Long Term (>10 Years) Effects of Airway Obstruction Treatment on Dentofacial Morphology.

Abstract

Background Airway obstruction, particularly when chronic, has been shown to lead to dento-facial dysmorphogenesis such as the long-face syndrome also known as “adenoid facies”. Despite the available evidence highlighting the importance of diagnosis of mouth breathing early in life, this condition remains widely misdiagnosed or underestimated among different medical specialists. The severity and the extent of the reported morphological changes depend on age, duration, and gravity of airway obstruction. Possibly confounding the issue are the facts that airway obstruction appears to be more acute at a younger age, but the amount of facial adaptation may allow regaining airway clearance. Consequently early examination (before age 6) is important to detect the problem and possibly reverse a negative effect on dentofacial development. Early intervention to promote nasal respiration has been shown to reverse such a course. The extent of normalization highly depends on the timing as well as the type of treatment.

Aims 1. To evaluate, at 10 years follow up, the craniofacial changes of a unique study population, who presented to pediatric Otolaryngologist for consultation during 2006-2008, with history of mouth breathing at the initial visit. 2. To recognize guidelines for airway obstruction treatment in relation to age and severity. 3. To observe the long term results of different treatment modalities on facial morphology.

Methods Upon IRB approval, a total of 57 patients (35 males and 22 females; age 19.09 years (range 15.1 - 25.2 years), who were previously enrolled in a study conducted at AUBMC (2006-2008), accepted to enroll in this study. Following a written consent at the initial visit, a clinical examination of the face and oral cavity was performed, medical history pertaining details about treatment of mouth breathing was recorded; moreover a lateral cephalogram, intra-oral and extra-oral photographs, and oral scan were taken. In addition two sets of questionnaires (Epworth sleepiness scale and STOP-BANG) were filled out to assess the risk of obstructive sleep apnea (OSA) in these individuals. The sample was divided into different groups based on surgical status, gender, breathing status and orthodontic treatment. Cephalometric and dental measurements, as well as OSA questionnaire scores, including the shortest adenoid distance (SAD) were compared between groups as well as at two time points.

Results Most of the variables revealed significant changes from T1 to T2. ANB and SNA angles in the surgical group normalized to controls, whereas in the non-surgical group they remained statistically significant (p=0.03 and 0.02). The Ar-Go-Me (p=0.01), PP/MP (p=0.02) and MP/SN (p=0.00) had smaller values than controls due to more extensive changes after surgery, the non-surgical group on the other hand normalized to controls. The surgical group revealed more proclination of maxillary and mandibular incisors, while in the non-surgical group the mandibular incisors were more protruded compared to controls. The patients who had surgery above age 6 showed a trend towards proclined and protruded mandibular incisors whereas in the younger age group the values were similar to controls. Patients who had their adenoids removed after the age of 6 (p=0.00) as well as mouth breathing patients (p=0.04) developed more mandibular crowding. The surgical group had significantly larger SAD measures than that of controls (p=0.01), in contrast the non-surgical group had significantly smaller SAD measurements when compared to controls (p=0.00). Orthodontic treatment and age at T2 were strong predictors for SAD measurement (r=0.57). Analysis of questionnaires could not delineate a connection between the severity of scores and the SAD measurements.

Conclusion The outcome of adenoidectomy and increased airway dimensions appear to be stable and permanent. Adenoidectomy to regain nasal patency results in normalization of dento-facial growth as well as corresponding bony bases, specifically of the mandible, enhancing better chin projection in the surgical group. Surgical treatment, specifically surgery before age of 6, helps in more horizontal mandibular growth direction. Adenoidectomy before age 6 leaves more growth potential to regain facial harmony. Nasal breathing must be ensured after treatment in order to benefit from the surgical procedure to the full extent. It is important that children with mouth breathing are diagnosed early and evaluated both from medical and dento-facial points of view. This demands interdisciplinary approach between pediatricians, otolaryngologists, orthodontists, and pediatric dentists.