Tomographic Pharyngeal Dimensions in Individuals with Unilateral Cleft Lip/Palate and Class III Malocclusion are Reduced When Compared with Controls

Evaluation of the impact of alveolar bone graft surgery on the nasal cavity of individuals with cleft lip and palate

OBJECTIVE

Cleft lip and palate are the most common congenital malformations in the craniofacial region, occurring at a rate of 1:700 births in Brazil. These conditions lead to functional impacts on patients, such as changes in breathing, teeth, speech, chewing, swallowing and sucking. Treatment begins with primary surgeries, including lip and palate repair, which aim to reconstruct the soft tissues. Secondary alveolar bone grafting (SABG) reconstructs the bone defect in the cleft region, with the main goal of supplying bone tissue to the cleft region and restore the continuity of the alveolar process. To measure the changes in cross-sectional areas (CSAs) and nasal volume in patients and their impact on the nasal cavity (NC) in the two-month postoperative period (PO2M).

METHODOLOGY

This study included 15 patients with complete unilateral cleft lip and palate (U/CLP) indicated for alveolar bone grafting (ABG). Cone beam computed tomography scans obtained prior to SABG and at PO2M were compared. Nasal volumes and CSAs were measured by marking the masks delimiting the nasal cavity on CT scans using Mimics™ software.

RESULTS

NC volumes (total, right and left sides) were statistically lower at PO2M in patients with left-sided UCLP. In right-sided UCLP, these volumes were only significant for the total NC and left NC. The CSAs of the internal nasal valve in both groups showed significantly lower values compared to the preoperative period (p≤0.05).

CONCLUSION

In the short term, alveolar bone graft surgery reduces the volume of nasal cavities and the cross-sectional areas of the right and left internal nasal valve as a whole, not only the cleft area where the graft material was placed.

Adults with Treacher Collins Syndrome Share Comparable 3D Upper Airway Dimensions with Nonsyndromic Individuals

Purpose

Sleep apnea symptoms, such as snoring and daytime somnolence, are commonly observed in individuals with Treacher Collins Syndrome (TCS) and may be related to airway obstruction due to micro- and retro-gnathia. This study aims to three-dimensionally evaluate the upper airway using cone-beam computed tomography (CBCT) exams of adolescents (TCS-ADOL) and adults (TCS-ADUL) with TCS compared to a nonsyndromic group (CON).

Materials and Methods

Twenty-six CBCT exams were divided into three groups: TCS-ADOL (n = 7) (13.14 ± 1.67 years): CBCT exams of TCS adolescents; TCS-ADUL (n = 10) (21.80 ± 4.39 years): CBCT exams of TCS adults; and CON (n = 9) (25.33 ± 8.57 years): CBCT exams of adult nonsyndromic individuals with Class II skeletal pattern. The variables analyzed were (1) total upper airway volume; (2) nasal cavity volume; (3) total pharyngeal volume; (4) nasopharyngeal volume; (5) oropharyngeal volume; (6) pharyngeal minimal cross-sectional area; (7) pharyngeal length; and (8) pharyngeal depth. Scans were analyzed by two examiners, and intra- and inter-rater agreement was calculated. A p-value of ≤0.05 was considered significant.

Results

Although not statistically significant, the TCS-ADUL group showed decreased airway volume and minimal cross-sectional areas compared to the CON group. There were also significant differences between TCS-ADOL and TCS-ADUL, with significantly lower airway volumes in the TCS-ADOL group. Strong positive correlations were found between certain airway measurements in the TCS-ADOL group, which were not observed in adults.

Conclusions

The upper airways of adults with TCS are dimensionally similar to those of nonsyndromic individuals, despite absolute value reductions found in the syndromic group. The reduced airway in the adolescent population suggests significant potential for growth, mainly in pharyngeal dimensions.

