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Residents' journal review
RESIDENTS' JOURNAL REVIEW
ARTICLES FROM THE CURRENT ORTHODONTIC LITERATURE, SELECTED AND REVIEWED BY: RESIDENTS FROM THE UNIVERSITY OF TEXAS AT HOUSTON Department Chair and Program Director, Jeryl D. English Dan Grauer, Associate Editor for Residents' Journal Review Los Angeles, Calif
Changes of the naso-maxillary complex after rapid maxillary expansion Bouserhal J, Bassil-Nassif N, Tauk A, Will L, Limme M. Three-dimensional changes of the naso-maxillary complex after rapid maxillary expansion. Angle Orthod 2014;84:88-95.
T
ransverse maxillary deficiency generally presents with other concomitant characteristics such as posterior crossbite, arch-form deformation, dental crowding, or narrowing of the nasal cavity. Rapid maxillary expansion (RME) is commonly used to correct transverse deficiencies. Previous studies have found that RME not only widens the maxilla transversely, but also can have expansion effects on surrounding structures and sutures, including the nasal cavity. These studies have been done to measure the effects on RME with dental casts, cephalograms, and finite element analysis. However, there are limitations to such studies. Therefore, the objectives of this study were to (1) assess the volumetric changes of the naso-maxillary complex after RME, (2) quantify the maxillary and nasal contributions to these changes, and (3) identify the response of the maxilla. Thirty subjects (ages, 7-13 years) with unilateral or bilateral posterior crossbite and requiring RME as part of their orthodontic treatment were selected. Preexpansion and postexpansion computed tomography images were taken. Three-dimensional reconstructions were done using 14 different landmarks. The authors found that all volumetric variables representing the nasomaxillary complex had statistically significant increases after RME. They concluded that the total volume of the naso-maxillary complex increased by 12%. The nasal volume increase represented 30.25% of the total volumetric increase. They also found that the suture
response to RME had a triangular opening pattern in the vertical direction, which decreased from the dental arch to the basal bone, as well as in the sagittal direction, with the widest part positioned anteriorly. The results of this study agree with other published results showing a volumetric increase of the naso-maxillary complex after RME. Further prospective studies are indicated to validate these results and further evaluate the relationship between increases in nasal volume and mode of breathing. Reviewed by Daniel Johnson
White spot lesion treatment modalities Yuan H, Li J, Chen L, Cheng L, Cannon RD, Mei L. Esthetic comparison of white-spot lesion treatment modalities. Angle Orthod 2014;84:343-9.
W
hite spot lesions (WSLs) are a prevalent side effect of fixed orthodontic treatment, affecting about 50% of patients. The aim of this in-vitro study was to compare the esthetic improvements of WSLs treated by 3 common methods—sodium fluoride, casein phosphopeptide amorphous calcium phosphate, and resin infiltration—using spectrophotometer measurements and quantitative light-induced fluorescence. After in-vitro creation of WSLs, measurements of color change (DE) and fluorescence loss (DQ) by quantitative light-induced fluorescence were performed for each of the 3 treatment groups and the control group (distilled deionized water). The DE and DQ measurements were repeated at 2-week intervals over a 6-week period, to see whether, with time after the orthodontic treatment, there was improvement or worsening of the WSLs under conditions mimicking the natural oral environment. The results showed that the color of the WSLs in the resin infiltration group was improved significantly by that treatment and had the lowest mean DE (2.9 6 1.2) compared with the other treatment groups (mean DE, 12.0 6 3.6) regardless of time after treatment (P \0.01). The fluorescence loss in the resin infiltration group was also significantly improved (P \0.01) after treatment. Because a DE value of less than 3.6 is considered a clinically acceptable color difference, an average DE of 2.9 6 1.2 after resin infiltration in the study indicated a better and clinically acceptable color recovery compared with the sodium fluoride and the casein phosphopeptide amorphous calcium phosphate treatments. Reviewed by Kevin Hallgren
647
Residents' journal review
648
Extraction of the deciduous canine in children Naoumova J, Kurol J, Kjellberg H. Extraction of the deciduous canine as an interceptive treatment in children with palatal displaced canines—part I: shall we extract the deciduous canine or not? Eur J Orthod 2014 Sep 22 [Epub ahead of print].
