Prevalence and Morphologic Features of Ponticulus Posticus in Koreans: Analysis of 312 Radiographs and 225 Three-dimensional CT Scans

C0-C1 joint injection: Anatomical, clinical and technical review

Background

Cervicogenic headaches (CGH) are proven clinical entities. The prevalence of CGH arising from the atlanto-occipital (AO) joint is unknown. The best evidence for treatment of CGH is for third occipital nerve radiofrequency neurotomy. Treatment of CGH includes intra-articular injections into upper cervical spine joints.

Objective

To perform a review of the anatomy and clinical presentation of AO joint (AOJ) pain referral as well as a technical description to safely access the AOJ.

Methods

A literature review was performed to explore the intricacies of the cranio-cervical junction (CCJ) with a focus on the relation between the AOJ and vascular anatomy. Our technical approach is described with complementary images.

Results

The AOJ lies anterior to a venous sinus and slightly superior to the horizontally oriented vertebral artery crossing the joint line.

Conclusion

The authors propose a modified superior needle trajectory that seeks to avoid these vascular structures and to access the AOJ safely.

Does ponticulus posticus affect vertebral artery diameter

PURPOSE

Ponticulus Posticus, atlantooccipital ligament ossification-induced anomaly, surrounds the vertebral artery and the first cervical nerve root. It is believed to wrap around the first cervical nerve root and the vertebral artery, causing compression. We hypothesized that it would also reduce the diameter of the vertebral artery.

METHODS

Between January 1, 2022, and December 31, 2022, cervical spine CT scans taken for any reason were retrospectively reviewed. The images of 1365 patients suitable for evaluation were evaluated by two expert radiologists in 3 dimensions. Among patients with PP, those who underwent cervical angiography were identified for vertebral artery diameter measurement.

RESULTS

The average age of the 1365 individuals included in the study (732 males, 633 females) was 55.78 (± 18.85) with an age range of 1-96. Among this group, PP was detected in 288 individuals, resulting in a total prevalence of 21.1%. Right and left vertebral artery diameters were significantly lower in patients with complete PP compared to the absent group (p < 0,001, p < 0,001, respectively). Additionally, it was observed that width and height diameters and artery diameters were positively correlated in patients with Complete PP.

CONCLUSIONS

Ponticulus posticus can cause vertebrobasilar insufficiency by reducing the diameter of the vertebral artery. Therefore, imaging and detailed evaluation of this region are important in symptomatic patients.

Ponticulus posticus and skeletal malocclusion: A pilot study in a Southern Italian pre-orthodontic court

Purpose

Ponticulus posticus (PP) is a bony protrusion located between the posterior portion of the superior articular process and the posterolateral portion of a posterior arch of the atlas vertebrae in the cervical spine. The aim of this study is to verify the presence of different types of PP in a Southern Italian pre-orthodontic cohort to understand its correlation with skeletal class and maturity.

Methods

A case-control retrospective study was conducted, utilizing 212 latero-lateral telecranium radiographs to analyze skeletal maturity according to the cervical vertebral maturation method, the Angle's classification of malocclusion (I, II, or III), and the presence or absence of the PP, whether complete (c-PP) or partial (p-PP). A total of 212 lateral cephalograms were analyzed.

Results

Of the 72 male patients, 67 (93%) exhibited PP, and 116 (88%) were PP. The chi-square value was 0.001, while Cramer's V was 0.270, indicating a significant correlation between age groups and PP presence, and a very strong association overall. Out of the 41 complete PP cases, class I was notably more prevalent than classes II and III.

Conclusion

Orthodontists should carefully consider PP when assessing and treating individuals with or without skeletal discrepancies and dental anomalies.

Prevalence of Ponticulus Posticus among Orthodontic Patients of Iranian Population by Lateral Cephalogram

Background

The term Ponticulus Posticus (PP) refers to a complete or partial bony bridge on the vertebral artery that passes through the superior-lateral surface of the posterior arch of the atlas. This study was conducted with the aim of investigating the prevalence of ponticulus posticus in orthodontic patients referred to Mashhad Dental School.

Methods

In this cross-sectional study, one thousand cephalograms were selected from the patients referred to the orthodontics department of Mashhad Dental School between 2017 and 2021. In lateral cephalogram images with appropriate quality, the type of malocclusion was determined using the AudaxCeph software (Audax d.o.o., Ljubljana, Slovenia). Then, the images were evaluated for the presence or absence of PP. For the statistical analysis, chi-square and t-test were used.

Results

In this study, 861 lateral digital cephalograms were analyzed. The overall prevalence of PP in the studied population was 17.5%. The prevalence of PP was higher in males than in females (P < 0.001). The variables "presence of PP" (P = 0.056) and "type of PP" (P = 0.522) were found to be independent of age groups. Although class II subjects showed a higher prevalence of PP, skeletal malocclusion classes were not found to be correlated with the presence of PP (P = 0.104) nor with its types (P = 0.958).

Conclusion

The current study is considered the primary study that provides data concerning the prevalence of PP in the East of Iran. Our study showed that PP was not rare in this region. More studies with 3D radiological examination are needed to increase the accuracy of diagnosing PP and its prevalence in Iran.

The Prevalence and Morphology-Wise Demographic Distribution of Ponticulus Posticus on CT Scans—A Retrospective Observational Study

Background and Objectives: The ponticulus posticus (PP) is a bony bridge that emerges from the posterior aspect of the superior articular process, to connect the posterior arch of the atlas. It is often associated with neurological symptoms. The aim of this study was to obtain an insight into this malformation, and prevalence in the North East region of the Romanian population. Materials and methods: This anatomical variant was analyzed through an observational and retrospective study which was carried out in St. Spiridon Hospital Iasi. The duration of the study was 10 months and, a number of 487 patients who presented neurological symptoms without cranio-cerebral traumatisms were enrolled and a computed tomography (CT) scan was performed. We proposed a new classification of PP in five types. The prevalence of PP was calculated and Skewness test, ANOVA test with Bonferroni correction, and Student’s t-test were used for statistical analysis. Results: Among the sample of 487 patients, PP was found in 170 cases (34.90%) in an age group of 8–90 years (mean age = 59.52 years, SD ± 19.94 years). Type I was found in 11.29%, followed by Type II—8.21%, Type III—5.13%, Type IV—5.54%, and Type V—4.72% (p = 0.347). It was 19.5%, mirroring the incomplete type, whereas the complete type was reported in 15.40% of cases (p = 0.347), the highest prevalence, namely 41.17% was found in the “41 to 60 years” age group, followed by 36.95% in the “21 to 40 years” group (p = 0.00148). The mean age was higher in patients with PP Type III (61.16 years, SD ± 19.98), while patients with PP Type V recorded the lowest mean age (56.48 years, SD ± 22.13). The differences between the comparative average ages on types were not statistically significant (p = 0.411). The gender and age were not good predictors of PP Type V (AUC < 0.600). Conclusion: according to our study, incomplete types of PP were found to be more prevalent as compared to complete types. No difference between males and females was detected. PP is more frequent in adults and young adults than in the elderly population. It is confirmed that gender and age were not good predictors of the bilateral complete type of PP.

