Cleft Lip and Palate - part 10 pot

The decision for prosthetic rehabilitation is made based on the individual patients’needs,motivation for improvement, and availability of the suggested reha- bilitative program. Approximately 50% of all patients with cleft lip and palate will need some type of fixed or removable prosthesis by 30years of age. As our knowledge and experience in the cleft palate field increased, those of us responsible for providing prosthetic care recognized the importance of estab- lishing a better prosthodontic concept and principles regarding treatment. In rendering these patients the best service, we should first follow all the rules and principles governing the fixed and removable partial denture prosthesis and, secondly, should remove any fear of causing harm because of existing anatomic, functional, and physiologic deviation. 720 M. Mazaheri Fig. 38.1. Designs by Fauchard showing early obturators employed for palatal de- fects. (From [26]. Reprinted in [27]) 38.1 Diagnosis and Treatment Planning In treating people whose oral-facial handicaps affect speech,the best results are achieved when the diagnosis and treatment are carried out by a group of clini- cians who represent the various interested specialities and work together as a team rather than independent- ly performing a series of procedures. In diagnosis and treatment planning,full consideration should be given to: (1) the type and width of the cleft, (2) the position and relation of the maxillary segments to each other in unilateral and bilateral clefts, (3) the form and lateral and anteroposterior dimensions of the maxillary arch, (4) the length, thickness, and mobility of the soft palate, (5) the perforations remaining in the hard and soft palate area and labial sulcus after surgery, (6) the posterior and lateral pharyngeal wall movement and the size of the nasopharynx, (7) a loose premaxilla, (8) the number of missing teeth, (9) malformed and malposed teeth, (10) partially erupted teeth, (11) teeth in the line of the cleft, (12) constricted maxillae, (13) the condition of the tonsils and adenoids, and (14) growth and development of the child. The patient’s articulation, voice quality, hearing acuity, mental attitude, and general health also must be considered. Socially acceptable speech cannot be produced without proper velopharyngeal valving. Therefore, surgical closure of the palate without due consideration of the depth of the nasopharynx and the length and function of the velum during phonation cannot satisfy this objective. Better understanding of the na- ture of the cleft, anatomy, and the physiology of the area involved would eliminate many of these difficul- ties. The results of surgical treatment of cleft palates should be evaluated with the aid of cineradiographic studies, nasal endoscopy, serial cephalometrics, maxillary and mandibular casts, speech recordings made before and after surgery, sound spectrographic analysis, measurements of nasal and oral air pressure and flow, and speech and audiometric evaluations. All members of the team should be thoroughly familiar with the problem at hand. Often the best result is not achieved when the knowledge of the specialists is not all-encompassing [2]. The total habilitation and rehabilitation in the field of oral,facial,and speech impairment is achieved only when the following objectives are kept in mind: (l) socially acceptable speech, (2) restoration of the masti- cating apparatus, (3) aesthetic facial and dental har- mony, and (4) psychologic adjustment of the patient to the condition. Use of a speech appliance simply as a last resort is poor procedure. Its use must be clearly indicated by the oral conditions. For example, the indications for a prosthesis are clearly defined for a patient who has undergone a series of unsuccessful palatal operations. There is no magic in a prosthetic speech aid. Howev- er, there are some patients for whom a prosthesis seems to be the only means of improving speech. In such situations it fills a definite need. A prosthetic speech aid should be used for palatal conditions where it is indicated,just as the pharyngeal flap operation should be used only where it is indicated. 38.2 Treatment Planning Treatment programs for cleft palate patients require careful planning and should include all factors involved in total health care. The interest of the dentist and physician in craniofacial growth and behavior of soft and hard tissues, both before and after surgery, has increased cooperation between surgeons and den- tists.As a result,a dental specialist has the opportunity to examine the cleft palate child, with the surgeon, before any surgery is undertaken.Analysis of longitudinal maxillary and mandibular casts, cephalometrics, and radiographs has shown that two major factors cause growth disturbances of oral-facial regions in individuals with clefts: first, the inherent potential for growth disturbance present among cleft palate patients and, second, the trauma caused by surgical and orthopedic intervention. Because the first factor can be neither predicted nor reduced, efforts have been directed toward minimizing growth disturbance by performing surgery with the least amount of trauma and scar tissue.Longitudinal data obtained during the past 4 years regarding the surgical closure of the cleft with minimum amount of scar tissue and trauma are very encouraging [17]. 