Three-dimensional radiographic features of craniometaphyseal dysplasia—a comparative CBCT study
Authors: Muttanahally Kavya Shankar , Chen I-Ping , Reichenberger Ernst J. , Tadinada Aditya , Vaddi Anusha 
Published: April 2023

Abstract
Purpose
Craniometaphyseal dysplasia (CMD) is a rare skeletal disorder that has progressive thickening and increased density of the craniofacial bones along with abnormal metaphyses of the long bones. Other features include a wide nasal bridge, paranasal bossing, hypertelorism, and an increase in the zygomatic width. We present a series of cases that showcase the three-dimensional radiographic features of this rare condition and compare it with an age and gender-matched controlled group using cone beam computed tomography (CBCT).

Objective
To evaluate the three-dimensional radiographic features of craniometaphyseal dysplasia (CMD).

Materials and methods
Retrospective analysis of CBCT scans of 7 patients who were diagnosed with the rare condition craniometaphyseal dysplasia was evaluated. Radiographic features of the craniofacial bones, the paranasal sinuses prominently maxillary, and frontal and sphenoid sinuses were evaluated. Skull bones were also evaluated, and the size and shape of the sella turcica and external auditory meatus were measured. Retained primary teeth and impactions were evaluated using a panoramic reformatted image. The type of occlusion and buccolingual dimensions of jaw bones were also assessed. Age and gender-matched control samples were used to measure the same features for comparing CMD patients to healthy controls. The quality of normal and syndromic patients’ cortical and trabecular bone was determined by measuring pixel intensity values (PIV) generated by CBCT scans.

Results
Cone beam CT images of patients with CMD were analyzed to evaluate cranial bones, their density, and any abnormalities associated with the sinuses and foramina. Patients with CMD had bones increased in size. A significant increase in the amount of bone formed was found in the inner table of the frontal and occipital bones. All seven patients with CMD had smaller foramina due to the deposition of sclerosed bone in the foramina of the skull base. The paranasal sinuses, prominently maxillary and frontal and sphenoid sinuses, were smaller than the age and gender-matched controls. The buccolingual dimensions of jawbones were increased. The maxillary and mandibular arch relationship ranged from class II to class III. The mean nasal bridge measurement for the CMD patients was 26.77 mm, while in the controls, the mean nasal bridge measurement was 19.48 mm. The mean measurements of the right and left orbits of CMD patients were 30.6 mm and 31.07 mm respectively, and the mean measurements of the right and left orbits of controls were 32.45 mm and 32.04 mm. Pixel intensity values (PIVs) representing density ranged between 100 and 1000 PIVs for cortical bone and between − 60 and 258 for trabecular bone suggesting a densely sclerotic texture, while in the control group patients, the PIVs for cortical bone were > 1000 and 150–300 for trabecular bone.

Conclusion
CMD patients had significantly larger bone widths, a lower density of the bone, and smaller sinuses compared to the control group.