Prevalence of Ponticulus Posticus and Migraine in 220 Orthodontic Patients: A Cross-Sectional Study

BACKGROUND

Ponticulus posticus (PP) is a medical term that describes an anomaly of the atlas (C1), which has a complete or partial bone bridge over the vertebral artery (VA) groove. The purpose of the study is to estimate the prevalence of PP in patients with a diagnosis of migraine.

METHODS

Cone beam CT (CBCT) scans (n = 220) were reviewed for the detection of PP in the University "G. D'Annunzio" of Chieti in the Department of Medical, Oral and Biotechnological Sciences. The sample included 220 Italian patients between 18 and 87 years. Pearson chi-square analysis (p < 0.05 and 95% CI) was used to establish an association between migraine and PP.

RESULTS

The present study found a prevalence of PP of 20.9% and a prevalence of migraine of 12.272%. The association between migraine and PP was confirmed by the chi-square statistic, since the p-value was 0.008065 (significant at p < 0.05). PP was more frequent in the migraine without aura group, without a statistical difference relative to the migraine with aura group.

CONCLUSIONS

The study concluded that PP is positively associated with migraine.

Prevalence of ponticulus posticus on the posterior arch of the atlas in symptomatic and asymptomatic patients

OBJECTIVE

To calculate the prevalence of ponticulus posticus and its association with headache.

METHODS

The presence and types of ponticulus posticus were investigated on 640 digital lateral cephalograms. Patients with complete or partial ponticulus posticus were further evaluated and questioned for a history of cervicogenic headache. Dissemination of attain values was analyzed using a Chi-Square test, and p values < 0.05 were considered statistically significant.

RESULTS

The prevalence of ponticulus posticus in our study was 9.8%, with complete form in 45 (7%) patients of which 29 (64.5%) were male and 16 (35.5%) were female. Partial ponticulus posticus was found in 18 (2.8%) of patients, of which 12 (66.6%) patients were male and six (33.33%) were female. In patients with the complete form of ponticulus posticus, 37 (82.22%) were symptomatic. Among these 37 patients, 22 (59.45%) were male and 15 (40.54%) were female. In complete ponticulus posticus patients, symptoms were slightly worse in males than females. Whereas in partial ponticulus posticus, 13 (72.22%) patients were found to be symptomatic. Of these 13 patients, seven (53.84%) were male and six (46.15%) were female. Of the 72 patients with a history of cervical pain, 50 (69.44%) showed ponticulus posticus on a lateral cephalogram. Of the 568 patients with no history of cervical pain, only 13 (2.2%) showed ponticulus posticus on the lateral cephalogram.

CONCLUSION

This study examination showed that ponticulus posticus is a common anatomic variation often associated with tension-type headaches.

Research Progress of Ponticulus Posticus: A Narrative Literature Review

Study Design

Narrative review.

Objective

The purpose of this review was to consolidate the current literature related to ponticulus posticus (PP) and to improve the systematic understanding of this anatomical variant of atlas among spine surgeons.

Methods

Articles reviewed were searched in PubMed, Ovid MEDLINE, and Embase. All articles of any study design discussing on PP were considered for inclusion. Two independent authors read article titles and abstracts and included appropriate articles. The relevant articles were studied in full text.

Results

A total of 113 literatures were reviewed and consolidated in this narrative review. These articles are roughly divided into the following five subcategories: (1) epidemiology, (2) pathology and anatomy, (3) clinical presentation, (4) surgical significance, and (5) radiographic examination.

Conclusion

The PP is non-negligible with a high prevalence. The PP compresses the V3 segment of the artery, the suboccipital nerve, and the venous plexus, consequently contributing to the incidence of neurological pathologies. When a PP is observed or suspected on a lateral radiograph, we recommend that a computed tomography (CT) scan of a patient who is about to receive a C1 lateral mass screw (C1LMS) should be performed, which could determine a safe entry point and the right trajectory of screw insertion.

The computed tomographic evaluation of bony bridge of C1 as bleeding risk factor at the screw placement

PURPOSE

To investigate the prevalence and morphological characteristics of ponticulus posticus (PP) and ponticulus lateralis (PL) using computed tomography (CT) images on a large study sample of the Anatolian population. The presence of the PP and PL bridges can limit gap available for placement procedure through the bony elements of C1. Routine screw techniques are contraindicated because of high risk of fatal bleeding of vertebral artery (VA).

METHODS

The CT images of 1000 subjects (500 males, 500 females) were examined for the morphological characteristics and presence of PP and PL. The anteroposterior diameter, superoposterior (transverse) diameter, surface area, and central thickness of the bony bridge of the PP, PL, and transverse foramina (TF).

RESULTS

The prevalence of PP was 14.8%, and bilateral complete PP was the most common PP type at 6.8%. The prevalence of PL was 4.1% and left-side complete PL was the most common PL type at 1.2%. The prevalence of both PP and PL was more common in males and bilateral complete PP were more predominant in males (p = 0.004, p = 0.038, and p = 0.010, respectively). The surface area of PP and PL were determined to be smaller than the surface area of the ipsilateral TF (p < 0.001 and p = 0.042, respectively).

CONCLUSION

PP is not an uncommon anatomic anomaly and PL is even less frequently encountered. The prevalence of PP and PL was more common in males and bilateral complete PP was more predominant in males. Detailed information about the prevalence and morphometry of the PP and PL obtained in the present study could guide the clinicians dealing with neurosurgery, physical medicine and rehabilitation, and radiology in their practice.