38.3 Requirements of a Speech Appliance 1. The prosthesis must be designed for the individual patient in relation to his oral and facial bal- ance, masticatory function, and speech. 2. Knowledge related to removable partial and complete dentures should be used in designing the maxillary part of the cleft palate prosthesis. Preservation of remaining dentition and sur- rounding soft and hard tissue in cleft palate patients is of utmost importance. Improperly designed cleft palate appliances can result in premature loss of both hard and soft tissue, further complicating prosthetic habilitation. 3. The prosthetic speech appliance should have more retention and support than most other restorations. The crowning and splinting of the abutment teeth in adult patients may increase re- Chapter 38 Prosthetic Speech Appliances for Patients 721 tention and support of the prosthesis and may extend the life expectancy of abutment teeth. 4. Mouth preparations should be completed before making final impressions. In cases where lateral and vertical growth of the maxilla is incomplete and partial eruption of the deciduous and permanent teeth is evident, careful mouth preparations should be made. To provide support of the prosthesis, these preparations may include gingivec- tomies to expose clinical crowns (to make them usable) and the placement of copings on remaining teeth to prevent decalcification and caries. Osseointegrated implants have been a great help in gaining adequate retention for the prosthesis. 5. The weight and size of the prosthetic speech appliance should be kept to a minimum. 6. The materials used should lend themselves easily to repair, extension, and reduction. 7. Soft tissue displacement in the velar and naso- pharyngeal areas by the prosthesis should be avoided. 8. The velar and pharyngeal sections of the prosthesis should never be displaced by movements of the lateral and posterior pharyngeal wall muscles or the tongue during swallowing and speech. 9. The superior portion of the pharyngeal section should be sloped laterally to eliminate the collec- tion of nasal secretions. The inferior portion of the pharyngeal section should be slightly concave to allow freedom of tongue movement. 10. The location and the changes of the speech bulb should include consideration of the following factors: a. The speech bulb should be positioned in the location of greatest posterior and lateral pharyngeal wall activity, because voice quality is judged best when the speech bulb is at these positions. b. The inferior-superior dimension and weight of the speech bulb may be reduced without apparent effect on nasal resonance. (The lateral dimension of the bulb does not change significantly as the position is varied.) (Fig. 38.2) c. The speech bulb should be placed on or above the palatal plane in cases where posterior and lateral pharyngeal wall activities are not present or where visual observation of the bulb is not possible, due to a long, soft palate (Fig. 38.3). d. The anterior tubercle of the atlas bone can be used as a reference point; however, investiga- tion has shown that the relative position of the tubercle of the atlas bone varies in different individuals,and that the positions of the velopharyngeal structures change in relation to the tubercle as the individual moves his or her head. Therefore, the atlas bone is no longer used as the reference point for positioning of the pharyngeal section of the bulb. 38.4 Indications for Prostheses in Unoperated Palates Cleft palate surgery is not a stereotyped exercise, but rather a service that demands an assessment of all factors presented by each patient and a reparative surgical plan based on proven principles. The majority of cleft palates can be reconstructed by surgery, enabling 722 M. Mazaheri Fig. 38.2. As a result of our studies, we have concluded that the inferior-superior dimensions of the speech bulb do not have a significant effect on speech quality as long as the bulb is prop- erly placed to facilitate good velopharyngeal closure. This dimension was reduced to one-quarter of its original size, as shown in cast made during fitting for one patient, without apparent effect on nasal resonance Fig. 38.3. Superimposed tracing of the original speech bulb and various experimental speech bulbs. The palatal plane was used as a plane of reference along with posterior pharyngeal wall activity, muscle bulge, or Passavant’s pad. The posterior nasal spine (PNS), absent in cleft palate subjects, is called posterior palatal point (Ppp) and represents the most posterior point of the remnants of the palatal shelves as shown in the lateral cephalometric film. Median position was judged best the patient to develop acceptable velopharyngeal closure. However, in some situations, a prosthesis is the physical restoration of choice.This decision should be made by the group charged with the habilitation of the cleft palate patient. Many clefts of the hard palate can be closed by a vomer flap [5, 23] and clefts of the soft palate by median suture with good anatomic