Chronic rhinitis, adenoid hypertrophy, tonsillar hypertrophy and nasal septum deviation are the main causes of airway obstruction. Airway obstruction in nasopharynx and other parts forces children to breathe Because of the abnormal breathing pattern, the mandible rotates backward and downward. The balance of the ascending jaw muscles (masseter, temporalis, medial pterygoid and extrapterygoid muscles) and the descending jaw muscles (digastric muscle, mandibular hyoid muscle and genioglossus muscle) are broken. A series of adaptive remodeling of craniomaxillofacial muscles will affect the growth and development of the jaw, leading to the occurrence of class II malocclusion However, the diagnosis and treatment of malocclusion caused by oral respiration have been controversial. This paper reviews the research progress of class II malocclusion associated with oral respiration
1. The effect of oral respiration on head, neck and maxillofacial region in children
Effects of 1.1 oral respiration on the soft and hard tissues of maxillofacial region
According to Moss’s functional matrix theory, functional matrix (non bone tissue, organ and functional space) is the determinant of craniomaxillofacial growth. The respiratory function of children with open mouth breathing and adenoid hypertrophy is abnormal. Long term oral breathing will lead to the imbalance of perioral muscle strength, affect the position and morphological changes of craniomaxillofacial soft and hard tissues, resulting in the formation of typical “adenoid face” in children; They are long face, separation of upper and lower lips, short upper lip, deep overbite of anterior teeth, retraction of mandible, narrow arch of dental arch, high arch of palatal cap, and dull face due to continuous mouth opening posture
The results of studies such as lione et al. Have shown that the width of maxillary arch of children with oral breathing is significantly reduced due to the compression of buccal muscles on the upper palate; Liu Xiaojun et al. Have shown that the width of maxillary base bone, the space between upper molars, the space between inferior canines and the width of bony nasal cavity in children with Angle Class II Division 1 malocclusion with oral breathing were significantly lower than those of normal children, showing abnormal development of transverse structure; Lione et al. Found that the palatal surface area of children with oral breathing is smaller than that of children with nasal breathing, which indicates that the changes of physiological function of upper respiratory tract lead to the adaptive changes of maxilla; Yang Kai et al. Showed that compared with children with nasal breathing, oral breathing children had higher palatal cap, narrower maxillary base bone, longer maxillary middle and posterior arch, and relatively narrow and long mandibular posterior arch. Their face was obviously vertical growth type, the mandibular plane angle was significantly larger, the length of mandibular body was smaller, the mandibular angle was larger, the chin and mandible retracted
Methods: a total of 1596 patients with oral respiration were divided into 5-12 years old group, 13-18 years old group and 19-57 years old group. The results showed that the development of jaw and occlusion in children was related to oral breathing, which would be more serious before puberty; However, malocclusion is associated with oral respiration.
Zhao Rui and others studied 176 children with upper respiratory tract obstruction, and found that the incidence of malocclusion was significantly higher than that of the general population. In terms of soft tissue of
, studies by souki et al. Found that compared with children with nasal breathing, oral breathing children had loose and valgus labial muscles, thinner base, more protruding upper lip and shorter lower lip. The thickness of nasolabial angle, nasal process and chin soft tissue of oral breathing children were smaller The sharp nasolabial angle of
is related to the compensatory position of the upper lip protrusion to promote air flow, and may also be related to the labial inclination of the upper anterior teeth.
Filho et al. Found that oral breathing children were more likely to suffer from oral diseases such as gingivitis and dental caries. The body mass index (BMI) of the patients with
adenoid hypertrophy was significantly lower than that of normal children
Effects of 1.2 mouth breathing on head and neck airway
When the nasal ventilation is insufficient due to airway obstruction, airflow passes through the mouth, leading to the decline of tongue position. The head and cervical spine of children with oral breathing are in the forward extension position compared with normal children, so as to expand the pharyngeal cavity permeability.
because of the weak respiratory force required by oral breathing and the inhibition of nasal afferent nerve, the lung capacity is affected, resulting in poor respiratory muscle activity and progressive muscle strength weakening According to Liu Xiaojun et al., the protrusion of head and cervical vertebrae in patients with oral breathing is caused by pharyngeal airway stenosis, rather than skeletal pharyngeal stenosis
Muntilde; The results showed that the position of hyoid bone was higher and nasopharynx airway was narrowed. The higher position of hyoid bone was probably due to the tension of suprahyoid muscle group and infrahyoid muscle group during mouth opening breathing, and the hyoid bone moved upward. The anteversion of cervical spine, the decrease of mandible position and the upward movement of hyoid bone could increase the space of airway Okuro et al. Found that the respiratory function and 6min walking test values of children with oral breathing were lower than those of children with nasal breathing. Oral breathing had adverse effects on respiratory function and motor ability. Moderate neck forward tilt as a compensatory mechanism can improve respiratory muscle function
The results of studies by Agostinho et al. Showed that children with oral breathing had longer anterior height, shorter mandible length and narrower pharyngeal airway than those with nasal breathing; Compared with other age groups, the airway obstruction is the most serious.
