Atlas of Orthodontic Case Reviews offers a comprehensive resource to the treatment of orthodontic malocclusions with a case-based approach.
* Discusses and illustrates the treatment of orthodontic malocclusions using actual clinical cases
* Presents more than 800 clinical photographs showing the stages of each treatment, to act as a visual reference
* Includes a description of each malocclusion, an explanation of the desired treatment outcomes, an account of the changes, and review questions for each case
Interceptive (Mixed Dentition): Case 1
- The records required for treatment of a mixed dentition
- The problem list for interceptive orthodontics: posterior crossbite
- The development of treatment objectives and formation of a treatment plan for a quad-helix appliance
This 8-year-old Caucasian male presented with maxillary constriction that manifested as a unilateral posterior crossbite of the mixed dentition.
- Development: pre-pubescent
- Motivation: good
- Medical history: non-contributory
- Dental history: seen regularly for dental visits
- Family history: no history of malocclusion
- Habits: none
- Limitations: none
- Facial form: mesoprosopic and ovoid
- Facial proportions: normal lower facial height
- Incisor-stomion (Figures 1.1 and 1.2):
- - At rest: 0?mm
- - Smiling: 6?mm
- Smile line: 0?mm gingival display
- Breathing: nasal
- Lips: together at rest
- Soft tissue profile: convex (Figure 1.3)
- Nasolabial angle: slightly obtuse
- Slightly high mandibular plane angle
Figure 1.1 Full face at rest displaying a symmetric, ovoid face.
Figure 1.2 Full face with smile showing full enamel appearance of the incisors and no gingival display.
Figure 1.3 Right lateral view of profile indicating a convex appearance and obtuse nasolabial angle.
Figure 1.4 Anterior view of the dentition demonstrating midline diastema and mandibular shift to the left.
- Teeth present clinically: 6edc21 12cde6 6edc21 12cde6
- Overjet: 4?mm
- Overbite: 0?mm with open bite tendency
- Diastema: 3?mm
- Midlines: maxillary midline coincident with face; mandibular midline 2?mm to left
Right Buccal View
The right buccal view can be seen in Figure 1.5.
- Molar, right: end-on, mixed dentition
- Canine: Class I
- Curve of Spee: flat
- Crossbite: none
- Caries: none
Figure 1.5 Right buccal view of dentition indicating an end-on mixed dentition molar relationship.
Left Buccal View
The left buccal view can be seen in Figure 1.6.
- Molar, left: Class II, mixed dentition
- Canine: cusp to cusp
- Curve of Spee: flat
- Crossbite: posterior crossbite
- Caries: none
Figure 1.6 Left buccal view of dentition indicating a Class II mixed dentition molar relationship and posterior crossbite due to the functional shift of the mandible.
Figure 1.7 Occlusal view of the maxilla displaying a catenary arch form and rotated first permanent molars with separating elastic in place.
- Symmetric, catenary curve form with no crowding: elastic separator (arrow) still in place in the left quadrant from previous orthodontic consult
- No caries
Figure 1.8 Occlusal view of the mandible displaying an ovoid arch form with a lingual holding arch in place.
- Ovoid arch form with lingual holding arch in place
- Slight rotation of erupting incisors
- No caries
- Maximum opening?=?40?mm
- Centric relation-centric occlusion (CR-CO): coincident
- Maximum excursive movements: right?=?6?mm; left?=?7?mm; protrusive?=?5?mm
- Temporomandibular joint palpation: normal
- Right and left masseter: negative to palpation
- Habits: none
- Speech: normal
- Late mixed dentition with all 32 permanent teeth present or developing
- Root length and periodontium appear normal
- Condyles appear normal (Figure 1.9)
Figure 1.9 Panoramic radiograph indicating an early mixed dentition with a lingual holding arch present.
Diagnosis and Treatment Plan
As the patient is in the mixed dentition and displays a Class I skeletal and dental pattern (Figure 1.10; Tables 1.1 and 1.2), correction of the posterior crossbite is considered interceptive.
Figure 1.10 Digitized cephalogram of a Class I skeletal relationship and a high mandibular plane angle indicative of a vertical growing patient.
Table 1.1 Significant cephalometric values Norm Patient pre-treatment
SNA 80° 83.2° SNB 78° 76.7° ANB 2° +6.5° WITS appraisal -1 to +1?mm +0.5?mm FMA 21° 32.6° SN-GoGn 32° 38.9° Maxillary incisor to SN 105° 108.5° Mandibular incisor to GoGn 95° 93.2° Soft tissue Lower lip to E-plane -2?mm 9.3?mm Upper lip to E-plane -1.6?mm 2.3?mm
SNA, sella-nasion-A point; SNB: sella-nasion-B point; ANB: A point-nasion-B point; WITS appraisal, Witwatersrand appraisal; FMA, Frankfort horizontal-mandibular plane (angle); SN-GoGn: sella nasion-gonion gnathion.
Table 1.2 The patient's problem list in three dimensions Transverse Sagittal Vertical
Soft tissue Normal Convex profile; full lower lip; obtuse nasolabial angle Hyperdivergent Dental Bilateral posterior crossbite presenting as a unilateral crossbite due to the functional shift Normal mixed dentition regarding molar and canine relationships 0?mm overbite Skeletal Maxillary constriction Class I Hyperdivergent
Maxilla - the maxillary first molars will be banded and a quad-helix appliance will be fabricated to rotate the molars and expand the palate. A lingual holding arch is presently on the mandibular arch to conserve leeway space and to maintain a non-extraction approach to further care in the future.
Once the posterior crossbite is over-corrected, the patient will be placed on a recall schedule and examined every 6 months for changes in the occlusion and eruption of the remaining permanent dentition.
An argument may be made for an additional radiograph to be taken to aid in the diagnosis and treatment plan in patients with posterior crossbites who will require palatal expansion. The radiograph of choice is a posterior-anterior cephalogram, or PA radiograph as it is more commonly termed. In young, growing children where the clinical examination demonstrates no gross asymmetries and only functional shifts due to the crossbite, it is unnecessary to further expose the child to additional radiation that would have negligible clinical benefit.
The patient's clinical problem in the mixed dentition will be addressed by correction of the posterior crossbite. Once corrected and maintained, the child will be evaluated annually for further orthodontic treatment if required. As the patient appears to be growing in a Class I direction both skeletally and dentally, it is anticipated that any further treatment would require only dental alignment.
The options presented to the parent and patient were two-fold:
- No treatment.
- Interceptive treatment to correct the posterior crossbite through palatal expansion followed by comprehensive orthodontic care if it became necessary.
Both the patient and parent wanted option 2. Based upon the patient's skeletal and dental development, crossbite correction and palatal expansion would be undertaken with a quad-helix appliance, although other fixed appliances such as a rapid palatal expander could have been utilized as well. The...