and functional result. The wide cleft and the short palate demand further attention. Additional length may be gained by a Dor- rance or V-Y type retropositioning operation.The raw nasal surface may be covered with a skin graft, nasal mucosa, or an island flap of palatal mucosa [2, 3, 23]. The incompetent palatopharyngeal valve can be aug- mented by a pharyngeal flap, as either a primary or secondary procedure [24].The need for additional tissue in a wide cleft can be satisfied by single or double regional flaps. Despite the surgical advances available to the cleft palate patient,a need remains for cleft palate prostheses. The prosthodontist can assist both the surgeon and patient,and the mutual understanding among the specialists in a well-organized team is of great benefit to the patient.Some situations indicating a prosthetic approach are discussed in the following paragraphs. 38.4.1 A Wide Cleft with a Deficient Soft Palate Some clefts of this type do not lend themselves to a surgical repair by means of local flaps. A prosthesis is preferable to the more time-consuming remote flaps in these situations.Many patients need a prosthesis to restore missing dental units, and the distant tissue provides only a dynamic mass (Figs. 38.4, 38.5). 38.4.2 A Wide Cleft of the Hard Palate In bilateral clefts, the vomer may be high and the cleft of the hard palate wide, so that a surgical repair may produce a low vaulted palate. It may be possible to close the soft palate with the aid of local flaps, and to restore the hard palate with a prosthesis. A situation similar to that once advocated by Gillies and Fry [4] is created: the primary repair of the velum may create a more favorable spatial arrangement for subsequent surgery on the hard palate. 38.4.3 Neuromuscular Deficiency of the Soft Palate and Pharynx Repair of the palate would not be conducive to the development of good speech. It is difficult to create and maintain a pharyngeal flap large enough to produce competent palatopharyngeal valving without ob- structing the airway in the presence of a neurogenic deficiency of the critical muscles. A pharyngeal flap serves best when surrounded by dynamic muscula- ture. When this situation does not exist, the pharyngeal section of a speech-aid prosthesis may serve better to reduce nasality and nasal emission. The prosthesis can also act as a physical therapy modality, providing a resistive mass for the muscles to act against. Should muscle function improve, definitive surgical measures can then be contemplated. Chapter 38 Prosthetic Speech Appliances for Patients 723 Fig. 38.4. a An edentulous patient with an unoperated cleft of the soft and hard palate that affects the retention and support of the prosthesis.At no time should a patient with a cleft, especial- ly an unoperated cleft, be rendered edentulous. b The completed prosthetic speech appliance in position ab 38.4.4 Delayed Surgery When surgery is delayed for medical reasons,or when the surgeon prefers to repair the palate when the patient is older, the cleft palate may be temporarily closed with a prosthetic speech aid (Fig.38.6). 38.4.5 Expansion Prosthesis to Improve Spatial Relations An expansion prosthesis may be used to restore and maintain more normal spatial relations of the maxillary segments prior to surgery.These segments can be gradually separated by an expansion prosthesis to create a space for the premaxilla or to stabilize the parts in a normal position in association with an au- togenous bone graft. The use of an expansion or repo- sitioning prosthesis, with or without bone grafting, is appropriate for selected cases. In the majority of cleft lip and palate patients, restoration of the anatomic continuity of the labial muscle would mold the segments into acceptable relationships to each other and to the mandible. 38.4.6 Combined Prosthesis and Orthodontic Appliance An orthodontic appliance may be combined with a prosthesis to move malposed teeth into a more favorable alignment.A prosthetic speech appliance,such as the one illustrated in Fig. 38.7, could be designed for a patient receiving full-band orthodontic treatment. 724 M. Mazaheri Fig. 38.5. a Patient at the age of 16 years with a very wide cleft of the soft and hard palate. b Prosthetic speech aid in position. Note that the pharyngeal section of the speech aid is placed directly over the posterior and lateral pharyngeal wall muscle activities. c Oral view of prosthetic speech aid. The utilization of second bicuspids and first and second molars for retention and support will prevent this prosthesis from dislodging into the nasal cavity during swallowing and speaking a c b Chapter 38 Prosthetic Speech Appliances for Patients 725 Fig. 38.6. a A 4 1/2-year-old girl with a rather wide cleft of the soft and hard palate.We elected to fit her with a prosthesis and to delay the palatal surgery until a later age. b The prosthetic speech aid in position. She tolerated the prosthesis, and the speech significantly improved within a 6-month period a b Fig. 38.7 a, b. A temporary prosthetic speech appliance was designed not to interfere with orthodontic treatment while the patient was under active therapy. a View of the palate without prosthesis. b The prosthesis