Adenoid hypertrophy is an “obstructive condition related to an increased size of the adenoids”. An acute or chronic adenoidal infection may accompany the disease or not [1].

Numerous conditions, including enlarged turbinate, adenoids hypertrophy (AH), nasal septum deviation, allergic reaction, edematous nasal mucosa with chronic inflammation and nasal and nasopharyngeal tumors, and can cause nasal obstruction that changes the way of breathe. “The study shows that 21% of adult nasal obstruction is due to adenoid hypertrophy. But in case of the patient with chronic tonsillitis only 9 % were associated with adenoid hypertrophy”[2]. However, Nasal obstruction is a common problem, and enlarged nasopharyngeal adenoids are a common cause.

Adenoid hypertrophy are classified according to American Allergy Association into Grades 1 and 2 airway obstruction of less than 50% which might not need surgical intervention on the contrary grades 3 and 4 were previously identified as airway obstruction greater than 50%. Therefore, a 50% or greater obstruction was considered AH and required ENT management [3].

Relationship between adenoid hypertrophy and breathing from the mouth and how it leads to unusual facial traits and dental arches malocclusion or the dental disarrangement is focused through different researches with controversies results. However, the majority of the earlier published work on hypertrophied adenoid with malocclusion focused on western patients with specific diagnoses. According to a literatures review, there aren’t many studies on this topic among Iraqi peoples Nineveh Province [4].

It is known that the fundamental contributing factors of the jaws position, tongue, and, to a lesser degree, the skull itself are respiratory demands [1]. In order to stabilize the airway, an altered respiratory pattern brought on by mouth breathing may result in postural changes including lips opening, or tongue anteriorly positioned, and inferior rotation of the posterior part of the jaw. It has been hypothesized that changes in posture affect soft tissues in a way that modifies the pressure which applied to teeth and face bones in balance [5].

Harvold et al.’s studies on primate oral respiration revealed that environmental factors like major malocclusion symptoms might result from a significant airway blockage [6]. In mouth breathers; which considered a very specific symptom in hyper adenoid patients, Linder-Aronson and colleagues also exhibited characteristics features such as a “high mandibular plane angle, narrow maxillary arches, and retroclined mandibular incisors” [7].

A variety of occlusions may be linked to mouth breathing, according to earlier research. However, it has been noted that patients with hypertrophied adenoids are somewhat more frequently linked to class II malocclusion [8,9].

In comparison study performed on 7 years children shows mouth breathers significantly more than nose breathers with atopic (allergic) illnesses in terms of class II and cusp-to-cusp sagittal molar correlations. As well as children with allergies who breathed through their mouths had narrower maxillary arches than those who breathed through their noses [10].

In orthodontics, having a solid understanding of occlusal features is crucial. Dental aesthetics, space availability, and dentition stability are all impacted by occlusal features [11].

Patients awareness with enlarged adenoids may now seek orthodontic treatment to rectify any dental defects that may be related to their disease, as the benefits of orthodontic treatment are becoming more widely known. On the other hand; orthodontic treatment cannot be beneficial if the adenoid not removed earlier. Therefore, it’s critical that the clinicians be conversant with the occlusal disharmony caused by adenoid hypertrophy.

Different cases are attain the maxillofacial department in different places whether dental specialist centers or hospitals complaining from different occlusal discrepancy caused by missed hypertrophied adenoids or respiratory problems consequently the authors think to perform a study classify the relation between these two problems. This study was therefore carried out to evaluate the effect of adenoid hypertrophy and sociodemographic variables on the occlusion of children and to compare the findings with that of control subjects.

Ethical Approval

The study was approved by the Nineveh Health Directorate’s Scientific and Ethical Committee in Liscen No. 2022190 and its session No. 238 on November 22, 2022.

Study Design

Case control study.

Study Setting

Oral and Maxillofacial Surgery Department in Al-Salam Teaching Hospital

Study Period

1 / 12 / 2022 - 1 / 3 / 2023

Study Sample

Child attain Maxillofacial Surgery Department for any cause

Case Definition (Adenoid Group or Group 1): children aged 3 to 12 years present with malocclusion regardless gender diagnosed clinically and radiographically with Parents concurred to share. When child diagnosed with malocclusion then they send for ENT consultation to confirm or exclude adenoid.

