CONTINUING EDUCATION

The frontal cephalometric analysis – the forgotten perspective

Dr. Bradford Edgren delves into the benefits of the frontal analysis

hen greeting a person for the first Wtime, we are supposed to make Educational aims and objectives This article aims to discuss the frontal cephalometric analysis and its direct eye contact and smile. But how often advantages in diagnosis. when you meet a person for the first time do you greet them towards the side of the Expected outcomes Correctly answering the questions on page xx, worth 2 hours of CE, will face? Nonetheless, this is generally the only demonstrate the reader can: perspective by which orthodontists routinely • Understand the value of the frontal analysis in orthodontic diagnosis. evaluate their patients radiographically • Recognize how the certain skeletal facial relationships can be detrimental to skeletal patterns that can affect orthodontic and cephalometrically. Rarely is a frontal treatment. radiograph and cephalometric analysis • Realize how frontal analysis is helpful for evaluation of skeletal facial made, even though our first impression of asymmetries. • Identify the importance of properly diagnosing transverse that new patient is from the front, when we discrepancies in all patients; especially the growing patient. greet him/her for the first time. • Realize the necessity to take appropriate, updated records on all A patient’s own smile assessment transfer patients. is made in the mirror, from the facial perspective. It is also the same perspective by which he/she will ultimately decide cephalometric analysis. outcomes. Furthermore, skeletal lingual if orthodontic treatment is a success Since all orthodontic patients are three- crossbite patterns are not just limited to or a failure. So why don’t orthodontists dimensional, they should be evaluated a narrow maxilla. Posterior skeletal lingual utilize the frontal analysis more? B. Holly three-dimensionally, and the frontal crossbites can also be the result of wide Broadbent is credited with developing analysis provides valuable information that mandibles, which are further exacerbated the cephalometric procedure in 1931 should be part of the diagnostic process1. by future, excessive lower jaw growth1. when he simultaneously took frontal and Additionally, with the increasing use of Cone True dental asymmetries can be lateral radiographs on his patients to Beam Computed Tomography (CBCT) treated by orthodontics alone. However, evaluate the craniofacial skeleton in all scans in orthodontics, a frontal analysis prior to the initiation of treatment, the three dimensions, including the posterior- should be made for all patients receiving a etiology of the dental asymmetry should anterior dimension. Interestingly, even CBCT scan; making use of the volume of be determined. If that dental asymmetry is though Broadbent took both frontal information obtained. CBCT scans provide the result of a skeletal issue, an orthopedic and lateral radiographs simultaneously, the opportunity for adjusting the orientation or surgical approach will be necessary orthodontists are generally trained to use of the patient’s head, improving the reliability because orthodontic treatment alone would the lateral cephalometric analysis on all of the cephalometric measurements, and likely result in an unfavorable outcome. patients, but only encouraged to use the simulating Broadbent’s cephalometric So, what about those skeletal frontal analysis when an asymmetry is procedure. asymmetries? It’s not uncommon for the suspected or a dental crossbite is clinically Skeletal facial asymmetries are more orthodontist to miss a skeletal asymmetry observed. Accordingly, many orthodontists the rule than the exception, and the frontal in a severely crowded and maligned rarely assess a patient with a frontal analysis is an excellent instrument to use malocclusion that only becomes obvious for their evaluation. However, skeletal after the leveling and alignment phase asymmetries are not always readily visible of treatment3. At this stage in treatment, clinically nor do skeletal lingual crossbite it may be more difficult to address the patterns reveal themselves with obvious skeletal asymmetry and, therefore, more posterior dental crossbites. It can be difficult to salvage. But, diagnosing the Bradford Edgren, DDS, MS, earned both his Doctorate of Dental Surgery, as Valedictorian, challenging to determine the presence skeletal asymmetry initially, prior to the start and his Master of Science in Orthodontics of a skeletal lingual crossbite pattern of treatment, provides informed consent to from University of Iowa, College of Dentistry. when it appears that there is a normal the patient and reduces the unintended He is a Diplomate, American Board of Orthodontics and an affiliate member of the SW Angle transverse relationship between the upper consequences of poor treatment planning. Society. Dr. Edgren has presented to numerous groups and lower jaws without a frontal analysis. Perfectly symmetrical faces are largely on the importance of cephalometrics, CBCT, and Many patients who appear to have normal theoretical concepts that seldom exist in upper airway obstruction. He has been published in AJODO, American Journal of Dentistry, as well as other transverse skeletal relationships have living organisms4. Minor facial asymmetries orthodontic publications. Dr. Edgren currently has a skeletal lingual crossbite patterns2 that are relatively common. In a study by Severt private practice in Greeley, Colorado. can negatively affect orthodontic treatment and Proffit of 1,460 patients, 34% had a