Correlation of ponticulus posticus with dentofacial skeletal patterns

Background:

Methods:

Results:

Conclusions:

Assessments of Prevalence of Ponticulus Posticus, Atlas Posterior Arch Deficiency, Sella Turcica Bridging, Maxillary Canine Impaction, and Associations Among Them in 500 CBCTs of Italian Orthodontic Patients

Background: The ponticulus posticus (PP) is an important anomaly of the atlas (C1 vertebra) with a complete or partial bone bridge that transforms the groove of the vertebral artery (VA) into a canal (arcuate foramen). The aim was to retrospectively determine prevalence of PP evaluating morphological features and the possible association with other dentoskeletal anomalies in the midface and neck area such as maxillary canine impaction (MCI), atlas posterior arch deficiency (APAD), and sella turcica bridging (SB).

Methods: This study was conducted in the Department of Medical, Oral and Biotechnological Sciences of the University “G. D'Annunzio” in Chieti. The detection of PP was performed on 500 patients with cone beam CT (CBCT) images (6 to 87 years).

Results: Analysis revealed the presence of uni- and bi-lateral PP in 110 patients (22%): 24 (4.8%) patients with bilateral complete PP, 12 (2.4%) patients with complete PP on the left, 6 (1.2%) patients with complete PP on the right, 8 (1.6%) patients with complete PP on the right and partial PP on the left, 6 (1.2%) patients with complete PP on the left and partial PP on the right, 26 (5.2%) patients with partial bilateral PP, 18 (3.6%) patients with partial left PP, and 10 (2%) patients with partial PP on the right. The Chi-squared statistic confirmed that there are significant associations between MCI and PP (p = 0.020) and between SB and MCI (p &lt;0.00001). No correlation between chronological age and presence of the PP (p = 0.982), between chronological age and morphotypes of the PP (p = 0.779), between APAD and the PP (p = 0.0757), between SB and the PP (p = 0.111), and between APAD and MCI (p = 0.222) were found.

Conclusion: This observational study showed how bilateral partial variant and bilateral complete variant are the most represented morphotypes in all the age groups. The prevalence of MCI is positively associated with PP and with SB.

The craniovertebral junction, between osseous variants and abnormalities: insight from a paleo-osteological study

The bony components of the craniovertebral junction (CVJ) have been investigated in 172 skeletons, dug up from several archaeological sites, to define the frequency of developmental dysmorphisms, and to acquire qualitative and quantitative data about their morphology. A review of the pertinent literature is also presented. Twenty-five individuals (14.5%) exhibited at least one dysmorphism, which ranged from a condition of simple variant to a true malformation. Four individuals presented two or more anomalies at the same time (2.3% of the whole sample, 16% of the affected individuals). The most frequently observed abnormalities were: (i) the presence of a complete bony bridge in the atlas, forming a canal surrounding the vertebral artery (arcuate foramen, supertransverse foramen, and the simultaneous occurrence of arcuate foramen and supertransverse foramen); (ii) the presence of basilar processes. Basilar processes displayed a great variety in shape and dimension. They also differed with respect to their relationship with atlas and axis. The less frequently detected anomalies were: (i) complete absence of the posterior arch of C1, (ii) fusion of C2 and C3, and (iii) irregular segmentation of C2. A broad array of structural defects has been described at the CVJ. They may occur either isolated or as part of complex multisystem syndromes. Although harmless in many cases, they can notwithstanding cause severe, even life-threatening complications. When unrecognized, they may generate trouble during surgery. Hence, accurate knowledge of CVJ arrangement, including its multifarious variations, is a critical issue for radiologists, clinicians, surgeons, and chiropractors.

Multiple Fractures of Cervical Vertebrae Combined with Arcuate Foramen and Vertebral Artery Occlusion: A Case Report and Literature Review

BACKGROUND

The arcuate foramen is a complete or partial bony bridge over the vertebral artery groove of atlas. The mechanism of the arcuate foramen is not clearly understood. Omission of the arcuate foramen sometimes causes lethal iatrogenic injury during spinal surgery.

CASE PRESENTATION

We describe a patient who was diagnosed with multiple fractures of the cervical vertebrae, arcuate foramen, and right vertebral artery occlusion based on clinical and radiological exams. After conservative treatment, he resumed a normal and productive life.

CONCLUSIONS

Arcuate foramen is a common variation that causes symptoms such as dizziness, headache, and migraine. If the patient does not develop severe symptoms, conservative treatment can achieve very good results without the necessity to remove the bone bridge. When serious symptoms occur, surgical treatment to resect the bony ridges can relieve the symptoms dramatically.

The C2 Pedicle Width, Pars Length, and Laminar Thickness in Concurrent Ipsilateral Ponticulus Posticus and High-Riding Vertebral Artery: A Radiological Computed Tomography Scan-Based Study

STUDY DESIGN

Retrospective radiological study.

PURPOSE

We aimed to determine the prevalence of ponticulus posticus (PP) and high-riding vertebral artery (HRVA) occurring simultaneously on the same side (PP+HRVA) and in cases of PP+HRVA, to assess C2 radio-anatomical measurements for C2 pars length, pedicle width, and laminar thickness.

OVERVIEW OF LITERATURE

PP and HRVA predispose individuals to vertebral artery injuries during atlantoaxial fixation. In cases of PP+HRVA, the construct options thus become limited.

METHODS

Consecutive computed tomography scans (n=210) were reviewed for PP and HRVA (defined as an internal height of <2 mm and an isthmus height of <5 mm). In scans with PP+HRVA, we measured the ipsilateral pedicle width, pars length, and laminar thickness and compared them with controls (those without PP or HRVA).

RESULTS

PP was present in 14.76% and HRVA in 20% of scans. Of the 420 sides in 210 scans, PP+HRVA was present on 13 sides (seven right and six left). In scans with PP+HRVA, the C2 pars length was shorter compared with controls (13.69 mm in PP+HRVA vs. 20.65 mm in controls, p<0.001). The mean C2 pedicle width was 2.53 mm in scans with PP+HRVA vs. 5.83 mm in controls (p<0.001). The mean laminar thickness was 4.92 and 5.48 mm in scans with PP+HRVA and controls, respectively (p=0.209).

CONCLUSIONS

The prevalence of PP+HRVA was approximately 3% in the present study. Our data suggest that, in such situations, C2 pedicle width and pars length create important safety limitations for a proposed screw, whereas the translaminar thickness appears safe for a proposed screw.