Control Cases (group 2): involved 50 children aged between 3–12 years recruited from patients as same as the case defined but without malocclusion send for consultant ENT to confirm adenoid presence or not.

Sampling Methods: 100 patients attain the maxillofacial department will be assessed prospectively for the presence of occlusal discrepancy and hypertrophied adenoid. Occlusal disturbance are detected through clinical examination and cast records in the maxillofacial department while the hypertrophied adenoid detected through both clinical and endoscopic assessment. Patients evaluated for their occlusal characteristics. The dental inter-arch relationships in all three dimensions are recorded. One hundred children in the primary and mixed dentition between the ages of 3 and 12 were included in this study. To further analyze the data, the participants were divided into three age groups based on their level of dental development.

• Primary dentition category was made up of 3- to 5-yearolds,
• Early mixed dentition category the 6- to 8-year-olds and the
• Late mixed dentition/early permanent category was made up of 9- to 12-year-olds.

Demographic data (name, age, gender, level of education and existence of additional children with the same issue) is all documented, as well as medical and dental histories (a complete dental history is obtained, including gingival health care, prior dental visits, and psychological distress).

Examination (extraoral and Intraoral) include: Extraoral examination include the most imperative point is the balance, harmony, and esthetic appearance of the face to detect the type of the occlusal and skeletal deformities.

Intraoral examination includes

1. Dental alignment: crowded, spaced, misaligned and rotated teeth, malocclusion class also recorded.
2. Coordination of the arch also examined

Investigations include

1. Radiographical assessment (Orthopantomography {OPG}).
2. Nasal endoscopy for adenoid diagnosis.
3. Study cast model for evaluation and detection of the occlusal discrepancy
4. Cephalometry in critical cases only (suspected skeletal discrepancy) on need.

Data collected by evaluating the patients includes demographical data, clinical data (sign and symptom), and type of occlusion. Intra-oral examination was carried out using examination gloves and a mouth mirror with the mouth open and later with the teeth in occlusion. Anterior- posterior arch relationship was determined in the permanent dentition using the British Standards Institute’s Incisor Classification [12], with the following classes:

• ”Class I incisal relationship: this was registered when the lower incisors edges occluded with or lay immediately below the cingulum plateau of the upper incisors.
• Class II incisal relationship: this was registered when the lower incisors occluded posterior to the cingulum plateau of the upper.
• Class III incisal relationship: this was registered when the lower incisors edges occlude anterior to the cingulum plateau of the upper and these teeth met either in an edge to edge relationship or there was an obvious reverse overjet”.

When” the upper primary canine occluded in the space between the lower primary canine and the first primary molar in the primary dentition, this was regarded as a class I dental connection. When the primary canine of the maxilla occluded mesially to class I, it was put in class II. When it occluded distally to class I, it was put in class III” [12].

In addition another symptoms are also recorded which can explore adenoid these are abnormalities in breathing, congestion, snoring, mouth breathing, sleep apnea, otitis media, facial growth abnormalities, swallowing difficulties and speech problems.

Following the intra-oral examination, all participants had their alginate impressions made using disposable trays. Before casting, impressions were cleaned with running water and sterilized with a diluted sodium hypochlorite solution. One researcher gathered all of the data.

ENT Consultant examines all the patients clinically and with endoscopic examination to confirm or exclude the presence of hypertrophied adenoid. Cases with less than 50% of airway obstruction considered with the normal cases while patients more than 50 % of airway obstruction are adenoid group [3]. According to the chart of case control study; cases divided to four minigroups (Table 1). which are:

a) Both Malocclusion and Adenoid Cases.

b) No Malocclusion but with Adenoid Cases.

c) Malocclusion but no Adenoid Cases.

d) Nor Malocclusion Neither Adenoid Cases.