in position. Retention is obtained by placing the retainers above the molar buccal tubes. c View of the prosthesis after 1year of velopharyngeal and lateral pharyngeal wall activity, resulting in acceptable speech. Prosthesis was then discarded a c b 38.5 Indications for a Prosthesis in Operated Palates 38.5.1 Incompetent Palato-pharyngeal Mechanisms If clinical, nasal endoscopic, and cineradiographic analyses suggest that the patient is near a functional closure, a prosthesis may serve as a physical therapy modality. The pharyngeal section of the prosthesis is gradually reduced as muscle function improves, and the prosthesis is eventually discarded. When the patient presents a large velopharyngeal gap associated with a neurogenic deficiency, the speech-aid prosthesis should be considered as a permanent treatment. 38.5.2 Surgical Failures A prosthesis should be considered when a patient presents a low vaulted, heavily scarred, and contract- ed palate, or a palate with large or multiple perforations (Fig. 38.8). Because of the surgical progress in the last 25 years, plastic surgeons today are not con- fronted with many failures in cleft palate surgery. Trained surgeons can now predict with greater accu- racy the possible success of an operation,and are like- ly to avoid failure because other alternatives are available. Approximately 50% of all cleft palate patients will need some type of prosthesis by the age of thirty. 38.6 Contraindications for a Prosthesis 1. Surgical repair is feasible only when surgical closure of the cleft will produce anatomic and functional repair. 2. Patients with mental retardation are not good can- didates for prostheses, because they frequently are not capable of giving the appliance the care it requires. 3. A speech aid is not recommended for an uncooperative patient,or for a child with uncooperative par- ents. 4. If caries are rampant and not controlled, a prosthesis will require unusual care, and frequent exami- nations are important. 5. The edentulous condition is not a contraindication for a speech-aid prosthesis. 6. Because the construction of a functional prosthesis requires the services of a dentist who has had train- ing in cleft palate prosthodontics, it would be better to resort to surgical ingenuity when experi- enced prosthodontic help is not available. 38.7 Constructing Prosthetic Speech Appliances For patients with deciduous, mixed, or permanent dentitions that are not fully erupted,all three sections of the prosthetic speech appliance are made of acrylic resin, and wrought wire retainers are used (Fig. 38.9). In patients whose permanent teeth are fully erupted, the anterior section of the prosthetic speech appliance should be made of cast metal or a combination of cast metal and acrylic resin (Fig. 38.10). 726 M. Mazaheri Fig. 38.8 a, b. Two patients with heavily scarred palates and perforations: surgical failures a b 38.7.1 Preliminary Impression A stock tray of adequate dimensions is selected. If a registration of the entire cleft is desirable, the stock tray is modified with modeling compound extending posteriorly to the postpharyngeal wall. The added section is underextended about 4–5mm in all direc- tions, leaving adequate space for impression material. Fast-setting, irreversible hydrocolloid is used for reg- istering the preliminary impression. The following suggestions should be kept in mind when the preliminary impression is made: 1. If the patient is a child, he or she should be given the opportunity to examine the tray; in some cases the child may be permitted to try the tray in his mouth. Children should be told that their cooperation is needed; otherwise, it will be necessary to make several impressions. Talking to children throughout the procedure is helpful. 2. The patient should have an early morning appoint- ment. 3. The patient should have an empty stomach. 4. A topical anesthetic should be used on a child who has a severe gag reflex. 5. The tray should not be overloaded with impression material. Excess material in the nasopharynx will increase the difficulty of removing the impression without a fracture (see Fig. 38.14). 6. All oral perforations should be packed with gauze that has been saturated with petroleum jelly. 38.7.2 Preparation of the Deciduous Teeth for Retention Most deciduous teeth do not have sufficient undercut for retention of the prosthesis. However, a small amount of bilateral undercut can give adequate retention. The following recommendations will help to produce adequate retention: 1. Carefully extend the clasp arms into interproximal areas of the teeth. 2. Insert, if necessary,serrated platinum pins into the buccal surface of deciduous molars to create an ar- tificial undercut for the clasp. 3. Place bands with soldered retention lugs on the teeth. 