How to recognize skeletal craniofacial and dental types: warning signs in child snorers and risk factors for OSAS

In children, obstructive sleep apnea syndrome (OSAS) is common but screening is poor. The orthodontist is strategically placed within the multidisciplinary team to detect respiratory disorder and suspected OSAS.The objective of this article is to consider indications for medical management of young patients. Parents do not always report their child’s snoring, and it is up to the orthodontist to raise the question. The orthodontist’s awareness of radiological anatomy and masticatory system physiology and experi-ence in observing the various functions in clinical examination of young patients can alert parents, guide referral to ENT or sleep medicine and allow early treatment.


INTRODUCTION
How to recognize skeletal craniofacial and dental types: warning signs in child snorers and risk factors for OSAS C. BOEHM-HUREZ The symptoms of OSAS are not sufficiently well known, are variable, and depend on growth stage and maturation.
Without suitable treatment, children may develop pulmonary dysfunction, neurocognitive impairment with learn-ing difficulties, mood disorder (anger, aggression), attention disorder and hyperactivity.
Daytime somnolence is not systematically reported.
Breaks in the growth curve are late warning signs. ENT   Interaction between obstructive respiratory disorder and craniofacial development and morphology is an important dimension of OSAS research. Certain skeletal types such as mandibular retrognathia or maxillary contraction are also found in the healthy population.
The orthodontist is thus an important link in the multidisciplinary chain, with a key role to play in screening for respiratory pathology in young children and adolescents who snore 7 .

Orthodontic consultation
In orthodontic consultation, the importance of certain signs needs highlighting during the interview with the patient and family.
Overweight and obesity should be screened for.
So should allergy and asthma. Extra-oral, intra-oral and functional examination provide preliminary information on skeletal and dental type and associated risk of onset of breathing disorder.
This clinical work-up is completed by a prescription for radiologic assessment, to be studied and interpreted by the orthodontist.
Taken together, these elements may found suspicion of OSAS.

Suspected OSAS
In case of suspected OSAS, the orthodontist refers the patient to pneumology, sleep medicine or ENT.
Clinical and radiological assessment is completed by PSG, to highlight obstructive respiratory events and rule out other sleep disorder.
Treatment associates pneumology, ENT and orthodontics.

Predisposing facial phenotype
A predisposing facial phenotype, involving mandibular retrusion or maxillary contraction, is found in the general population. Children presenting with obstructive respiratory disorder show significant morphological specificities at the skull base, maxilla and mandibular divergence. -

Screening factors in child and adolescent snorers
-Hypoplasia or micromaxilla.
-Short mandibular body and ramus.
The skeletal types described in the literature are frequently encountered in orthodontic patients presenting with snoring or disordered breathing.
There are interactions between obstructive respiratory disorders, development and craniofacial type.
The orthodontist plays a major role, as clinical examination screens for certain craniofacial and functional risk factors for obstructive respiratory pathology and may allow early treatment 16 .
What are the important points to note in the various extra-oral, intra-oral and functional examinations, completed by photographic and cephalometric analysis?
Extra-oral and photographic study AP and lateral study of the face begins with clinical examination, with the patient seated in the chair, and is continued by photographic study.

Mandibular arcade (fig. 5)
The mandibular arcade is very often non-congruent with the maxillary arcade, and is usually U-shaped.

Adjacent tissue
It is important to examine: -soft palate; -palatine tonsils, which may be hypertrophic; -volume and position of the tongue.
Various patterns of soft-tissue/skeletal or skeletal/soft-tissue relations may be found: excessive soft tissue volume or insufficient skeletal framework. It is also important to assess muscle tonus. Hypotony may be associated with soft-tissue/skeletal dysharmony.

Functional examination:
"Preventive or pre-therapeutic action on dento-maxillo-facial dysmorphia should always include screening for oral breathing. " Jean Delaire. Dysfunction is never isolated and can induce morphologic and anatomic modifications liable to disturb or prevent various functions.

Occlusion relations
Occlusion relations are examined in 3 dimensions.

Anteroposterior (fig. 6)
Yong patients who snore and/or present with OSAS very often have Angle class II division 1 or 2. Anterior overhang or corono-palatine incisor version may be observed. All patterns are, however possible, including class I or III.

Radiology and cephalometry
The radiology file comprises: -panoramic X-ray;  Before performing cephalometry, it is important to "read" the lateral teleradiograph to screen for certain elements found in oral breathers: -double nasal and oral entry in the oropharyngeal lumen; -reduced oropharyngeal diameter; -palatine tonsil and adenoid hypertro- Anteroposterior study focuses on the SNA, SNB and ANB angles.
Riley introduced specific measurements for OSAS: -posterior pharyngeal space (PPE) measured in the goniac angle region; -distance between hyoid bone and Downs' mandibular plane (HMP).
-Height and proportions of facial levels.
Vertical study focuses on the Frankfort mandibular plane angle (FMA), anterior and posterior height, and facial height index (FHI).
While it is true that a majority of apnea patients show an increased vertical dimension, hyperdivergent skeletal pattern and oral breathing, this is not systematic, and cases of vertical insufficiency with considerable overlap and hypodivergence may be found.
Dentally, assessment focuses on: -incisor position on lateral view (maxillary and mandibular incisor axes/ Frankfort plane); -inter-incisor angle. Clinical example ( fig. 11a, b, c, d) ( fig. 12a, b) C. BOEHM-HUREZ Esthetic analysis situates the lips and chin with respect to Merrifield's Z line and measures the Z angle (Z line/ Frankfort plane).
Sleep is indispensable for everyone, but especially for children, being essential for growth and the development of the brain.
Before 4 years of age, 8 out of 10 children are estimated to encounter occasional sleep-related problems.
More than half under-4 year-olds snore.
There is nothing negligible about snoring, which can impact health in childhood and adolescence.
Snoring is caused by obstructed air passage, which normally runs through a series of conduits comprising nose, pharynx, larynx and trachea before reaching the lungs.
When there is an obstacle in the nose or pharynx, the child's breathing be-comes abnormal and very noisy, which often worries the parents. It may cause sleep apnea.
Childhood snoring should not be taken lightly. It may reveal a serious pathology: obstructive sleep apnea syndrome.
Craniofacial skeletal architecture influences the etiopathogenesis of OSAS.
Management of OSAS has to be multidisciplinary, and the role of the orthodontist in screening and possible early treatment of maxillary contraction and retromandibulism in children is essential.