|STATE OF THE ART
|Year : 2020 | Volume
| Issue : 1 | Page : 1-7
Treatment of maxillary hypoplasia in cleft lip and palate patients: Keeping the total burden of care as low as possible
Maria Costanza Meazzini
Scientific Director, Cleft Lip and Palate Regional Center, Smile House, Operation Smile, S.Paolo Hospital, Milano; Consultant for Craniofacial Anomalies, Department of Maxillo-Facial Surgery, S.Gerardo Hospital, Monza; Adjunct Professor in Craniofacial Anomalies, University of Milano, Italy
|Date of Submission||10-Sep-2019|
|Date of Acceptance||23-Sep-2019|
|Date of Web Publication||20-Jan-2020|
Dr. Maria Costanza Meazzini
V. di Rudinì 8, Milano 20100
Source of Support: None, Conflict of Interest: None
Introduction: Maxillary hypoplasia is a common problem in cleft patients. The literature has shown that early treatment is unstable; nevertheless, early maxillary protraction may still be taken into consideration, if specific functional problems exist. On the other hand, long-term results of the application of the Alternate Rapid Maxillary Expansion and Constriction (Alt-RAMEC) technique, a maxillary protraction technique applied closer to the peak of growth, have been shown to be stable. Therefore, a later approach might be considered if the objective is purely occlusal/esthetic. Objective: The objective of this study was to describe the rationale behind a protocol for the treatment of maxillary hypoplasia in cleft lip and palate (CLP) patients where timing is guided by the different indications. Materials and Methods: We subdivided this study into two groups. (1) Early treatment group (preliminary study): 30 unilateral CLP (UCLP) and bilateral CLP patients were treated early with expansion and face mask with two specific functional indications: 22 were affected by middle ear infection, otitis media (OM), with subsequent hearing impairment, and 8 by obstructive sleep apnea (OSAS). The objective of early treatment thus, was purely functional. (2) Late adolescence treatment group (follow-up study): a different group of older patients was treated at a later stage with an esthetic-occlusal aim. Thirty-nine UCLP patients were consecutively treated with the Alt-RAMEC technique at an average age of 13.2 years (11.3–14.2 years) before protraction. The average age at long-term follow-up was 18.3 years (17.4–24.7 years). Results: (1) Early treatment group (preliminary results): the sagittal advancement of A-point, after the application of the face mask and expander, was 2.6 ± 1.2 mm. About 65% of the OM patients had a net improvement of all audiological symptoms (audiometric tests and tympanograms), and 100% of OSAS patients had a significant improvement of obstructive parameters (apnea-hypopnea index). (2) Late treatment group (follow-up study): the sagittal advancement of A-point, after the application of the Alt-RAMEC technique, was 5.6 ± 2.7 mm. The position of the maxilla was stable in the long term. Conclusion: Our results suggest that, even though skeletal relapse is expected after early correction of maxillary hypoplasia, there might be an indication in patients with functional problems, such as hearing or breathing disorders, to avoid more complex treatments. On the other hand, to correct the occlusal esthetic problem related to maxillary hypoplasia, it is advisable to wait till after growth peak and apply a modified Alt-RAMEC technique, with a double-hinged expander and to obtain more stable long-term results. This technique seems to significantly reduce, especially in female patients, the need for final orthognathic surgery.
Keywords: Cleft maxilla, expansion, maxillary hypoplasia, OSAS, otitis media, protraction
|How to cite this article:|
Meazzini MC. Treatment of maxillary hypoplasia in cleft lip and palate patients: Keeping the total burden of care as low as possible. J Cleft Lip Palate Craniofac Anomal 2020;7:1-7
|How to cite this URL:|
Meazzini MC. Treatment of maxillary hypoplasia in cleft lip and palate patients: Keeping the total burden of care as low as possible. J Cleft Lip Palate Craniofac Anomal [serial online] 2020 [cited 2020 May 28];7:1-7. Available from: http://www.jclpca.org/text.asp?2020/7/1/1/276201
| Introduction|| |
Over 300 cephalometric studies have been conducted on patients with cleft lip and cleft palate, and all have shown significant differences in maxillary growth compared to normals. Anomalies have been reported in shape, position, and in size in the sagittal, transverse, and vertical planes. The incidence of maxillary hypoplasia in unilateral cleft lip and palate (UCLP) patients needing osteotomies at the completion of growth varies in the literature: 25%; 48%; and 26%.