Statistical Analysis and Sample Size

Statistical analysis was done using SPSS version 20. Odd ratio analysed. Descriptive criteria such as number, percentage and mean were used in the statistical analysis of the data. ShapiroWilk test for normality is done. Mann -Whitney test are used to show the degree of significant differences in comparison between the groups. To examine associations between variables, the correlation coefficient (r) was used. The significance level was set at p ≤ 0.05 and highly significant at p ≤ 0.01.

In this comparison study cases are divided into two groups each group are composed of fifty cases group one are the adenoid (case defined group) while group two considered as control cases. Shapiro-Wilk test for normal distribution are used for cases analysis (Table 2) for the two groups in the variable included (Symptom, Minigroups and Occlusion Classes) which show that all parameters are highly significant, i.e. the all are non-normality, and, i.e. the measures for all are non-parametric.

In comparison of the demographical variables (Table 3); starting with the age group nine to twelve years old are the highest present (14%, 8%). Male as a gender are the uppermost percent than female in both group (64%, 50%) and the male percent in regards to adenoid group about one and half than female. Ultimate cases are in primary school age from 6-12 years for both groups consequently (86%, 92%). Through clinical examination authors reflect the symptoms present in the cases whether adenoid or normal these includes (stuffy nose, ear problem, snoring, swallowing abnormal, dry mouth, sleep apnea, eating problem and esthetic problem). Symptoms are varied in both groups shown in table three in details; the most maximum symptom seen in adenoid cases were snoring (84%) followed by ear problems (24%) quite the reverse only 7 cases with 14% were recorded in the normal individuals and only 2% for ear problems. The other symptoms varied in percent (10%, 2%, 14%, 4%, 6%, 8%) and quit the opposite in normal cases these symptoms are nil. As well as the psychological evaluation including upset from the occlusal discrepancy are evaluated and shown in in table 3 too. Twenty percent recording upset from their occlusion (Table 4).

Table 4 explore the diagnosis of cases which distributed to four types normal cases ,occlusal discrepancy only, adenoid only and both (occlusal discrepancy with adenoid ). Eight cases are discovered to have abnormality from the control group dispensed as 2 participants have occlusal discrepancy and 6 cases diagnosed as adenoid. In the adenoid group; thirty four cases have both occlusal discrepancy and adenoid.

Occlusal discrepancy type are revealed in Table 5 divided to three standard occlusion classes ( Class I, II, and III) in both groups as 43 cases are detected as class II in group one and 7 are show class III manifestation. In the control group eight cases diagnosed as class II only the other rest are class I.

Mann-Whitney test are used to show the degree of significant differences in comparison between the Adenoid and control groups. P value considered significant level of differences at level ≤ 0.05 and highly significant at ≤ 0.01level. Table 6 shows that age groups have significant differences (0.028*), but gender and education have no significance.

In regards to symptom significant difference level; stuffy nose and esthetic problems are significant whereas ear problem, snoring and dry mouth show highly significant result at p value ≤ 0.01 level added to that the psychological problem also.

Table seven also show the diagnosis and occlusal class range of differences and significancy in both groups. High significant differences shown in cases have both occlusal discrepancy and adenoid. As same as Class III also show high significant level of differences at P value ≤ 0.01 level.

For correlation between the age and gender with the occlusal classes; spearman test are used for both Adenoid and control group. As well as same test used for diagnosis correlation to age and gender.

Table 8 show spearman’s correlations between age / gender and diagnosis in both groups which highlight that no significant relations between the variables (age/ gender) and the diagnosis whether patient has adenoid or occlusal discrepancy or even both. On the contrary; significant relation is shown in the Adenoid group for class II in gender variable while no significant relation for age (Table 9).

Finally Odd ratio was calculated for the sample was equal to (11.15); which mean patient with malocclusion had eleven time to had an adenoid i.e., adenoid is a risk factors to malocclusion.