4. Use chrome-cobalt crowns with retention lugs for teeth with extensive carious lesions or areas of decalcification. After the clasp design has been determined on the diagnostic casts and the teeth have been prepared for retention,the final impression is made.If adequate retention is not available in the permanent dentition, crowning of the molars might be desirable to provide proper retentive areas (Figs.38.11, 38.12). Chapter 38 Prosthetic Speech Appliances for Patients 727 Fig. 38.9. A temporary acrylic resin speech appliance with wrought wire clasps and full palatal coverage designed for a 4-year-old child Fig. 38.10. A permanent cast gold speech appliance with partial palatal coverage for an adult with no missing teeth 38.7.3 Final Impression An acrylic resin tray is constructed over the diagnostic cast (Fig. 38.13). The patient is prepared in the same manner as for the preliminary impression, and the final impression is then made with an irreversible hydrocolloid impression material (Fig. 38.14). The master cast is made of dental stone. 38.7.4 Jaw Relation Records Jaw relation records such as vertical dimension, cen- tric relation, and protrusive relation are made and used in the adjustment of the articulator. 728 M. Mazaheri Fig. 38.11 a, b. Crowning and splinting of the abutment teeth will increase the retention and support of the prosthesis and the life expectancy of the abutment teeth. a Patient before dental restoration. b After restoration with prosthesis in position ab Fig. 38.12. Patient with wide cleft of the hard and soft palate, treated with prosthetic speech appliance Fig. 38.13. An acrylic tray is made over the diagnostic cast and the border trimmed with green modeling compound Fig. 38.14. The final impression is made with alginate material. Note the extent of the registration of the cleft ᮣ 38.8 Design and Construction of the Prosthesis The master casts are surveyed and the prosthesis is designed (Fig. 38.15). For patients with severely constricted maxillary and mandibular arches, teeth are arranged outside the remaining natural teeth to estab- lish the proper aesthetics and occlusion. The prosthetic speech appliance is constructed in three sections. The design of the anterior portion is similar to that of a partial or complete denture. After this section is completed, the patient is instructed to wear it for at least 1week. The length of this adjustment period depends on the ability of the patient to adapt to this part of the prosthesis. The construction of the middle part,the tailpiece or velar section,varies for operated and nonoperated clefts. In unoperated clefts with the maxillary prosthesis in position, the extent of the tailpiece over the margin of the cleft is marked on the posterior part of the appliance. The tailpiece extends posteriorly to the anterior extent of the uvula. In operated palates that are short and require a prosthesis, the position of the tailpiece is marked on the posterior margin of the prosthesis. The tailpiece extends approximately 3mm behind the posterior margin of the soft palate. The width of the tailpiece is approximately 5mm, and its reinforced thickness is about l.5mm. 38.8.1 Construction of Velar Section A piece of shellac baseplate material of the required width and length is used as a tray. It is securely at- tached to the posterior part of the prosthesis with about 2-mm relief.This assemblage is examined in the patient’s mouth for proper extension. The tissue side of the tray is filled with zinc oxide and eugenol impression paste, and the appliance is inserted into the mouth. The patient is instructed to hold his or her head in a vertical position to prevent escape of the impression material into the nasopharynx. The head is held in this position for 1minute, then the patient is instructed to swallow a little water so that the muscular movement of the soft palate will be registered in the impression. After the material has hardened, the prosthesis is removed from the mouth, and the tailpiece is processed with self-curing acrylic resin. The denture portion with the finished tailpiece is placed in the mouth for testing.Swallowing of small amounts of water will stimulate muscle action along the lateral edge of the velar section. If the velar section is over- extended laterally, undue muscle displacement and eventual tissue soreness will occur. 38.8.2 Construction of Pharyngeal Section or Speech Bulb Two holes are drilled in the posterior part of the tailpiece.A piece of separating wire is drawn through the holes to form a loop that extends superoposteriorly beyond the superior part of the tailpiece. The ends of the wire are twisted together inferiorly (oral side),and secured to the appliance by sticky wax (Fig. 38.16). The wire loop that is extended into the nasal pharyngeal area is manipulated into an oval form,and the appliance is inserted into the mouth (Fig.38.17).The patient is asked to swallow, and the wire is adjusted so that it will not contact the pharyngeal walls at any time. Posterior and lateral pharyngeal wall activity can be stimulated by spraying those tissues with water. The desired position of the wire is in the area of the maximum posterior and lateral pharyngeal con- striction.Green modeling compound is added around the wire loop to reinforce it and its attachment to the tailpiece (Fig. 38.18).The appliance is inserted into the patient’s mouth, and he is asked to swallow a little water. Adaptol, softened in water at 150° to 160°F for 4–5 min, is added over the green compound, and the appliance is inserted into the mouth.Again the patient is instructed to swallow a little water to produce muscle activity, and thus the impression material is mold- ed (Fig. 38.19). The prosthesis is reinserted a number of times,and the patient is instructed to swallow each time when Chapter 38 Prosthetic Speech Appliances for Patients 729 Fig. 38.15. Cast gold framework. The prosthetic speech appliance requires more retention and support; therefore, all the remaining maxillary teeth of this patient have been used for this purpose. The posterior extension of the framework reinforces the tailpiece and the speech bulb [...]