adenoid is lymphoid tissue, which exists after birth and changes with age. The largest airway volume is around 6 years old and begins to atrophy after 10 years old A series of morphological changes caused by hypertrophic adenoid are a continuous process, which starts from the nearest structure of maxilla and causes changes of jaw and occlusion in children. The study of
suggests that children before 6 years old are most seriously affected by adenoid hypertrophy and should be intervened by multiple disciplines in time
2. Clinical identification of oral respiration and related malocclusion in children
Oral breathing is one of the most common manifestations of sleep disordered breathing (SDB) in children. However, due to the lack of good subjective expression ability, the symptoms described by oral breathing can not be used as the basis for diagnosis SDB includes snoring, upper airway resistance syndrome (UARS) and obstructive sleep apnea syndrome (OSAS). The diagnostic procedures recommended by the American guidelines for the clinical identification of mouth breathing in children are: visual assessment, questionnaire survey and breath test In the visual evaluation, the children were observed for lip sealing, dark circles, long face, anterior open bite, anterior gingivitis, posterior crossbite, etc
The contents of the questionnaire include asking parents whether children keep their mouth open, snore and salivate when they sleep, lack of concentration, and are prone to fatigue, allergy and cold;
breath test includes: (1) lip sealing test, observing whether children can continue to breathe peacefully or keep quiet sleep after closing their lips.
(2) mirror test, the mirror is placed under the nostrils of children to draw a fogging outline. Children with severe nasal obstruction will have a fog halo less than 30mm in diameter
(3) water test: the children’s mouth contained 15ml water and kept their lips sealed for 3min
According to Brodsky’s criteria, tonsillar hypertrophy was classified as tonsil fossa, tonsil palatal arch, lingual palatal arch, lingual and palatal arch, respectively. According to Brodsky’s criteria, tonsillar hypertrophy was classified as tonsillar fossa only; grade 1 was tonsillar hypertrophy accounting for lingual and palatal arch space le; 25%; grade 2 was tonsil hypertrophy accounting for lingual and palatal arch distance gt; 25% ~ 50%; grade 3 was tonsillar hypertrophy accounting for lingual and palatal arch distance gt; 50% ~ 75%; grade 4 was tonsillar hypertrophy accounting for lingual palatal arch distance gt; 50% ~ 75%; grade 4 was tonsillar hypertrophy accounting for lingual palatal arch distance gt; 25% ~ 50% ~ 75%;
for the detection of adenoid hypertrophy, we can use lateral cephalometric X-ray film to measure the value of a and n. A is the vertical distance from the most convex point of adenoid shadow to the external side of the occipital clivus skull; n is the distance between the posterior upper edge of the hard palate and the anterior inferior edge of the sphenoid occipital junction; a / N = 0.50 ~ lt; 0.60 is normal, a / N = 0.60 ~ lt; 0.70 is moderate hypertrophy, a / N = 0.70 ~ lt; 80 was pathological hypertrophy, a / N Ge; 0.80 was significant hypertrophy
According to Cohen’s method, the size of adenoids can be classified according to the ratio of the soft palate thickness at 1 cm below the hard palate to the airway width between the soft palate and the adenoids; The accuracy of measuring airway obstruction by lateral cephalometric X-ray has also been verified by scholars at home and abroad, which can be used as a screening tool for airway obstruction
The combination of fixed-point measurement of adenoid A and N values and LCR measurement (automatic calculation and display of airway volume and area after defining airway boundary from sagittal plane with dolphin 3D software) can be used as a reliable airway obstruction screening tool to determine whether further diagnosis and treatment of Otolaryngology is needed In recent years, it has been suggested that otorhinolaryngology (ENT) should be used to diagnose fracture respiration or OSAS, such as polysomnography (PSG), acoustic rhinometry (AR) and nasopharynx flexible fiber endoscope
Treatment of malocclusion in children
Treatment of oral respiration and related malocclusion
At present, the treatment of children’s mouth breathing is mainly divided into surgical treatment and conservative treatment; Patients with severe craniomaxillofacial malformations should be treated with combined orthodontic and orthognathic treatment after adulthood to improve the appearance and airway obstruction. The conservative treatment of
includes nasal continuous positive airway pressure (CPAP) treatment, orthodontic treatment, etc; After 3 months of treatment, the immune function of the children returned to normal
Before and after the operation, 33 children with oral respiration underwent adenoidectomy or tonsillectomy; Compared with the 6-year-old children with oral breathing, those who received surgical intervention before the age of 6 were corrected. The incidence of malocclusion was lower and the prognosis was better Becking et al. Carried out a meta-analysis on 461 children with oral breathing from 1196 literatures. The results showed that the inclination of upper and lower incisors tended to be normal, the growth direction of mandible tended to be horizontal, and there was no vertical or sagittal change in maxillary growth after adenoidectomy; Adenoidectomy should be completed as early as possible before the age of 6 years. Orthodontic treatment is still needed for oral breathing children who have formed malocclusion after operation, and the respiratory mode does not affect the time of orthodontic treatment. The treatment of patients with
breath should be multidisciplinary treatment. Even if the tooth and bone factors are corrected, the oral respiratory symptoms still exist
3.2 appliance for respiratory related malocclusion
3.2.1 guided mandibular forward appliance
For children with mouth breathing and mandibular retrusion, the use of guided mandibular forward appliance can promote the development of mandible, adjust the distal relationship of molars, increase the volume of airway, correct the sagittal imbalance of mandible, and improve the coordination of mandible.