Histological and embryological studies, cephalometric evaluations, the association of growth and facial anomalies, the study of surgical procedures, animal research, and other scientific disciplines have contributed to our growing understanding of craniofacial development in humans. Even with all of these investigations, however, a universal agreement on the mechanism that regulates craniofacial tissue has yet to emerge [13]. Basically it’s well known that two growth spurts are occur during childhood which responsible for the vast majority of facial growth and development. The 1st one occurs between the ages of 5 and 10, coinciding with the transition from primary to permanent dentition, and the 2nd occurs between the ages of 10 and 15, just before puberty sets in [13]. In order to predict and stop changes in the dental arches, facial bones, and muscle function, pathological conditions that can cause the upper airways to become blocked must be found and treated early. Normal development of the head and face depends on how well the nose is used when a child is young.

Approximately 60% adult size of the craniofacial skeleton has been attained by the age of four, according to studies of early childhood development. Ninety percent of facial growth is complete by the time a per son reaches the age of 12 [14]. The maxilla has finished developing to a large extent by age seven, while the mandible has reached this stage by age nine. Accordingly the age group chosen in this article is from (3-12 years).

Proper facial bone, muscle, and soft tissue support with aesthetics properties, depends on the connection between the naso-maxillary complex and the cranial base. The maxilla must be wide enough to fit the mandible and allow the mandible to rotate correctly downward and forward. Articles emphasize that an improper airway will affect the global individual growth [14].

“The Waldeyer’s ring is the system of lymphoid tissue that surrounds the pharynx. This system of tissue includes adenoids and pharyngeal tonsils, lateral pharyngeal tonsils, lateral pharyngeal bands, palatine tonsils, and lingual tonsils” [15].

During the first few months of a baby’s life, lymphoid tissue is typically not noticeable. Adenoid symptoms typically peak between the ages of 2 and 12, when the child is still in the early stages of development. With the development of the adult nasopharynx, the size of the adenoids shrinks during puberty. Adenoid tissue is extremely uncommon in adults and, when found, is typically atrophic. Waldeyer’s ring involution has yet to have its cause pinpointed. Reduced patent nasopharyngeal airway and increased nasopharyngeal obstruction can result from an unbalanced relationship between nasopharyngeal airway enlargement and the growth of adenoid tissue [16].

In this study cases with less than 50% of nasopharyngeal obstruction are quite normal with slight adenoid tissues are present but show no effect in regards to occlusion abnormalities this agree to systematic review performed by Lara Pereira 2018. (11).

According to this study significant difference are observed between the two groups regarding the age variable, in spite of that, no significant correlations between the occlusion disturbances and age in either groups or even the occlusal discrepancy classes. This result matching the result of ELTON [17], stated that preschoolers were more likely to have crooked teeth if they used a pacifier for more than two years and if they breathed through their mouths a lot. Hypertrophic adenoids and sucking one’s fingers all the time were not found to be linked to any other factor in a significant way and the development of crooked teeth. Male in the Adenoid group are more than the female as well as its shows a significant correlation with the class II occlusal discrepancy in adenoid cases.

There are a number of studies that link adenoids to skeletal and dental development in children who experience nasopharyngeal airway obstruction abnormalities [18]. Others have argued that there is no causal link between adenoids and either crooked teeth or breathing through the mouth [19,20]. Thus, the role of hypertrophied adenoids in their development remains unknown.

The growth of adenoidal tissue, as demonstrated by a bell curve, peaks at or near age six and also begins involution at or near this age as well. Facial growth is coupled with adenoidal growth. As the cranial base forms the roof of the nasopharynx, a close examination of the growth and development of the craniofacial complex becomes significant for the evaluation of the size and configuration of the nasopharyngeal airway. Abnormal adenoidal growth can start as early as childhood and can eventually consume the nasopharynx and the posterior choanae of the nose. This excessive adenoidal growth can cause problems with breathing, congestion, snoring, mouth breathing, sleep apnea, eustachian tube dysfunction/otitis media, rhinosinusitis, facial growth abnormalities, swallowing, difficulty smelling and tasting, reduced sense of taste, and speech [21].

Symptomatic evaluations of cases show significant result in stuffy nose and esthetic problem in Adenoid group and highly significant ear problem, snoring, dry mouth and psychological effect on the other side sleep apnea, eating problem and abnormal swallowing show no significant differences between the groups.