... rates and the change in growth rate before and after intervention were correlated with the estimated size of the closure at surgery 755 756 S Berkowitz a b c d e Fig 40.2 a–e Computer-generated images of various cleft palate types a Complete unilateral cleft lip and palate b Complete bilateral cleft lip and palate c Isolated cleft palate d Normal palate: occlusal view e Normal palate: postero-anterior... 40.3 Serial dental casts for Case JH (AQ-74) show: 0-1 Separated palatal segments soon after birth 0-3 Palatal segments move together forming a butt joint relationship 757 758 S Berkowitz Fig 40.3 (continued) 0-7 , 0-9 , 1-6 , and 1-9 What appears to be a “collapsed” state is not so 2-1 and 2-6 The buccal teeth are in an ideal occlusal relationship 1 0-0 , 1 0-5 and 1 0-8 Palatal growth maintains the excellent... infant with complete cleft of the lip and palate, and he recognized that three-dimensional measurements would be more appropriate for longitudinal and comparative studies At present in the realm of cleft lip and cleft palate therapy, treatment planning is at best an “educated art.” Clinical reports of various treatment protocols, emanating from the many and widely separated cleft lip and palate treatment... management of cleft lip and cleft palate, together with an evaluation of the cumulative data from longitudinal palatal growth studies, has led most or- 750 S Berkowitz thodontists to the following hypothesis: Conservative lip and palatal surgery facilitates rather than inhibits growth in both the maxillo-facial skeletal complex and the soft tissue of the labio-facial complex In cleft palate cases,... normal to non -cleft subjects with velopharyngeal inadequacy Cleft Palate J 1964; 1:199–209 17 Mazaheri M, Athanasiou AE, Long Jr RE, Kolokitha OG Evaluation of maxillary dental arch form in unilateral clefts of lip, alveolus, and palate from one month to four years Cleft Palate- Craniofac J 1993; 30(1) 18 Mazaheri M, Harding RL, Ivy RH The indication for a speech-aid prosthesis in cleft palate habilitation... the size and form of the palate and the extent of the cleft defect, as well as the surgical-orthopedic procedures, in differential diagnosis Pruzansky [8] frequently stated that his most important contribution to the cleft palate literature was the conclusion that cleft lip and the palate does not represent a single fixed entity subject to generalizations of description and classification and least... differences in location and dimension of speech bulbs Cleft Palate J 1965; 2:167 20 Mazaheri MS, Nanda S, Sassouni V Comparison of midfacial development of children with clefts and their siblings Cleft Palate J 1967; 4:334 21 Mazaheri M, Sahni PO Techniques of cephalometry, photography and oral impressions for infants J Prosthet Dent 1969; 3:315 22 Millard DR Wide and/ or short cleft palate Plast Reconstr... state-of-the-art monograph in 1972, Spriestersbach and coworkers [1] wrote: “Perhaps the 2 3 4 5 6 greatest drawback to genetical and epidemiological research on clefts of the lip and palate has been the unfortunate tendency to lump them together.” Twenty years prior to that report, the first line in the first paper to emerge from Pruzansky’s [2] research stated: “Not all congenital clefts of the lip and. .. Pc and PC9 to P9, P9 to Ac9 After cleft closure: Includes cleft space bounded by AC to AC9 and PC to PC9 Cleft Space Area: Anterior limit AC-AC and posterior boundary PC to PC9 In Bilateral Clefts: Anterior Cleft Space: Bounded anteriorly by the premaxilla’s outer point of the alveolar crest RPM or LPM to AC and posteriorly by line AC to AC9 Posterior Cleft Space: Bounded by AC to AC, AC to PC, and. .. palatal shelves and soft palate inherently smaller The causative factor has important clinical implications because it suggests that, in some unilateral clefts of the lip and palate, the size of the cleft space may be disproportionately very large and more variable in shape than in other clefts of the secondary palate The velum in this cleft type also may be deficient in muscular tissue and predispose . the maxillary part of the cleft palate prosthesis. Preservation of remaining dentition and sur- rounding soft and hard tissue in cleft palate patients is of utmost importance. Improperly designed cleft. patient. Many clefts of the hard palate can be closed by a vomer flap [5, 23] and clefts of the soft palate by median suture with good anatomic and functional result. The wide cleft and the short palate. lateral and anteroposterior dimensions of the maxillary arch, (4) the length, thickness, and mobility of the soft palate, (5) the perforations remaining in the hard and soft palate area and labial

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