Illusions of fusions: Assessing cervical vertebral fusion on lateral cephalograms, multidetector computed tomographs, and cone-beam computed tomographs

Associations across 22 dental and craniovertebral anomalies or variations, sagittal skeletal relationships, and vertical growth patterns: a comprehensive epidemiological study of 43 dentoskeletal traits

INTRODUCTION

Despite researchers' recent interest in identifying links between some dental and craniovertebral abnormalities, there are many important, unassessed gaps in our knowledge of this matter. In addition, previous samples were small. This large study aimed to examine, for the first time, the occurrence/severity of numerous dental and skeletal anomalies or variations and their correlations with each other and with growth patterns.

METHODS

This epidemiological study was conducted on pretreatment radiographs of 1194 patients from 3 cities (815 females). Skeletal sagittal skeletal relationships and vertical growth patterns were determined. The occurrence/severity were assessed for: cervical vertebral fusion (CVF), atlas posterior arch deficiency (APAD), ponticulus posticus (PP), sella turcica bridging (STB), hypodontia, oligodontia, hyperdontia, missing of maxillary laterals, microdontia, macrodontia, root dilaceration, odontoma, taurodontism, dental fusion, dental gemination, enamel pearl, permanent molar ankylosis, primary molar ankylosis, dens in dente, dens invaginatus, dental impaction, ectopic eruption, and dental transposition. Incidental findings were recorded as well. Concurrent anomalies, sex dimorphism, and correlations across variables were examined statistically, adjusting for the false discovery rate (α = 0.05).

RESULTS

Prevalence was calculated for 43 dentoskeletal traits/anomalies (22 abnormalities/variations [plus their severities/types] as well as 21 incidentally found traits/anomalies). Dental impaction may be more common in hyperdivergent and severer cases of sella bridging; also, primary molar ankylosis was associated with missing teeth. Dental impaction was associated only with STB and not with PP, APAD, or vertebral fusion. The only association observed among the four skeletal anomalies was seen between APAD and CVF. Merely the variables 'sagittal skeletal relationships, vertical growth patterns, PP, and APAD' showed sexual dimorphism; of these, only vertical growth pattern and APAD remained sexually dimorphic after adjusting for the FDR; still, the other two remained marginally significant and worth further evaluations. Sex dimorphism did not exist in concurrent abnormalities. The skeletal Class III was associated with the concurrent occurrence of craniovertebral, dental, and dentoskeletal abnormalities. Skeletal Class I was associated with fewer occurrences of concurrent dental anomalies. Vertical growth patterns were not associated with concurrent dental or dentoskeletal anomalies. However, the hyperdivergent pattern was associated with fewer cases of concurrent craniovertebral abnormalities.

CONCLUSIONS

STB and hyperdivergent pattern were associated with dental impaction. However, APAD, CVF, or PP were not associated with dental impaction. APAD was associated with CVF. Sexual dimorphism existed conclusively in the case of vertical growth patterns and APAD. Concurrent abnormalities (dental, skeletal, and dentoskeletal) were associated with skeletal Class III.

A Concomitant Occurrence of the Atlantoaxial Subluxation with Rare Vertebral Formation and Segmentation Defects

An atlantoaxial subluxation from the unstable Os odontoideum by the failure of proper integrations between the embryological somites might be a commonly reported pathology. However, its suspicious origin or paralleled occurrence with other congenital anomalies of vertebral body might be a relatively rare phenomenon. The authors present two cases, who simply presented with clinical signs of prolonged, intractable cervicalgia without any neurological deficits, revealed this rare feature of C1–2 subluxation from the unstable, orthotropic type of Os odontoideum that coincide with congenitally fused cervical vertebral bodies between C2–3. Surprisingly, in one case, when traced from the lower cervical down to the thoracic-lumbar levels during the preoperative work-up process, was also compromised with multi-level butterfly vertebrae formations. Presented cases highlight the association of various congenital vertebrae anomalies and the rationale to fuse only affected joints.

Evaluation of the three-dimensional (3D) position of cervical vertebrae in individuals with unilateral posterior crossbite

OBJECTIVE

To evaluate the three-dimensional (3D) position of the cervical vertebrae of growing subjects with unilateral posterior crossbite (UPC).