The Association between Ponticulus Posticus and Dental Agenesis: A Retrospective Study

Objective:

Neural tube defects may increase the risk of an abnormal development of skull, vertebral column and teeth formation, including dental agenesis in non syndromic patients. The association between the presence of a congenital Dental Agenesis (DA) and the Atlantooccipital Ligament (AOL) calcification, known as “Ponticulus Posticus” (PP), as possible links can be investigated.

Design:

After a systematic review of the scientific literature on this topic, two independent examiners assessed the AOL calcification in lateral cephalograms of 350 non syndromic patients(7-21 years old). The results were compared with a control group (non syndromic patients, without congenital missing teeth).

Results:

The 16.3% of the population studied by cephalometric analysis revealed a prevalence rate of PP (both complete and partial) with a slight male predominance is seen, not statistically significant (χ square test = 0.09; p= 0.76). In both sexes complete PP is more observed. In the patients affected by DA the frequency of PP is the 66.6% (both complete than partial). The χ square test with Yates correction showed a significative difference(χ= 66.20; p value= 0.00) between PP in patients with DA compared to not affected by DA.

Conclusions:

PP is not an uncommon anomaly. Since orofacial pain like migraine and other symptoms are often associated to PP, during routine radiographic examination, if detected, it should be documented in patients’ health record and with symptoms, further investigation should be sought for. These findings encourage to think there’s an association between DA in non syndromic patients and neuro-crestal cells defects.

How Common Is the Ponticulus Posticus?: A Computed Tomography Based Analysis of 2917 Patients

STUDY DESIGN

A computed tomography (CT) study of the morphology of the C1 vertebra.

OBJECTIVE

Is to determine the prevalence of ponticulus posticus (PP) by analyzing CT scans performed on a large, diverse population in the northeast United States. This study also proposes a CT-based classification system both to aid in unifying the description of PP, and to aid in future research.

SUMMARY OF BACKGROUND DATA

The prevalence of PP varies from 5% to 68% in published studies. There may be geographic variation in the prevalence of PP. Our objective was to establish the prevalence of PP in the general population, and to develop a comprehensive classification system to describe PP.

METHODS

We evaluated cervical spine CT scans performed on patients in the emergency room of a level I trauma center over a 1-year period (January 1, 2014-December 31, 2014). The CT images were evaluated for the presence of a PP, and if present the following demographic data were collected: age, sex, race/ethnicity, and body mass index (BMI). We propose a novel classification system to standardize the description of PP identified on CT scan.

RESULTS

Two thousand, nine hundred and seventeen cervical spine CT scans were reviewed in this study. The prevalence of PP was 22.5%. Men had a higher prevalence of PP than women (53.5% male vs. 46.5% female P ≤ 0.01). When compared with the overall population, African-Americans were more likely to have a PP (P ≤ 0.01), while Caucasian patients were less likely (P ≤ 0.01). The novel classification consisted of a two letter designation for each patient, with the first letter denoting the right sided arch and the second letter the left sided arch. Each side of the arch described as an A, B, or C type. The A type had no presence of a PP, B type had in incomplete PP, and C type had a complete PP. The most common type of a PP was CC encompassing 25% of the patients. The presence of a PP was more common in the left sided arch than the right side (B and C type Left 89.2% vs. B and C type Right 84.7%, P = 0.02).

CONCLUSION

We found a 22.5% prevalence of PP in 2917 patients undergoing a cervical spine CT. This is the largest study to evaluating the prevalence of PP.

LEVEL OF EVIDENCE

4.

The Ponticulus Posticus as Risk Factor for Screw Insertion into the First Cervical Lateral Mass

BACKGROUND

Awareness of the osseous anomaly of ponticulus posticus (PP) is crucial in avoiding vertebral artery (VA) injuries during C1 instrumentation. The aim of this study was to investigate PP and its relationship with the VA with three-dimensional computed tomography angiography.

METHODS

PP and the VA were investigated as intraoperative landmarks. The intersection of the VA to the posterior arch of C1 and the medial line and the posterior arch and VA curve around lateral masses were measured as intraoperative references.

RESULTS

PP was identified in 14.3% of samples. The anomaly was more common in women and on the right side. Of cases, 48.2% had PP bilaterally. In PP cases, the VA had variable courses through C2 before it passed under its bony bridges on the posterior arch of C1. Mean distances were found at the intersection of the VA to the posterior arch of C1 and the medial line to be larger and the posterior arch of C1 and the VA curve around lateral masses to be narrower than normal cases. Dual computed tomography scan data from C1 with PP were used to create three-dimensional patient-specific life-sized cervical spine models. Models revealed how the bone bridge affected the VA. The feasibility (>4 mm) of a safe lateral mass screw fixation was not influenced by PP anomalies.

CONCLUSIONS

The presence of the PP loop can limit space available for placement of the screw through the bony elements of C1. Standard screw techniques are contraindicated owing to the unacceptable high risk of VA injury.

Posterior inferior cerebellar artery with an extradural origin from the V3 segment: higher incidence on the nondominant vertebral artery

OBJECTIVE The posterior inferior cerebellar artery (PICA) and the vertebral artery (VA) often exhibit anatomical variations at the craniovertebral junction (CVJ). An example of this is the PICA originating extradurally from the V₃ segment of the VA. To date, some cadaveric investigations have been reported, but the incidence and relationship of this variation to the VA and the atlas as observed on clinical imaging have not been discussed. This study evaluated the prevalence of PICAs originating from the V₃ on CT scanning. Other variations of the atlas and VA were also analyzed. METHODS CT images from a series of 153 patients who underwent 3D CT angiography (CTA) were analyzed, and variations of the PICA, VA, and atlas were investigated. RESULTS A total of 142 patients (284 sides) were analyzed; 11 patients (7.2%) were excluded due to poor image quality. The most common VA variation was the PICA originating from V₃ (9.5% of 284 sides), which was more frequently observed on the nondominant VA than the dominant VA (22.5% vs 6.25%, p = 0.0005). A VA with a PICA end was identified in 4 sides (1.4%), which is the same incidence as observed in the persistent first intersegmental VA (1.4%). VA fenestration was only found in 1 side (0.35%). Regarding the atlas, ponticulus posticus was observed in 24 sides (8.5%). There was no relationship between the incidence of ponticulus posticus and the variations of the VA. CONCLUSIONS A PICA originating from V₃ was the most common VA variation at the CVJ and was more common on the nondominant VA. Three-dimensional CTA is useful for the evaluation of this variance. Surgeons should be mindful of this variation during operations.

