An occasionally irregular blog about orthodontics

Does rapid maxillary expansion cure bedwetting?

Does rapid maxillary expansion cure bedwetting?

Does rapid maxillary expansion cure bedwetting?

While we’re clear on some of the benefits of orthodontic treatment. We have less confidence about other potential effects of our treatment, for example, breathing, muscle function and other related problems.  I find that these are interesting areas and this blog post is on a paper that investigated whether rapid maxillary expansion can cure nocturnal enuresis or “bedwetting”.

Rapid maxillary expansion in therapy-resistant enuretic children: An orthodontic perspective

Farhan Bazargan et al

Angle Orthod. 2016;86:481–486.

DOI:10.2319/051515-329.1

In the introduction, the authors pointed out that children over the age of five years, who wet the bed while asleep, are defined as having nocturnal enuresis (NE). This is a distressing condition that can have a deep impact on a child’s emotional well-being and social life.  Nocturnal enuresis is one of the most common paediatric health issues and it has a prevalence of 15-20% in children aged five years. There is also a spontaneous resolution rate of approximately 15% per year.

There is uncertainty about possible treatments for this condition. Treatments that have been used are, for example, an enuresis alarm and pharmacological therapies such as desmopressin which reduces urine production.

There have been several case reports that suggest using RME to reduce  upper airway obstruction may influence nocturnal enuresis. However, this is low-level scientific evidence and should not underpin the provision of this type of treatment.

What did they do?

The authors attempted to evaluate whether rapid maxillary expansion could reduce the frequency of nocturnal enuresis in children who are resistant to therapy.

They enrolled 34 participants, 29 boys and 5 girls, aged 8 to 15 years, with primary nocturnal enuresis into this prospective cohort study. All the participants were defined as therapy resistant.

They carried out polysomnography,  rhinomanometry and acoustic rhinometry to measure airway volumes. They also took lateral cephalograms and study casts for orthodontic measurements.

  1. They carried out the following orthodontic treatment.
  2. They fitted  a rapid maxillary expansion appliance and left this  passive for four weeks. This was defined as a placebo phase of the study.
  3. After 4 weeks the screw was turned at .5 mm per day for 10 to 14 days
  4. The RME  appliance was replaced by a transpalatal arch to retain the expansion for 6 months

After six months they removed the  retention appliance and they continued to monitor the participants for another six months.

They took records at baseline (T0), directly after the expansion (T1), and six months after the retention was removed (T3).

They also measured the amount of dental expansion with a digital calliper.

The families were asked to document wet and dry nights for four consecutive weeks at baseline, with the rapid maxillary expansion appliance in place but not expanded (they felt this was a placebo), directly after the expansion and finally six months post retention.

They carried out rather simplistic statistics; I would have liked to see a multivariate analysis.

What did they find?

One child withdrew from the study and three other children could not come to the post retention follow-up visit.

I have done a screen shot of their data on bedwetting and this is below.

Screen Shot 2016-05-27 at 14.24.25

 

 

 

 

 

 

They pointed out the following important findings:

  • The long-term cure rate for NE, after one year, was 60%.
  • Following the maxillary expansion there was a significant increase in nasal airflow and nasal volume. There was also a significant correlation between reduction in enuresis and increase in nasal volume.
  • All the expansion had relapsed at the one-year follow-up and there were no other side-effects on the dentition.
  • They pointed out that they had incorporated a placebo into the study because they had placed the expansion appliance and left this inactive for a month.

 

They concluded that rapid maxillary expansion may help some children with enuresis.

They explained the findings by stating that children with NE may have suffered from persistent arousal stimuli due to partly obstructed nasal airways. This in turn made the children more difficult to awaken from sleep leading to the enuresis. Therefore, when the airway obstruction is alleviated by RME, the  arousal thresholds can return to normal and the child will notice when micturition is about to occur. They pointed out that this was purely speculation.  I could not really understand this because I would have thought that if the children were restless then they would wake more easily and not bedwet.  Or have I missed something?

Their conclusion was that further studies with an adequate sample size and proper design are needed.

What did I think?

I thought that this paper provided us with some information on the effect of rapid maxillary expansion on enuresis. Nevertheless, the authors are cautious in their conclusions and they suggest that clinicians should not expand all cases in an attempt to correct this condition.

We also need to look carefully at their study method. The main problem is that this was a cohort study and the NE could have resolved spontaneously. In this respect we need to remember that there is a 15% spontaneous resolution per year and we do not know the duration of this study.

