Jeffrey C. Posnick, DMD, MD

Functional Aspects

Clinical Characteristics

Dental Findings

Radiographic Findings

Fields and colleagues presented simplified cephalometric diagnostic criteria.⁴⁴ If a patient has all three of the following criteria, he or she can be considered to have a long face growth pattern:

Etiologic Considerations

Current thinking is that both environmental influences and inherited tendencies play a role in the development of a long face.53,66,67,85–87 A significant percentage of patients with long faces have been found to have an increased oral and decreased nasal breathing pattern.^{25,33,37,52,59,82,134,146,150} Interestingly, nasal obstruction is not always present with long face growth patterns, but an open-mouth posture during development is typical. Other causes of an open-mouth posture in the preadolescent patient have been shown to result in similar long face dysmorphology.^{1,2,4,51,61,78,80,140} This includes muscle weakness syndromes (e.g., Moebius syndrome, facial nerve palsy, cerebral palsy, muscular dystrophy) and the presence of a large tongue (e.g., Beckwith-Wiedemann syndrome, hemangioma, vascular malformations, neurofibromatosis, Proteus syndrome; see Chapter 4).

There is experimental animal model research to support the theory that a long face anterior open-bite malocclusion is a physiologic adaptation to an open-mouth protrusive tongue posture that is present during facial development (see Chapters 4 and 10).^62–65 It has also been clarified that, in humans, a resting open-mouth protrusive tongue posture is an etiologic factor in the development of a long face with an anterior open bite. Interestingly, the intermittent occurrence of tongue thrust during speech and swallowing is not thought to be the cause of an open bite. In fact, periodic tongue thrusting is an adaptive response to an open bite rather than the cause.⁴⁷ When the incisors overlap in an average way (i.e., with a normal overbite), the normal-sized tongue is naturally placed behind the teeth to create the necessary anterior seal for successful swallowing and the articulation of specific consonant sounds (see Chapter 8). In the presence of anterior open bite, the normal tongue must protrude past the teeth to seal against the lips. This is an expected adaptive mechanism to assist with swallowing and speech. Confirmation that the protrusive tongue position during swallowing and speech is a reversible adaptation has been routinely documented after the individual with a long face and an anterior open bite undergoes successful orthognathic surgery and orthodontic treatment.^89,142,155 When the open bite is closed with the use of sound biologic mechanics (i.e., without orthodontic dental compensation) and when lip competence is achieved through surgery (i.e., there is no longer excess lower facial height), there is a fairly reliable elimination of the tongue thrust without the need for active myofunctional physical therapy retraining. However, if a skeletal anterior open bite has been closed with the use of unsound orthodontic maneuvers (i.e., excessive eruption of the anterior teeth or buccal tipping of the molars outside of the alveolar bone housing) and if lip competence is not achieved (i.e., inadequate facial height shortening), dental relapse is to be expected. In this case, tongue thrusting should not be blamed for the recurrent malocclusion.

The Role of Growth Modification in the Preadolescent Patient

When standard growth modification maneuvers for a long face growth pattern are attempted in the preadolescent patient, the primary objective is to restrain the hypereruption of the posterior maxillary teeth. In theory, this would limit the abnormal downward and backward rotation of the mandible. Unfortunately, effective and practical methods for accomplishing this seemingly limited objective have been difficult to orchestrate. It has also been shown that the natural progression of the deformity may persist through adolescence. This means that the effective containment of the maxillary posterior dental hypereruption would need to continue throughout the teenage years. The two traditional methods that are used to impede excessive vertical growth of the posterior maxilla are 1) the use of high-pull headgear connected to a complete or partial maxillary fixed appliance and 2) the use of a functional intra-oral appliance that incorporates a bite-block device (i.e., an activator) between the teeth.

