Dr. Mala Ram ManoharProfessor

Dept. of OrthodonticsCollege of Dental Sciences

Dr. Sahil AgrawalPostgraduate StudentDept. of Orthodontics

College of Dental Sciences

INTRODUCTION answers to such issues as:

Interpretation of the significance of variations in thegrowth and function of the nasal cavities, thenasopharynx and the oropharynx is dependent uponan understanding of the normal growth of the skull.In this respect, however, knowledge of normalgrowth has often been gained by recognition, andobservation of abnormal cranial function, anddevelopment. Thus, aberrant respiratory modes suchas chronic mouth-breathing have frequently beenassociated with dentofacial deformities. From theoutset it is recognized that not all research workershave reported significant evidence that a relationshipexists between mouthbreathing and dentofacialform. Many current concepts concerning the role ofrespiration in the aetiology of malocclusion arebased on somewhat subjective impressions andanecdotal reports that form a significant part of theliterature on this subject. It is on record thatmouth-breathing may be associated with all types ofmalocclusions as well as with normal occlusion.'The purpose of this article is to review the availableevidence. If both data and untested popular beliefsare subjected to the same rigorous criteria,indications for the orthodontic management ofpatients with nasorespiratory obstruction may gain amore rational approach to treatmentrecommendations.

BETWEEN' FACIALCORRELATIONAND NASOREPIRATORYGROWTH

FUNCTION

The orthodontic relevance of nasorespiratoryobstruction and its effect on facial growth continuesto be debated after almost a century of controversy.The continuing interest in nasal obstruction is fueledby strong convictions, weak evidence, and theprevailing uncertainty of cause and effectrelationships that exist. The essence of any debate isto provide opposing evidence from which a majorityvote is obtained. Political issues may beappropriately resolved by such means as a majorityvote. Scientific issues, however, can only beresolved by data and appropriately structuredhypotheses put to the test.' One of the problems indebating nasorespiratory obstruction and facialgrowth is the inability to provide unequivocal

Nasorespiratory Considerations In Orthodontics

How much nasal obstruction is clinicallysignificant? At what age is the onset critical and forhow long does it have to exist before an effect onfacial growth can be expected?

These questions depend on the fundamental premiseof being able to define nasal obstruction. The nosehas an anterior opening designated as the nares, amiddle portion that is influenced by the turbinatesand their associated vascular mucosa that enlargesand becomes engorged in those persons with allergicrhinitis, and the posterior nares that open into thenasopharynx and may be affected by adenoidal������������ An important issue in nasal obstructionis therefore to identify where the obstruction occurs.Various methods have been proposed and used indifferent studies. These include:

(1) Cross sectional area, which will be affected byturbulence;

(2) Peak nasal flow rate, which was used in studies;

(3) Nasal resistance, which may vary over time; and

(4) Respiratory mode, which identifies nasal/oralratio of air flowing through the nose and the mouth.

If the evidence from which we make clinical'decisions is the result of studies that are notcomparable, then one method of treatment cannotnecessarily be compared with an alternative.2

Hence to provide unequivocal answers, clinicalstudies need to be designed to identify and quantifythe degree of nasorespiratory obstruction andcompare individuals for any clinically relevantdifferences.

MALOCCLUSION - THE ISSUE STILL INDEBATE

Is there a cause and effect relationship betweenadenoids, nasal obstruction and malocclusion?

Dentofacial changes associated with nasal airwayblockage have been described by CV Tomes in 1872as adenoid facies. Tomes coined this term based onhis belief that enlarged adenoids were the principlecause of airway obstruction and resulted innoticeable dentofacial changes.' Tomes reported thatchildren, who were mouth breathers, often exhibited

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narrow V-shaped dental arches (fig 1).4

This narrow jaw is a result of mouth breatherskeeping their lips apart and their tongue positionlow. The imbalance between the tongue pressure,

FIG 1

and the muscles in the cheek, result in cheek musclescompressing the alveolar process in the premolarregion. Simultaneously, the lower jaw postures back.These simultaneous actions have been termed thecompressor theory.'

Tomes' views were supported in the 1930's bynumerous leading orthodontists. These supportingclinicians reported airway obstruction as animportant aetiologic agent in malocclusion. Rubinadvocated that in order for these patients to fully beassessed they must be thoroughly evaluated by botha rhinologist and orthodontist.' Malocclusion is thedeparture from the normal relation of the teeth in thesame dental arch or to teeth in the opposing arch."

Airway obstruction, coupled with loss oflingual andpalatal pressure of the tongue, produces alterationsin the maxilla. The positioning of the tongue alsoplays an important role in mandibular development.The tongue displaced downward can lead to aretrognathic mandible; and an interposed tongue canlead to anterior occlusal anomalies.