MATERIALS AND METHODS

In this cross-sectional study, cone beam computed tomography (CBCT) scans of 1455 patients were screened, and ultimately 58 scans (26 patients with UPC and 32 controls with normal occlusion) were included after imposing inclusion/exclusion criteria. Roll, yaw, and deviation of the geometric center of C1, C2, and C3 vertebrae were measured and compared between groups. A correlation between these parameters and different variables on mandibular positioning was also carried out.

RESULTS

A statistically significant difference (p < 0.05) was observed between groups for the deviation of pogonium (Pog), mandibular plane roll, and C3 roll, and patients with UPC showed higher cant or deviation. A significant correlation was reported for the roll of C2 and C3 with the deviation of Pog, a roll of the occlusal plane, and roll of the mandibular plane (p < 0.05). The greater the deviation of the Pog to one side, the greater the roll of the vertebrae with this same side up. The same tendency was observed between the roll of the occlusal plane or the mandibular plane with the roll of these cervical vertebrae.

CONCLUSIONS

There is a positive correlation between transverse occlusal changes and positional deviations of the cervical vertebrae, especially C2 and C3.

CLINICAL RELEVANCE

The study results do not allow us to infer the clinical/functional consequences of these deviations, as well as if malocclusion's treatment would result in an improvement of intervertebral relationships.

Three-Dimensional Assessment of Cervical Vertebrae Anomalies in Patients With Cleft Lip and Palate

OBJECTIVE

To evaluate the occurrence of cervical vertebrae anomalies (CVA) in patients with unilateral (UCLP) and bilateral cleft lip and palate (BCLP) using cone beam computed tomography (CBCT) examinations.

DESIGN

Retrospective assessment of CBCT images. Descriptive statistics were calculated. Fisher exact test or χ² test was performed to evaluate the differences among each CVA between sex and type of cleft.

SETTING

School of Dentistry.

PARTICIPANTS

One hundred fifty-one patients with cleft lip and palate (103 UCLP/48 BCLP).

INTERVENTIONS

No relevant intervention.

MAIN OUTCOME MEASURES

Cone beam computed tomography images were assessed for the presence or absence of 12 most commonly observed CVA: spina bifida, dehiscence, cleft of the posterior arch, cleft of the anterior arch, fusion between cervical vertebrae, block fusion, occipitalization, narrowing of the intervertebral space, posterior ponticle, os odontoideum, ossiculum terminale, and subdental cartilaginous remnants.

RESULTS

The presence of subdental cartilaginous remnants was the most frequently observed alteration-found in 81.45% of the sample-and it was the only CVA with statistically significant frequencies in the individuals with BCLP. Considering only the other CVA, 22.51% presented 1 and 5.29% presented 2 or more CVA.

CONCLUSIONS

Patients with cleft lip and palate may present an overall high incidence of CVAs. However, when comparing the distribution of the CVAs among sex and types of cleft, the only significant difference noted was a higher incidence of subdental cartilaginous remnants among patients with BCLP.

Prevalence of cervical vertebrae anomalies in patients with cleft lip and palate

Objective

To investigate the prevalence of cervical vertebral anomalies (CVA) in a group of patients presenting with cleft lip and palate (CLP) and to compare with a non-cleft population.

Material and methods

The sample comprised of 150 lateral cephalograms of non-syndromic patients with CLP and 150 non-cleft age-matched controls. The age range of both groups covered 6 to 20 years. An expert radiologist blinded to the cleft status evaluated the cephalograms for CVA and categorised them into normal, fusion, dehiscence and multiple cervical anomalies. The cleft group was subdivided according to the types of cleft (UCLP/ BCLP/ CPO) and gender (male/female). The CVA prevalence was compared between the cleft and non-cleft patients.

Results

The prevalence of CVA was 37.7% and 20.7% in cleft and non-cleft patients, respectively. The difference was statistically significant with a p-value <0.01. Of the types of clefts, a left UCLP had the highest prevalence of CVA (47.2%), with fusion (35.8%) most commonly seen. On comparing CLP with CPO, no significant variation was observed between the types of anomalies.

Conclusions

A high prevalence of CVA was observed in cleft patients compared with non-cleft subjects. The prevalence of CVA was similar between males and females. The practitioner should carefully evaluate the lateral cephalogram of CLP patients for CVA, which otherwise may remain undetected and lead to neurological symptoms later in life.

Cone beam computed tomography incidental findings of the cervical spine and clivus: retrospective analysis and review of the literature

OBJECTIVE

The aim of this study was to analyze and describe incidental findings in the cervical spine (C-spine) and the clivus encountered in cone beam computed tomography (CBCT) imaging. The wide range of possible anatomic variants and pathoses is discussed in the context of the medical and dental literature to clarify their radiographic appearance and clinical implications as a guide for the oral and maxillofacial radiologist.