Effects of 3D Airway Geometry on the Airflow of Adults with Cleft Lip and Palate and Obstructive Sleep Apnea: A Functional Imaging Study

Objective  Individuals with cleft lip and palate (CLP) are at a high risk of developing obstructive sleep apnea (OSA). Hypothetically, the severity of OSA might be associated with the morphology of the upper airway (UAW) and the characteristics of the airflow. Thus, the present study aimed to assess and compare, in adults with CLP and skeletal class-III discrepancy, with or without OSA, simulations of airflow resistance and pressure according to the geometrical characteristics of the UAW and cephalometric parameters. Materials and Methods  According to the results of type-I polysomnography tests, the sample ( n  = 21) was allocated in 2 groups: 1) without OSA (N-OSA; n  = 6); and 2) with OSA (OSA; n  = 15). Cephalometric measurements were performed on the cone-beam computed tomography (CBCT) scans of the groups. After three-dimensional (3D) reconstructions, the volume (V) and minimal cross-sectional area (mCSA) of the UAW were generated. Computational fluid dynamics (CFD) simulations were used to assess key airflow characteristics. The results were presented at a significance level of 5%. Results  The UAW pressure values and airway resistance did not differ between the groups, but there was a tendency for more negative pressures (26%) and greater resistance (19%) in the OSA group. Volume and mCSA showed a moderate negative correlation with resistance and pressure. The more inferior the hyoid bone, the more negative the pressures generated on the pharyngeal walls. Conclusion  The position of the hyoid bone and the geometry of the UAW (V and mCSA) exerted effects on the airway-airflow resistance and pressure. However, key airflow characteristics did not differ among subjects with CLP, were they affected or not by OSA.

Three-dimensional assessment of airway volumes in patients with unilateral cleft lip and palate

Background

Considering the adverse consequences of respiratory insufficiency in cleft lip and palate (CLP) patients, this study aimed to assess the pharyngeal airway dimensions in 9–12-year-old patients with unilateral CLP. This historical cohort evaluated the cone-beam computed tomography (CBCT) scans of 30 patients with non-syndromic unilateral CLP between 9 and 12 years and 30 age- and sex-matched non-cleft controls. Three-dimensional (3D) images were reconstructed by the Mimics software, and the nasopharyngeal, oropharyngeal, and total airway volumes, as well as the minimal cross-sectional area of the airway (minAx), and posterior airway length (PAL) were all measured in the sagittal plane. Data were analyzed by the Student’s t test.

Results

The oropharyngeal and the total airway volumes, as well as the minAx and PAL in CLP patients, were significantly smaller than the corresponding values in the control group (P < 0.05). Despite smaller nasopharyngeal airway volume in CLP patients than controls, this difference was not statistically significant (P > 0.05).

Conclusions

Nine- to twelve-year-old non-syndromic unilateral CLP patients have smaller pharyngeal airway dimensions than non-cleft controls, and are therefore at higher risk of respiratory insufficiency.

Adults With Unilateral Cleft Lip and Palate Present Reduced Internal Nasal Volumes: Findings of a Three-Dimensional Morphometric Assessment in Cone-Beam Computed Tomography Scans

ABSTRACT

The main purpose was to assess and compare nasal cavity (NC) volumes among adults with unilateral (UCLP) and bilateral cleft lip and palate (BCLP) and in noncleft controls (CON), by means of cone-beam computed tomography (CBCT) three-dimensional reconstructions. Forty-five scans of individuals with class III skeletal pattern, matched by age, were gathered in 3 groups: UCLP (n = 15), BCLP (n = 15) and (CON) (n = 15). The NC volume was assessed three-dimensionally, using Dolphin 11.8 software. Descriptive normally distributed data was presented as mean (±SD). Comparisons of NC volume among groups was performed using ANOVA test (P ≤ 0.05). The NC mean volumes corresponded to 14.7(±2.2) cm3 (UCLP), 17.1(±2.2) cm3 (BCLP) and 18.1(±3.8) cm3 (CON), respectively. UCLP individuals presented a significantly reduced NC volume when compared to controls (P = 0.006). No differences were observed between UCLP versus BCLP or BCLP versus CON. The intraclass correlation coefficient suggested a high intra- and inter-examiners agreement (>.075). Individuals with unilateral cleft lip and palate presented reduced NC when compared to individuals without cleft lip and palate. CBCT scans can be considered a highly accurate tool for morphometric assessments of craniofacial structures.