Developing midfacial retrusion in CLP children has been conventionally treated with protraction face mask at an early age. Maxillary skeletal base protraction with face mask in UCLP is reported to range between 0.95 and 1.68 mm. Some authors reported up to 2.5 mm. While the literature agrees on the fact that a face mask is more efficient when applied early and that, when applied after the age of 9–10 years, its effect is generally more dentoalveolar than skeletal (Kim et al., 1999), there is no scientific evidence that this device has any long-term effect on the subsequent growth of the maxilla. In most cases, the original skeletal pattern of growth gradually reappears within 3 years after the completion of active treatment. Susami et al. have shown, in a 10-year follow-up study, that most patients ended either with dental compensations or needed surgical correction (Susami et al., 2014).
Rapid maxillary expansion (RME) loosens the articulations of the maxillary complex from the rest of the skull, whereby rendering more effective maxillary protraction.
The Alternate Rapid Maxillary Expansion and Constriction (Alt-RAMEC) technique is a protocol which allows to disarticulate all circummaxillary sutures in patients who are close to the end of craniofacial growth; the technique does not use a traditional expander, but a two-hinged rapid palatal expander [Figure 1]a, which is unique in its biomechanics, expanding and rotating each half of the maxilla outward, while buttressing against the pterygoids posteriorly. Timing of treatment seems fundamental for the success of the technique in the long term. The treatment is started when the vertebral stage of maturation is close to V3. Liou and Tsai have shown a significant the advancement of A-point (5.8 ± 2.3 mm) in 6 months and those results remained stable without significant maxillary relapse after 5 years. Meazzini confirmed these data in a consecutive sample of Caucasian UCLP patients, with a slightly modified technique adapted to the different esthetic requirements, obtaining similar maxillary advancement (mean 5.7 mm).
The objective of this study was to give some guidelines, supported by evidence, in terms of indications and timing of the treatment of maxillary hypoplasia in cleft patients: early treatment mainly for functional reasons and only later treatment (adolescence) for skeletal long-term effect.
| Materials and Methods|| |
Early treatment patients (4–9 years)
Only children affected by functional problems other than the mere Class III malocclusion were included in this preliminary study. Therefore, the inclusion criteria were as follows:
- Unilateral, bilateral CLP patients affected by maxillary hypoplasia, and skeletal Class III malocclusion with no CO-CR shift
- Deciduous dentition or early mixed dentition
- Associated problems:
- Audiometric test depicting hearing loss and Type B or C tympanograms
- Obstructive sleep apnea (OSAS) with Apnea Hypopnea Index (AHI) >4.
- Full cooperation of the patients.
Thirty patients were treated early with expansion and face mask with two specific functional indications: 22 were affected by middle ear infection, otitis media (OM), with subsequent hearing impairment, and 8 by OSAS. The objective of early treatment, thus, was purely functional.
Late treatment patients (11–14 years)
A modification of the original Liou Alt-RAMEC technique has been applied since 2005 by the authors in 106 patients: of these patients, 48 where noncleft, nonsyndromic, Class III patients. The results of the first 29 patients affected by UCLP, consecutively treated with this technique, were reported in a previous study (Meazzini et al., 2018). Ten additional patients were included in this study.
Therefore, the inclusion criteria were as follows:
- Complete UCLP patients consecutively treated with Alt-RAMEC
- Vertebral stage of maturation V3 at the beginning of treatment (usually corresponding to late deciduous or permanent dentition)
- Skeletal Class III malocclusion with no CO-CR shift
- Full cooperation of the patients.
Therefore, the actual total study sample was 39. The average age of the patients in the sample was 13.2 years (11.3–14.2 years) before protraction. The average age at long-term follow-up was 18.3 years (17.4–24.7).
