Sex differences in adult craniofacial parameters

Does Gender Have an Effect on Craniofacial Measurements?

Objective

The aim of this cross-sectional study was to evaluate craniofacial structures in terms of different sagittal relations and gender in adolescent individuals.

Methods

Pre-treatment dental models, lateral cephalometric, and hand-wrist radiographs of 223 adolescent subjects (102 male, 121 female) were evaluated. Subjects were divided into the Angle Class I, II, and III (skeletally) subgroups according to the ANB angle. Four angular and 33 linear measurements were used to evaluate the lateral cephalometric radiographs relative to the R1 and R2 coordinate system. The Kolmogorov-Smirnov test was performed to assess the normal distribution of the data. The independent samples t-test and Mann-Whitney U test were used for the comparison of male and female subjects in each group. The values were considered statistically significant at p<0.05.

Results

The vertical facial dimension was found to be significantly greater in Class I male subjects than in female subjects (SGo, p=0.023; ANS-M, p=0.036), and there was a protrusive maxilla (R2ANS, p=0.038; R2A, p=0.016), while the mandibular sagittal position and the mandibular dimension were similar. The maxilla was placed protrusively (R2ANS, p=0.001; R2A, p=0.002), while the mandible was found to be larger both in the position and dimension (CoGn, p=0.003; R2M, p=0.014) in Class II male subjects. Class III male and female subjects were found to have similar maxillary and mandibular vertical and sagittal location and dimensions.

Conclusion

Class I and II subjects showed more gender variation than Class III subjects. The gender-related results of this study declare that treatment planning of malocclusions should be based on gender differences rather than general treatment procedures, which will be useful in achieving successful orthodontic treatment results.

Surgical Parameters for Minimally Invasive Trans-Eustachian Tube CSF Leak Repair: A Cadaveric Study and Literature Review

BACKGROUND

Cerebrospinal fluid rhinorrhea from a lateral skull base defect refractory to spontaneous healing and/or conservative management is most commonly managed via open surgery. Approach for repair is dictated by location of the defect, which may require surgical exploration. The final common pathway is the eustachian tube (ET). Endoscopic ET obliteration via endonasal and lateral approaches is under development. Whereas ET anatomy has been studied, surgical landmarks have not been previously described or quantified. We aimed to define surgical parameters of specific utility to endoscopic ET obliteration.

METHODS

A literature review was performed of known ET anatomic parameters. Next, using a combination of endoscopic and open techniques in cadavers, we cannulated the intact ET and dissected its posterior component to define the major curvature position of the ET, defined as the genu, and quantified the relative distances through the ET lumen. The genu was targeted as a major obstacle encountered when cannulating the ET from the nasopharynx.

RESULTS

Among 10 ETs, we found an average distance of 23 ± 5 mm from the nasopharynx to the ET genu, distance of 24 ± 3 mm from the genu to the anterior aspect of the tympanic membrane and total ET length of 47 ± 4 mm.

CONCLUSIONS

Although membranous and petrous components of the ET are important to its function, the genu may be a more useful surgical landmark. Basic surgical parameters for endoscopic ET obliteration are defined.

The radioanatomical assessment of the Körner's septum

PURPOSE OF THE STUDY

Körner's septum (KS) is a developmental remnant formed at the junction of mastoid and temporal squama, representing the persistence of the petrosquamosal suture. During mastoid surgery, it could be taken as a false medial wall of the antrum so that the deeper cells might not be explored. The aim of the study was to assess a Körner's septum prevalence and to analyze its topography.

METHODS

The study was performed on 80 sets of cone-beam computed tomography (CBCT) images of temporal bone (41 male, 39 female, 160 temporal bones). Körner's septum was identified and its thickness was measured on axial sections at three points: at the level of superior semicircular canal (SCC), at the level of head of malleus (HM) and at the level of tympanic sinus (TS).

RESULTS

KS was encountered at least in one point of measurements in 50 out of 80 sets of CBCT images (62.5%). The average thickness at the level of SCC was 0.87 ± 0.34 mm, at the level of HM was 0.99 ± 0.37 mm and at the level of TS was 0.52 ± 0.17 mm.

CONCLUSIONS

Körner's septum is a common structure in the temporal bone-air cell complex. It is more often encountered in men. In half of the patients, it occurs bilaterally. However, in most of the cases it is incomplete with anterior and superior portions being the most constant.

Auditory Brainstem Implant Array Position Varies Widely Among Adult and Pediatric Patients and Is Associated With Perception

OBJECTIVES

The auditory brainstem implant (ABI) provides sound awareness to patients who are ineligible for cochlear implantation. Auditory performance varies widely among similar ABI cohorts. We hypothesize that differences in electrode array position contribute to this variance. Herein, we classify ABI array position based on postoperative imaging and investigate the relationship between position and perception.

DESIGN

Retrospective review of pediatric and adult ABI users with postoperative computed tomography. To standardize views across subjects, true axial reformatted series of scans were created using the McRae line. Using multiplanar reconstructions, basion and electrode array tip coordinates and array angles from vertical were measured. From a lateral view, array angles (V) were classified into types I to IV, and from posterior view, array angles (T) were classified into types A to D. Array position was further categorized by measuring distance vertical from basion (D1) and lateral from midline (D2). Differences between array classifications were compared with audiometric thresholds, number of active electrodes, and pitch ranking.

RESULTS

Pediatric (n = 4, 2 with revisions) and adult (n = 7) ABI subjects were included in this study. Subjects had a wide variety of ABI array angles, but most were aimed superiorly and posteriorly (type II, n = 7) from lateral view and upright or medially tilted from posterior view (type A, n = 6). Mean pediatric distances were 8 to 42% smaller than adults for D1 and D2. In subjects with perceptual data, electrical thresholds and the number of active electrodes differed among classification types.

CONCLUSIONS

In this first study to classify ABI electrode array orientation, array position varied widely. This variability may explain differences in auditory performance.