References
Dry mouth in children: an under-reported condition?
From Volume 44, Issue 11, December 2017 | Pages 1057-1064
Article
The problem of dry mouth is well-recognized in adults but receives relatively little attention in the dental literature when it presents in children and young people.1 Prevalence has been shown to have a wide range in the population as a whole (0.9% to 46%) with a shortage of population-based studies carried out in younger age groups.2 There is a wide scope of potential underlying causes3,4 across all age groups (Table 1). An important difference, however, is that children do not always report xerostomia, the subjective feeling of oral dryness, even when salivary hypofunction is found to be severe.5 It is suggested that children with congenital salivary hypofunction do not readily perceive a problem compared to individuals whose oral environment alters in later life.6,7
| Congenital salivary gland aplasia5,6,7 |
| Syndrome-related |
| ▪ 22q11 deletion syndrome8 |
| ▪ Prader-Willi syndrome9 |
| ▪ First branchial arch syndromes, eg Treacher Collins,10 hemifacial microsomia |
| ▪ Papillon Lefèvre syndrome11 |
| ▪ Down's syndrome |
| ▪ Ectodermal dysplasia12 |
| Infection-induced |
| ▪ HIV |
| Malnourishment-related |
| ▪ Anorexia and other eating disorders13 |
| ▪ Dehydration |
| ▪ Malnutrition14 |
| Alteration in sympathetic activity |
| ▪ Anxiety or depression |
| Systemic disease-related |
| ▪ Diabetes |
| ▪ Sjögren's syndrome |
| ▪ Thyroid disorders |
| ▪ Connective tissue diseases |
| ▪ Graft-versus-host disease |
| ▪ Sarcoidosis15 |
| ▪ Cystic fibrosis |
| Medication/therapy-induced |
| ▪ Drugs, including methylphenidate and other stimulants for ADHD |
| ▪ Chemotherapy |
| ▪ Radiotherapy16 |
Reduced or absent saliva can have a profound impact on the oral health of an individual, leading to difficulties with mastication, speech and taste, oral acid imbalance and increased susceptibility to infections, such as oral candidosis. Characteristic oral signs are usually present (Table 2), often including a particularly high rate of dental caries.5 Yet because severe early childhood caries is regrettably such a common clinical scenario in paediatric dentistry, and dietary aetiological factors are often readily detected, it is possible for a clinician to overlook salivary hypofunction as a contributory aetiological factor. This can lead to missed opportunities to prevent tooth loss. In contrast, a timely diagnosis of dry mouth would enable enhanced preventive care to be offered according to contemporary guidance17 for children ‘giving concern’.
| ▪ Thick, frothy or bubbly saliva |
| ▪ Glue-like mucinous plaque |
| ▪ Dry, glazed and erythematous mucosa |
| ▪ Lobulated tongue with loss of filiform papillae |
| ▪ Caries affecting smooth surfaces, cusp tips and cervical edges |
| ▪ Rapid breakdown of lower incisors |
| ▪ Erosive tooth surface loss |
| ▪ Evidence of oral candidosis |
The aim of this paper is to raise awareness, using four case examples, of the possible initial presentations, underlying causes and impacts of dry mouth in children and young people. It may enable vigilant dental practitioners to diagnose the problem at an earlier stage, so that intensive preventive care and additional support can be offered promptly. Detailed discussion of the management of this condition is outside the scope of this article and readers are referred to other texts,3,4 but tips for children's own self-management are provided in Table 3.
| ▪ Sip water frequently and keep a drink of water at the bedside; |
| ▪ Moisten lips with petroleum jelly (eg Vaseline); |
| ▪ Choose softer or moister foods, take small bites and eat slowly; |
| ▪ Chew sugar-free chewing gum; |
| ▪ Carefully follow your dentist's advice to prevent tooth decay (eg brush with fluoride toothpaste, use fluoride mouthrinse, apply CPP-ACP paste eg GC Tooth Mousse); |
| ▪ Ask your dentist about saliva substitutes, fluoride varnish and fissure sealants. |
Case reports
Case 1
Background
A 12-year-old boy was referred to a dental hospital for treatment of dental caries following orthodontic assessment at a district general hospital. There was a long history of difficulty in co-operating with dental treatment and several previous dental general anaesthetics. Initially, he was diagnosed with dental caries and dental anxiety, with high-risk status for further dental caries. He was scheduled for treatment under local analgesia with inhalation sedation. However, after two unsuccessful attempts at treatment, reassessment was arranged, the dentist suspecting a much more complex picture. Further discussion with his mother, using targeted and gently probing questions, revealed a history of mild learning difficulties, hearing and speech impairments and a cardiac ventricular septal defect which had spontaneously closed shortly after birth. There was also a family history of congenital cardiac defects. He had recently been diagnosed with a submucous cleft palate and was awaiting genetic investigation.
