# Characterization of Pterygomaxillary Suture Morphology: A CBCT Study
## 4 Discussion  
To date, controversy exists in the literature regarding the preferred method for pterygomaxillary separation [18; 19; 20]. [PERSON] and [PERSON] [9] suggested that the position and orientation of the curved osteetome are critical to avoid complications during PMS separation, in particular, to avoid damage to the maxillary artery. In contrast, [PERSON] and [PERSON] [15] reported that use of a curved osteetome created unfavorable fractures in the pterygoid plate when used to separate the PMS. [PERSON] et al. [19] compared the outcomes of PMS separations using CT when it was performed with and without an osteetome. They found that an ideal separation was successful in 27% of cases in which it was performed without an osteetome, and in 29% of cases in which it was performed with an osteetome. Others proposed a technique for pterygomaxillary separation performed anterior to the PMS in order to avoid vascular damage during the osteotomy [20; 21]. A survey of 205 oral and maxillofacial surgeons investigated surgeons' preferences for pterygomaxillary separation [22]. Importantly, 78% of the participants reported that they use an osteetome or a micro-oscillating saw for pterygomaxillary separation: 8% reported serious vascular complication outcomes. Others, who used leverage alone or tuberosity osteotomy, did not report any vascular complications. Although the literature presents diverse approaches for pterygomaxillary separation [12; 23], the most popular approach is to use a curved osteetome through PMS separation. Therefore, knowing the PMS size and position relative to the midsagittal plane is essential for surgeons performing this procedure. Our study investigated PMS morphology in an adult Israeli population with respect to patients' age, sex, and the measured side. The vertical height of the PMS, its maximal thickness, and its angulation relative to the midsagittal plane were measured based on the CBCT scans. We found that in an adult Israeli population, the PMS mean height was 16.9 \(\pm\) 2.3 mm and 16.4 \(\pm\) 3.0 mm, in males and females, respectively, with no significant difference between the sexes (Figure 5). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**PMS Measurement** & **Sex** & **Mean** & \(\pm\)**SD** & **Min** & **Max** & \(p\)**-Value * \\ \hline Thickness (mm) & Male & 1.00 & 0.130 & 0.76 & 1.22 & \\ Female & 0.90 & 0.170 & 0.54 & 1.27 & 0.029 \\ \hline Height (mm) & Male & 16.89 & 2.322 & 12.85 & 22.45 & \\ Female & 16.36 & 2.994 & 12.05 & 23.35 & 0.486 \\ \hline Angulation (\({}^{\circ}\)) & Male & 58.30 & 4.557 & 66.85 & 50.35 & \\ Female & 58.44 & 4.755 & 67.35 & 49.95 & 0.915 \\ \hline \hline \end{tabular}  
* \(p\)-values for the differences between the sexes. Significant values are denoted in bold. PMS: pterygomaxillary suture; SD: standard deviation; min: minimum; and max: maximum.  
\end{table} 
Table 4: Comparison of the PMS morphology between the sexes. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**PMS Measurement** & **Sex** & **r** & \(p\)**-Value * \\ \hline Thickness (mm) & Male & 0.17 & 0.400 \\ Female & 0.04 & 0.858 \\ \hline Height (mm) & Male & \(-\)0.16 & 0.411 \\ Female & 0.13 & 0.558 \\ \hline Angulation (\({}^{\circ}\)) & Male & 0.16 & 0.439 \\ Female & 0.14 & 0.516 \\ \hline \hline \end{tabular}  
* \(p\)-values for the correlation analysis between the PMS parameters and age.  
\end{table} 
Table 5: Association between PMS morphology and age (Pearson correlation analysis) by sex. However, this finding differs from what was previously reported in the Thai (15.14 \(\pm\) 2.5 mm), American (14.6 \(\pm\) 3.1 mm), and Chinese (12.1 \(\pm\) 2.0 mm) populations [7,9,24]. These differences could result from a different methodology used in these studies; however, they also may reflect ethnical anatomical differences [5]. The blade length of the osteotome used to separate the PMS should resemble the PMS height.