Prevalence of foramen arcuale and its clinical significance: a meta-analysis of 55,985 subjects

OBJECTIVE

The foramen arcuale (FA) is a bony bridge located over the vertebral artery on the posterior arch of the atlas. The presence of an FA can pose a risk during neurosurgery by providing a false impression of a broader posterior arch. The aim of this study was to provide the most comprehensive investigation on the prevalence of the FA and its clinically important anatomical features.

METHODS

Major electronic databases were searched to identify all studies that reported relevant data on the FA and the data were pooled into a meta-analysis.

RESULTS

A total of 127 studies (involving 55,985 subjects) were included. The overall pooled prevalence of a complete FA was 9.1% (95% CI 8.2%–10.1%) versus an incomplete FA, which was 13.6% (95% CI 11.2%–16.2%). The complete FA was found to be most prevalent in North Americans (11.3%) and Europeans (11.2%), and least prevalent among Asians (7.5%). In males (10.4%) the complete FA was more common than in females (7.3%) but an incomplete FA was more commonly seen in females (18.5%) than in males (16.7%). In the presence of a complete FA, a contralateral FA (complete or incomplete) was found in 53.1% of cases.

CONCLUSIONS

Surgeons should consider the risk for the presence of an FA prior to procedures on the atlas in each patient according to sex and ethnic group. We suggest preoperative screening with computerized tomography as the gold standard for detecting the presence of an FA.

How common is ponticulus posticus on lateral cephalograms?

Background

Ponticulus posticus is an anomaly of first cervical vertebra visible on lateral cephalogram and has some serious medical and surgical implications. Unfortunately, it is often overlooked or undetected by orthodontists. The general objective of this study is to sensitize orthodontists about this anomaly by depicting its prevalence among a group of Nepalese orthodontic patients.

Methods

Four hundred and fourteen digital lateral cephalograms of orthodontic patients were retrieved from the archives of the department. The lateral cephalograms were carefully assessed for the presence of ponticulus posticus in the posterior spine of atlas vertebra by two investigators independently and the findings were recorded.

Results

Ponticulus posticus was observed in 35.7% of the cases, of which 30.9% had partial ponticulus posticus and 4.8% had complete ponticulus posticus. Even though there was some female predilection, no statistically significant association was found between gender of the patient and presence of ponticulus posticus.

Conclusion

Ponticulus posticus is a fairly common anomaly with more than one-third (35.7%) of a group of Nepalese orthodontic patients affected and is independent of gender. Since, this anomaly is associated with numerous medical conditions and has surgical implications, orthodontists should use lateral cephalogram as screening radiograph for this anomaly.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-017-2494-z) contains supplementary material, which is available to authorized users.

Surgical Morphometry of C1 and C2 Vertebrae: A Three-Dimensional Computed Tomography Analysis of 180 Chinese, Indian, and Malay Patients

Study Design

Clinical imaging study.

Purpose

To study the surgical morphometry of C1 and C2 vertebrae in Chinese, Indian, and Malay patients.

Overview of Literature

C1 lateral mass and C2 pedicle screw fixation is gaining popularity. However, there is a lack of C1–C2 morphometric data for the Asian population.

Methods

Computed tomography analysis of 180 subjects (60 subjects each belonging to Chinese, Indian, and Malay populations) using simulation software was performed. Length and angulations of C1 lateral mass (C1LM) and C2 pedicle (C2P) screws were assessed.

Results

The predicted C1LM screw length was between 23.2 and 30.2 mm. The safe zone of trajectories was within 11.0°±7.7° laterally to 29.1°±6.2° medially in the axial plane and 37.0°±10.2° caudally to 20.9°±7.8° cephalically in the sagittal plane. The shortest and longest predicted C2P screw lengths were 22.1±2.8 mm and 28.5±3.2 mm, respectively. The safe trajectories were from 25.1° to 39.3° medially in the axial plane and 32.3° to 45.9° cephalically in the sagittal plane.

Conclusions

C1LM screw length was 23–30 mm with the axial safe zone from 11° laterally to 29° medially and sagittal safe zone at 21° cephalically. C2P screw length was 22–28 mm with axial safe zone from 26° to 40° medially and sagittal safe zone from 32° to 46° cephalically. These data serve as an important reference for Chinese, Indian, and Malay populations during C1–C2 instrumentation.

Discrete morphological variants of human cervical vertebrae: Exploring pattern of distribution and biological significance

Studies on discrete traits of the human cervical vertebrae, appearing at certain intervals during the last century, posed some questions regarding evolutionary processes that human cervical spine underwent during phylogenesis. To address questions of significance of these morphological traits we need first a good knowledge of the extent of their variation in modern humans. The aim of the current work was to integrate available data on the occurrence of various non-metric traits in the human cervical spine and search for the pattern of their distribution on intra- and inter-population levels. The study was based on data from five osteological samples from North America (Terry and Grant collections) and Russia (mid 20th c. and 18th c.); and data taken from literature. Traits were categorized into rare (<3%), low frequency (up to 10%), often encountered (10-30%) and characteristic for modern humans (>50% on average). Several traits showed mild to strong association with each other indicating interrelation between various spine characteristics. Of the traits analyzed, the following had consistent pattern of sex-related variability: complete dorsal ponticle, bifid spinous processes and cervical ribs; and ancestry-related variability: dorsal ponticle and bifid spinous processes. Each ancestry group (European, African, Asian and North American) had its specifics regarding the latter two traits which might be related to genetic isolation. Most of the traits, however, showed relatively similar pattern of distribution among various populations, including the pattern of within-spine variability. This suggests a common intraspecific pattern and a possible link to some fundamental characteristics of the human vertebral column.

Is C1 lateral mass screw placement safe for the Chinese, Indians, and Malays? An analysis of 180 computed tomography scans

INTRODUCTION

C1 lateral mass (C1LM) screw is a common procedure in spine surgery. However, related studies are lacking in Asia. We aim to determine the safety of C1LM screw for the Chinese, Indians, and Malays.

METHODS

Three-dimensional computed tomographies of 180 subjects (60 from each ethnic) were analyzed. The length and angulations of C1LM screw and the location of internal carotid artery (ICA) in relation to C1LM were assessed and classified according to the classification by Murakami et al. The incidence of ponticulus posticus (PP) was determined and the differences among the population of these three ethnics were recorded.

