hotz et al. 1978, 1984; Hotz and Gnoinski 1979; Konst et al. 1999, 2000, 2003a, b, c, 2004), and by (2) sporadic, inconsistent use of obturating plates while the hard palate remained open. In fact, in reviewing these studies, it is very difficult to differentiate the information given about infant obturating plates from that pertaining to infant presurgical orthopedics. For example, in the patient population of Hotz et al. (1979, 1984

Only gold members can continue reading. Log In or Register to continue

Oct 18, 2015 | Posted by in General Dentistry | Comments Off on Optimal Age for Palatoplasty to Facilitate Normal Speech Development: What Is the Evidence?
Premium Wordpress Themes by UFO Themes