Pharyngeal Airway Space in Cleft Lip and Palate

Cleft-affected individuals face a surfeit of orofacial problems which include various
dentoalveolar aberrations and respiratory difficulties such as mouth breathing and snoring. The
parents of CLP individuals often notice their children suffering from such breathing

These conditions are linked to pharyngeal airway aberrations which are proposed to be common
in cleft lip and palate due to the inherent anatomy of the maxillofacial complex of such
individuals. If unaddressed, it may further lead to an increased risk of cardiovascular, and
cerebrovascular diseases and hypertension.

The article that will be discussed here will be as follows:

Comparative Evaluation of the Pharyngeal Airway Space in Unilateral and
Bilateral Cleft Lip and Palate Individuals with Noncleft Individuals: A Cone
Beam Computed Tomography Study

By Narayan H. Gandedkar, Chng Chai Kiat, Mohammad Abdul Basheer, Por Yong Chen, Yeow
Kok Leng Vincent

The Cleft Palate-Craniofacial Journal, 2016;

What did the authors assess?
The authors evaluated the pharyngeal airway space in UCLP and BCLP individuals and compare
those results to class I Non-cleft individuals using CBCT

What were the methods used?

The sample size was calculated. This study had 3 groups.
Group 1 – 20 UCLP individuals (mean age: 13.4 ± 0.5 years),
Group II – 18 BCLP (mean age: 13.5 ± 0.5 years),
Group III – 20 skeletal Class I subjects (mean age: 13.4 ± 0.6 years).
The cleft patients for whom primary lip and palate closure surgery done before two years of age
with no history of previous orthodontic treatment; nonsyndromic, isolated complete cleft lip and
palate; no history of tonsillectomy or adenoidectomy and orthognathic surgery were included in
the study.

The control group consisted of non-cleft skeletal class I individuals based on ANB angle of 2°
with no previous orthodontic treatment, and no history of tonsillectomy, adenoidectomy or
CBCTs were taken for controls who had impacted canines.

In the CBCT image, the pharyngeal airway space was divided into the nasopharynx and
oropharynx. The boundaries were marked based on a previous study by Celikoglu et al (2014), in
which instead of using PNS as the anterior border, it was modified considering varied positions
of PNS in bilateral cleft patients.

What did the results show?
Let’s go to the demographic details.

All 3 groups had matched chronologic age and gender distribution.

And there was no difference in the pharyngeal dimensions between the gender in all 3 groups.

When the nasopharyngeal, oropharyngeal and total airway volume was compared between the 3
groups, the BCLP group had a significant reduction in all the 3 pharyngeal spaces as compared
to UCLP and controls.

The authors attributed these results to the bimaxillary retrognathia and the retrognathic
framework of the BCLP individuals leading to reduced Pharyngeal airway spaces.

The authors conclude by saying that, the pharyngeal airway space was significantly reduced in
the BCLP group than in the UCLP and control groups. This reduced PAS should be taken into
account while planning treatment for these individuals.

Strength of this study:

Separate unilateral and bilateral cleft groups – Most of the previous studies that have
assessed the pharyngeal dimensions in cleft patients, did not categorize the patients according to
the type of cleft and have pooled both the UCLP and BCLP into one group. This study has
specifically studied the pharyngeal dimensions based on the type of cleft

Age and gender matching – One of the major strengths of this study is that they have matched
the age and sex of the samples in all 3 groups. As the pharyngeal volume varies with age, age
could have been one of the confounding factors in the results. The authors addressed this
component in their study wisely by matching the age.

Three-dimensional imaging modality – The use of CBCT for assessing the pharyngeal spaces
was a major strength of the study. Many previous studies have evaluated only 2 dimensionally

Use of modified landmarks instead of PNS – As identification of PNS in cleft patients would
be difficult, the authors addressed this issue by using a more stable landmark from the cranium.
(Sella to Nasion – basion plane)

However, there are also some limitations to this study:

Firstly, the sample size was selected by employing a convenience sampling methodology.

The study was retrospective in nature, and all the individuals were recruited from the same
hospital. Hence, the generalizability of the results is questionable

The extent of the cleft and type of surgery could have also played a role in the extent of the
reduction of airway volume. The authors did not produce relevant information on the same.

Although this was a 3- Dimensional study, it corresponds to a static representation of a dynamic,
complex structure that can be influenced by several factors (swallowing, inspiration, expiration,
muscle tone, etc.)

Hence, the use of a 4- Dimensional, dynamic representation (such as the use of dynamic MRI) of
these structures would be more representative.

Contributors : Dr. Ramyaja, Dr. Annapurna