RESULTS

The average base length was 8.5 ± 1.4 mm. The lengths within the lateral mass were between 14.7 ± 1.6 mm and 21.7 ± 2.3 mm. The prevalence of PP was 8.3%. 55.3% (199) of ICA were located in zone 0, 38.3% (138) in zone 1-1, 6.4% (23) in zone 1-2, and none in zone 1-3 and zone 2. The average angulation from the entry point to the ICA was 8.5° ± 6.4° laterally. The mean distance of ICA from C1 anterior cortex was 3.7 ± 1.7 mm (range: 0.6∼11.3). There was no difference in distribution of ICA in zone 1 among the three population (Chinese-47%, Indians-61%, and Malays-53%; p > 0.05).

CONCLUSIONS

No ICA is located medial to the entry point of C1LM screw. If bicortical purchase of C1LM screw is needed, screw protrusion of less than 3 mm or medially angulated is safe for ICA. The incidence of PP is 8.3% with higher prevalence among the Indian population.

Prevalence of ponticulus posticus among patients with different dental malocclusions by digital lateral cephalogram: a comparative study

PURPOSE

The aim of the present study was to investigate the prevalence of ponticulus posticus among patients with dental Angle class I, II, and III malocclusions in Middle Anatolian population.

METHODS

A total of 1246 cephalometric radiographs were examined in a 6 months period. Each patient was assigned an identification number, and demographic information, absence/presence of PP, if present, type of PP and type of dental malocclusion were recorded by two observers. In cases where there was any disagreement, a third observer was consulted. Distributions of obtained values were analysed using Pearson's Chi-square test.

RESULTS

The mean age of subjects was 20.98 ± 6.95 years (range 10-39). In the analysed sample, PP had a prevalence of 18.8 % (complete form 9.6 %, incomplete form 9.2 %). There was a significant difference between genders (p = 0.002) (more prevalent in male patients: 119/522; 23 %). No significant difference was found between age groups (p > 0.05). PP was most frequently detected in Angle class III patients (78/351; 22.2 %) but there was no significant difference between malocclusion groups (p > 0.05).

CONCLUSION

In the present study, PP is found to be a relatively common anomaly in patients with dental malocclusions. Although Angle class III patients showed a higher frequency of PP, statistically no significant difference was found among dental malocclusion groups.

The feasibility of inserting a C1 pedicle screw in patients with ponticulus posticus: a retrospective analysis of eleven patients

BACKGROUND

Ponticulus posticus is a common anatomic variation that can be mistaken for a broad posterior arch during C1 pedicle screw placement. When the atlas lateral mass screws are placed via the posterior arch, injury to the vertebral artery may result. To our knowledge, there are few clinical studies that have analyzed the feasibility of C1 pedicle screw fixation in patients with ponticulus posticus, in clinical practice.

PURPOSE

To evaluate the feasibility of inserting a C1 pedicle screw in patients with ponticulus posticus.

METHODS

Between January 2008 and January 2012, 11 consecutive patients with atlantoaxial instability, and with a ponticulus posticus at C1, underwent posterior fusion surgery in our institution. According to preoperative computed tomography (CT) reconstruction, a complete ponticulus posticus was found unilaterally in nine patients and bilaterally in two. Postoperative CT reconstructive imaging was performed to assess whether C1 pedicle screw placement was successful. Patients were followed up at regular intervals and evaluated for symptoms of ponticulus posticus syndrome.

RESULTS

Thirteen C1 pedicles (atlas vertebral artery groove), each with a complete ponticulus posticus, were successfully inserted with thirteen 3.5- or 4.0-mm diameter pedicle screws, without resection of the bony anomaly. No intraoperative complications (venous plexus, vertebral artery, or spinal cord injury) occurred. The mean follow-up period was 21 (range 14-30) months. Postoperative CT reconstructive images showed that all 13 pedicle screws were inserted in the C1 pedicles without destruction of the atlas pedicle cortical bone. In the follow-up period, none of the patients demonstrated clinical symptoms of ponticulus posticus syndrome or developed bone fusion.

CONCLUSION

Three-dimensional CT imaging should be considered prior to C1 pedicle screw fixation in patients with ponticulus posticus, to avoid mistaking the ponticulus posticus for a widened dorsal arch of the atlas. If there is no ponticulus posticus syndrome preoperatively, C1 pedicle screw fixation can be successfully performed without removing the bony anomaly.

Prevalence and Morphologic Characteristics of Ponticulus Posticus: Analysis Using Cone-Beam Computed Tomography

OBJECTIVE

This study evaluated the prevalence and morphologic characteristics of ponticulus posticus (PP) by using cervical 3-dimensional (3-D) cone-beam computed tomography (CBCT) scan images.

METHODS

This was a retrospective study conducted by selecting cervical 3-D CBCT images of 698 patients, which were examined for the presence and types of PP.

RESULTS

In 257 patients, 438 PPs, complete or partial, bilateral or unilateral, were identified on the 698 cervical 3-D CBCT scans; therefore, the prevalence was 36.8%. Bilateral complete PP and partial PP were observed in 6.3% and 16.2% of subjects, respectively. There was a significant difference in the prevalence between males and females (P = .001) and between the right and left sides between males and females, but not between age groups.

CONCLUSION

Ponticulus posticus is a relatively common anomaly in this Turkish sample, which may have implications for those who perform clinical procedures on the upper cervical spine.

Distraction Arthrodesis of the C1-C2 Facet Joint with Preservation of the C2 Root for the Management of Intractable Occipital Neuralgia Caused by C2 Root Compression

STUDY DESIGN

Prospective observational cohort study.

OBJECTIVE

To compare the outcomes of our new technique, distraction arthrodesis of C1-C2 facet joint with C2 root preservation (Study group), to those of conventional C1-C2 fusion with C2 root transection (Control group) for the management of intractable occipital neuralgia caused by C2 root compression.

SUMMARY OF BACKGROUND DATA

We are not aware of any report concerning C2 root decompression during C1-C2 fusion.

MATERIALS AND METHODS

Inclusion criteria were visual analogue scale (VAS) score for occipital neuralgia 7 or more; C2 root compression at the collapsed C1-C2 neural foramen; and follow-up 12 months or more. The Study group underwent surgery with our new technique including (1) C1-C2 facet joint distraction and bone block insertion while preserving the C2 root; and (2) use of C1 posterior arch screws instead of conventional lateral mass screws during C1-C2 segmental screw fixation. The Control group underwent C2 root transection with C1-C2 segmental screw fixation and fusion. We compared the prospectively collected outcomes data.

