Posterior Palatal Expansion via Subnasal Endoscopy (2PENN) for Maxillary Deficiency: A Pilot Study

Surgically assisted rapid palatal expansion (SARPE) addresses transverse maxillary deficiency, a known contributor to nasal obstruction. The purpose of this study was to assess the feasibility, preliminary outcomes, and safety of posterior palatal expansion via subnasal endoscopy (2PENN), a modified SARPE procedure, aimed at achieving anterior and posterior maxillary expansion.

This prospective case series included consecutive adult patients with findings of transverse maxillary deficiency that underwent the 2PENN procedure from 4/2021 to 4/2022. Patients completed pre- and post-operative clinical evaluations, Nasal Obstruction and Septoplasty Effectiveness (NOSE) questionnaires, and computed tomography (CT), with measures including expansion at the level of the posterior nasal spine (PNS), first maxillary inter-molar distance (IMD), and anterior nasal spine (ANS).

The cohort (N = 20) was middle-aged (39 ± 11 years), predominantly male (80%), and overweight (BMI 28 ± 4 kg/m² ). The majority (85%) of patients had sleep breathing issues, of which 10 (59%) had polysomnography-confirmed obstructive sleep apnea (OSA). Full anterior-posterior separation of the mid-palatal suture line was evident on all post-operative CT scans, with mean expansion at the PNS of 3.6 ± 1.3 mm, IMD of 6.1 ± 1.6 mm and ANS of 7.0 ± 1.6 mm (p < 0.001). Following surgery, mean NOSE scores improved from 57 ± 23 to 14 ± 13 (p < 0.001). One patient required maxillary antrostomy for post-operative sinusitis.

2PENN is an effective and safe technique for achieving both anterior and posterior maxillary expansion in patients with transverse maxillary deficiency. Further study is warranted to better understand the effect of 2PENN in patients with OSA, particularly as it relates to improving pharyngeal patency.

4 Laryngoscope, 134:1970-1977, 2024.