Internal nasal dimensions of children with unilateral cleft lip and palate and maxillary atresia: comparison between acoustic rhinometry technique and cone-beam computed tomography

PURPOSE

To compare the nasal cavity geometry of children and teenagers with cleft lip and palate and maxillary atresia by two methods: cone-beam computed tomography, considered the gold standard, and acoustic rhinometry.

METHODS

Data on cone-beam computed tomography and acoustic rhinometry examinations of 17 children and teenagers with cleft lip and palate and maxillary atresia, previously obtained for orthodontic planning purposes, were evaluated prospectively. Using Dolphin Imaging 11.8 software, the nasal cavity was reconstructed by two evaluators, and the internal nasal volumes were obtained. Using rhinometry, the volumes of regions V1 and V2 were measured. The values of each examination were then compared at a significance level of 5%.

RESULTS

Statistical analysis showed high intra- and inter-rater reproducibility in the cone-beam computed tomography analysis. The mean internal nasal volumes (± standard deviation) obtained using acoustic rhinometry and cone-beam computed tomography corresponded to 6.6 ± 1.9 cm3 and 8.1 ± 1.5 cm3, respectively. The difference between the examinations was 17.7%, which was considered statistically significant (p = 0.006).

CONCLUSION

The nasal volumes measured via the two methods were different; that is, they presented discrepancies in the measurements. The gold standard technique identified larger volumes than acoustic rhinometry in the nasal cavity. Therefore, determining which test reflects clinical reality is an essential future step.

Nasopharyngeal structure development in patients with cleft palate who underwent repair surgery

OBJECTIVE

This study aimed to compare the developmental characteristics of bony nasopharyngeal (NP) in children with cleft palate (CP) and non-cleft subjects.

METHODS

This study was conducted on 64 non-syndromic CP patients who underwent repair surgery and 23 non-cleft subjects as controls. Lateral cephalograms were performed on participants at rest in the natural head position. The X-coordinate and the Y-coordinate of three points on cephalograms were determined as Hormion (Ho), posterior maxillary point (PMP) and anterior point of the atlas (At) representing the anterior-posterior (AP) and vertical dimension of the NP. The linear dimension of the NP (i.e. Ho-At, Ho-PMP, At-PMP) and its area was also calculated.

RESULTS

The bony structures of NP in the clef-affected subjects in isolated CP subgroup, had a significantly greater downward development in the maxillary region (PMP) (both with p = 0.001), more linear growth in cranial-maxillary (Ho-PMP) dimension (p = 0.017 and 0.004, respectively), and larger area (p = 0.017 and <0.001, respectively), when compared to normal subjects. There was no significant difference between either the unilateral cleft lip and palate (CLP) or bilateral CLP group with the control group regarding AP, vertical, and linear growth of the NP and its area (P > 0.05).

CONCLUSIONS

Patients with repaired CP had downward deviated posterior maxilla, more linear growth in cranial-maxillary dimension and larger area compared to normal subjects. Among CP subtypes, a balanced growth was observed among repaired UCLP and BCLP patients, suggesting that with appropriate repaired surgery, normal development of the NP region could be expected in these subtypes.

Three-dimensional tomographic assessment of the upper airway using 2 different imaging software programs: A comparison study

INTRODUCTION

Several imaging software programs with different tools are available for upper airway (UAW) analysis by means of cone beam computed tomography. Because of this wide variability, this study aimed to compare the reproducibility of two of the most used software programs on UAW segmentation, that is, Dolphin Imaging (Dolphin Imaging and Management Solutions, Chatsworth, Calif) and Mimics Research (Materialise, Leuven, Belgium).