One study design that could give us more robust data is a randomised trial. I certainly could not think of any ethical issues that could prevent the random allocation of RME vs a control. However, while this is feasible, we must be aware of a possible placebo effect in the RME group, as the children could respond to the fact that they felt that they were having a treatment. Another option would be to test RME against another treatment, for example an alarm system. This would not only  provide data on the relative effects of the two treatments, but also provide further information on the effects of RME on the airway etc.

Should we treat NE with expansion? The authors of this paper are tentative in their conclusions and I agree with them. There is certainly not sufficient evidence that suggests RME is effective in reducing NE.

As with other studies into some of the effects of orthodontic treatment, there is a high degree of uncertainty with this treatment.  It is really up to individual clinicians to interpret this paper and then discuss the findings and the uncertainty with their prospective patients.

(Visited 2,916 times, 1 visits today)

Tags: , , , , ,

There Are 18 Comments

Trackback URL | Comments RSS Feed

  1. Dr Dharma says:

    Very interesting and thought provoking topic Dr Obrien

  2. Andy Sonis says:

    Agree with your thoughts on study design. The controls for this study were inadequate to draw any significant conclusions. The authors ideally should have randomized subjects to have received no treatment, passive RME appliance, and active treatment.

  3. Osama Alsaddik says:

    In my opinion; as a sleep Apnea researcher, Hypoxia resulting from obscured breathing may affect the threshold of awakening by decreasing the conductivity of respiratory center in the Pons and Medulla directly (centrally), which I may call a Coma-like state, and hence they can not control the micturition.

    • Osama Alsaddik says:

      In addition to my notice; Arousal Center is in Hypoactive state too from the hypoxemia in bedwetting kids; and will not respond to signalling from brain Cortex.

  4. Dear Kevin,
    I`m a very interesting Reader of your blog but because my english is not so perfect until now I didn`t dare to reply.
    During the last 2 years I`m very interested in the cause of malocclusion. I read a lot about myofunktion, MRC myobrace Treatment, the book of John Mew (the cause and cure of malocclusion) and came in contact with the buteyko breathing therapy.
    I want to share with you what I learned about bedwetting. It is a Problem of lack of C02 in the blood. It is part of the “Bohr effect: less C02 in the blood means less 02 for the cells especially for the smooth muscles and so for the bladder following constriction of the bladder.
    By the way unrestless sleep is one way for the body to produce C02 during the night. Mouth breathing is one factor that leeds to reduced C02 in the blood. Mouth breathing could be reduced after the RME, that is the connection and the Explanation of the results.
    I`m very interested in your answer.
    Andrea Freudenberg, orthodontist from Germamy/Weinheim

    I don`t know if all that is scientifically proven but it sounds logical for me.
    the relationship is

  5. Lou Chmura says:

    I would suspect that expansion does not have a DIRECT effect on bedwetting. However, it does have a positive effect on airway and reduction in sleep apnea, both of which are associated with bedwetting. I wonder what the associations were between PSG and bedwetting and whether the PSG scores improved with RPE?

  6. This study simply reinforces others that have shown that airway is systemically impactful on adults and children. It appears that widening the airway allows for less Sleep Disordered Breathing and therefore secretion of antidiuretic hormones. The idea is to develop a wider posterior airway space with RPE. Might this not be impactful if one were to remove all four bicuspids creating a smaller palatal cross sectional area, only anterior to the posterior airway space, and therefore less room for the airway? Then combine low tongue level, swallow patterns, nasal patency etc. and the subtle long term implications for overall health. Ripe area for research. Orthodontics is impactful with the rest of the bodily functions other than straight teeth. There is more research available I am sure but I simple took these articles that were close at hand.

    Rapid Maxillary Expansion Effects on Nocturnal Enuresis in Children A Follow-up Study, Ulrike Schu¨ tz-Franssona; Ju¨ ri Kurolb
    Angle Orthodontist, Vol 78, No 2, 2008

    Results: Positive effects of RME were observed in nearly 50% of the patients within 1 month of treatment: six were completely dry and five had notable improvements. Relapse in the over expanded arches to a normal transversal occlusion was noted within 1 year. No correlation was
    found between success and improved airways, familial heritage, school performance, or other social factors. Younger children responded better to the treatment. Results were stable at the 10- year follow-up, and no adverse reactions were reported.
    Conclusion: Orthodontic RME is a new option for treating children with NE who are resistant to medical therapy; the treatment has no adverse side effects.