X Orthodontic practice Volume 4 Number 5 CONTINUING EDUCATION X practice Orthodontic Figure 3: Lateral CBCT image Figure 3: Figure 2: Frontal cephalometric analysis demonstrating significant dentofacial asymmetry Figure 2: to the right and occlusal cant The panoramic radiograph Early interceptive treatment included lateral radiographic image alone does not vertical and lateral the of degree the display passed be easily could that asymmetries off as poor patient positioning (Figure 3). demonstrated a hypoplastic right ramus and condyle (Figure 4). The maxillary canines and lateral incisors were ectopically erupting due to an anterior maxillary constriction. rapid maxillary expansion followed by upper and lower fixed appliances. Following the removal of the fixed appliances at the end CBCT a treatment, interceptive early of scan was taken. The scan revealed an improvement in the facial asymmetry and significantly improved permanent tooth eruption and root parallelism (Figures . . In this case, the patient 4 6 . Moreover, facial asymmetries 5 The frontal cephalometric analysis is Significant skeletal asymmetries are more frequently associated with Class II are more frequently associated with Class malocclusions than with Class and Class III I malocclusions useful in diagnosing skeletal asymmetries and skeletal crossbite patterns for both of: jaws. It is also aids in the evaluation occlusal cants, nasal widths, turbinate enlargements, dental arch widths, bucco- lingual angulation of first molars, angulation location canines, impacted of position and of the maxillary incisors to the skeletal midline, location of the mandibular incisors to the mandibular midline and skeletal of the maxilla midline, and the morphology and mandible. The frontal analysis can also aid in determining if an off-centered dental midline is due to a tooth-size discrepancy, a mandibular functional shift, or skeletal dysplasia. can be congenital, developmental, or acquired. Hemifacial microsomia is a defect where the lower half congenital birth of the face is typically unilaterally, or rarely bilaterally, underdeveloped. This common facial birth defect, second only to clefts, most frequently affects the ears, mouth, and lower jaw Volume 4 Number 5 clinically apparent facial asymmetry. Of clinically apparent facial asymmetry. the facial asymmetries that were present, 5%, in affected only was face upper the in the middle third (primarily the nose) 36%, and the lower third in 74% of cases. Vertical asymmetries were present in 41% of cases Figure 1: Posterior-anterior image demonstrating right- Posterior-anterior Figure 1: sided lateral and vertical facial asymmetries [Imaging Sciences (CBCT images taken with i-CAT International]) has a significant unilateral dentofacial asymmetry to the right. Complete diagnostic records were taken, including a CBCT scan, followed by lateral and frontal cephalometric analyses. The frontal image cephalometric the corresponding and analysis demonstrate the effects of the hemifacial microsomia on the right side of the patient’s face (Figures 1 and 2). The CONTINUING EDUCATION

Figure 4: Panoramic image demonstrating a hypoplastic right condyle and ramus, and ectopic maxillary canines Figure 5: Posterior-anterior image following early inter- ceptive treatment

Figure 7: Note, in the lateral radiographic image, the difference in the borders of the left and right sides of the mandible. When the borders of the mandible present this large of a difference, and the orbits are aligned, a facial asymmetry should be suspected

Figure 6: Panoramic image following early interceptive treatment. The anterior maxillary constriction has been resolved, and the maxillary canines have erupted nicely

