Computerized Cephalometric Study of the Pharyngeal Airway Space in Patients Submitted to Orthognathic Surgery

Abstract

Introduction Pharynx is a muscular organ with is sustained by craniofacial bones. It is divided into nasal, oral and hipopharynx, and can be considered as a tube that serves both respiratory and digestive systems. Its anatomical morphology permits that factors facilitate its obstruction, leading to the sleep apnea syndrome. One of the treatment consists of surgical mandibular advancement, increasing pharyngeal dimensions. The aim of this study was evaluate the cephalometric changes in the pharyngeal airway space after orthognathic surgery procedures for correction of mandibular prognathism. Materials and Methods Pre and post-operative cephalometric analysis was performed on 19 patients submitted to mandibular setback by mandibular bilateral sagittal split osteotomy associated with maxillary advancement by Le Fort I osteotomy, using the Dolphin Imaging 10.0 software. Results Results did not reveal statistically significant changes in the upper (nasopharyngeal), middle (oropharyngeal) and lower (hypopharyngeal) airway spaces, but showed increase in the nasal pharynx due the maxillary advancement and a lower position of the hyoid bone due the mandibular setback.Discussion Maxillomandibular orthognathic surgery for correction of mandibular prognathism does not seem to statistically significantly change the pharyngeal airway space, but it increases the maxillary airway. Conclusion It seems to be important to consider the double jaw surgery in cases of mandibular prognathism, aiming prevention of a possible reduction of whole upper airway.

Correlation between the position of hyoid bone and subregions of the pharyngeal airway space in lateral cephalometry and cone beam computed tomography

“…7,9 Changes in the development of the maxilla and mandible (due to developmental deformities, orthognathic surgery, and orthodontic treatment), may cause a predisposition for changes in the volume of the pharynx, which are also accompanied by changes in the positioning of the hyoid. 2,10 The main areas of change are the soft palate (nasopharynx), the lateral walls of the pharynx (oropharynx), and the base of the tongue (hypopharynx), thus emphasizing the importance of evaluating the different pharyngeal subregions. 2 The present study found that the hyoid bone position was more highly correlated to measures of the oropharynx and hypopharynx.…”

“…2,10 The main areas of change are the soft palate (nasopharynx), the lateral walls of the pharynx (oropharynx), and the base of the tongue (hypopharynx), thus emphasizing the importance of evaluating the different pharyngeal subregions. 2 The present study found that the hyoid bone position was more highly correlated to measures of the oropharynx and hypopharynx.…”

“…The pharynx is responsible for the functions of swallowing and breathing [1][2][3] and is important for the development and growth of cranial and facial bones. 4,5 This structure can be divided anatomically into the nasopharynx, oropharynx, and hypopharynx.…”

“…4,5 This structure can be divided anatomically into the nasopharynx, oropharynx, and hypopharynx. 1,2 The airway is bordered superiorly by the bones of the skull base, posteriorly by the spine, anterosuperiorly by the nasal septum, and anteriorly by the mandible and hyoid bone. 6 The hyoid is the only bone that does not articulate with other bones.…”

“…1,3,9,10 Tension generated in these structures, 7 due to movement of the head and body and resulting from oral and tongue function, will change its position. 2,9 Changes in the positioning of mandible (physiological, surgical, or due to orthodontic treatment) are also accompanied by changes in the positioning of hyoid. 3,11 This mechanism of compensation of hyoid position may result in changes in the dimension of the pharyngeal airway and may therefore have clinical implications.…”