    Changes of circulating atrial natriuretic peptide and antidiuretic hormone in obstructive sleep apnea syndrome.
    Ichioka M1, Hirata Y, Inase N, Tojo N, Yoshizawa M, Chida M, Miyazato I, Taniai S, Marumo F. Respiration. 1992;59(3):164-8.

    Author information
    Abstract
    Patients with obstructive sleep apnea (OSA) syndrome are known to exhibit nocturnal natriuresis/diuresis. We studied plasma and urinary levels of atrial natriuretic peptide (ANP), a potent natriuretic hormone released from the heart, and plasma antidiuretic hormone (ADH) levels in patients with OSA during awake and sleeping periods, to compare with those of normal subjects. Seven patients with OSA and 6 normal subjects were studied. Arterial blood samples were drawn during the awake and the sleeping period, while in patients with OSA, blood samples were obtained during the apneic period. Urine samples were collected over two 12-hour periods (9 a.m.-9 p.m. and 9 p.m.-9 a.m.) In patients with OSA, plasma ANP as well as urinary ANP excretion increased during the apneic period compared with the awake period. There was a significant negative correlation between plasma levels of ANP and ADH in patients with OSA. On the other hand, normal subjects had no apparent differences in plasma and urinary ANP levels between the two periods. It is suggested that nocturnal increase in ANP and decrease in ADH are responsible for the nocturnal diuresis and natriuresis associated with OSA.

    Secretion of antidiuretic hormone in children with obstructive sleep apnea-hypopnea syndrome.
    Yue Z1, Wang M, Xu W, Li H, Wang H. Acta Otolaryngol. 2009 Aug;129(8):867-71.
    CONCLUSIONS:
    Obstructive sleep apnea-hypopnea syndrome (OSAHS) in children with hypoxemia might influence the nocturnal secretion of antidiuretic hormone (ADH) that is associated with polyuria, even nocturia.
    OBJECTIVE:
    The impact of OSAHS on the secretion levels of ADH was studied in pediatric patients with adenotonsillar hypertrophy.
    SUBJECTS AND METHODS:
    Forty-eight children (28 with OSAHS, 20 as normal controls) were recruited in this study. Respiratory indexes of all subjects were monitored by polysomnography and 12-h urinary volume was recorded during sleep. Vein blood was sampled to detect the levels of ADH in serum using a radioimmunoassay technique, both before and after adenotonsillectomy.
    RESULTS:
    After surgery for OSAHS, the mean value of the apnea-hypopnea index (AHI) decreased (from 17.36±2.61 to 3.32±1.41, p<0.001), lowest arterial oxygen saturation (LSaO(2)) increased (from 78.34±13.44 to 95.35±6.24, p<0.001), urine volume (UV) in nocturnal 12 h reduced (from 492±90 to 332±56, p<0.001), and ADH level increased (from 63.08±35.15 to 83.10±21.05, p0.05)
    [Influence on antidiuretic hormone secretion in children with obstructive sleep apnea hypopnea syndrome].
    Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi. 2008 Mar;43(3):179-82.
    OBJECTIVE:
    To explore the influence of obstructive sleep apnea hypopnea syndrome (OSAHS) in children on the secretion of antidiuretic hormone (ADH).
    METHODS:
    Thirty pediatric patients with OSAHS were examined with polysomnography (PSG) and urinary volume was recorded during sleep, and vein blood was sampled in deep sleep to detect the level of ADH in serum using radioimmunoassay technique, which were performed before and after adenotonsillectomy. Among twenty heath children were also detected the secretion of ADH as normal controls.
    RESULTS:
    After surgery, apnea-hypopnea index (AHI) decreased (from 17.4 +/- 2.6 to 3.3 +/- 1.4, t = 27.68, P < 0.001), lowest SaO2 increased (from 0.783 +/- 0.134 to 0.954 +/- 0.062, t = 6.45, P < 0.001). The level of ADH in OSAHS patients (63.1 +/- 35.2) ng/L was much lower than that in health children (85.1 +/- 22.2) ng/L (t = 2.75, P < 0.01). The serum ADH level in postoperative patients (83.1 +/- 21.2) ng/L was increased significantly compared with that of preoperative (t = 2.56, P 0.05). Nycturia volume of preoperative OSAHS children (492 +/- 90) ml was significant higher than that of postoperative (332 +/- 56) ml or normal controls (346 +/- 62) ml (t was 7.85 and 6.43, both P 0.05).
    CONCLUSIONS:
    After adenotonsillectomy in children with OSAHS caused by adenotonsillar hypertrophy, the sleep pattern and ADH secretion could become normal.