I
mpaction of palatally displaced canines (PDCs) should be prevented, whenever possible, to avoid high treatment costs, minimize the side effects of orthodontic mechanics, and increase treatment efficiency. The authors of this study aimed to evaluate the effect of interceptive extraction of the deciduous canines in children with PDC compared with a control group using a randomized controlled trial method and conebeam computed tomography. The trial was registered in “FoU i Sverige” (http://www.fou.nu/is/sverige) with the registration number 40921. Forty girls and 27 boys were recruited for the study. Their ages ranged between 10 and 13 years. The subjects had maxillary unilateral or bilateral PDC, persisting deciduous canines, and no previous experience of orthodontic treatment. Random allocation was performed using permuted block randomization to the extraction and the nonextraction groups in the sample. The PDCs erupted at a significantly higher prevalence on the extraction side compared with the untreated control side (69% vs 39%). The mean eruption time in the extraction group was 3 months shorter than that in the nonextraction group. During the follow-up time, significantly more angular and distance changes occurred in the extraction group compared with the control group; this indicated more eruptional movement. However, no significant differences in root resorption of adjacent teeth were found between the groups at the end of the observation period. Interceptive extraction of the deciduous canine is an effective treatment in patients with PDCs. Reviewed by Grace Nam
Ajmera S, Venkatesh S, Ganeshkar SV. Volumetric evaluation of root resorption during orthodontic treatment. J Clin Orthod 2014;48:113-9.
oot resorption is a common problem encountered during orthodontic treatment and can be difficult
June 2015 Vol 147 Issue 6
Retained deciduous molars without successors Hvaring CL, Øgaard B, Stenvik A, Birkeland K. The prognosis of retained primary molars without successors: infraocclusion, root resorption and restorations in 111 patients. Eur J Orthod 2014;36:26-30.
Root resorption during orthodontic treatment
R
to detect with conventional radiography; severe resorption can occur even in teeth with no radiographic signs of root resorption. Previous studies have examined root resorption with periapical and panoramic radiographs, methods that are subject to magnification and reproducibility errors, and are only a 2-dimensional representation of a 3-dimensional phenomenon. The authors of this study used cone-beam computed tomography (CBCT) to measure the external root resorption during orthodontic mechanics of intrusion and retraction of anterior teeth. Forty-eight patients with mild-to-moderate crowding or severe proclination were treated with extraction of the first premolars and with edgewise appliances. Mini-implants were placed for anchorage and used for simultaneous en-masse intrusion and retraction. The CBCT images of the maxillary anterior teeth taken before treatment and after space closure were imported into volume and surface rendering software for assessment of root-volume loss. Root volume decreased in every tooth, with significantly greater losses in the lateral incisors. Root volume loss was greatest for the incisors on the palatal aspect of the root, and greatest for the canines on the distal aspect of the root, most likely due to concentration of forces in those areas during en-masse retraction. The authors noted that the increased resorption could have partly been due to the use of maximum anchorage with the implants, resulting in longer treatments and increased tooth movement; both are established factors in root resorption. The authors concluded that since CBCT is the only method to diagnose root resorption on the buccal and palatal surfaces, they were limited in comparison with other studies because of the novelty of their study. Reviewed by Lacey Harris
E
xcept for the third molars, the mandibular second premolars are the most commonly missing teeth. A significant association between agenesis of the second premolars and infraocclusion of the deciduous molars has previously been demonstrated. Factors
American Journal of Orthodontics and Dentofacial Orthopedics
Residents' journal review
that must be considered during treatment planning include (1) number and position of missing teeth, (2) condition of retained deciduous teeth, (3) skeletal relationship and occlusion, (4) space requirements, (5) facial profile, (6) the patient's dental age, and (7) the patient's attitude toward treatment. Retaining healthy mandibular deciduous molars has been reported to be a viable treatment alternative, but deciduous molars left in situ carry a risk of developing progressive root resorption or infraocclusion. The ability to predict the morbidity of retained deciduous molars with no permanent successors is important for treatment planning. The aim of this study was to assess infraocclusion, root resorption, and restorations, and their importance for the prognosis of retained mandibular deciduous molars. The sample comprised 188 persisting mandibular deciduous second molars in 111 subjects, 48 boys and 63 girls, with a mean age of 12.6 years. The patients had been referred to an interdisciplinary clinic because of extensive hypodontia; they were missing 8.4 teeth on average. Panoramic radiographs were used to assess infraocclusion, resorption of the mesial and distal roots, and whether restorations were present. Clinically significant infraocclusion was observed in 43.6% of the patients and classified as severe in 18.8%. The mesial and distal roots had no resorption in 18.9% and 33.3%, respectively. Most deciduous molars had no restorations (78.4%). Infraocclusion is considered to be the most critical factor for the prognosis of retained deciduous molars, whereas root resorption and restorations had limited clinical importance. Reviewed by Preston Greer
649
Active treatment effects of the Forsus fatigue-resistant device Cacciatore G, Alvetro L, Defraia E, Ghislanzoni LT, Franchi L. Active-treatment effects of the Forsus fatigue resistant device during comprehensive Class II correction in growing patients. Korean J Orthod 2014;44:136-42.