Additionally, maxillary changes can be viewed inthe transverse direction, producing a narrow faceand palate often linked with cross bite; in theanteroposterior direction, producing maxillaryretrusion; and in the vertical direction causing anincrease in palatal inclination as related to the cranialbase and excessive increases of the lower anteriorface height. The most commonly found occlusalalterations are cross bite (posterior and/or anterior),open bite, increased over jet, and retroclination ofthe maxillary and mandibular incisors." Mahony andLinder-Aronson's findings were in agreement withthe significant correlation between changed mode ofbreathing and diminished mandibular / palatal planeangle (MLINL) found in adenodectornized children."

Several authors have taken the position that allegedfaces are not consistently found to be associated with

N~sorespiratory Considerations In 0n:hodontics

adenoids, mouth breathing, nor a particular type ofmalocclusion; and that there is no cause and effectrelationship between· adenoids, nasalobstruction/mouth breathing and malocclusion.

Proponents of this position believe that the V-shapedpalate was inherited and not acquired through mouthbreathing. (Hartsooh 1946) on a review of literaturerelated to mouth breathing, concluded that mouthbreathing is not a primary etiological factor inmalocclusion. Additionally, Whitaker (1911) foundthat in a study of 800 children, who underwentadenoidectomy or tonsillectomy only 30% haddental anomalies that needed orthodonticintervention. There is some suggestion that adenoidsand hypertrophic tonsils are a consequence of athyroid hormone deficiency. This hormonedeficiency acts as a catalyst for activating theorganism's defense mechanisms which includehypertrophy of lymphoid tissue.9 Anotherorthodontic clinician, Vig, took the position thatwithout documented total nasal obstruction, anysurgery or other treatment to improve nasalrespiration, is empirical and difficult to justify froman orthodontic point of view. 10

NASAL RESPIRATORY EVALUATION

The relationship of airway obstruction anddentofacial structures/malocclusion is still thesubject of investigation and controversy amongstorthodontists. The correlation between functionalproblems and morphologic characteristics is yet tobe solidified. Regardless of varied opinion in thisarea practitioners should observe each patientcarefully.

Suggested protocol:

As the patient enters the room, facial and headposture should be noted to see if the lips are closedduring respiration.

1. Signs of allergic rhinitis should be noted, as wellas histories of frequent colds or sinusitis.

2. Assessment of family history for allergies isimportant.

3. Sleep history should be evaluated: sleep apnoea,loud snoring, open mouth posture while asleep.

4. Patient is asked to seal their lips - difficultybreathing through nose should be noted. One nostrilcan be occluded and the response noted - sameprocedure on the other side (fig 2).

The evaluation of nasal airway patency iscomplicated, especially when the possibility existsthat airways may clinically appear inadequate but bequite functional physiologically. Lip separating oran open-mouth habit is not an infallible indicator of

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, -

FIG 2

mouth breathing. Often complete nasal respiration iscoupled with 'dental conditions that causeopen-mouth posture."

ADENOID EVALUATION

Nasopharyngeal space and the size of adenoids havebeen evaluated using different' methods ofassessment:

Determination of the roentgenographicadenoid/nasopharyngeal ratio (a lateralcephalometric xray);

Flexible optic endoscopes;

Acoustic rhinometry; and

Direct measurements during surgery.

Direct measurements are considered to be the mostaccurate because space can be assessed in threedirections (fig 3).11 A lateral cephalometicradiograph is an added valuable diagnostic tool forthe orthodontist in the evaluation of children withupper airway obstructions (fig 4)_12

The use of lateral cephalometric radiographs toevaluate the upper airway is somewhat limited asthey provide two-dimensional pictures of thenasopharynx, which consists of complex

FIG 3 FIG 4

three-dimensional anatomical structures. Notwithstanding this observation Linder-Aronsonfound a high level of correlation between the resultsof posterior rhinoscopy and radiographiccephalometries, in the assessment of adenoid size.'

Nasorespiratory Considerations In Orthodontics

TREATMENT OF NASAL OBSTRUCTION

Adenoidectomy with or without tonsillectomy isindicated if hypertrophied adenoids (and-tonsils) arethe cause of upper airway obstruction.'

Powered-Shaver AdenoidectomyAdenoidectomy coupled with EndoscopicVisualization will assist in achieving adequateremoval of adenoids particularly high in thenasopharnx. Use of the powered-shaver techniqueallows for better clearance of obstructive adenoids.The end result is more reliable restoration of nasalpatency. 13

Septal surgery (rarely indicated in the child) butmay be considered in the presence of a marked nasalseptal deflection with impaction. Conservativeseptal surgery in growing patients will not have andverse effect in dentofacial growth. 14,15,16

Maxillary expansion (RME or SPME) - anorthodontic procedure that widens the nasal vault.3

Cryosurgery or electrosurgery - this is a viableoption for patients with vasomotor rhinitis.'