METHODS

The sample consisted of 50 scans of adult subjects with Class III malocclusion; pharyngeal volume and minimal cross-sectional area (mCSA) were assessed twice by 2 experienced evaluators using both software programs. Intra- and intersoftware and/or evaluator agreement were calculated using the intraclass correlation coefficient (ICC). Bland-Altman analysis was used to visualize the intersoftware and interevaluator agreement.

RESULTS

Using Mimics Research and Dolphin Imaging, the respective mean values of volume (cm³) were 27.1 ± 8.4 and 24.7 ± 8.1 (P < 0.05) and of mCSA (mm²) were 167.8 ± 95.5 and 176.5 ± 102.3 (P < 0.05). Although differences between software packages were observed on both the analyzed variables, the results showed a high intersoftware agreement, with ICC of 0.87 (volume) and 0.97 (mCSA) and mean bias of 24.6 (volume) and -8.8 (mCSA). A high intrasoftware agreement was also observed, with values varying from 0.83 to 0.99. Excellent intra- and interevaluator agreement was also obtained, with ICC values from 0.93 to 0.99.

CONCLUSIONS

Dolphin Imaging and Mimics Research individually provide highly reproducible results, with clinically acceptable agreement between them for UAW segmentation, providing consistent values for volume and mCSA.

Three-Dimensional Upper Airway Assessment in Treacher Collins Syndrome

Objectives:

The purpose of this investigation was to assess the pharyngeal dimensions and the craniofacial morphology of individuals with Treacher Collins syndrome (TCS) when compared to vertical skeletal class II individuals. It is our hypothesis that the upper airways of individuals with TCS are reduced in view of the skeletal pattern and the maxillomandibular dysmorphologies.

Materials and Methods:

Cone-beam computed tomography scans of 26 individuals had the pharyngeal volume (V) and minimal cross-sectional area (mCSA) evaluated. Study group (TCS) was formed by 13 scans of patients with TCS (7 males and 6 females; 20.2 ± 4.7 years). Control group (CG) assembled 13 scans of nonaffected individuals with the same type of skeletal pattern (2 males and 11 females; 26.6 ± 5.4 years). Cephalometric data of maxillomandibular position, maxillomandibular dimensions, and growth pattern were assessed. Statistical analysis ( P ≤ .05) included Student t test and Pearson correlation coefficient.

Results:

Although reduced, pharyngeal V and mCSA of TCS were not statistically different from the CG. On both groups, mCSA was mostly at the oropharyngeal level. Individuals with TCS presented retrognathic chin, reduced maxillomandibular dimensions, and increased clockwise rotation of the palatal plane. Maxillary and mandibular lengths were correlated with pharyngeal V and mCSA.

Conclusions:

The pharyngeal dimensions of individuals with TCS are impacted by the micrognathia and retrognathia. In association with the skeletal pattern, the reduction of the airways, although not statistically significant, may explain the increased prevalence of airways disorder in this syndrome.

Cone-Beam Computed Tomography Evaluation of Skeletal Deformities and Pharyngeal Airway in Chinese Han Individuals With Nonsyndromic Unilateral Cleft Lip and Palate

Objective:

This study examined the relationships between skeletal deformities and the pharyngeal airway of patients with nonsyndromic unilateral cleft lip and palate (UCLP).

Design:

Retrospective study.

Setting:

Orthodontics and Oral and Maxillofacial Surgery Departments in the Affiliated Hospital of Stomatology, Nanjing Medical University, China.

Patients, Participants:

The sample comprised 30 nonsyndromic UCLP patients and 30 healthy controls. Each group has 23 males and 7 females.

Interventions:

All cone-beam computed tomography images were obtained with the participant in the standard supine position and asked to bite with intercuspal position without swallowing or moving their heads and tongues during scanning.

Main Outcome Measure(s):

SNA, SNB, ANB, anterior cranial base, Wits appraisal, maxillary length (PTM-ANS || FH), maxillary position (S-PTM || FH), mandibular length (Go-Pog || MP), FMA, posterior face height, anterior face height, Posterior-Anterior face height, lower face height, pharyngeal airway volumes, and areas were evaluated by Dolphin imaging software.