O
rthodontists have a vast array of Class II correction alternatives available. However, compliance has always been a main concern. One fixed appliance for correcting Class II malocclusion is the Forsus fatigueresistant device (3M Unitek, Monrovia, Calif). Although many studies have documented the clinical effects of this noncompliance appliance, no previous study has evaluated the contribution of active treatment with the Forsus to the overall effects of comprehensive treatment. Fifty-four patients (27 boys, 27 girls; mean age, 12.5 6 1.2 years) with Class II Division 1 malocclusions were studied. Lateral cephalometric assessments were done before fixed appliance therapy, at Forsus installation, at the completion of Forsus application, and at the end of comprehensive therapy. Their results showed that overjet and overbite decreased significantly ( 3.5 and 1.5 mm, respectively), and the molar relationship improved by 4.3 mm in the sample. The period between Forsus installation and completion of Forsus application showed the greatest contribution to the overall treatment outcome. The significant improvement in the Wits appraisal was associated with the significant posterior rotation of the occlusal plane rather than to the sagittal effects in the jaws, because the therapeutic effects consisted mainly of dentoalveolar changes in the mandibular dentition characterized by significant mesial movement of the teeth (80% of the overall effects). Reviewed by Taylor Collazo
American Journal of Orthodontics and Dentofacial Orthopedics
June 2015 Vol 147 Issue 6
ARTICLES FROM THE CURRENT ORTHODONTIC LITERATURE, SELECTED AND REVIEWED BY: RESIDENTS FROM THE UNIVERSITY OF TEXAS AT HOUSTON Department Chair and Program Director, Jeryl D. English Dan Grauer, Associate Editor for Residents' Journal Review Los Angeles, Calif
Changes of the naso-maxillary complex after rapid maxillary expansion Bouserhal J, Bassil-Nassif N, Tauk A, Will L, Limme M. Three-dimensional changes of the naso-maxillary complex after rapid maxillary expansion. Angle Orthod 2014;84:88-95.
T
ransverse maxillary deficiency generally presents with other concomitant characteristics such as posterior crossbite, arch-form deformation, dental crowding, or narrowing of the nasal cavity. Rapid maxillary expansion (RME) is commonly used to correct transverse deficiencies. Previous studies have found that RME not only widens the maxilla transversely, but also can have expansion effects on surrounding structures and sutures, including the nasal cavity. These studies have been done to measure the effects on RME with dental casts, cephalograms, and finite element analysis. However, there are limitations to such studies. Therefore, the objectives of this study were to (1) assess the volumetric changes of the naso-maxillary complex after RME, (2) quantify the maxillary and nasal contributions to these changes, and (3) identify the response of the maxilla. Thirty subjects (ages, 7-13 years) with unilateral or bilateral posterior crossbite and requiring RME as part of their orthodontic treatment were selected. Preexpansion and postexpansion computed tomography images were taken. Three-dimensional reconstructions were done using 14 different landmarks. The authors found that all volumetric variables representing the nasomaxillary complex had statistically significant increases after RME. They concluded that the total volume of the naso-maxillary complex increased by 12%. The nasal volume increase represented 30.25% of the total volumetric increase. They also found that the suture
response to RME had a triangular opening pattern in the vertical direction, which decreased from the dental arch to the basal bone, as well as in the sagittal direction, with the widest part positioned anteriorly. The results of this study agree with other published results showing a volumetric increase of the naso-maxillary complex after RME. Further prospective studies are indicated to validate these results and further evaluate the relationship between increases in nasal volume and mode of breathing. Reviewed by Daniel Johnson
White spot lesion treatment modalities Yuan H, Li J, Chen L, Cheng L, Cannon RD, Mei L. Esthetic comparison of white-spot lesion treatment modalities. Angle Orthod 2014;84:343-9.