The intraoral functional appliance is usually designed to exert force on the posterior teeth when the masticatory muscles contract. The occlusal force is then transferred through the biting surfaces of the upper and lower posterior teeth to the periodontal ligaments to limit molar eruption. To be effective, most clinicians recommend that the functional appliance be worn for 14 to 16 hours per day. When headgear is used, it is designed to apply direct external force to the teeth through a fixed maxillary appliance. Unfortunately, true vertical pull is almost impossible to achieve, and this results in a degree of added backward pressure. Because the majority of patients with long faces do not have protrusion of the maxilla, this unavoidable posterior force is counterproductive and results in further horizontal maxillary deficiency. The combination of vertical intrusion vectored headgear and an intra-oral functional appliance to affect the posterior dentition—when initiated during childhood and sustained through the teenage years in a compliant child—is thought to have the potential to produce improvement in the patient with a long face growth pattern. In all but borderline long faces, which are recognized during childhood, growth modification is not likely the preferred approach.

The Orthodontic Camouflage Approach

The patient with a long face often perceives a visual prominence of his or her upper incisors. For this reason, it is apparently tempting for the orthodontist to proceed with a camouflage treatment plan to neutralize the occlusion via the retraction of the upper incisors. This approach seems to be especially difficult for the orthodontist to avoid when viewing the problem primarily as a Class II malocclusion without fully considering the vertical and horizontal skeletal disharmony, the lip incompetence, the upper airway dysfunction, and the overall facial aesthetics. The extraction of the maxillary first premolars followed by the retraction of the anterior teeth will improve and may even neutralize the occlusion, but it does nothing to relieve the vertical facial problem, and it will further accentuate the horizontal facial deficiency. As the incisors are orthodontically retracted, they are also elongated (i.e., extruded), and the nasolabial angle opens, which results in unattractive effects on the lips and the nose.

Before embarking on an orthodontic camouflage approach, the clinician should confirm that the patient and his or her family understand the aesthetic limitations of closing the anterior open bite by extruding the incisors (i.e., residual or worsening gummy smile, residual lip incompetence with mentalis strain, lack of facial aesthetic improvement). The patient’s long-term dental stability and periodontal health must also be considered. In addition, the maxilla, the mandible, and the chin will remain horizontally deficient and vertically long, thereby further accentuating lip incompetence and the long, flat, retrusive appearance of the profile.

An Orthodontic Molar Intrusion Approach

Sato and colleagues believe high-angle Class II malocclusions can be corrected with the use of “multiloop edgewise arch wires.”¹²⁴ With the use of tip-back mechanics and vertical elastics, the researchers believe that the occlusal plane inclination can be altered by intruding the molars via the autorotation of the mandible and the closure of the open bite. Unfortunately, scientific evidence in support of this method of treatment for a patient with a long face and an anterior open bite has not been forthcoming.

With the use of skeletal temporary anchorage devices, the intrusion of the molars has been recommended by some to close an open bite.105,157,158 Man-Suk and colleagues completed a study to examine the long-term stability of anterior open-bite correction via the intrusion of the maxillary posterior teeth in adults.⁸⁸ In the first group (n = 5 adults), mini-screw implants were placed on the buccal and palatal sides, between the roots of the maxillary second premolars and first molars and between the roots of the maxillary first and second molars. Intrusion forces were directly applied to the molars with elastomeric chains. In the second group (n = 4 adults), mini-screw implants were placed on the buccal side only between the roots of the maxillary second premolars and first molars and between the roots of the maxillary first and second molars. A rigid transpalatal arch was placed before applying the intrusive forces to prevent the buccal tipping of the teeth. Lateral cephalograms were taken at the initial evaluation and again at 1 and 3 years after treatment. The cephalograms were traced and analyzed. The study documented that the maxillary first molars were intruded on an average of 2.39 mm during treatment, with relapse of 0.45 mm at the 3-year follow up (i.e., 22.9% relapse). A majority of the relapse occurred during the initial posttreatment year. The molar relapse had a significant effect on the eventual incisal overbite. There was no significant difference in molar relapse or the maintenance of overbite between the two different methods of skeletal anchorage used. It would appear as though there is currently no known way to fully retain an orthodontically intruded molar.

For patients with borderline long face growth patterns in whom the open bite has been successfully closed with the use of orthodontic mechanics and in whom the remaining gummy smile and lip incompetence is only mild, a vertical reduction with horizontal advancement genioplasty may improve the profile aesthetics and lip competence enough to be a satisfactory compromise for the patient (see Chapter 37 and 40).

Definitive Reconstruction