such appliances include twin block, oblique guide, Herbst, etc Shi Jianlu et al. Used twin block appliance to treat children with mandibular retrusion. The CBCT images before and after treatment showed that the total volume of upper airway and the volume of palatopharynx, glossopharynx, laryngopharynx and oropharynx were significantly increased, and the respiratory function was improved.
can be combined with muscle function training at the same time
3.2.2 rapid maxillary expansion (RME) appliance
Lack of airflow stimulation in nasal cavity leads to maxillary dysplasia, low lingual body causes insufficient pressure of lingual muscles on palate, and buccal muscles exert too much lateral pressure on maxilla and dental arch, which can lead to upper arch stenosis, posterior crossbite and crowding of dentition in children with oral breathing RME can open the middle palatal suture, move the base bone laterally, increase the width of nasal floor, indirectly relieve airway stenosis, promote the development of maxilla and improve the coordination of maxilla and mandible. The orthodontic method of
is to rotate once a day, 1 / 4 turn each time, for 12 days, and maintain for 3-6 months
Zhang Yi et al. Performed RME treatment on class II Division 1 malocclusion patients with oral breathing habits. Cephalometric analysis showed that after treatment, SNB angle (angle composed of sellar center, nasal root point and lower alveolar base point) increased significantly, SGN FH angle (anterior angle below the intersection of sellar center and chin apex line and eye ear plane) decreased significantly, and the ratio of posterior height to anterior height of s-go / N-Me increased
tecco et al. Treated 55 children with mouth breathing from 8 to 15 years old by RME. After treatment, the actual airway size increased significantly, the cervical lordosis increased significantly, and the head flexion and craniocervical angle decreased
A hypothesis about the role of RME in cervical posture change is that the increase of palatal diameter leads to the expansion of pharyngeal airway space. With the increase of cervical lordosis angle and the decrease of craniocervical angle, dyspnea and cervical anteversion are improved In this hypothesis, muscle neural network may play an important role, but RME has no effect on the sagittal and vertical direction of dental arch, and may recur before the growth peak
High elastic appliance without bracket
The high elastic appliance without bracket is a convenient functional appliance, which can provide muscle function training, improve mandibular retrusion, interfere with mouth breathing and provide nasal breathing environment.
also can intervene oral breathing by vestibular shield, lip block, etc Hong et al. Used high elastic appliance without bracket to treat malocclusion caused by oral breathing. It was found that high elastic appliance without bracket can not only correct malocclusion in children with OSAS, but also enlarge the upper respiratory tract.
high elastic appliance without bracket can move forward the position of the mandible forward with the support of the maxillary anterior teeth, so as to improve the sagittal direction Vanderveken et al. Found that the custom-made silicone appliance completely covered all teeth or even a part of the gingiva by comparing the customized silicone appliance with the prefabricated silicone appliance in the treatment of patients with oral respiration, which was in line with the shape of dental arch, increased the retention, and had a higher success rate of treatment
Blanco et al. Found that sleep apnea index, snoring status and perceived sleep quality of OSAS patients were improved after using high elastic mandibular protraction appliance without brackets.
therefore, we should correct oral breathing habits in time to avoid malocclusion and airway obstruction It should be noted that high elastic appliance without bracket is a kind of functional appliance. It should be used with caution for patients with high angle and should be followed up in time
In conclusion, oral breathing can lead to malocclusion, maxillofacial soft and hard tissue, head and neck airway changes.
simple adenoidectomy or tonsillectomy can not improve the malocclusion, which needs early intervention and correction before 6 years old It is necessary to prevent and control dental caries and gingivitis in children with oral breathing during orthodontic treatment, and long-term follow-up should be carried out. At present, there are still controversies about the treatment of ororespiratory related malocclusion, which needs further study
Source: Liang Yue, Lin Huidong, Sambo Sok, Huang Hua. Research progress on class II malocclusion associated with oral respiration in children [J]. Chinese Journal of Practical Stomatology, 2019 (08): 499-503