Clinical findings
Intra-oral examination revealed a permanent dentition with first permanent molars and lower central incisors missing, presumed extracted, and lower second premolars presumed unerupted (Figure 1). Caries was present in all second molars and mandibular lateral incisors, affecting smooth surfaces and incisal edges; an unusual pattern. Erosive tooth surface loss was also present. The saliva was described as sticky and stringy. A panoramic radiograph showed that UL1 had previously been root treated (Figure 1d).
He acknowledged always feeling thirsty and frequently asking for a drink, including at night-time. Sugared drinks were usually chosen, because of a dislike of water. Saliva flow rates were found to be very low: resting < 0.02 ml/min (low = 0.16 ml/min), stimulated 0.16 ml/min (normal = 1 ml/min).
Diagnosis and treatment
Several features of his presentation, including dental features and facial appearance,18 alerted the dentist to the possibility of 22q11 deletion syndrome (Table 4) in which dry mouth is a frequent finding.8 Having first explained to the parent that the dental findings might be related to other health problems, this was communicated to the geneticist by letter. A FISH (fluorescence in situ hybridization) test proved positive for the syndrome and medical screening for associated conditions was arranged thereafter.
| ▪ Includes syndromes previously described as Di George, velocardiofacial, conotruncal face anomaly and Catch 22; |
| ▪ One of the commonest multiple anomaly syndromes; |
| ▪ Incidence 1:4,000; |
| ▪ Autosomal dominant inheritance; 80–90% new mutations; |
| ▪ Diagnosis: 22q11 FISH test. |
| General features |
| ▪ Heart defects (74%); learning difficulties (70–90%); velopharyngeal insufficiency +/- cleft palate (69%); hypoplasia of thymus, immune problems (77%); hypocalcaemia (50%); psychiatric disorders; other malformations: urinary tract (37%), skeletal, neurologic and gastrointestinal tract |
| Oral manifestations |
| ▪ Enamel hypoplasia; enamel hypomineralization; hypodontia; peg-shaped teeth; delayed tooth development/eruption;4 |
| ▪ Saliva – reduced flow rate, buffering capacity, output of Ca, phosphate and bicarbonate – compared with healthy controls with similar caries experience.16 |
An intensive caries prevention programme was instigated with use of high fluoride toothpaste (2800 ppm sodium fluoride) and symptomatic relief provided by saliva substitute oral spray (Saliva Orthana). Comprehensive dental care was provided under general anaesthesia. Despite the difficulties of coming to terms with the diagnosis of a genetic condition, the family expressed relief at having received an explanation for the extent of his dental needs, for which his mother felt she had herself repeatedly been blamed by dental staff in the past despite her best efforts to follow caries prevention advice.
After five years of regular follow-up, at the age of 17, this young man requested further treatment to improve his dental appearance and was, by then, able to co-operate fully with advanced restorative treatment under local analgesia.
Case 2
Background
A 10-year-old girl attended for routine review at a dental hospital where she had received regular dental care since the age of 6 for progressive tooth surface loss and dental caries (initially attributed to ongoing dietary causes). Treatment had included preventive advice, fissure sealants and restorations. Her medical history was of mild asthma, controlled with beclomethasone and salbutamol inhalers, and eczema. There was a family history, affecting solely her mother, of aplasia of the parotid and left submandibular salivary glands, absent nasolacrimal ducts, IgA deficiency and unspecified thyroid problems. No such conditions had been suspected in the child to this point.