    • Fenris Ulfr says:

      I remove four bicuspids very frequently…haven’t heard any complaints of bed wetting. Might the converse actually not be true – removal of four bicuspids to resolve crowding and align the arches increases space for the tongue anteriorly, improves oral, mental health and function and prevents enuresis? Seems equally plausible…

  7. Interesting study, Kevin:

    First, I believe the mechanism of arousal is related to atrial natriuretic factor (ANF), a hormone produced in the cardiac atria, which inhibits renin secretion and thus the production of angiotensin, which stimulates aldosterone release. Its overall effect is to increase excretion of water and sodium, which likely leads to enuresis – although its target is a lowering of blood pressure, which reduces the work of the heart. The cardiac effect is likely secondary to changes in thoracic pressure, due to upper airway resistance and/or obstruction. In adults, we were able to increase nasal cavity volume, thru increased midfacial bone volume, and thus eliminate obstructive sleep apnea (OSA).

    Second, are dentists/orthodontists now claiming to treat a Medical condition i.e. nocturnal enuresis? This is a medico-legal issue, which needs to be clarified. For example, OSA is diagnosed by medical colleagues who may then refer their patient to a dental colleague. I guess a similar principle may apply to nocturnal enuresis and other related conditions.

    • Arash Poorsattar says:

      Hi Prof.Singh
      I believe that the main involved hormone is anti diuretic hormone (ADH), secreted from posterior pituitary. Higher ANF could be explained by higher venous return and more dilated atrium accompanied by the airway obstruction and increased intra-thoracic negative pressure associated with posing a deep breath
      against a narrowed or collapsed airway. The dilation of atrium leads to ANF secretion. Three possible mechanisms by which RPE could aid improving nocturnal enuresis may be summarized as:

      1 ) It had been had suggested in 1964 that the correction of maxillary deformity would indirectly increase the lymph circulation
      of pituitary gland by means of bulging effect of maxillary vault beneath the floor of sella turcica.It was further approved by Al-Taai et al., who indirectly traced antidiuretic hormone (ADH) by measuring the plasma osmolality. They stipulated that the decreased plasma osmolality at the end of treatment of enuretic
      children with rapid palatal expansion was assumed to be consequence of increased ADH level
      2) improved neuromuscular coordination
      3) lesser deep phase of sleep related to a higher oxygen saturation level derived by smoother and higher nasal airflow.
      Suggested by Capdevila et al, higher brain natriuretic peptide (BNP)may play a role in imbalanced hormonal secretion in disease and normal condition
      Regards,
      Arash

  8. Craig Dreyer says:

    The late Donald Timms from Preston, England, brought the attention of the medical world to the possible link between nocturnal enuresis and management via an RME. The medical profession guffawed and so I am glad to see that attention is being directed to the matter. I refer to Donald Timms’ book on RME published by Quintessence in 1981.

  9. Farhan Bazargani says:

    Dear prof. O’Brien,
    Thank you for your thoughts and comments on our article.
    Just wanted to clarify some points! The spontaneous resolution is 15% per year which is less than 60% improvement of NE we found in our study. So the spontaneous resolution could not have been the answer. The duration of study, as it´s clearly stated in our study, was one year. The study stopped one year post expansion (6-months post-retention) in all cases.
    At the moment we have an ongoing RCT on effects of RME on NE, which could provide us with hopefully more evidence in couple of yeas!
    Cheers!/Farhan

    • Dear Farhan
      We conducted a meta-analysis on efficacy of RPE to treat nocturnal enuresis which is published as ” Rapid Palatal Expansion to Treat Nocturnal Enuretic Children: a Systematic Review and Meta-Analysis”, J Dent (Shiraz). 2015 Sep;16(3):138-48.
      We assessed the effect of

      1) frequency of bed wetting,
      2) signs and symptoms of upper airway obstruction (e.g., snoring, open mouth during sleep and sleep apnea),
      3) parental divorce (i.e., indicator of pre-existing stressor),
      4)skeletal Angle’s classification
      5) presence of cross-bite
      6) average palatal expansion,
      7) response rates (i.e., responders, partial responders and non-responders),
      8) time to become completely dry or improved, follow ups and
      9) enuresis type (i.e., primary or secondary) were gathered
      Here is what we performed, found and concluded:
      MATERIALS AND METHOD:

      A sensitive search of electronic databases of PubMed (since 1966), SCOPUS (containing EMBASE, since 1980), Cochrane Central Register of Controlled Trials, CINAHL and EBSCO till Jan 2014 was performed. A set of regular terms was used for searching in data banks except for PubMed, for which medical subject headings (MeSH) keywords were used. Children aged at least six years old at the time of recruitment of either gender who underwent rapid palatal expansion and had attempted any type of pharmacotherapy prior to orthodontic intervention were included.

