Abstract
Background:Functional appliances have been used since many decades for the correction of mandibular retrognathism. Similar oral appliances are atreatment modality for patients with Obstructive sleep apnoea. Hence, interception at the rightage with these growth modification appliances might benefit a child from developing long term respiratory insufficiency. Therefore, the purpose of our study was to assess the short term effects of Twin block appliance (CTB) on pharyngeal airway size in subjects with skeletal Class-II pattern in a sample of Pakistani population.Methods:A retrospective study was conducted from orthodontic records of 62 children (31 males, 31 females) with retrognathic mandibles using lateral cephalograms obtained at initial visit and after CTB treatment.Paired t-test was used to compare the pre-functional and post-functionaltreatment airway size. Independent sample t-test was used for comparison between the genders and statistical significance was kept at≤0.05.Results:Theupper airway width(p<0.001), nasopharyngeal depth (p=0.03) and upper airway thickness (p=0.008) was substantially improved after CTB treatment. Males showed a greater increase inupper airway width (p=0.03) and nasopharyngeal depth (p=0.01) incomparison to the females.Conclusion:Functional appliance therapy can improve the narrow pharyngeal airway of growing children presenting with deficient mandibles having Class-II skeletal pattern.Keywords: airway, twin block, Skeletal Class II, pharyngeal passage, lateral cephalogramJ Ayub Med Coll Abbottabad 2015;27(4):759–63INTRODUCTIONThe prevalence of dental and skeletal malocclusion varies from population to population. Skeletal class II malocclusion has been reported as the most common pattern of malocclusion in Pakistani population. Waheed-ul-Hamidet al1 in his study concluded that amongst subjects having skeletal class-IImalocclusion, 65% presented with the mandibular deficiency in comparison to the maxillary excess resulting in an unfavourable facial profile. Besides affecting the aesthetics of a pleasing profile, mandibular retrognathism is also associated with deficient chin projection, crowded arches and reduced airway dimensions.The growth of dento-facial structures and pharyngeal dimensions have an interchangeable cause-effect relationship, where, restricted growth of the cranio-facial structures can result in narrowing ofthe pharyngeal airways, and reduction in the dimensions of the naso-pharyngeal areadue to anatomical obstruction, can lead to altered cranio-facial growth.2–4 Altered morphology of different oro-facial structures like shortened mandible, enlarged adenoids, tonsillar hypertrophy and macroglossia play a vital role in reducing the airflow through the nasopharynx and the oropharynx.5–7 An elongated and hypertrophied soft palate can also impinge on the posterior airway at the level of the nasopharynx.8 In addition, a retropositioned mandible or maxilla can push an enlarged tongue posteriorly to impinge on the retropharyngeal area resulting in breathing difficulties.9Respiratory difficulties due to any of the above mentioned etiological factors result in a shift to oral mode of breathing which affects the growth of an individual. Narrow airway dimensions lead to adecreased production of stomatomedin hormone in a growing individual affecting the body growth and stature.10,11Abnormal mode of breathing also affects the maxillo-mandibular growth resulting in adenoid facies, skeletal Class II malocclusion and posterior crossbite.12 The mandible growth resumes in a normal direction, once the obstruction of the airway is released and vice versa.A growing child diagnosed with a class-II skeletal pattern due to mandibular micrognathism or retrognathism is ideally treated with functional orthopaedic appliances,whereas, orthognathic surgeries to advance the mandible is the only viable option of correcting a skeletal deformity in a non-growing adult. Growth modifying functional appliances can redirect the mandibular growth in a favourable direction, markedly augment the facial aesthetics and prevent oro-pharyngeal collapse by modifying the posterior position of the tongue.13Functional appliances have beenused since many decades for the correction of mandibular retrognathism. A wide variety of these appliances
Dr. Batool Ali, , Attiya Shaikh, , Mubassar Fida. (2015) CHANGES IN ORO-PHARYNGEAL AIRWAY DIMENSIONS AFTER TREATMENT WITH FUNCTIONAL APPLIANCE IN CLASS II SKELETAL PATTERN, JOURNAL OF AYUB MEDICAL COLLEGE ABBOTTABAD, Volume 27, Issue 4.
-
Views
501 -
Downloads
54
Article Details
Volume
Issue
Type
Language