Results:

The UCLP group showed significantly decreased SNA, SNB, ANB, PTM-ANS || FH, S-PTM || FH, P-A Face Height compared with the controls. However, the airway volumes and areas showed no significant difference between 2 groups. The total airway volume and minimum cross-sectional area in UCLP patients were related to the Go-Pog || MP and FMA.

Conclusions:

Patients with UCLP have both the maxillary and mandibular deficiencies in the sagittal dimension. Both the sagittal and vertical relationships of the jaw might affect the airway volume and area. However, no significant difference was detected in airway volume and area in UCLP patients when compared with the controls.

Volumetric reconstruction and determination of minimum crosssectional area of the pharynx in patients with cleft lip and palate: comparison between two different softwares

Objective:

The aim of this study was to assess the accuracy of volumetric reconstruction of the pharynx by comparing the volume and minimum crosssectional area (mCSA) determined with open-source applications (ITK-Snap, www.itksnap.org ; SlicerCMF) and commercial software (Dolphin3D, 11.8, Dolphin Imaging & Management Solutions, Chatsworth, CA, USA) previously validated in the literature.

Material and Methods:

The sample comprised of 35 cone-beam computed tomography (CBCT) scans of patients with unilateral cleft lip and palate, with mean age of 29±15. Three-dimensional volumetric models of the pharynx were reconstructed using semi-automatic segmentation using the applications ITK-Snap (G1) and Dolphin3D (G2). Volumes and minimum cross-sectional areas were determined. Inter- and intra-observer error were calculated using ICC test. Comparison between applications was calculated using the Wilcoxon test.

Results:

Volumes and minimum crosssectional area were statistically similar between applications. ITK-Snap showed higher pharynx volumes, but lower mCSA. Visual assessment showed that 62.86% matched the region of mCSA in Dolphin3D and SPHARM-PDM.

Conclusion:

Measurements of volume and mCSA are statistically similar between applications. Therefore, open-source applications may be a viable option to assess upper airway dimensions using CBCT exams.

Upper Airway 3D Changes of Patients With Cleft Lip and Palate After Orthognathic Surgery

Objectives:

The purpose of this study was to 3-dimensionally assess the airway characteristics of patients with unilateral cleft lip and palate (UCLP) and bilateral cleft lip and palate (BCLP) who underwent orthognathic surgery.

Design:

This was a retrospective study.

Setting:

The study took place at a national referral center for cleft lip and palate rehabilitation.

Patients and Participants:

The sample comprised cone-beam computed tomography (CBCT) scans obtained before and after orthognathic surgery of 15 individuals (30 CBCT scans), divided into 2 groups: UCLP group (n = 9 patients/18 CBCT scans) and BCLP group (n = 6/12 CBCT scans). All patients had a nonsyndromic UCLP or BCLP and a skeletal class III malocclusion at the preoperative period.

Interventions:

Airway volume, pharyngeal minimal cross-sectional area (mCSA), location of mCSA, sella-nasion-A point (SNA) and sella-nasion-B point (SNB) angles, and condylion-A point and condyloid-gnathion linear measurements were assessed in open-source software (ITK-SNAP and SlicerCMF).

Main Outcome Measure:

Airway dimensions of patients with UCLP and BCLP increase after orthognathic surgery.

Results:

After orthognathic surgery, UCLP group showed a significant 20% increase in nasopharynx volume. Although not significant, BCLP group also showed an increase of 18% in the same region. Minimal cross-sectional area remained dimensionally stable after surgery and was all located in the oropharynx region, on both groups. Additionally, a positive correlation was observed between volume and mCSA on both groups.

Conclusion:

Overall, individuals with UCLP and BCLP showed an increase in the upper airway after orthognathic surgery and this might explain the breathing and sleep improvements reported by the patients after the surgery.