5 and 6). This patient will be monitored This case of acquired condylar until the eruption of the permanent hypoplasia was a transfer into my office. dentition is complete. Second phase She had had previous Phase I treatment, treatment will include full fixed appliances including the extraction of the maxillary first and orthognathic surgery to correct the premolars. At her clinical exam, a right- remaining asymmetries. sided facial asymmetry was noted. After Condylar hypoplasia is the unilateral taking progress records, which included a or bilateral underdevelopment of CBCT scan (Figures 7 and 8), both lateral Figure 8: Posterior-anterior image revealing the significant the mandibular condyle(s). Condylar and frontal cephalometric analyses were right-sided vertical and lateral asymmetries hypoplasia can be either congenital or made. A frontal analysis revealed a severe acquired, and is often associated with head mandibular asymmetry to the right, a right and neck syndromes as in the previous vertical asymmetry, as well as a skeletal most likely become more pronounced. case7. Bilateral condylar hypoplasia is lingual crossbite pattern due to both jaws The best solution for this patient is considerably less common than unilateral (Figure 9). The mandibular asymmetry maxillary expansion, leveling and aligning, involvement, even though both can lead amounted to a total of 8 mm to the patient’s and eventually orthognathic surgery to to significant facial deformities. In acquired right. The source of the asymmetry was a correct the facial asymmetry. Note, this is a cases, the extent of the facial deformity is hypoplastic right condyle. The patient’s case where the significant facial asymmetry dependent upon the severity of the injury right ramus was also significantly shorter and the skeletal lingual crossbite were not that caused the disruption in condylar and comparatively broader when compared documented until a frontal analysis was growth, the duration of that injury, and the to the left. Since this patient still has several made. Consequently, this case is a perfect age that it occurred.8 years left to grow, the facial asymmetry will example of where a facial asymmetry

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Figure 10: Panoramic image exhibiting condylar hypoplasia of the right condyle and subsequent widening of the ramus. The patient’s maxillary first premolars were extracted to aid in the eruption of the maxillary canines. If expansion had been performed on this patient initially, it may have been unnecessary to extract the maxillary first premolars to make room for the eruption of the canines

Figure 9: Posterior-anterior image revealing the significant right-sided vertical and lateral asymmetries

Figure 11: Initial panoramic image exhibiting severe crowding and multiple impacted teeth

went undiagnosed until the frontal analysis that required attention before continuing was made, after irreversible orthodontic orthodontic treatment in patients already in treatment had been already initiated, orthodontic appliances. including extractions of permanent Like facial asymmetries, skeletal teeth. It only disputes the myth that the lingual crossbites due to either the maxilla frontal analysis should only be made if and/or mandible are more the norm an asymmetry is suspected. Obviously, than the exception. Transverse maxillary significant facial asymmetries do exist constrictions frequently result in significant and can be missed without a posterior- crowding and impacted teeth. This anterior radiograph and subsequent 7.3-year-old Caucasian female presented analysis. Routinely taking a posterior- with loss of arch length in both arches anterior radiograph reduces the chances of due to premature loss of the deciduous Figure 12: Initial posterior-anterior image. Note the missing an asymmetry. Even this patient’s lateral incisors. The left maxillary molar significant rotation of the right maxillary incisor panoramic image illustrates the extent of was ectopically erupting and had resorbed the right condylar hypoplasia, shortened the distal root of the left maxillary second and subsequent impaction of the maxillary ramus, and noticeable asymmetry (Figure deciduous molar, blocking out the eruption canines. 10). path of the second premolar (Figure A posterior-anterior image taken from This case also illustrates why it is 11). But, it was the patient’s overall pre- the diagnostic CBCT scan of the patient necessary to take appropriate, updated existing maxillary deficiency, including demonstrates the significant rotation of records on all transfer patients. I have the transverse constriction, that was the the maxillary lateral incisors and severe found previously undiagnosed tumors, original source for the loss of maxillary maxillary anterior crowding (Figure 12). severe facial asymmetries, cysts, arch length, severe crowding, disruption The frontal cephalometric analysis not only supernumeraries, and other pathologies of the eruption of the maxillary laterals, illustrated a dental lingual crossbite pattern

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Figure 13: Initial frontal cephalometric analysis

Figure 14: Progress panoramic image exhibiting improved eruption of the maxillary canines and the erupted lateral inci- Figure 15: Progress posterior-anterior image. Note the sors with complete root formation. Also, note maxillary right third molar blocking the eruption of the maxillary right second significantly improved angulation of the maxillary canines molar and lateral incisors