      RESULTS:

      Six non-randomized clinical trials were found relevant, of which five studies had no control group. Eighty children were investigated with the mean age of 118 (28.12) months ranged from 74 to 185 months. The median time to become completely dry was 2.87 months [confidence interval (CI) 95% 2.07-2.93 months]. After one year, the average rate of becoming complete dry was 31%. The presence of posterior cross bite [relative risk (RR): 0.31, CI 95%: 0.12-0.79] and signs of upper respiratory obstruction during sleep (RR: 5.1, CI 95%: 1.44-18.04) significantly decreased and increased the chance of improvement, respectively. Meanwhile, the other predictors did not significantly predict the outcome after simultaneous adjustment in Cox regression model.
      CONCLUSION:

      Rapid palatal expansion may be considered when other treatment modalities have failed. The 31% rate of cure is promising when compared to the spontaneous cure rate. Though, high-level evidence from the rigorous randomized controlled trials is scarce (Level of evidence: C).

      Regards,

      Arash

      • Kevin O'Brien says:

        Hi Arash, thanks for the input, this is very interesting and suggests that RME may be helpful, but the strength of evidence is low and we clearly need some trials in this area

        • Arash Poorsattar says:

          Hi Prof.O’Brien, Thanks for your attention. I agree that current data are scarce and the level of evidence/recommendation is still low. It seems that there is a growing worldwide interest to implement RPE to treat some medical conditions such as OSA, enuresis, chronic otitis media, etc.

    • Kevin O'Brien says:

      Hi Farhan, thanks for the comments. it is great that you are doing the trial. Have you registered it so that I can do a post about it?
      Best wishes: Kevin

  10. Dear Prof.O’Brien.
    We conducted a meta-analysis on efficacy of RPE to treat nocturnal enuresis which is published as ” Rapid Palatal Expansion to Treat Nocturnal Enuretic Children: a Systematic Review and Meta-Analysis”, J Dent (Shiraz). 2015 Sep;16(3):138-48.
    We assessed the effect of

    1) frequency of bed wetting,
    2) signs and symptoms of upper airway obstruction (e.g., snoring, open mouth during sleep and sleep apnea),
    3) parental divorce (i.e., indicator of pre-existing stressor),
    4)skeletal Angle’s classification
    5) presence of cross-bite
    6) average palatal expansion,
    7) response rates (i.e., responders, partial responders and non-responders),
    8) time to become completely dry or improved, follow ups and
    9) enuresis type (i.e., primary or secondary) were gathered
    Here is what we performed, found and concluded:
    MATERIALS AND METHOD:

    A sensitive search of electronic databases of PubMed (since 1966), SCOPUS (containing EMBASE, since 1980), Cochrane Central Register of Controlled Trials, CINAHL and EBSCO till Jan 2014 was performed. A set of regular terms was used for searching in data banks except for PubMed, for which medical subject headings (MeSH) keywords were used. Children aged at least six years old at the time of recruitment of either gender who underwent rapid palatal expansion and had attempted any type of pharmacotherapy prior to orthodontic intervention were included.

    RESULTS:

    Six non-randomized clinical trials were found relevant, of which five studies had no control group. Eighty children were investigated with the mean age of 118 (28.12) months ranged from 74 to 185 months. The median time to become completely dry was 2.87 months [confidence interval (CI) 95% 2.07-2.93 months]. After one year, the average rate of becoming complete dry was 31%. The presence of posterior cross bite [relative risk (RR): 0.31, CI 95%: 0.12-0.79] and signs of upper respiratory obstruction during sleep (RR: 5.1, CI 95%: 1.44-18.04) significantly decreased and increased the chance of improvement, respectively. Meanwhile, the other predictors did not significantly predict the outcome after simultaneous adjustment in Cox regression model.
    CONCLUSION:

    Rapid palatal expansion may be considered when other treatment modalities have failed. The 31% rate of cure is promising when compared to the spontaneous cure rate. Though, high-level evidence from the rigorous randomized controlled trials is scarce (Level of evidence: C).

Post a Comment

Your email address will not be published. Required fields are marked *

Top

Pin It on Pinterest