Dimensional Changes of the Nasal Cavity After Transpalatal Distraction Using Bone-Borne Distractor: An Acoustic Rhinometry and Computed Tomography Evaluation

Abstract

The aims of this study were as follows: 1) evaluation of the effects of transpalatal distraction (TPD) on nasal minimum cross-sectional area (MCA) and nasal volume, and assessment of long-term stability of TPD outcomes on the nasal cavity, using acoustic rhinometry (AR); 2) quantifying the alveolar, basal, and nasal components of the maxillary expansion at both canine and molar levels by computed tomography (CT); 3) investigation of the relationship between CT transverse measurements and AR measurements. The sample was comprised of 11 adult patients with maxillary transverse deficiency and partial/near total nasal obstruction. Standard corticotomies were carried out and bone-borne transpalatal distractors were used in all cases. AR recordings were used to determine nasal minimum cross-sectional area of the anterior (MCA1) and posterior (MCA2) and the volume of the nasal cavity in these regions (Volume1, Volume2) before surgery (T1), when the distractor was removed (T2), and at least 1 year after the expander was removed (T3). CT images were taken at T1 and T2. CT measurements included maxillary base, alveolar, and nasal cavity widths at both canine and first molar slices. There were significant increases in MCAs and volumes of nasal cavity between T1 and T2 and between T1 and T3 with the exception of the right MCA2 and right Volume2 at the latter time (P < .05). All maxillary transverse dimensions in canine and molar CT slices displayed significant increases (P < .05). The change in binasal width at the canine level showed significant correlations with the changes in total MCA1 and total Volume1 (P < .05). TPD provided great increases in MCA and volume of the nasal cavity, and these changes generally remained stable long term. The use of TPD in adult patients granted the opportunity of efficient maxillary expansion concurrent with increases in the nasal dimensions.