RESULTS

There were 15 patients in the Study group and 8 in the Control group. Although there was no significant difference in the VAS score for the occipital neuralgia between the 2 groups preoperatively (8.2 ± 0.9 vs. 7.9 ± 0.6, P = 0.39), it was significantly lower in the Study group at 1, 3, and 6 months postoperatively (P < 0.01, respectively). At 12 months, it was 0.4 ± 0.6 versus 2.5 ± 2.6 (P = 0.01). There was no significant difference in improvement in the VAS score for neck pain and neck disability index and Japanese Orthopedic Association recovery rate, which are minimally influenced by occipital neuralgia.

CONCLUSION

Our novel technique of distraction arthrodesis with C2 root preservation can be an effective option for the management of intractable occipital neuralgia caused by C2 root compression.

Prevalence of ponticuli posticus among patients referred for dental examinations by cone-beam CT

BACKGROUND CONTEXT

Ponticulus posticus (PP) is the bony bridge that can completely or partially embrace the vertebral artery and the suboccipital nerve root at the atlas posterior arch. The PP can be a possible cause of vertigo, vertebrobasilar insufficiency, neck pain, shoulder pain, and cervicogenic headache. Moreover, the vertebral artery injury may happen during atlas lateral mass screw insertion in the presence of PP.

PURPOSE

The purpose of this study was to determine the prevalence of PP in a population of patients undergoing dental cone-beam computed tomography (CBCT) and the association between PP and atlas superior articular facet (SAF).

STUDY DESIGN

This is a retrospective study.

PATIENT SAMPLE

Five hundred consecutive patients who had undergone dental CBCT scans were included.

OUTCOME MEASURES

Outcome measures were age, sex, and radiologic measures.

METHODS

The maximum anteroposterior and transverse dimensions of atlas SAF were measured on the axial image, and then the area was calculated by using the formula for an elliptical area. The left-right differential ratios of the SAF in patients with unilateral PP were compared with those in age- and gender-matched patients without PP. The relationships among imaging findings, age, and sex were assessed with the two-tailed paired t test, χ(2) test, and logistic regression model, as appropriate.

RESULTS

The overall prevalence of PP was 7% (35 of 500 patients). There were no significant differences in the prevalence of PP with gender and age. The anteroposterior dimension, transverse dimension, and area of atlas SAF on the PP side were significantly larger than those on the non-PP side in the 18 unilateral complete PP patients (p<.001, p<.001, and p<.001, respectively) and in the 11 unilateral partial PP patients (p=.001, p=.007, and p<.001, respectively). The SAF area differential ratios in patients with unilateral PP were greater than those in the patients without PP (29.8% vs. 2.9%, p=.002 for 18 complete lesions, and 23.5% vs. 1.8%, p<.001 for 11 partial lesions).

CONCLUSIONS

The prevalence of PP and the measurement of SAF can be assessed by CBCT. The imaging findings show the larger SAF on the PP side and greater left-right difference of SAF area in the patients with unilateral PP.

Normal anatomy and anatomic variants of vascular foramens in the cervical vertebrae: a paleo-osteological study and review of the literature

We investigated 923 cervical vertebrae belonging to late-antiquity and medieval skeletal remains and assessed the qualitative and quantitative structural characteristics of transverse foramens (TF) and additional vascular canals. We also reviewed the pertinent literature. Double TF were chiefly observed in C6 (with a right/left side prevalence of 35.7 and 44.4%, respectively) and C5 vertebrae (23.6 and 23.9%, right/left side, respectively), while unclosed TF were mainly documented in C1 vertebrae (8.4%). Retrotransverse canal and retrotransverse groove were present in 8.5 and 17.8%, respectively, of C1 vertebrae examined, while arcuate foramens and supertransverse foramens were found in 7.3 and 3.7% of specimens, respectively. TF diameter decreased from C6 to C2 vertebrae, being smallest in C7 and greatest in C1 vertebrae, with no left/right significant difference. There was a significant correlation between TF diameter and stature, but only on the right side. The mean area of the arcuate foramen was lower than the mean area of the ipsilateral TF (24.5 ± 5.7 vs 28.5 ± 7.7 mm(2), respectively; p = 0.048), possibly causing compression of the vertebral artery within the arcuate foramen. The study of human vertebrae excavated from archaeological sites is a simple and effective way to analyze the morphology and quantitative anatomy of vascular foramens.

Ipsilateral arcuate foramen and high-riding vertebral artery: implication on C1-C2 instrumentation

BACKGROUND CONTEXT

Several methods for C1-C2 stabilization have been described in the literature. These include C1-C2 transarticular and C1 lateral mass screws. In patients with aberrant anatomy such as a high-riding vertebral artery (VA) or the presence of an arcuate foramen at C1, there exists a higher risk of VA injury. This may lead to excessive bleeding, stroke, and possibly death. There have been several studies determining the incidence of arcuate foramen and high-riding VA occurring individually in the general population, but none have determined their occurrence simultaneously.

PURPOSE

To determine the prevalence of ponticulus posticus and high-riding VA occurring simultaneously in the general population.

STUDY DESIGN

Radiological study.

METHODS

One hundred consecutive computed tomography (CT) scans of the cervical spine were reviewed. Scans that contained an arcuate foramen were identified, and it was indicated whether the foramen was right sided, left sided, or bilateral. In the same group, the thickness of the isthmus and the internal height of the lateral mass of C2 were measured. The VA was considered high riding if the isthmus thickness was less than 5 mm or the isthmus internal height was less than 2 mm.

RESULTS

Fourteen out of one hundred (14%) patients had a fully formed arcuate foramen. Of these, six were left sided, three were right sided, and five were bilateral. In addition, there were 24 (24%) patients with partially formed ponticulus posticus. Thirty-two (32%) patients were identified to have a high-riding VA. Of these, 13 were left sided, 9 were right sided, and 10 were bilateral. Five (5%) had an ipsilateral arcuate foramen and high-riding VA.

CONCLUSIONS

The arcuate foramen and high-riding VA are common anomalies that are often not recognized. Although ipsilateral high-riding VA and arcuate foramen rarely occur in the general population, proper identification of these anomalies on preoperative CT scan facilitates planning the safest technique for C1-C2 instrumentation.