Clinical findings
The patient was in the mixed dentition with substantial tooth surface loss affecting the remaining primary teeth. The mouth appeared moist, yet was observed to dry after prolonged opening; the tongue was red. Saliva was bubbly and white. Oral hygiene was good. The parotid papillae were absent and an indistinct duct opening was located on the left only. The floor of the mouth was unusual in appearance with a reduced sublingual fold and no submandibular duct openings apparent. Saliva could not be expressed from any major gland by palpation.
On further questioning, the patient acknowledged occasional difficulty eating without an accompanying drink. She had noticed she could not spit or blow saliva bubbles like her brother. She had experienced a single past episode of oral thrush with hoarseness of voice, treated with nystatin lozenges (medication no longer available) and thereafter prevented by rinsing following use of her steroid inhaler. Saliva pH was normal and flow rate was low: resting 0.06 ml/min, stimulated 0.42 ml/min.
Diagnosis and treatment
An ultrasound scan confirmed the presence of both parotid glands, the right submandibular gland and the thyroid gland, all with normal echo-texture but small in size. The left submandibular gland could not be detected. On receipt of the diagnosis of left submandibular gland aplasia, the patient's mother explained that she had always felt guilty about her daughter's high caries experience. She described her own distressing experience of coping with the social impact of dry mouth when growing up, particularly the effect on intimate relationships due to difficulty kissing and her reported associated vaginal dryness. She expressed anxiety about her daughter's future treatment needs and verbalized her intention to provide her with emotional support.
As symptoms were mild, use of sugar-free gum was advised to stimulate salivary flow and the patient continued to receive regular care. Investigations were also arranged for her brother, who was found to have normal saliva flow rates (resting 1.39 ml/min, stimulated 2.19 ml/min) and pH. With intensive preventive support, our patient successfully completed orthodontic treatment with functional and fixed appliances between age 12 and 15, without notable adverse effect.
Case 3
Background
A 6-year-old girl, a regular dental attender at her general dental practitioner, was referred to a dental hospital for dental extractions and advice following a diagnosis of sarcoidosis affecting the kidneys, lacrimal glands and parotid glands, confirmed by ultrasound scans and biopsy. She complained of toothache with cold drinks. She had initially presented to the medical profession 12 months previously with parotid and periocular swelling. Under the care of paediatric rheumatology and nephrology teams, she was taking prednisolone, methotrexate and enalapril to manage her systemic disease and using artificial tears and artificial saliva for dry eyes and dry mouth. Her general dental practitioner had provided interim restorations and preventive advice.
Clinical findings
Extra-oral examination revealed no abnormalities. Intra-orally the mucosa appeared moist. Oral hygiene was suboptimal. All primary teeth were present and all except LRC were carious: the primary molars and primary central incisors (both upper and lower) being unrestorable. The pattern of caries predominantly affected buccal/labial surfaces. There was a sinus associated with LRD. The patient was unable to co-operate with sialometry.
Diagnosis and treatment
Intensive caries prevention advice and treatment was provided. The saliva substitute in use was noted to be acidic so a neutral pH alternative was prescribed in its place and the medical team advised accordingly. Comprehensive dental care under general anaesthetic was provided, including restoration of the few remaining saveable teeth (Figure 2). Regular dental reviews followed to reinforce preventive measures. She and her parents subsequently reported her mouth less dry, and that she was eating better and no longer waking in the night thirsty. Her mouth usually appeared moist but abnormally frothy saliva was noted on more than one occasion.
Case 4
Background
A 14-year-old boy, with a history of difficulty co-operating with dental treatment, was referred by his general dental practitioner to a community clinic for restoration of carious teeth. His medical history was of learning difficulties, autism spectrum disorder and attention deficit hyperactivity disorder. He had been taking methylphenidate hydrochloride and melatonin on a long-term basis, both medications having the known side-effect of dry mouth. He had no concerns about his teeth. He reported frequent sugar intakes, consuming sugared breakfast cereals between meals in addition to fizzy drinks and dilute cordials. His mother reported that he only brushed his teeth about twice a month.
Clinical findings
All permanent teeth were erupted with the exception of third molars (Figure 3 a–c). Abundant dental plaque was present, particularly at cervical margins, with widespread gingival inflammation. Caries was obvious in UR7, UR4 cusp tip, UL1, UL7, LL7, LR6, LR7. Additionally, there were prominent circumferential cervical white bands of enamel decalcification on all molars, including the lingual aspects of lower molars, but no obvious soft tissue signs of dry mouth. Bitewing (Figure 3 d–e) and panoral radiographs showed additional caries in UL2, UL3, UL6, LL6 and confirmed the presence of unerupted third molars.