W
hite spot lesions (WSLs) are a prevalent side effect of fixed orthodontic treatment, affecting about 50% of patients. The aim of this in-vitro study was to compare the esthetic improvements of WSLs treated by 3 common methods—sodium fluoride, casein phosphopeptide amorphous calcium phosphate, and resin infiltration—using spectrophotometer measurements and quantitative light-induced fluorescence. After in-vitro creation of WSLs, measurements of color change (DE) and fluorescence loss (DQ) by quantitative light-induced fluorescence were performed for each of the 3 treatment groups and the control group (distilled deionized water). The DE and DQ measurements were repeated at 2-week intervals over a 6-week period, to see whether, with time after the orthodontic treatment, there was improvement or worsening of the WSLs under conditions mimicking the natural oral environment. The results showed that the color of the WSLs in the resin infiltration group was improved significantly by that treatment and had the lowest mean DE (2.9 6 1.2) compared with the other treatment groups (mean DE, 12.0 6 3.6) regardless of time after treatment (P \0.01). The fluorescence loss in the resin infiltration group was also significantly improved (P \0.01) after treatment. Because a DE value of less than 3.6 is considered a clinically acceptable color difference, an average DE of 2.9 6 1.2 after resin infiltration in the study indicated a better and clinically acceptable color recovery compared with the sodium fluoride and the casein phosphopeptide amorphous calcium phosphate treatments. Reviewed by Kevin Hallgren
647
Residents' journal review
648
Extraction of the deciduous canine in children Naoumova J, Kurol J, Kjellberg H. Extraction of the deciduous canine as an interceptive treatment in children with palatal displaced canines—part I: shall we extract the deciduous canine or not? Eur J Orthod 2014 Sep 22 [Epub ahead of print].
I
mpaction of palatally displaced canines (PDCs) should be prevented, whenever possible, to avoid high treatment costs, minimize the side effects of orthodontic mechanics, and increase treatment efficiency. The authors of this study aimed to evaluate the effect of interceptive extraction of the deciduous canines in children with PDC compared with a control group using a randomized controlled trial method and conebeam computed tomography. The trial was registered in “FoU i Sverige” (http://www.fou.nu/is/sverige) with the registration number 40921. Forty girls and 27 boys were recruited for the study. Their ages ranged between 10 and 13 years. The subjects had maxillary unilateral or bilateral PDC, persisting deciduous canines, and no previous experience of orthodontic treatment. Random allocation was performed using permuted block randomization to the extraction and the nonextraction groups in the sample. The PDCs erupted at a significantly higher prevalence on the extraction side compared with the untreated control side (69% vs 39%). The mean eruption time in the extraction group was 3 months shorter than that in the nonextraction group. During the follow-up time, significantly more angular and distance changes occurred in the extraction group compared with the control group; this indicated more eruptional movement. However, no significant differences in root resorption of adjacent teeth were found between the groups at the end of the observation period. Interceptive extraction of the deciduous canine is an effective treatment in patients with PDCs. Reviewed by Grace Nam
Ajmera S, Venkatesh S, Ganeshkar SV. Volumetric evaluation of root resorption during orthodontic treatment. J Clin Orthod 2014;48:113-9.
oot resorption is a common problem encountered during orthodontic treatment and can be difficult
June 2015 Vol 147 Issue 6
Retained deciduous molars without successors Hvaring CL, Øgaard B, Stenvik A, Birkeland K. The prognosis of retained primary molars without successors: infraocclusion, root resorption and restorations in 111 patients. Eur J Orthod 2014;36:26-30.