Bipolar Radiofrequency Ablation (allergicrhinitis) - performed under local anesthetic

Inferior turbinectomyinstrumentation

Using powered

Use of nasal sprays.

CONCLUSION

The effect of adenoids on facial expression,malocclusion and mode of breathing has been a topicof debate and investigation by practitioners in thefield for the last one hundred years. A review of theliterature exposes several theories.

A health care provider, with a practice philosophybased on prevention of malocclusion development,cannot ignore the early years of the patient's growthcycle. By age twelve, 90 percent of facial growth hasalready occurred. This is the age when manypractitioners begin orthodontic treatment. 3 This isthe age when 80-90 percent of craniofacial growth iscomplete, so most formation and/or deformation hasoccurred." To wait until 90 percent of theabnormality has occurred, before beginningtreatment, is not consistent with a preventivephilosophy. Interceptive measures must be initiatedsooner. Early intervention requires an acceptance ofa multidisciplinary approach to total patient health.An integrated approach to patient evaluation,diagnosis and treatment is most effective. Primarycare physicians, dentists, allergists,otorhinolaryngologists, and orthodontists must allwork together for early prevention and managementof young patients with increased nasal airway

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resistance.

After diagnosis, a comprehensive risk benefitanalysis regarding early intervention must beconsidered. Although hereditary and environmentalfactors must be considered, the universal goal is thepromotion of proper nasal respiration throughout achild's early years of facial growth.

Despite the considerable attention given to thegrowth of the pharynx, the statement of Scott (1955)that, "less is known about the growth of thepharyngeal region than any other part of the face" isstill largely true.

REFERENCES

1. e. Brian Preston. The Upper Airway in OrthodonticsSeminars in Orthodontics VOL 10, NO 1 MARCH2004

2. Katherine W. L. Vig. Nasal obstruction and facialgrowth: The strength of evidence for clinicalassumptions. Am J Orthod Dentofacia1 Orthop1998;113:603-11

3. Rubin. RM. Effects of Nasal Airway Obstruction onFacial Growth, Ear, Nose & Throat J, May;66:44-53,1987.

4. Diamond. O. Tonsils and Adenoids: Why the Delima?Am 1. Orthod., Nov. 78(5) 495-503, 1980.

5. Linder-Aronson. Adenoids: Their Effect on the Modeof Breathing and Nasal Airflow and TheirRelationship to Characteristics of the Facial Skeletonand the Dentition, Acta Oto-laryng Suppl, 265: 5-132,1970.

6. Khurana, AS, Arora, MM, Gajinder S. RelationshipBetween Adenoids and Malocclusion, J Indian DentalAss., April 1986; 58: 143-145.

7. Valera, FC, Travitzk, LV, Mattar, SE, Matsumoto,

Nasorespiratory Considerati<:'1s In Orthod_ontics,

MA, Elias, 'AM, Anselmo-Lima. Muscular,Functional and Orthodontic Changes in Pre-SchoolChildren with Enlarged Adenoids and Tonsils, Int JPediatr Otorhinolarynga12003, Jul; 67(7):761-70.

8. Mahony D., Linder-Aronson. Effects ofadenoidectomy and changed mode of breathing onincisor and molar dentoalveolar heights and anteriorface heights. AOJ; 20:93-98,2004.

9. Linder-Aronson. Adenoids: Their Effect on the Modeof Breathing and Nasal Airflow and. TheirRelationship to Characteristics of the Facial Skeletonand the Dentition, Acta Oto-laryng Suppl, 265: 5-132,1970.

10. Vig, PS, Sarver, Hall. Quantitative Evaluation ofNasal Airflow in Relation to Facial Morphology, AmJ Orthod, 79:263-272; 1981

11. Casselbrant, Me. What is Wrong in ChronicAdenoiditis/Tonsillitis Anatomical Considerations,IntJ Pet. Oto 49(1):S 133-S135, 1999.

12. Oulis, CJ, Vadiaka, GP, Ekonomides, J, Dratsa, J. TheEffect of Hypertrophic Adenoids and Tonsils on theDevelopment of Posterior Crossbite and Oral Habits,J Clin Pediatr. Dent, Spring; 18(3) 197-201, 1994.

13. Havas, T, Lowinger, D. Obstructive Adenoid Tissuean Indication for Powered-Shaver Adenoidectomy,Arch Otolaryngol Head Neck Surg: July 2002;128:789-791.

14. Gary, LP, Brogan, WF. Septil DeformityMalocclusions and Rapid Maxillary Expansion,Orthodontist 4; 1-13, 1972.

15. Cottle. Nasal Surgery in Children, Eyo, Ear, Nose andThroat Monthly; 30:32-38, 1951.

16. Jennes. Corrective Nasal Surgery in Children: LongTerm Results, Arch Otolaryngal; 79: 145-151, 1964.

17. Mahony, J). The Airway, Breathing and Orthodontics;Ortho Tribune,8-11.

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