Diagnosis and treatment
Oral hygiene instruction and dietary advice was provided and fluoride toothpaste 2800 ppm was prescribed for twice daily use. The plan was to extract all second molars and restore the remaining carious teeth under local analgesia, with inhalation sedation if required, and to measure salivary flow rate. However, after a promising improvement in oral hygiene and good response to behavioural management at initial visits, when urgent care was prioritized, he was not brought for subsequent appointments and no further investigations could be performed. Information was promptly shared with other health and social care professionals according to local safeguarding children protocols because of concerns that this might indicate neglect.
Discussion
This article draws attention to dry mouth in children and young people by documenting four cases with different underlying medical conditions: a microdeletion syndrome, salivary gland aplasia, sarcoidosis and medication-associated. None complained spontaneously of symptoms of dry mouth. Since children and young people do not seem to complain of dry mouth in the same way that adults do, dental professionals need to be particularly vigilant to ensure that the problem is not overlooked.
Perhaps children do not complain because they lack self-awareness of the feeling of oral lubrication, do not recognize any change (in sensation, tastes or function) or have no experience of a well-lubricated mucosa for comparison if a condition is lifelong. Alternatively, they may lack the vocabulary to explain their symptoms in a way that adults understand, contributing to parents' and dentists' lack of awareness. They may benefit from prompting with questions relevant to childhood activities and concerns, such as the girl who had noticed she could not spit or blow saliva bubbles like her brother (Case 2).
Furthermore, clearly obvious clinical signs of oral dryness were absent in the cases reported. Use of a clinical oral dryness scale (CODS)19 has shown good reliability in the assessment of severity of dry mouth in adults,20 but these children would have scored few if any features on such a scale. However, all had experienced significant tooth destruction by caries or erosion before assessment of salivary function was considered. With the exception of Case 4, all had attended regularly for treatment and were accompanied by motivated parents, yet presented with unexpectedly high caries experience compared to their siblings or peers. In Case 1, despite multiple previous dental interventions, dry mouth did not come to light until the patient was in his early teens when it then contributed to the choice of appropriate investigations culminating in the late diagnosis of an underlying genetic condition. In Case 3, presentation with acute facial swelling, managed by a multidisciplinary medical team, appeared to have led to quicker recognition of the possibility of dry mouth yet, by that time, severe childhood caries was already established.
These cases also highlight that, when treating children and young people with a very common disease such as dental caries, it is easy for clinicians to overlook the possibility of uncommon contributory aetiological factors. Dental caries so often appears fully explained by reported adverse dietary factors, poor oral hygiene and suboptimal fluoride use that many dentists do not routinely perform further investigations, such as determining saliva flow rate. Yet consumption of frequent drinks, including cariogenic drinks, may itself be a symptom of dry mouth in an attempt by children to moisten their oral soft tissues, thus exacerbating the problem.1 A combination of targeted questioning, particularly to those with known conditions or medication linked to dry mouth, followed by routine assessment of saliva flow rate could reduce missed or delayed diagnoses.
Cases 1 and 2 also draw dental professionals' attention to important emotional impacts for the families involved, in respect of the diagnoses, so that sensitive and supportive care can be offered to the child and family. Both children received late diagnoses of previously unrecognized congenital abnormalities but not before their mothers had felt misplaced guilt for their children's high caries experience. This echoes research findings from Sweden in which parents report struggling in vain for good oral health in their children.21 Despite coping with the anxiety of additional medical investigations, the family in Case 1 expressed a sense of relief to have an explanation for his longstanding high caries experience. In Case 2, the mother's own experience provided an insight into the adverse impact of mucosal dryness.
Conclusion
Dry mouth is a condition that can affect any age group but may be under-reported in children and young people and may present with different signs and symptoms to those observed in adults. However, an awareness of its possible presentations, underlying causes and impacts will enable vigilant dental practitioners to be alert to diagnosing the problem at an earlier stage, so that appropriate enhanced preventive care and additional support or onward referral can be offered promptly.