Papid palatal expander (RPE) and face mask protocol
A traditional RPE, either bonded (Mcnamara type) or soldered to bands on deciduous molars was cemented to which a face mask was applied at least 14 h/day [Figure 2]a and [Figure 2]b. All patients had at least 8 mm expansion, even when the maxillary arch was overcorrected relative to the mandibular arch, as the objective of the treatment was functional and not occlusal. In [Figure 3], the lateral clinical photographs pretreatment and posttreatment of a female UCLP patient are shown.
|Figure 2: (a) Traditional RPE soldered to bands on deciduous molars. (b) Face mask, which was applied at least 14 h/day|
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|Figure 3: Example of a unilateral cleft lip and palate female patient, protracted early for hearing disorder: (a) Profile of a female unilateral cleft lip and palate patient at 7 years of age pre-treatment. (b) Lateral occlusal photograph pretreatment. (c) Audiometric test pre-treatment. (d) Otoscopy pre-treatment (Tympanogram Type B). (e) Profile at the end of maxillary protraction. (f) Lateral occlusal photograph post-treatment. (g) Audiometric test post-protraction (h) Otoscopy post-treatment (Tympanogram Type A) |
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Alternate Rapid Maxillary Expansion and Constriction protocol
The double-hinged maxillary expander (DHME) consisted of a jackscrew in the center, and two hinges of rotation posteriorly [Figure 1]a. In the lower arch, a double lingual arch with anterior hooks was soldered on molar and premolar bands (Meazzini et al., 2018). The treatment protocol consisted in seven cycles with 7 days of expansion and 7 days of constriction, 1 mm/day, alternatively. After 7 weeks of alternate expansion-constriction, a mild mobility of the whole maxilla was felt clinically and a mild discomfort was reported by the patient, especially at the paranasal area. In 30% of the patients, there was a need to go up to 9 or 11 cycles, to achieve mildly perceivable maxillary mobility.
When no dental movement was desired, the original protocol was modified adding temporary skeletal anchorage devices (TADs) provided by two maxillary and two mandibular titanium miniscrews (Cortical Anchorage Miniscrews, OrthoEasy®). Two TADs were positioned in the maxilla between the roots of the first molars and the second premolars, in the mandible between the roots of the canines and the lateral incisors. TADs were used indirectly, with ligature wires to the dental appliances. In 13 of the patients, who had significant lower anterior crowding and missing lateral incisors in the maxillary arch, some dental movement was needed to close the lateral space and relieve mandibular crowding, and therefore, no TADs were used.
After the completion of the expansion/constriction cycles, the technique included 5–7 months of active maxillary protraction.
The maxillary protraction was delivered by a pair of tooth-borne, intraoral maxillary protraction springs, which produced a force of 300 gr per side [Figure 1]b. Given the relatively frequent breakage of the β-titanium springs, all patients continued protraction with intraoral elastics (300 gr), to be used 24 h per day, also during mealtimes.
For each patient, a lateral cephalometric radiograph was taken before (T0) and after maxillary protraction (T1), and at long term (Tlt). Cone-beam CT scans were not offered by our national health system until recently, and were, therefore, not available for most patients.
Lateral cephalometric tracings were superimposed on the anterior cranial base, orienting on the Sella-Nasion (SN) line. The method was previously described., In [Figure 4], the lateral X-rays and clinical photographs pretreatment, posttreatment, and at the long-term follow-up of a female UCLP patient are shown.
|Figure 4: Example of a patient, protracted late (during adolescence) to treat the progressive Class III: (a) Profile at smile of a female unilateral cleft lip and palate Van der Woude patient at 11.9 years of age pre-treatment. (b) Lateral occlusal photograph pre-treatment. (c) Lateral X_ray pre-treatment (d) Profile at smile of the patient at the end of maxillary protraction. Note the support of the upper lip. (e) Lateral occlusal photograph post-treatment. (f) Lateral X_ray post-treatment. In this patient TADs were used in the mandibular arch. (g) Profile at smile 7 years post-treatment. (h) Lateral X_ray 7 years post-treatment. (i) Lateral occlusal photograph 7 years post-treatment|
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Tympanometry was used to test the condition of the middle ear and mobility of the tympanic membrane and the conduction bones by creating variations of air pressure in the ear canal. Tympanograms were executed and scored as A, B, and C: (1) normal tympanogram (Type A): normal pressure in the middle ear with normal mobility of the eardrum and ossicles. (2) Type B: tympanogram may reveal (a) fluid in the middle ear, (b) perforation of the tympanic membrane or patent pressure equalization tube. (3) Type C: negative pressure in the middle ear space resulting from compromised Eustachian tube More Details function and a retracted tympanic membrane.
