The principal impediment to achieving a pleasing, harmonious facial result in orthodontic and orthodontic/surgical treatment is the dental training of the doctors.

As dentists, we are schooled to focus on teeth and occlusion. This is the center of our universe and we take as an article of faith that all desirable outcomes orbit around our dental parameters. Dr. Arnett has years of surgical results attesting to the fallacy of this view of the cosmos.

Get an Outside-In Perspective

Successful dental and occlusal corrections do not always result in an acceptable facial appearance. We are encouraged to wipe the slate clean and develop a new orientation. There is a large body of evidence that assumes that fixing the occlusion will fix the face. It is not tenable. We need to replace our inside-out thinking with an outside-in perspective to ensure a more predictable overall treatment result.

There is a big distinction between occlusion-directed and facial-directed treatment plans. All too often the former results in a facial decline, while the latter predictably results in a positive facial result. The three most common ingredients in a negative facial outcome are 1) occlusion-directed treatment planning, 2) no facial diagnosis, and 3) no facial treatment plan.

Accepted diagnostic tools of the trade are often misleading. Model analysis may be adequate in the well-balanced face, but not always. It is less than inadequate for the patient with facial compromises.

Similarly, traditional cephalometric analyses are ill suited to facial diagnosis and treatment planning. Only a few incorporate facial measurements at all and these are seldom of significance. The central reference for cephalometric norms is the cranial base, but the speaker states that there is no correlation between the cranial base and facial evaluation. The prevailing cephalometric assumption that profile imbalance correlates to abnormal cranial base and skeletal and dental values must be abandoned.

Almost 30 years of surgical experience and suboptimal results have made this perfectly clear to Dr. Arnett and long ago led him to conclude that there had to be a better way. The result is his advocacy of an outside-in analysis to facial diagnosis and treatment planning. Successfully executed, the treatment outcome will be more stable occlusally and periodontally with facial enhancement supplanting facial compromise.

The first step is a clinical facial analysis. This is conducted in all three planes of space. It is completely subjective and without objective measurement. The face is viewed segmentally and extraneous anatomy is masked from view with a clip board.

From top down, he evaluates facial projections antero-posteriorly, noting projections of soft tissue glabella, orbital rim, malar prominence, and sub-orbital anatomy. He will then note maxillary landmarks - the prominence of nasal base, nasal tip, upper lip and upper lip support. Finally comes an appraisal of mandibular contributions: lower lip position, soft tissue pogonion, throat length, and overjet. Next he notes vertical facial landmarks: lower face height, lip lengths, interlabial gap, incisor exposure (relaxed and smile), overbite and upper anterior crown height.*

At this point, a reasonably accurate interpretation of the plusses and minuses of the face can be made, and we have the beginnings of a facial diagnosis. The next step is a soft tissue cephalometric analysis. Cephalometrics emphasizes soft tissue landmarks and their relationship to important dento/skeletal structures. Frankfort and SN are not used. The purpose is to meld subjective facial analysis into a quantifiable, objective tool for treatment planning.

Postural requirements for headfilm exposure are the same as for the clinical facial analysis: seated condyles, first tooth contact, relaxed lip posture, and natural head position.

Since male and female values differ substantially-a fact that is ignored by all conventional cephalometric analyses, save Ricketts-comparisons are made to separate gender- appropriate norms.

Dr. Arnett will quantify incisor positions, facial, and skeletal dimensions horizontally and vertically. Measurements of soft tissue thickness and projections are also incorporated in the analysis. "Soft tissue cephalometric analysis identifies the etiology of malocclusions."

Comparisons of anatomic regional components: forehead and orbits to maxilla and mandible, maxilla to mandible, and intramandibular components reveals their harmonious interplay. "Harmony values are sensitive indicators of facial profile imbalance." Harmony values can indicate abnormal balance between two landmarks that are within a normal range.

Treatment planning proceeds through seven steps. In essence, desirable facial changes are established and then occlusal and skeletal manipulations are designed to achieve the facial objectives.

The seven-step method to reach the goal of facially- directed treatment planning, treatment planning from outside-in, is a concept with which most of us are familiar. Angulation is established for upper and lower incisors.

The maxillary incisor is positioned relative to soft tissue requirements. Next, the mandible is autorotated to three millimeters of overbite, disregarding molar overlap, to achieve correct anterior vertical height. The mandible is secondarily translated to an appropriate relationship with the maxilla. Finally, the maxillary occlusal plane is repositioned and the ideal location of pogonion established. Chin augmentations greater than four millimeters are undesirable and, if necessary, adjustments to the other seven steps in the sequence may be indicated to avoid this.

Dr. Arnett's message to the orthodontist: "Occlusal treatment based on model and/or traditional cephalometric analyses may lead to facial decline or leave preexisting facial imbalances uncorrected. Occlusal treatment based on clinical and cephalometric facial analysis produces optimal facial balance with bite correction."

* (For a full description of the method, see: Soft tissue cephalometric analysis: Diagnosis and treatment planning of dentofacial deformity, Arnett, et.al., American Journal of Orthodontics and Dentofacial Orthopedics, September 1999, Volume 116 , Number 3,p239 to p253, Facial keys to orthodontic diagnosis and treatment planning. Arnett GW, Bergman RT. Part I. Am J Orthod Dentofacial Orthop, 1993;103:299-31, and, Facial keys to orthodontic diagnosis and treatment planning. Arnett GW, Bergman RT. Part II. Am J Orthod Dentofacial Orthop 1993;103:395-411.)

Next Article

Top of the Page

Copyright © 1999 - 2006 Pacific Coast Society of Orthodontists. All Rights Reserved.

Please review our legal notices and privacy policy.

Created by WebResults.