STUDY DESIGN

A retrospective analysis of radiographic reports was conducted based on CBCT images from 2 oral and maxillofacial imaging centers. Reports documenting incidental findings in the C-spine or the clivus were selected. Data on patient age and sex were collected, and each incidental finding was categorized as degenerative, congenital, or developmental/pathologic. Each finding is discussed with clinical importance and is pictorially presented.

RESULTS

From a total of 7689 CBCT reports, there were 732 incidental findings (9.5%) in the C-spine or the clivus. Most findings were in the C-spine (92.3%), were degenerative in nature (78.7%), and occurred in females in their sixth decade. Logistic regression analysis showed that the odds of presenting with a degenerative incidental finding in the C-spine or the clivus did not differ based on sex but were 5.5 times (95% confidence interval, 3.77-8.04) higher if the patient was aged 50 years or older.

CONCLUSIONS

This review is the largest and the first to characterize incidental findings in the C-spine and the clivus. Such findings were reported in 9.5% of radiographic reports. Several presented as uncommon congenital variants that are not usually spotlighted during oral and maxillofacial radiology training.

Influence of skeletal class in the morphology of cervical vertebrae: A study using cone beam computed tomography

OBJECTIVES

To quantify the prevalence of cervical vertebrae anomalies and to analyze any association between them and skeletal malocclusions or head posture positions in the same study.

MATERIALS AND METHODS

Two hundred forty patients who were attending the Department of Orthodontics of the University of Valencia for orthodontic treatment were selected and divided into three groups: skeletal Class I (control group, 0° <ANB < 4°), Class II (ANB ≥ 4°), and Class III (ANB ≤ 0°) according to ANB Steiner angle. The morphology of the first five cervical vertebrae was analyzed with cone beam computed tomography to identify any anomalies. Intra- and interobserver error methods were calculated.

RESULTS

Dehiscence and fusion of one unit (both 23.3%) and partial cleft (11.7%) were the most frequent anomalies, while occipitalization was the least common (3.3%). Dehiscence anomaly was observed when the control group was compared with Classes II and III and partial cleft anomaly when Class I was compared with Class III. Furthermore, NSBa and ss-N-sm/ANB angles were associated with partial cleft anomaly, while NSL/NL angle and extended head posture were associated with fusion anomaly.

CONCLUSIONS

Fusion, dehiscence, and partial cleft were the most frequent cervical vertebrae anomalies. Dehiscence and partial cleft were found to present statistically significant differences between Class I and Classes II and III. Cervical vertebrae anomalies and head posture were associated with fusion.

Cervical vertebral column morphology and head posture in preorthodontic patients with anterior open bite

INTRODUCTION

Cervical vertebral column morphology and head posture were examined and related to craniofacial morphology in preorthodontic children and adolescents with anterior open bite.

METHODS

One hundred eleven patients (ages, 6-18 years) with an anterior open bite of more than 0 mm were divided into 2 groups of skeletal or dentoalveolar open bite. The skeletal open-bite group comprised 38 subjects (19 girls, 19 boys). The dentoalveolar open-bite group comprised 73 subjects (43 girls, 30 boys). Visual assessment of the cervical column and measurements of craniofacial morphology and head posture were made on profile radiographs.

RESULTS

Deviations in the cervical vertebral column morphology occurred in 23.7% of the subjects in the skeletal open-bite group and in 19.2% in the dentoalveolar open-bite group, but the difference was not significant. Head posture was significantly more extended in the skeletal open-bite group compared with the dentoalveolar open-bite group (craniovertical angle [Mx/VER], P <0.05; craniocervical angles [Mx/OPT, Mx/CVT], P <0.01. Only head posture was associated with craniofacial morphology: extended posture was associated with a large cranial base angle (P <0.01, P <0.001), large vertical craniofacial dimensions (P <0.05; P <0.01; P <0.001), and retrognathia of the jaws (P <0.001).

CONCLUSIONS

Cervical column morphology is described for the first time in children and adolescents with open bite. No significant differences in the cervical vertebral column's morphologic deviations were found between the skeletal and the dentoalveolar open-bite groups. Significant differences were found in head posture between the groups and with regard to associations with craniofacial dimensions. This might indicate a respiratory etiologic component in children with anterior open bite.