Audiometric tests were also carried out. For the assessment of hearing thresholds, pure-tone audiogram was used. Audiograms were taken under standard conditions in a room isolated from outside sounds. The hearing thresholds at the speech frequencies of 250, 500, 1000, and 2000 Hz were obtained separately for each ear.
Records were obtained from each subject: (1) before protraction, (2) after protraction.
Polysomnography was carried out in patients with respiratory distress. In this preliminary report, only AHI will be reported as parameter to evaluate improvement in breathing.
A paired t-test was carried out to evaluate the changes of measurements from different time points of the study samples. A Cronbach α intraclass correlation coefficient (ICC) was used to assess cephalometric intra-examiner reliability. Point detection and measurements were performed twice by the same operator at 4-month interval, which is suitable to assess test-retest reliability. Statistical analysis was carried out with Stata 10 software (StataCorp. 2007. Stata Statistical Software: Release 10. College Station, TX, USA: StataCorp LP).
| Results|| |
The ICC used to assess the consistency of the single rater was 0.982, thus providing an indication of good intrarater reliability.
Early treatment patients
The average advancement of point A in these patients was 2.6 ± 1.2 mm. As skeletal changes were not the objective of this preliminary evaluation of early protraction, no other skeletal parameters are reported.
About 35% of the patients had no ENT improvement, and 8% needed, even after protraction, T tubes placement to improve hearing loss. Nevertheless, 65% of the patients had an average improvement of hearing in both ears. Hearing threshold decreased significantly of 21 db (range 11–26 db).
Tympanograms went from Type C and even from Type B to Type A bilaterally in 60% of the patients [Figure 3]. Long-term results are not available yet.
Obstructive sleep apnea results
Average initial AHI was 13.1 ± 3. After over-expansion and protraction average AHI was 3.3 ± 2. No long-term results are available yet.
Late treatment results
At T1 (immediate postprotraction) the maxilla was advanced at A point on an average 5.6 mm (P < 0.001). The mandibular posterior rotation was not significant. Two patients developed reciprocal TMJ click, which were addressed with physical therapy.
In the long term (at least 6 years postprotraction), the maxilla remained stable, with no significant relapse, in all patients followed long-term posttreatment [Figure 4]. The mandible grew, after the completion of treatment, at B point on an average 3 mm. Clinically, none of the patients presented periodontal problems or loss of vitality of teeth. None of the patients had a permanent TMJ dysfunction in the long term. One of the female patients (16% of the females) and two male patients (32% of the males) at the completion of growth required a le Fort I osteotomy.
| Discussion|| |
Early treatment (functional) sample
Even though the literature available agrees on the skeletal recurrence of early treatment (Susami et al., 2013),, the results both in the ENT sample and in the OSAS sample justify the additional burden of care.
OM with effusion (OME) is very common in CLP patients and is characterized by an accumulation of thick fluid behind the eardrum in the middle ear space, generally with no signs and symptoms of acute infection and no perforation of the tympanic membrane, but often severe hypoacusia, which in many centers is treated with ventilation tube insertion (grommets).
In 65% of the patients, hearing was significantly improved, avoiding in most patients the need for T tubes or hearing aids. The findings of the present preliminary study show that the hearing thresholds decreased significantly up to 10–20 decibels after protraction. Therefore, skeletal and soft-tissue expansion induced by the palatal separation forces, transversally and sagitally, affected the nasomaxillary complex, tubal dilator muscles, and Eustachian tube dysfunction.
The results in the OSAS group justify the early treatment as well, as all patients had a final AHI lower than 4–5. The average AHI pre-protraction was 13.1 ± 3. After expansion and protraction average AHI was 3.3 ± 2. We believe this result is superior to that reported after treatment with RPE only, as significant protraction was added to the skeletal modification.