due to both arches but also a skeletal Orthodontic treatment without expansion, This 30-year-old Caucasian, female lingual crossbite pattern due to the maxilla when a transverse maxillary constriction patient presented with a chief complaint and mandible (Figure 13). After distalization exists, does not address the root of the of myofascial pain disorder (MPD) and of the maxillary left first molar, the patient problem. Extraction of permanent teeth an anterior open bite. Her maxillary first was expanded with a bonded expansion in a growing patient, to promote eruption premolars were extracted as a child as part appliance to correct the dental and skeletal of the maxillary canines, may result in of her orthodontic treatment. However, lingual crossbite patterns. future crossbite patterns when the patient what may have been a well-treated case After 29 months of Phase I treatment, becomes an adult and dentofacial growth at the finish as an adolescent became a the maxillary and mandibular lateral incisors is complete. A case that appears to be significant problem as an adult. Because have erupted into proper position, and the treated to proper balance may indeed her skeletal lingual crossbite pattern was maxillary canines are erupting appropriately become a significant malocclusion years never initially diagnosed, extraction of (Figures 14 and 15). Early extraction of later because future growth and the the first permanent premolars negatively the maxillary deciduous canines was not skeletal lingual crossbite patterns were enhanced her transverse discrepancy. necessary, nor was it indicated. Studies never addressed, nor treated.8 Additional facial growth only intensified her have suggested that impacted canines This adult case exemplifies the transverse discrepancies. Over time, this are a result of maxillary constriction, and importance of properly diagnosing patient developed an anterior open bite and rapid maxillary expansion can aid in the transverse discrepancies in all patients crossbite, bilateral posterior crossbites, proper eruption on maxillary canines.9,10,11 and especially in the growing patient. gingival recession, and MPD (Figures 16

X Orthodontic practice Volume 4 Number 5 CONTINUING EDUCATION X practice Orthodontic OP Figure 17: Posterior-anterior image demonstrating bilat- Posterior-anterior Figure 17: anterior open bite eral posterior crossbites and orthodontic result, using a frontal analysis called the mirror. 7. Neville BW, Damm DD, Allen CM, Bouquot JE. Oral and Damm DD, Allen CM, 7. Neville BW, Saunders; W.B. Maxillofacial Pathology. Philadelphia, PA: 1995:16. BN. Upper airway obstruction - poor 8. Edgren function becomes poor form. Orthodontic Practice US. 2013;4(2):34-37. Janzen EK, DL, Forbes DP, 9. McConnell TL, Hoffman NH. Maxillary canine impaction in patients Weintraub ASDC J Dent Child. with transverse maxillary deficiency. 1996;63(3):190-195. SL. Maxillary transverse 10. Schindel RH, Duffy and potentially impacted maxillary canines discrepancies in mixed-dentition patients. Angle Orthod. 2007;77(3):430- 435. M, Cozza P. M, Leonardi Mucedero 11. Baccetti T, of palatal impaction of maxillary treatment Interceptive canines with rapid maxillary expansion: a randomized clinical trial. Am J Orthod Dentofacial Orthop. 2009;136(5):657-661. Figure 18: Cephalometric tracing revealing a skeletal lingual crossbite Cephalometric tracing revealing Figure 18: and a lingual crossbite due to both pattern due to the maxilla and mandible, arches References analysis BN. The combined value of the frontal 1. Edgren Orthotown. 2013;56-57. prediction. and growth 2. Miner RM, Al Qabandi S, Rigali PH, Will LA. Cone- beam computed tomography transverse analysis. Part 1: Normative data. Am J Orthod Dentofacial Orthop. 2012;142(3):300-307. cephalometrics: 3.Ricketts RM, Grummons D. Frontal . J Orthod practical applications, part I. World 2003;4(4):297-316. etiology, Lo LJ. Facial asymmetry: 4. Cheong YW, evaluation, and management. Chang Gung Med J. 2011;34(4):341-351. of facial WR. The prevalence 5. Severt TR, Proffit asymmetry in the dentofacial deformities population at Int J Adult Orthodon the University of North Carolina. Orthognath Surg. 1997;12(3):171-176. 6. The National Craniofacial Association. Hemifacial http://www.faces-cranio.org/Disord/Hemi. Microsomia. htm. Accessed August 19, 2013. Remember, the patient will be making his/ her own quality assessment of the final The patient is currently being treated The use of the frontal analysis should Figure 16: Panoramic image demonstrating anterior open bite Figure 16: Volume 4 Number 5 and 17). The frontal analysis made from her CBCT scan revealed a significantly narrow (Figure 18), a wide mandible maxilla and indicating that rapid maxillary expansion would have been a more appropriate teeth. extraction of than regimen treatment for her myofascial pain disorder. Future her improving on focus will treatment and a combined periodontal condition surgical orthodontic approach to address her orthodontic problems. be more the norm than the exception. Many facial asymmetries and skeletal lingual crossbite patterns go undiagnosed, only becoming apparent later and adversely affecting the quality of care. Performing a frontal analysis may take more time, patient. the of interest best the in is it but