Postoperative Changes in Tongue Area and Pharyngeal Airway Space following Mandibular Setback Surgery through Intraoral Vertical Ramus Osteotomy

Abstract

Purpose. The aim of this study was to determine changes in the tongue area and pharyngeal airway space (PAS) after intraoral vertical ramus osteotomy (IVRO). Materials and Methods. Serial lateral cephalograms of 40 patients with mandibular prognathism who underwent IVRO were evaluated before (T1), immediately after (T2), and more than 1 year after (T3) surgery. Paired t -tests and Pearson’s correlation analysis were used to evaluate the postoperative changes in the mandible, nasopharyngeal airway (NOP), retropalatal pharyngeal airway (RPP), retroglossal pharyngeal airway (RGP), hypopharyngeal airway (HOP), PAS, and tongue area (TA). The null hypothesis states that there are no significant correlations among the extent of mandibular setback and the changes in the TA and PAS after IVRO. Results. Immediately after the operation (T12), the mandible was set back by 12.6 mm. The NOP, HOP, and PAS were significantly reduced by 35.7 mm2, 116 mm2, and 185 mm2, respectively. The TA was increased by 69.6 mm2. The changes in PAS and TA revealed no significant difference between female and male patients at T12, T23, and T13. Moreover, no significant correlations were found among the extent of mandibular setback, TA changes, and PAS changes after IVRO. Thus, the null hypothesis was accepted. Conclusions. At the final follow-up (T13), no significant change was found in the PAS (including NOP, RPP, RGP, and HOP) and TA. The changes in PAS and TA revealed no significant difference between female and male patients at T12, T23, and T13.

Changes in Pharyngeal Airway Space and Oxygen Saturation Following Mandibular Setback Surgery: A Narrative Review

“…showed that the pharyngeal airway space is negatively affected after mandibular setback surgery after the long-term follow-up [2]. A previous study done by Kang et al demonstrated that mandibular setback surgery showed a significant reduction in pharyngeal airway compared to bimaxillary surgery (posterior impaction).…”

“…The oropharynx is divided into the retroglossal and retropalatal pharynx and separated by the soft palate. The tongue is the highest functioning part of the oropharyngeal structure and is affected by any alteration to the oro-dental system, particularly the mandible [ 2 ]. The changes in the position of hyoid bone are dependent on the resistance that is provided by the elastic membranes of the larynx and trachea and the action of supra-hyoid and infra-hyoid muscles [ 8 ].…”

“…The attached musculature and hyoid bone move backward and downward during mandibular setback surgery which causes changes in the supra and infrahyoid muscle tension [ 1 ]. This result in posterior positioning of the tongue and an increase in height which can affect the pharyngeal airway space, thus, careful estimation of tongue size is critical in diagnosis and treatment after mandibular setback surgery [ 1 , 2 , 9 ]. Genioplasty, debulking of the tongue, and bi-jaw surgery are considered alternative treatment options to prevent these unfavorable effects [ 1 ].…”

“…Angle class III malocclusion prevalence differs between different population groups and ranges from 0% to 10% [ 1 ]. Asian population demonstrates the highest prevalence of angle class III malocclusion [ 1 , 2 ]. These days, the treatment of class III patients using bimaxillary surgery is increasing [ 3 ].…”

“…Orthognathic surgery can alter the dental, skeletal, soft tissue, and dimensional changes in the oropharyngeal region. Previous studies showed a posterior positioning of the hyoid bone and tongue after mandibular setback surgery, this, in turn, can have a negative influence on the upper airway space that could lead to breathing problems such as obstructive sleep apnea [ 1 , 2 ]. This study aims to review and illustrate the changes in pharyngeal airway space and oxygen saturation following mandibular setback surgery.…”