Root resorption during orthodontic treatment
R
to detect with conventional radiography; severe resorption can occur even in teeth with no radiographic signs of root resorption. Previous studies have examined root resorption with periapical and panoramic radiographs, methods that are subject to magnification and reproducibility errors, and are only a 2-dimensional representation of a 3-dimensional phenomenon. The authors of this study used cone-beam computed tomography (CBCT) to measure the external root resorption during orthodontic mechanics of intrusion and retraction of anterior teeth. Forty-eight patients with mild-to-moderate crowding or severe proclination were treated with extraction of the first premolars and with edgewise appliances. Mini-implants were placed for anchorage and used for simultaneous en-masse intrusion and retraction. The CBCT images of the maxillary anterior teeth taken before treatment and after space closure were imported into volume and surface rendering software for assessment of root-volume loss. Root volume decreased in every tooth, with significantly greater losses in the lateral incisors. Root volume loss was greatest for the incisors on the palatal aspect of the root, and greatest for the canines on the distal aspect of the root, most likely due to concentration of forces in those areas during en-masse retraction. The authors noted that the increased resorption could have partly been due to the use of maximum anchorage with the implants, resulting in longer treatments and increased tooth movement; both are established factors in root resorption. The authors concluded that since CBCT is the only method to diagnose root resorption on the buccal and palatal surfaces, they were limited in comparison with other studies because of the novelty of their study. Reviewed by Lacey Harris
E
xcept for the third molars, the mandibular second premolars are the most commonly missing teeth. A significant association between agenesis of the second premolars and infraocclusion of the deciduous molars has previously been demonstrated. Factors
American Journal of Orthodontics and Dentofacial Orthopedics
Residents' journal review
that must be considered during treatment planning include (1) number and position of missing teeth, (2) condition of retained deciduous teeth, (3) skeletal relationship and occlusion, (4) space requirements, (5) facial profile, (6) the patient's dental age, and (7) the patient's attitude toward treatment. Retaining healthy mandibular deciduous molars has been reported to be a viable treatment alternative, but deciduous molars left in situ carry a risk of developing progressive root resorption or infraocclusion. The ability to predict the morbidity of retained deciduous molars with no permanent successors is important for treatment planning. The aim of this study was to assess infraocclusion, root resorption, and restorations, and their importance for the prognosis of retained mandibular deciduous molars. The sample comprised 188 persisting mandibular deciduous second molars in 111 subjects, 48 boys and 63 girls, with a mean age of 12.6 years. The patients had been referred to an interdisciplinary clinic because of extensive hypodontia; they were missing 8.4 teeth on average. Panoramic radiographs were used to assess infraocclusion, resorption of the mesial and distal roots, and whether restorations were present. Clinically significant infraocclusion was observed in 43.6% of the patients and classified as severe in 18.8%. The mesial and distal roots had no resorption in 18.9% and 33.3%, respectively. Most deciduous molars had no restorations (78.4%). Infraocclusion is considered to be the most critical factor for the prognosis of retained deciduous molars, whereas root resorption and restorations had limited clinical importance. Reviewed by Preston Greer
649
Active treatment effects of the Forsus fatigue-resistant device Cacciatore G, Alvetro L, Defraia E, Ghislanzoni LT, Franchi L. Active-treatment effects of the Forsus fatigue resistant device during comprehensive Class II correction in growing patients. Korean J Orthod 2014;44:136-42.
O
rthodontists have a vast array of Class II correction alternatives available. However, compliance has always been a main concern. One fixed appliance for correcting Class II malocclusion is the Forsus fatigueresistant device (3M Unitek, Monrovia, Calif). Although many studies have documented the clinical effects of this noncompliance appliance, no previous study has evaluated the contribution of active treatment with the Forsus to the overall effects of comprehensive treatment. Fifty-four patients (27 boys, 27 girls; mean age, 12.5 6 1.2 years) with Class II Division 1 malocclusions were studied. Lateral cephalometric assessments were done before fixed appliance therapy, at Forsus installation, at the completion of Forsus application, and at the end of comprehensive therapy. Their results showed that overjet and overbite decreased significantly ( 3.5 and 1.5 mm, respectively), and the molar relationship improved by 4.3 mm in the sample. The period between Forsus installation and completion of Forsus application showed the greatest contribution to the overall treatment outcome. The significant improvement in the Wits appraisal was associated with the significant posterior rotation of the occlusal plane rather than to the sagittal effects in the jaws, because the therapeutic effects consisted mainly of dentoalveolar changes in the mandibular dentition characterized by significant mesial movement of the teeth (80% of the overall effects). Reviewed by Taylor Collazo
American Journal of Orthodontics and Dentofacial Orthopedics
June 2015 Vol 147 Issue 6