One of the most common causes of difficulty breathing in the upper respiratory tract is enlargement of the adenoids and palatine tonsils which can be treated in many ways, such as by changing the diet and environment, using dentofacial orthopedics, doing breathing exercises, or even having surgery [21]. Different studies agree on that in children, abnormal adenoidal growth can invade the nasopharynx and spread to the posterior choanae. Abnormalities in breathing, congestion, snoring, mouth breathing, sleep apnea, eustachian tube dysfunction/otitis media, rhinosinusitis, facial growth abnormalities, swallowing difficulties, reduced ability to smell and taste, and speech problems can all result from this excessive adenoidal growth because it interferes with normal facial growth. . One third of the children in the Havas and Lowinger study had ineffective adenoidectomies because of intranasal adenoid extensions blocking the posterior choanoe. Postural patency was maintained in this study’s sample population after “powdered- shaver adenoidectomy,” which was used to remove obstructive adenoid tissue [22].

In comparison of diagnosis and presence of adenoid and or occlusal discrepancy; the study show significant differences between the groups in both (adenoid and occlusal discrepancy) case at same. Class II presence in most of adenoid cases regardless the significant differences in both Class I and Class III in comparison between the two groups. Although in this article we don’t separate the type of Class II whether one or two but the main goal is to highlight the importance of adenoid presence in the children. In a systematic review performed by Bibi E. Becking [23] in 2017, he stated that there were 1196 papers found in the initial search for hypertrophied adenoid effect on occlusion, but only 16 were usable according to his inclusion criteria. Each study reported on a prospective cohort of 461 patients and controls, and all were controlled (mean age, 4.1–13.9 years). Dentofacial development: a quantitative and qualitative analysis is discussed after surgery. The normalization of upper and lower incisors toward labial inclination and toward a more horizontal mandibular growth pattern was consistent across studies. Surgical intervention did not have an impact on maxillary growth either vertically or sagittally. Maxillary arch width and lateral crossbite occurrences were both reported to improve following surgery. The results on the overjet, overbite, and SNB-angle, as well as the mandibular arch width and gonial angle, were all over the place [23].

The exact correlation and effect understanding are actually mystery a long time ago which is clear in article published by Linder-Aronson who found low agreement between observers. Even more so, only 25% of all cases the presence of this face in people with enlarged adenoids, leading the authors to the conclusion that “in examining the literature on this subject from the past 100 years, speculative theories without conclusive evidence were presented” [24].

In a study done by Bernardo in 2008 stated that “mouth breathing children, the obstructive size of adenoids or tonsils and the presence of rhinitis were not risk factors to the development of class II malocclusion, anterior open bite or posterior crossbite” [25].

Author think that from the cases included in this study or from the other cases observed later most of adenoid children can be affected to some extent with occlusal disharmony unless they treated earlier from adenoid hypertrophy with one or more symptoms reflect effect. In addition many cases of adenoid discovered in this study lately after disharmony occurs which need orthodontic treatment. Along with as published articles highlight that advanced cases of hypertrophied adenoid only affecting the occlusion; in this article we presumed that too. In un- expected result class II are the most common result class of occlusion.

Limitations of this study include long follow up periods are need for cases especially those with less than 50% of nasopharyngeal closure and increasing the sample.

This investigation established a correlation between adenoid hypertrophy and the severity of angle malocclusion. This finding may indicate that Class II individuals are predisposed to nasopharyngeal obstruction. Therefore, both dentists and ENT specialists should be made more aware of this through the use of simple, definitive, and well-known diagnostic tools and consultations.

Ethics Approval Statement

The study ethically approved by the Human Ethical Scientific Approval Application Form for Research of the Nineveh Health Directory / Ministry of Health / Iraq with Liscen No. 2022190 and its session No. 238 on November 22, 2022.

Patient Consent Statement

Authors can confirm that written informed consent obtained from study participants parents and clearly stated this in the manuscript.

Author contributions

sDr. Rawaa Al-Rawee Conceived the ideas, led the writing and collected the data with the help of Dr. Waleed analysed the data; and Dr. Bashar A. Tawfeeq and Dr. Firas approve the writing scientifically.

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