A cone beam CT investigation of ponticulus posticus and lateralis in children and adolescents

OBJECTIVES

To determine the prevalence and pathogenesis of ponticulus posticus (PP) and ponticulus lateralis (PL) in children and adolescents.

METHODS

Cone beam CT scans of 576 patients were examined for PP and PL. The patients were divided into three age groups: 10 years and younger, 11-13 years and 14 years and older. Ponticulus formation was categorized as absent, partial or complete. Gender, race and location (right, left or bilateral) were recorded. Data were analysed with the χ(2) test, with significance at p < 0.050. Institutional review board approval was granted.

RESULTS

Overall prevalence of PP was 26.2%, with complete lesions in 10.4%. The frequency of PP was greater in patients aged 14 years and older (p ≤ 0.038). The occurrence of complete PP was greater in patients aged 11 years and older (p = 0.028). Lesions were more common in males (p = 0.014) and in blacks compared with other non-white races (p = 0.035). Bilateral PP was more common than right-sided lesions (p = 0.008) and more frequent in the oldest cohort (p = 0.006). Overall prevalence of PL was 6.1% (3.0% complete), with no differences between age groups, genders, races or by location.

CONCLUSIONS

PP is not uncommon even in the first decade and increases in frequency, completeness of calcification and numbers in mid-adolescence. It appears to be more common in males and in blacks. PP may be a congenital osseous anomaly of the atlas that mineralizes at various times. PL is less frequent with no demographic predilections.

Clinical application of a revised screw technique via the C1 posterior arch and lateral mass in the pediatric population

OBJECTIVE

Pediatric patients with insufficient height (≤4 mm) of the C1 posterior arch may restrict atlas screw placement via the posterior arch and lateral mass (PALM). For these patients, we modified this technique, called the 'pedicle exposure technique' (PET). We aimed to analyze the clinical feasibility and safety of the PET in the pediatric population.

METHODS

Twenty pediatric patients with atlantoaxial instability (AAI) were enrolled in this study. The average C1 posterior arch was 3.1 (2.5-3.9) mm on CT scan. All patients underwent the C1 PET and C2 pedicle screw fixation. The imaging was performed to evaluate the accuracy of screw placement and bony fusion.

RESULTS

Forty screws were inserted via C1 PALM using the PET. Venous plexus bleeding occurred in 1 patient and the internal wall of the C1 lateral mass was perforated in 1 patient. There were no perioperative neurological deficits or vertebral artery injury. Follow-up was performed in all 20 cases over a period ranging from 6 to 80 months. Bony union was seen within 3-6 months. At the final follow-up visit, 14 patients had experienced an improvement, while 6 had complete resolution of their neck pain. Myelopathy symptoms were improved in 9 patients with spinal compression.

CONCLUSION

The PET is an effective alternative for pediatric AAI when the height of the C1 posterior arch is <4 mm. Because of the higher screw entry point through the C1 posterior arch, there is effective biomechanical stability and less irritation of the venous plexus and C2 nerve root.

Routine insertion of the lateral mass screw via the posterior arch for C1 fixation: feasibility and related complications

BACKGROUND CONTEXT

To our knowledge, there is no clinical study analyzing the feasibility and complications of the routine insertion of the lateral mass screw via the posterior arch for C1 fixation in a live surgical setting.

PURPOSE

To evaluate the feasibility of routine insertion of the lateral mass screw via the posterior arch and related complications.

STUDY DESIGN

Prospective clinical-radiological analysis.

PATIENT SAMPLE

Fifty-two consecutive patients with 102 C1 lateral mass screws inserted via the posterior arch.

OUTCOME MEASURES

Cortical perforation, vertebral artery injuries, and visual analog scale score of occipital neuralgia recorded on a prospective database.

METHODS

All consecutive patients in whom lateral mass screw placement via the posterior arch was attempted as the first choice whenever C1 posterior fixation was necessary were enrolled. Prospective database, clinical records, questionnaires regarding occipital neuralgia, pre- and postoperative computed tomography (CT) angiograms, and follow-up radiographs and CT scans were analyzed. This study was supported by a $9,000 academic research grant by the first author's hospital. The last author receives royalties for a posterior cervical fixation system, which is not the topic of this study and is not used or mentioned in this article.

RESULTS

One hundred two screws were attempted in 52 consecutive patients by a single surgeon. The height of 43 posterior arches (42%) was smaller than 4 mm on preoperative CT angiography. Lateral mass screws could be inserted via the posterior arch in all cases including eight with nine ponticuli posticus and seven with seven persistent first intersegmental arteries, but the posterior arch was perforated cranially by 7, caudally by 30, and craniocaudally (partially) by 3 screws and vertically split by 14 screws. Among the last 28 screws for which the authors' overdrilling technique was used, only one vertical split occurred, whereas among the first 74 screws without overdrilling, 13 vertical splits occurred. None of them led to screw loosening or nonunion. There were no vertebral artery injuries. Among the 19 patients with preoperative occipital neuralgia, 12 had complete resolution and seven had alleviation at the last follow-up. Among the 33 patients without preoperative neuralgia, seven developed new neuralgia postoperatively. Three of them underwent C2 root transection and the other four underwent C2 root dissection for intraarticular fusion of the facet joints. Of the seven, five had complete resolution and two had mild discomfort at the last follow-up.

CONCLUSIONS

Routine insertion of the lateral mass screw via the C1 posterior arch was feasible in even those with a small posterior arch, ponticulus posticus, or persistent first intersegmental artery. Although cortical perforation or vertical splitting of the posterior arch was often inevitable, it did not lead to significant weakening of the fixation or nonunion. Vertical split could be minimized by overdrilling the posterior arch. Vertebral artery injury was preventable by mobilization before screw insertion. Occipital neuralgia was not uncommon but thought to be unrelated to screw placement in most cases.

Prevalence of ponticulus posticus in Indian orthodontic patients

OBJECTIVES

The purpose of this study was to investigate the prevalence of complete ponticulus posticus in Indian orthodontic patients.

METHODS

The presence and types of ponticuli posticus were investigated on 858 lateral cephalograms.

RESULTS

Complete ponticulus posticus was found in 4.3% of the subjects studied with a male (5.33%) predominance over female in the population (3.76%).

CONCLUSIONS

Ponticulus posticus is not a rare anomaly and the patient must be told of the implications and importance of detecting ponticulus posticus on a lateral cephalogram. This information can prove beneficial for the diagnosis of head and neck symptoms later.