All patients needed overcorrection of the Class III to obtain full improvement of OSAS. Therefore, treatment time was relatively long (average time 19 months ± 4). Nevertheless, both patients and families perceived the functional and esthetic gradual improvement, making this treatment more acceptable.
Trying to give a list of possible main indications for early protraction, we would consider:
- Hypoacousia and tympanic membrane distortions
- OSAS (more common in cleft children with pharyngeal flaps).
We would consider as well:
- Large soft-tissue gaps, which do not allow the surgeon to perform bone graft and soft-tissue closure. Protraction of the posterior segments allows to avoid flaps such as lingual flaps or buccal flaps which might otherwise be indicated
- Seldom indication is given by the speech pathologist for difficulties in articulation
- Severe incisal trauma might also be a functional indication for early treatment.
Late treatment sample
The results of this clinical retrospective study confirmed the data present in the literature (Meazzini et al., 2018) that a repetitive weekly protocol of Alt-RAMEC, using a two-hinged expander with skeletal anchorage and intraoral traction, allows to obtain significant advancement of the maxilla in cleft patients and that the maxillary results remain stable in the long term.
The patients selected for this study were all UCLP. The total amount of maxillary advancement was almost 6 mm in 6 months; the long-term evaluation revealed that the maxillary advancement was stable. Other authors have reported treatment with a modification of the Alt-RAMEC technique, but, contrary to the original protocol, they all use a traditional RPE., Kaya et al. reported an average maxillary advancement of 2 mm adding miniplates and a face mask, whereas Canturk reported over 3 mm maxillary advancement applying night-time face mask and daytime Class III elastics. None of these studies show any long-term follow-up data.
The reasons which may have allowed a greater advancement in the present study may be more than one. First, the two-hinged expander has a specific geometry which allows a better loosening of all circumaxillary sutures. Therefore, studies which apply a normal RPE, instead of a DHME, might obtain less advancement, as the lateral circumaxillary sutures only bend, but do not open sufficiently. Histologically, Wang et al., demonstrated that what occurs at the circumaxillary sutures, is not a simple deposition of osteoid, as found in RPE, but a process of sutural stretching and protraction osteogenesis. Second, springs or intraoral elastics are used 24 h/day, even during eating time, and this is a fundamental advantage over face mask, which is usually only worn during night-time. Third, the skeletal anchorage allows distributing the forces of traction directly to the bones, with greater maxillary advancement and significant reduction of dentoalveolar compensation. Another clinical aspect which justifies the success in the long term of this technique is certainly the timing of treatment. The expansion/constriction cycle is started when sutures are still open, though growth peak is almost reached. The protraction mechanics are held until the process of craniofacial growth is significantly decelerated. The timing seems to be the key to stability, given the fact that it has been shown that in cleft patients treated in early mixed dentition there is a recurrence of the malocclusion during the subsequent 2–3 years of growth.
Other methods for maxillary advancement involving zygomatic and mandibular plates, though interesting, seem to allow for a much lower advancement of the maxilla in UCLP patients (1.6 mm–2.2 mm) and until now have provided no long-term data. Thus, the burden of care of those other techniques does not seem to be justified at this stage.
The maxillary advancement obtained with our late protraction technique is lower than that reported in patients treated later with orthognathic surgery at the completion of growth (6.8 ± 1.7 mm). This suggests that some of the patients treated with Alt-RAMEC will not avoid surgery. Especially in male cleft patients, we are still unable to predict the proportion of patients who will not require orthognathic surgery.
A noteworthy advantage of this technique, though, is the psychological aspect: the appearance of the patient improves significantly during adolescence, which is a particularly difficult period for CLP children in terms of awareness and psychosocial adjustment.
| Conclusions|| |
Our results suggest that early correction of maxillary hypoplasia, even though skeletal relapse is expected, might be indicated in patients with functional problems, such as hearing or breathing disorders, to avoid more complex treatments.
On the other hand, to correct the occlusal esthetic problem, it is advisable to wait till after growth peak and apply a modified Alt-RAMEC technique, with a double-hinged expander, to obtain more stable maxillary long-term results. This technique seems to significantly reduce, especially in female patients, the need for final orthognathic surgery.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]