Maxillary development revisited: relevance to the orthopaedic treatment of Class III malocclusions

Abstract

Normal development of the maxilla results not only from movements of its constituent skeletal units and bony apposition-resorption superficially, but also from the specific development of the antero-lateral regions. In Class III cases, correction of the skeletal dysmorphosis requires not only that the maxilla is in a correct position (in relation to the mandible) and that the correct occlusion is achieved, but also that there is good development of the exo-peri-premaxilla. This requires normalization of muscular posture (labio-mental, lingual, velo-pharyngeal) and of orofacial functions (nasal ventilation, swallowing, mastication). Postero-anterior traction using an orthopaedic mask can only accomplish part of the treatment of Class III. The action must always be complimented by other therapy aimed at correcting the underdevelopment of the antero-lateral regions. Facemask therapy is not only simple sagittal distraction, but is truly a method for treatment of Class III which is well understood and achieves excellent results. Taking into account the great diversity of anatomical forms of Class III malocclusion, it is not surprising that extra-oral postero-anterior traction gives widely varying results. The quality, however, depends principally on the method used. Orthodontists must not hesitate to call for the assistance of a surgeon each time the functional treatment is insufficient, particularly in cleft patients where the results depend more on surgical procedures, both primary and secondary, than on dentofacial orthopaedics.

Treatment and posttreatment effects of a facial mask combined with a bite-block appliance in Class III malocclusion

“…8,9 Initial observations on the effects of posteroanterior traction of the maxillary complex in the treatment of Class III malocclusion demonstrated skeletal protraction of the maxilla and the dentition, improvement of the ANB angle, backward and downward rotation of mandible with augmentation of facial height, and lingual tipping of the mandibular incisors. [10][11][12][13] These results were often confirmed in controlled trials that usually included combined maxillary expansion and FM therapy. [14][15][16][17][18][19][20][21] Clinical studies have also shown variable effects of maxillary protraction therapy on the amount of mandibular growth, with a tendency toward Class III relapse when the mandible rotated downward and backward during treatment.…”

Orthopedic treatment of Class III malocclusion with rapid maxillary expansion combined with a face mask: a cephalometric assessment of craniofacial growth patterns

“…2,5,9,19,29 The orthopedic alterations are responsible for 75% of the correction (25% dental) with maxillary advancement representing 75% of the skeletal correction (25% due to downward and backward mandibular rotation). 27 In comparison with the average, the results of this research are in agreement with other findings in the literature.…”

“…17 The finding that maxillary deficiency is often a component of skeletal Class III enhanced the potential of orthodontic-orthopedic treatment in promoting maxillary growth. 3,5,6,18,27 However, by the time most of this growth is completed, treatment options become limited. 1,4,13 Angle Class III with maxillary deficiency, with a well positioned or retruded mandible and a reduced anterior facial height, provides the best treatment prognosis.…”

A myofunctional approach to treatment of anterior cross bites

“…Such treatment allowing young patients to once more masticate properly thanks to the restoration of anterior guidance will greatly improve the chances of achieving optimum facial development especially of the antero-lateral sectors of the maxillae 10 because the tongue will again be able to exert positive force against the palatal vault and the occlusal forces generated by the incisocanine sectors of the dental arches will again function properly.…”